National Evaluation of Sires for the Production of Quality Cashmere RIRDC Publication No. 10/153
RIRDC
Innovation for rural Australia
National Evaluation of Sires for the Production of Quality Cashmere by Stephen Gray, Graeme Martin, Aprille Chadwick, John Milton and Johan Greeff
October 2010 RIRDC Publication No. 10/153 RIRDC Project No. PRJ-000457
© 2010 Rural Industries Research and Development Corporation. All rights reserved.
ISBN 978-1-74254-121-1 ISSN 1440-6845 National Evaluation of Sires for the Production of Quality Cashmere Publication No. 10/153 Project No. PRJ-000457 The information contained in this publication is intended for general use to assist public knowledge and discussion and to help improve the development of sustainable regions. You must not rely on any information contained in this publication without taking specialist advice relevant to your particular circumstances. While reasonable care has been taken in preparing this publication to ensure that information is true and correct, the Commonwealth of Australia gives no assurance as to the accuracy of any information in this publication. The Commonwealth of Australia, the Rural Industries Research and Development Corporation (RIRDC), the authors or contributors expressly disclaim, to the maximum extent permitted by law, all responsibility and liability to any person, arising directly or indirectly from any act or omission, or for any consequences of any such act or omission, made in reliance on the contents of this publication, whether or not caused by any negligence on the part of the Commonwealth of Australia, RIRDC, the authors or contributors. The Commonwealth of Australia does not necessarily endorse the views in this publication. This publication is copyright. Apart from any use as permitted under the Copyright Act 1968, all other rights are reserved. However, wide dissemination is encouraged. Requests and inquiries concerning reproduction and rights should be addressed to the RIRDC Publications Manager on phone 02 6271 4165. Researcher Contact Details Winthrop Professor Graeme Martin UWA Institute of Agriculture M082, University of Western Australia, Crawley WA 6009 Phone: (08) 6488 2237 Fax: (08) 6488 1029 Email:
[email protected] In submitting this report, the researcher has agreed to RIRDC publishing this material in its edited form. RIRDC Contact Details Rural Industries Research and Development Corporation Level 2, 15 National Circuit BARTON ACT 2600 PO Box 4776 KINGSTON ACT 2604 Phone: Fax: Email: Web:
02 6271 4100 02 6271 4199
[email protected]. http://www.rirdc.gov.au
Electronically published by RIRDC in October 2010 Print-on-demand by Union Offset Printing, Canberra at www.rirdc.gov.au or phone 1300 634 313
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Foreword Australian Cashmere production has remained stagnant in recent times. This is due partly to lack of genetic progress in the national herd. This problem can be overcome by the adoption of breeding technologies such as estimated progeny differences (EPD). EPDs provide an objective measure of an animal’s genetic worth and can be used to greatly accelerate genetic gain, improving production and economic returns. In addition, there is a need to identify the least stressful protocol for artificially controlled reproduction because stress causes sub-fertility and because ‘animal-friendly’ practices will be seen in a positive light by community, a critical factor in the long-term survival of the industry. The key output of the project is a web page with a list of sires ranked on the basis of performance traits using EPD: down fibre diameter, down fleece weight (or the McGregor Index), birth weight and growth rate to 12 months in kids, and worm resistance to drench. This enables producers to make informed choices for breeding for a range of economically important traits. The second output is clear evidence that the least stressful methods for artificial reproductive management are semen collection by artificial vagina (rather than electro-ejaculation) and transcervical AI (rather than laparoscopic AI). Adopting the least-stressful techniques will also give the industry a more ‘animal-friendly’ image. Producers can now participate in their national industry through the web page of ACGA and use the genetic tools available to them to improve their productivity. They should also adopt semen collection by artificial vagina and transcervical AI to improve reproductive efficiency, reduce costs, and show consumers that the cashmere industry is ‘animal-friendly’. Policy-makers should find means to encourage enterprise diversity in rural communities so as to encourage stability. They should also encourage animal industries to become ‘clean, green and ethical’, so as to guarantee a long-term future in high-price markets. This project was funded primarily from industry levies which was matched by funds provided by the Australian Government through RIRDC. This report is an addition to RIRDC’s diverse range of over 2000 research publications and it forms part of our Rare Natural Animal Fibres R&D program, which aims to promote industry development, commercial viability, and communication and research capacity. Most of RIRDC’s publications are available for viewing, free downloading or purchasing online at www.rirdc.gov.au. Purchases can also be made by phoning 1300 634 313.
Craig Burns Managing Director Rural Industries Research and Development Corporation
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About the Authors Mr Stephen Gray [Dip Agric] President of the WA Branch of the Australian Cashmere Growers Association; Member of the Federal Council of ACGA. Senior Technical Officer (UWA) and Manager of Allandale Farm. Winthrop Professor Graeme Martin [BSc (Agric) PhD] Chair of Animal Science (University of WA), Leader of Animal Production Systems (UWA Institute of Agriculture). Graduated in Agricultural Science (University of WA) in 1975, gained a doctorate in reproductive physiology in 1981, then worked for 2 years at the INRA Station de Physiologie de la Reproduction at Nouzilly (France) and for 3 years at the Medical Research Council’s Reproductive Biology Unit in Edinburgh (Scotland). In 1986, took up a joint position in Animal Science (University of WA) and the CSIRO Division of Animal Production. Ms Aprille Chadwick [BSc (Animal Science)] Graduated in Animal Science at The University of Western Australia (UWA) in 2003. Worked fulltime at UWA for 5 years as a research assistant on sheep and goat research projects. In 2007, she enrolled part time in a Masters degree also at UWA to start her own research in Animal Welfare. In 2009, her Masters degree was upgraded to a PhD which also incorporates the study of the attitudes of goat producers towards farm animal welfare. John Milton [BSc (Agric) PhD] Senior Research Fellow at the University of WA. Graduated in Agricultural Science and then a PhD in ruminant nutrition at the University of Queensland. Hands-on experience through his own farming activities has given him the ability to view his research with a farmer’s perspective. Spent 6 years leading a foreign aid project to assist in the development of agriculture in southern Thailand, for which he was made an Officer of the Most Noble Order of the Crown of Thailand by His Majesty, The King of Thailand. Adjunct Associate Professor Johan Greeff [BSc (Agric) MSc (Agric) PhD] Based in the Department of Agriculture and Food, Western Australia, since 1993. Project Leader for Sheep Breeding and Genetics and Genetics Extension. His main contribution is breeding for disease resistance but he leads research in the genetics of fibre traits (fleece weight, fibre diameter, staple strength, fibre variability traits, fibre curvature, feltability, wool). He has developed and carried out an effective extension strategy to generate genetic change in industry, initiating a number of innovative programs for improving genetic progress in economically important traits for livestock and has designed breeding programs for stud breeders.
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Acknowledgments We wish to thank • The ACGA executive for their support of the Sire Referencing Scheme project; • Bob Adamson of Wundowie, for his contribution of 70 does in 2005 and 2006 of the project; • The members of the ACGA who provided the selected sires for evaluation and to all those that put their sire up for nomination over the course of the project; • Trish Esson who organised and carried out the sampling of the 2007 fleeces using the whole fleece coring machine designed by Charles Esson. • Paul Hamilton from Semtech Animal Breeding Services who travelled throughout NSW and Victoria to obtain semen from the sires selected in this project and then conducted two very successful artificial insemination programmes in WA.
Abbreviations ACGA
Australian Cashmere Growers Association
EPD
Estimated Progeny Differences
SRS
Sire Referencing Scheme
AI
Artificial Insemination
AV
Artificial vagina
EEJ
Electro-ejaculation
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Contents Foreword ............................................................................................................................................... iii About the Authors ................................................................................................................................ iv Acknowledgments .................................................................................................................................. v Abbreviations ......................................................................................................................................... v Executive Summary............................................................................................................................ viii 1. Introduction ...................................................................................................................................... 1 2. Objectives .......................................................................................................................................... 2 3. Methodology ..................................................................................................................................... 3 4. Chapters ............................................................................................................................................ 6 Statistical analysis ............................................................................................................................. 6 Sire Reference Scheme 2005 ............................................................................................................ 6 Buck selection ............................................................................................................................ 6 Kidding, 2005 ............................................................................................................................. 6 Sire Reference Scheme 2006 ............................................................................................................ 7 Buck selection ............................................................................................................................ 7 Kidding, 2006 ............................................................................................................................. 8 Sire Reference Scheme 2007 ............................................................................................................ 9 Buck selection ............................................................................................................................ 9 Kidding, 2007 ............................................................................................................................. 9 Animal Welfare – the Supplementary Project ................................................................................ 10 Why it is important? ................................................................................................................. 10 Artificial Insemination .................................................................................................................... 10 Temperament .................................................................................................................................. 11 5. Results ............................................................................................................................................. 12 Estimated Progeny Differences 2005–2007 .................................................................................... 12 Fleece Characteristics – 1st Shearing ........................................................................................ 12 Fleece Characteristics – 2nd Shearing ....................................................................................... 13 Growth – Birth to 12 Months ................................................................................................... 13 Worm Resistance ...................................................................................................................... 13 Temperament ............................................................................................................................ 14 Stress and Semen Collection Procedure ................................................................................... 14 Stress and Insemination Procedure ........................................................................................... 15 6. Implications..................................................................................................................................... 16 7. Recommendations .......................................................................................................................... 17 Appendices ........................................................................................................................................... 18 References ............................................................................................................................................ 19
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Tables Table 1.
Bucks selected for evaluation in 2005 ...............................................................................................6
Table 2.
Summary data for the 2005 kidding for each sire. ................................................................................7
Table 3.
Bucks selected in 2006 for evaluation ..................................................................................................8
Table 4.
Summary data for the 2006 kidding for each sire. ................................................................................8
Table 5.
Bucks selected in 2007 (final year) for evaluation ...............................................................................9
Table 6.
Summary data for the 2007 kidding for each sire. ................................................................................9
Table 7.
Estimated progeny differences for fleece characteristics of sire group kids at first shearing. ............12
Table 8.
Estimated progeny differences for fleece characteristics of sire group kids 2nd shearing. ..................13
Table 9.
Estimated progeny differences for body weight of sires from birth to 12 months of age.. .................14
Table 10.
Estimated progeny differences for faecal worm egg count and temperament score.. .........................15
Figures Figure 1.
Pregnant does in fox-proof kidding paddocks sown with Saia grazing oats. .....................................3
Figure 2.
Weighing of kids at birth by Steve Gray. ...........................................................................................4
Figure 3.
Aprille Chadwick releasing a doe kid from the isolation box during temperament testing. ...............4
Figure 4.
Shearing of an adult doe. ....................................................................................................................5
Figure 5.
Collection of semen using electro-ejaculation. .................................................................................10
Figure 6a).
Laparoscopic insemination performed by a veterinarian ..................................................................11
Figure 6b).
Trans-cervical artificial insemination ‘over the rail’ ........................................................................11
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Executive Summary What the report is about This report describes a 5-year project that has produced a genetic tool for the Australian cashmere industry. A 3-year controlled breeding program was used to provide estimated progeny differences (EPDs) that can help accelerate genetic progress in the national herd an thus address the stagnation of cashmere production. The EPD values were published on a web site and growers can use them to choose superior sires for down fibre diameter, down fleece weight (or the McGregor Index), birth weight and growth rate to 12 months in kids, and worm resistance to drench. This report also describes the assessment of methods for semen collection and artificial insemination with a view to identifying the least stressful technique for controlled reproduction. Who is the report targeted at? The primary target is the cashmere growers of Australia. Where are the relevant industries located in Australia? The cashmere industry is a national industry, but most growers are located in New South Wales, Victoria, with a few in Queensland and Western Australia. There are about 80 producers shearing around 13 000 goats for cashmere. Gross value is about $100,000. The average yield of the down is 50 to 300 g per goat per annum but quantities of about 1kg have been recorded. The cashmere growers will benefit from this research in the first instance and, once production increases, the processors will also be able to benefit. Background Australian Cashmere production has remained stagnant in recent times. This is due partly to lack of genetic progress in the national herd. This problem can be overcome by the adoption of breeding technologies such as estimated progeny differences (EPD). EPDs provide an objective measure of an animals’ genetic worth and can be used to greatly accelerate genetic gain, improving production and economic returns. In addition, we need to identify the least stressful protocol for artificially controlled reproduction because stress causes sub-fertility and because ‘animal-friendly’ practices will be seen in a positive light by community, a critical factor in the long-term survival of the industry. Objectives To estimate EPDs for fleece weight, fibre quality, birth weight, growth rate, faecal worm egg counts; To evaluate the stress associated with protocols for semen collection and artificial insemination so we can identify the least stressful practice; To foster a national approach for development of the Australian cashmere industry. Methods used Estimation of EPDs: we used about 300 cashmere does at Allandale, Western Australia, and semen from 11 bucks from herds from across Australia in artificial insemination (AI) programs over 3 successive breeding seasons. One buck was used in both years to act as a link sire to allow valid
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comparisons among the progeny from each year. The data were analysed to identify significant factors affecting the traits, and to estimate breeding values. Semen was collected by artificial vagina or by electro-ejaculation and used in transcervical or laparoscopic AI. During these procedures, stress was evaluated by analysing physiological (heart rate and core temperature), hormonal (cortisol) and behavioural (vocalizations and struggles) variables. Outcomes for the bucks were compared with natural mating. Results/key findings A web page was created and published with a list of sires ranked on the basis of performance traits using an objective measure. This enables producers to make informed choices to meet their individual breeding objectives for a range of economically important traits: down fibre diameter, down fleece weight (or the McGregor Index), birth weight and growth rate to 12 months in kids, and worm resistance to drench. The least stressful methods for artificial reproductive management are semen collection by artificial vagina (rather than electro-ejaculation) and transcervical AI (rather than laparoscopic AI). In addition, transcervical AI appears to provide far greater fertility. Adopting the least-stressful techniques will also give the industry a more ‘animal-friendly’ image. If adopted by industry, semen collection by artificial vagina and transcervical AI will improve reproductive efficiency, reduce costs, and, for the long term, show consumers that the cashmere industry is ‘animal-friendly’. Implications for relevant stakeholders Cashmere producers can increase the production of cashmere to the quality standards specified by manufacturers. This should lead to increased demand that, in turn, will directly benefit the entire industry by improving production and economic returns for Australian cashmere growers. Because this process is based on genetic improvement, the benefits will accumulate and for many years into the future. In addition, the adoption of low-stress techniques should improve reproductive efficiency and give the industry an ethical image, helping secure its long-term future. A successful cashmere industry will benefit rural communities by providing a possibility for farmers to diversify their enterprises, leading to greater economic stability and security. Policy makers need to invest in diversification for the same reason. Stable rural communities are an essential element of the fabric of our society.
Recommendations To the Australian cashmere industry: 1) Adopt EPDs for choosing superior sires from across the entire national herd. 2) Use the website of the Australian Cashmere Growers Association as an avenue for communication among growers. Without a national approach, the industry cannot develop. 3) Adopt semen collection by artificial vagina and transcervical AI. To RIRDC: Consider investing in the development of a behavioural test for temperament of goats.
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1. Introduction Australian Cashmere production has remained stagnant in recent times while its counterpart in the wool industry, the superfine sector, has enjoyed success with increased production of high quality wool. Cashmere producers need to emulate this by increasing the production of cashmere to the quality standards specified by manufacturers. This will lead to increased demand that, in turn, will directly benefit the entire industry. At a workshop hosted by the Australian Cashmere Growers Association (ACGA), it was recognized that the biggest impediment to the industry’s sound financial future was its inability to identify the elite bucks in the Australian herd. Therefore, a focus on the identification of superior genetics was established as a first step towards restoring the Australian cashmere industry to a pre-eminent position as a supplier of elite cashmere to the world. This could be done with a sire referencing scheme in which the genetic worth of sires for important cashmere traits is measured independently of environmental effects. The scheme produces an estimated progeny difference (EPD) for each important trait for each sire, and the EPDs can be used to rank the sires and promote the dissemination of superior genes throughout Australia. Because this process is based on genetic improvement, the benefits will accumulate and continue to flow to the whole Australian industry for many years into the future. The ACGA executive approached the University of WA (who already had a high performing cashmere herd) to run a sire referencing scheme on their Allandale Research Farm near Wundowie in WA. The proposal was to progeny-test cashmere sires from grower herds from around Australia with the aim of identifying the genetically superior bucks in terms of cashmere quantity and quality. Funding was sought from the Rural Industries Research and Development Corporation for a five-year project, commencing in 2005. The project entailed three years of mating (2005, 2006, 2007) and a further two years of evaluation of progeny. The outcomes form the foundation of this report. In addition, the presence of the project at the University of WA allowed us to leverage funding for three other projects that could run alongside, but not interfere with, the sire referencing scheme and provide extra benefits for the management of cashmere herds: 1) We compared AI methods so we could identify the least stressful approach, an issue considered important for the project and also to the wider cashmere industry because stress causes sub-fertility and because adopting more animal-friendly practices will be seen in a positive light by community; 2) Data were also collected on the temperament of the progeny, an important factor in ease of management that has been shown to be moderately heritable in the sheep flock at Allandale; 3) Data were collected on resistance to gastrointestinal worms with a view to providing alternatives to drenching.
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2. Objectives To estimate progeny differences (EPDs) for economically important traits (fleece weight, fibre quality, body weight/growth rate, resistance to internal parasites/worm egg counts, temperament) so we can identify superior sires by central progeny evaluation and enable industry to produce more quality cashmere. To evaluate the stress associated with different artificial insemination methods so we can identify the least stressful practice, helping to improve the welfare of goats and improve the consumer perception of the cashmere goat industry. To foster a national approach for Australian production of more quality cashmere by communicating the outcomes to industry, helping re-establish Australia’s position as a supplier of elite cashmere to the world.
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3. Methodology The project was be based on the cashmere does retained at Allandale Farm (The University of WA) since 1998, after the conclusion of another RIRDC project (Increasing the production of mohair and cashmere sought by processors). These relatively homogeneous does provide an ideal breeding flock for genetic evaluation of cashmere sires from all over Australia. Nominations of bucks to be evaluated were sought from Cashmere growers around Australia each year (see Appendix 1), with preference given to bucks from herds that have a history of performance recording. Once the bucks were selected, arrangements were made for semen to be collected and frozen on farm. The original plan was to use up to 20 sires identified by the ACGA as the basis of the national sire evaluation program over five years. However, the number of does made available for mating limited the evaluation to fewer sires. Semen from eighteen bucks from Queensland, NSW, Victoria and WA herds was used in artificial insemination (AI) programmes during the project. One buck was used in both years to act as a link sire so that valid comparisons between the two year’s progeny could be made. The AI programme was conducted over two days in March each year using 300 does from the Allandale herd. These does were evenly allocated to the bucks on the basis of their measured cashmere production, age and body weight to ensure that there was no bias in the evaluation of the bucks. During pregnancy the does were run as one flock but, just prior to kidding, they were drafted into their sire groups and run in separate kidding paddocks (about 1 hectare) at a stocking rate of 20-30 does/ha. This enabled correct pedigrees to be recorded for all progeny to ensure accurate sire evaluation. Grazing oats had been sown at the break of the season (May) and, when the does were put into the paddocks, the oats were 20-25 cm high (Figure 1). This provided good protection against wind-chill for the new-born kids and plenty of quality green feed for the does.
Figure 1.
Pregnant does in fox-proof kidding paddocks sown with Saia grazing oats.
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At birth, kids were tagged and their weight (Figure 2), litter size and sex were recorded. Kidding lasted about ten days and, as soon as it was complete, all of the does and kids were run together as a single herd.
Figure 2.
Weighing of kids at birth by Steve Gray.
The traits to be measured were decided upon in consultation with the ACGA and the processors. Progeny were regularly weighed to detect different growth patterns in the sire groups. Fibre growth was monitored for non-seasonal production of cashmere and at shearing time fibre length and coverage were recorded. Data were also collected on the temperament of the progeny (Figure 3) and their resistance to gastro-intestinal worms.
Figure 3. Aprille Chadwick releasing a doe kid from the isolation box during temperament testing.
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After shearing, the whole fleeces were cored to obtain samples for testing for fibre diameter and cashmere down weight. Fleece quality was also measured by the McGregor Index, calculated as McGregor Index = Downweight/(1.12^(Diameter-13) with Downweight in grams and Diameter in microns.
Figure 4.
Shearing of an adult doe.
All the records were corrected for non-genetic variables such as sex, birth type (1, 2, 3 or 4), and birth date. Estimated Progeny Differences (EPDs), being the genetic worth of the sires, were determined for the measured traits for each sire based on the performance of his progeny. The results were communicated in two ways: First, the data collected from the previous year were analysed then presented directly to members of ACGA at their annual general meeting; Second, a web page was developed that shows all relevant EPDs and a ranking of sires for their quantitative genetic value. This is accessible through the web page of the Australian Cashmere Growers Association, hosted at The University of Western Australia: http://www.cashmere.animals.uwa.edu.au/
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4. Chapters Statistical analysis The data were analysed by Dr Johan Greeff. The primary data source was the total number of kids born and the number alive at different ages. The dataset was cleaned and records with empty cells for factors (eg, age of dam, litter size, sex) were deleted. This resulted in up to 300 records per year for the critical variables. The data were analysed with Genstat using a mixed model approach to identify significant factors affecting the traits. Age of dam, sex of kid, litter size and fertility cycle were fitted as fixed effects with day of birth as a covariate. Sire was fitted as a random effect. When the data were not normally distributed, they were transformed to natural logarithms. Some variables required transformation to cube roots to normalise the data. A univariate analysis was carried out fitting a sire model with PEST, a statistical program to estimate progeny differences values (EPD), in which only the significant environmental factors sex, litter size and cycle are included. A heritability estimate of 0.25 was assumed for birth weight (based on sheep information as no goat information was available). A heritability estimate of 0.30 was assumed for body weight (Restall & Pattie, 1991) and a heritability of 0.2 was assumed for temperament tests and for WEC to estimate the breeding values of the sires. BLUP (Best linear Unbiased Prediction) breeding values of the traits were calculated for the different sires.
Sire Reference Scheme 2005 Buck selection In November 2004, a buck selection committee was formed comprising four leading cashmere growers chaired by Dr Bruce McGregor from the Victorian DPI. A nomination form and explanatory letter was sent to 115 cashmere growers throughout Australia. Nominations were received from Victoria (4), NSW (2), Queensland (1) and WA (5). Restricted numbers of does were available on Allandale and we needed to ensure enough progeny per sire to make the measurements valid, so only seven bucks could be included (Table 1). An additional buck (UWA2002A 272) from the second cycle was included because the first back-up sire (UWA2002A078) had been used in the AI programme. This link enabled the evaluation of an eighth buck in 2005. The bucks were selected primarily on objectively measured fleece attributes and their semen was collected and frozen on farm during February. Table 1.
1 2 3 4 5 6 7 8
Bucks selected for evaluation in 2005
Grower S Adamson B Bell T Esson A James P Muirhead K Rix UWA UWA (2nd cycle)
State WA Vic Vic Qld NSW NSW WA WA
Buck ID DIA 377 BRB 301 DYN B50/4800 ATJ 113 HTE 23 DYN R205/1847 UWA2002A078 UWA2002A 272
Kidding, 2005 The does that were inseminated to one of the seven bucks in SRS Year 1 kidded over late July and early August. Just prior to kidding, the does were separated into their respective sire groups and put into kidding paddocks. Kidding starting 143 days after the AI (somewhat earlier than expected) and
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finished 11 days later, peaking on Day 148. The does were observed at least twice daily to check for new-born kids and records were taken of the doe tag number, number of kids born, sex and birth weight. All the kids were double tagged. A summary of kidding is provided in Table 2. Table 2.
Summary data for the 2005 kidding for each sire.
Buck ID DIA 377 BRB 301 DYN B50/4800 ATJ 113 THE 23 DYN R205/1847 UWA2002A078
Does inseminated
Kidding %
Kids tagged
44 40 43 43 43 46 46
75 38 86 65 25 71 74
33 15 37 28 11 33 34
As soon as kidding finished, the dividing fences were all removed and the goats were run as one mob. On September 1 (average kid age 35 days), the mob was yarded, the kids weighed and vaccinated and the does drenched after a worm egg count was carried out. The goats were then moved to a fresh paddock. The production records of the seven bucks used in the AI programme varied greatly (down weight 206-596g, fibre diameter 13.1-16.8μm) so, as the project evolves, it was useful to study how their progeny compared when run under the same management and environmental conditions.
Sire Reference Scheme 2006 Buck selection Again, we sought nominations from growers for bucks to be included in the Year 2 of the project. The funding by RIRDC paid for all semen collection expenses but was only going to be available for another two years of mating so, with shearing fast approaching for most growers, it was an opportune time to check through buck records and fleece tests for nominees. Nomination forms were sent out in September – earlier than 2005 so as to allow more time to organize the collection and transport of semen. The original link sire had poor conception to AI in 2005 so was replaced. Originally, six bucks were selected, including one from Queensland, but the Queensland buck was excluded because the semen quality was poor. We addressed this problem by using semen that was still in store from two sires (Bell and Muirhead) from 2005 (Table 3). The AI was carried out by Paul Hamilton from Semtech in Victoria, using a non-surgical intrauterine insemination technique which appeared to be far less stressful (to goat and human) than the laparoscopic method used in 2005. Scanning was done 70 days later to determine pregnancy and litter size. The conception rate was 65%, a marked improvement compared to 2005, where the overall conception was only 52%.
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Table 3.
1 2 3 4 5 6 7
Bucks selected in 2006 for evaluation
Grower B Bell T Brown T Esson (link sire) B Edwards D Reid B Bell (2005 sire) P Muirhead (2005 sire)
State Vic NSW Vic Vic NSW Vic NSW
Buck ID BRB 102 ATJ U084 DYN B50/4800 KAB B 39 DMR 131 BRB 301 HTE 23
Kidding, 2006 Due to a higher conception rate and high proportion of multiple births, 353 live kids were born compared to only 185 in 2005, given a similar number of does inseminated. In addition, most does that did not conceive to AI this year recycled and were mated to back-up bucks whereas, in 2005, many does that did not conceive to the AI did not return to service and consequently were dry at kidding. After these results came to light, and because of our understanding of the effect of stress on reproduction in sheep, we initiated a Masters degree study (A Chadwick) to add an extra dimension to the SRS project. It was well-suited to the project because AI was central to the SRS objectives and is widely used in goat management to hasten genetic gain. Does were drenched and moved into the kidding paddock just before the start of kidding and stocked at 40 does per hectare. The paddock had been dry-sown to grazing oats in early May and to feed was 30 cm high, again providing an ideal environment for kidding. All new-born kids were tagged and weighed 2 or 3 times a day (Table 4). Table 4.
Summary data for the 2006 kidding for each sire.
Buck ID
Does inseminated
Kidding %
Kids tagged
BRB 102
50
152
76
KAB B39
50
120
60
DYN B50/4800
48
114
55
ATJ U084
50
116
58
DMR 131
49
112
55
HTE 23
25
60
15
BRB 301
18
72
13
The weather during kidding was wet but kid mortality (not including stillborn) up to 5 weeks was 16%, quite reasonable considering the conditions and the numbers of multiple births. The overall mortality from birth to weaning was 17%, with a range of 7-25% between sire groups. Buck DYN B50/4800 which was used in 2005 and again in 2006 and acted as the link sire between the two years. HTE 23 and BRB 301 were both used in 2005 but had low numbers of kids so were included again in 2006 to add to the number of progeny to be evaluated.
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All female kids and a random selection of male kids (wethers) were retained for testing and evaluation over the next two years. A minimum of 32 kids per sire were kept. Surplus males were sold as capretto to the local market as they reached 15 kg live weight.
Sire Reference Scheme 2007 Buck selection Growers were again requested to nominate bucks for evaluation in this the third and final year of matings. Seven bucks were selected from growers around Australia (Table 5) and semen was collected on farm from these bucks immediately prior to the AI programme in March. Of these growers, five had not previously participated in the project. A total of 307 does were inseminated trans-cervically and pregnancy status was determined by ultrasound 60 days later. The conception rate to the AI was 71% with a range between sires of 48% to 87%. Table 5.
Bucks selected in 2007 (final year) for evaluation
Grower 1 2 3 4 5 6 7
State
P McDougall D Shears A James S Hurley S Meek C Deakin Allandale (link sire)
NSW NSW Qld Vic NSW NSW WA
Buck ID Y40 Y1584 W052 GZ158 Z26 A005 UWA2002A078
Kidding, 2007 The does were stocked at 35 does/Ha and kidded in sire groups over a 13-day period in mid-August. Rainfall was quite high during kidding (70 mL) but this did not increase mortality greatly – a total of 437 kids were still tagged at birth. The low mortality rate of new-born kids was apparently again facilitated by the use of grazing oats as shelter during kidding. The grazing oats were sown in the kidding paddocks at the commencement of kidding and were about 40 cm high. A summary of kidding by sire is presented in Table 6. Only female kids needed to be retained for evaluation in the final year, due to the good survival rate of kids born. Table 6.
Summary data for the 2007 kidding for each sire.
Buck ID
Does inseminated
Kidding %
Kids tagged
MACA005
46
176
81
KDCGZ158
43
113
49
ATJW052
36
80
29
MTAY40
45
148
67
RBGZ26
49
132
65
Y1584
47
136
64
UWA2002A078
41
200
82
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Animal Welfare – the Supplementary Project Why it is important? Animal welfare, referring to the animal’s quality of life, is a major consideration for animal industry in modern times. The push for improved animal welfare in farming has gathered momentum and these pressures will only continue over time due to pressures from animal activists, the genuine concerns of animal users, and consumers demanding more ethically produced products. To improve the welfare of farmed animals, we must continue to refine and develop management practices that are less invasive and that cause less pain and distress. Welfare is assessed on the animal’s physical and psychological state and indicates how well an animal is coping with its environment.
Artificial Insemination AI hastens genetic gain by providing access to superior sires nationally and internationally, allowing use of frozen semen with good conception rates, reducing the kidding window and allowing for better feed management of does, reducing the risk of disease (by not needing to transfer bucks between farms) and allowing access to the genetics of a superior sire after the life of the buck. Semen collection Semen can be collected via electro-ejaculation or by artificial vagina (AV). Electro-ejaculation (Figure 5) involves the restraint of the buck and the insertion of a probe into the rectum. An electrical current passes through the probe providing stimulation which induces ejaculation. This is known to be painful in humans and other animals. By contrast, the use of an AV is less invasive, although it requires the presence and restraint of an oestrous doe to stimulate the buck. When the buck mounts the doe, the penis is diverted into the AV and this provides enough stimulation to cause ejaculation. Accurately quantifying the level of pain and distress is complex but, in general, it can be assumed that animals subjected to less invasive procedures usually exhibit a lower amount of pain Figure 5. Collection of semen using electroand distress. ejaculation.
If the AV technique is to be adopted by industry for the improvement of animal welfare, it must be shown to be less stressful than electro-ejaculation by quantifying the level of stress caused by the two methods. We therefore measured physiological and behavioural responses during both procedures. Artificial insemination In sheep and goats, the most commonly used and accepted method is laparoscopic AI in which the animal is sedated and then placed in a trolley with all four legs restrained and tilted so the head of the animal is near the ground (Figure 6a). During laparoscopy, the abdominal cavity is inflated with CO2 to aid access to the uterus. Semen is then deposited directly into the uterine horns. The alternative method is trans-cervical AI which involves placing the hindquarters of the doe over a rail and, while the doe is restrained in this position, a speculum is used to open the vagina and a bluntended pipette is inserted across the cervix so semen can be deposited into the uterine body (Figure 6b).
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Figure 6a) Laparoscopic insemination performed by a veterinarian
Figure 7b) Trans-cervical artificial insemination ‘over the rail’
Trans-cervical AI is less invasive but not used in the sheep industry because of very poor conception rates due to biological constraints of the ewe. However, in the cashmere doe, this method has been successful, producing conception rates that are equal or better to those from laparoscopic AI. Importantly, it is also far less invasive. If trans-cervical AI is to be adopted by industry for the improvement of animal welfare, it must be shown to be less stressful than laparoscopic AI. We therefore measured physiological and behavioural responses during both procedures.
Temperament Temperament is defined as the emotional reactivity to a novel environment or stressor. We used an ‘isolation box’ to isolate the animal from its herd mates, During a period of one minute, we measured the level of agitation: ‘calmer’ or less agitated animals have low counts whereas ‘nervous’ animals have high counts.
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5. Results Estimated Progeny Differences 2005–2007 The measure of the breeding value passed onto the progeny by both sire and dam can be expressed as an Estimated Breeding Value (EBV). In this project, however, we focussed only on the sire so we produced an Estimated Progeny Difference (EPD) for each sire.
Fleece Characteristics – 1st Shearing In Table 7 are fleece characteristics on progeny of sires selected in 2005 for the Sire Reference Scheme. There are large differences among sires in the ranking of fleece characteristics. DYNB50/4800 is ranked highest using the McGregor Index; his fibre diameter was not the finest (0.50 µm above the mean) but the overall ranking was compensated for by the high down fleece weight (41 g). MTAY40 had the finest fleece. Both ATJW052 and Y1584 had a finer than average fibre diameter as well as a down fleece weight that was above average. Ideally, a sire will have a high positive EPD for down fleece weight and a more negative EPD for fibre diameter, but the correlation between these two traits is negative so selection is generally made in one direction (eg, down fleece weight) before the other (eg, fibre diameter). Table 7.
Estimated progeny differences for fleece characteristics of sire group kids at first shearing. Sires are ranked on the basis of McGregor Index.
Sire/Rank DYNB50_4800 ATJW052 Y1584 RBGZ26 MACA005 UWA2002A078 MTAY40 ATJU084 DMR131 KABB39 UWA2002A272 DIA377 BRB102 ATJ113 DYNR205_1847 HTE23 BRB301 KDCGZ158
Down Fibre diameter (µm)
Down Fleece weight (g)
0.50 -0.08 -0.11 -0.43 0.22 0.14 -0.71 -0.50 0.08 0.27 0.15 0.65 0.38 -0.45 0.11 0.18 -0.32 -0.08
41.34 20.04 6.93 -0.28 9.18 4.51 -4.82 -5.34 -1.80 -0.56 -2.04 6.16 -0.18 -13.59 -8.66 -6.73 -22.17 -21.98
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McGregor Index 23.05 13.69 5.57 3.61 3.40 3.32 2.95 0.71 -0.84 -1.64 -1.81 -2.83 -3.23 -3.56 -7.00 -7.52 -12.61 -15.25
Fleece Characteristics – 2nd Shearing Table 8: Large differences among sires were also seen in the ranking for the second shearing. DYNB50/4800 is ranked highest using the McGregor Index: again, its fibre diameter was not the finest but this was compensated for by a high down fleece weight. MTAY40 had the finest fleece but was below the mean for down fleece weight. ATJW052 had finer than average fibre diameter as well as a down fleece weight that was above average. Table 8.
Estimated progeny differences for fleece characteristics of sire group kids 2 shearing.
Sire/Rank DYNB50_4800 ATJW052 Y1584 RBGZ26 UWA2002A078 DIA377 MTAY40 KABB39 ATJU084 BRB102 UWA2002A272 MACA005 DMR131 DYNR205_1847 HTE23 ATJ113 KDCGZ158 BRB301
Down Fibre diameter (µm)
Down Fleece weight (g)
0.78 -0.13 -0.01 -0.07 -0.16 1.00 -0.83 0.27 -0.60 0.83 -0.16 0.38 -0.14 0.01 0.06 -0.55 -0.24 -0.43
65.94 39.97 38.43 5.20 1.08 29.73 -10.44 -0.24 -13.21 7.54 -10.23 -0.86 -14.51 -17.65 -14.30 -35.67 -32.93 -37.85
nd
McGregor Index 30.35 26.26 22.23 5.31 4.82 4.29 4.22 -1.74 -2.52 -2.62 -2.76 -5.89 -8.54 -9.38 -10.95 -14.61 -18.94 -19.54
Growth – Birth to 12 Months The EPD for birth weight and growth until 12 months of age are compared across sires from all 3 years (Table. 9). UWA2002A272 had the heaviest weight at birth (0.24 kg above the mean). HTE23 and UWA2002A272 were heaviest at weaning (an extra 0.20 kg and 0.19 kg, respectively). At 6 months, kids of BRB102 were heaviest (1.05 kg above the mean). By twelve months, kids from UWA2002A272, HTE23 and BRB102 had lost weight whereas those from Y1584 had gained 1.28 kg above the herd mean.
Worm Resistance The sires with worm egg count (more resistance) lower than the herd mean were DYNR2005/1847 and MTAY40. Sire Y1584 showed least resistance followed by UWA2002A078 (Table 10).
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Table 9.
Estimated progeny differences for body weight of sires from birth to 12 months of age. NB: sires are ranked on birth weight (kg).
Body weight (kg) Sire/Rank
Birth*
Weaning
6 months
12 months
UWA2002A272
0.24
0.19
0.98
0.49
BRB102
0.20
0.13
1.05
0.76
ATJW052
0.11
0.04
0.29
0.77
DMR131
0.09
0.04
0.37
0.49
Y1584
0.08
0.08
0.56
1.28
HTE23
0.05
0.20
0.83
0.53
KABB39
0.02
-0.17
-0.59
-1.66
ATJU084
0.02
-0.11
-0.57
-0.45
ATJ113
0.01
0.01
0.50
0.56
DIA377
-0.05
-0.01
-0.66
-0.28
MACA005
-0.05
0.00
-0.38
-0.04
DYNR205_1847
-0.05
-0.26
-1.08
-0.44
MTAY40
-0.06
0.01
-0.22
-0.92
KDCGZ158
-0.09
-0.01
-0.06
0.24
DYNB50_4800
-0.10
-0.16
-0.81
-1.43
BRB301
-0.11
0.09
-0.11
0.14
RBGZ26
-0.12
-0.07
-0.24
-0.78
UWA2002A078
-0.19
0.01
0.14
0.73
Temperament Sire DMR131 had the calmest progeny whereas ATJU084 had the most nervous progeny (Table 10). These data are a good indication of the possibilities but the tests have been developed for sheep so might not be the most suitable for goats, for which further development is needed.
Stress and Semen Collection Procedure Bucks that had their semen collected using an AV expressed pawing and licking, but no flehmen response, as seen with the natural mating. The absence of this behaviour did not appear to be a response to stress. During semen collections using an AV, the bucks did not vocalise or struggle. The decibel reading for vocalisations was higher in bucks subjected to EEJ (88.7 ± 1.1 db) compared to natural mating (56.3 ± 0.6 db; P < 0.01). There were large differences between the treatments in the time from when the buck entered the pen to ejaculation: EEJ 275 ± 10 seconds; natural mating 83 ± 15 seconds; AV 43 ± 6 seconds (P < 0.05). Within a few minutes after semen collection, plasma cortisol concentration had peaked at higher values (P < 0.05) in the EEJ group (18.3 ± 1.8 µg/L) compared to bucks collected by AV (8.5 ± 1.1 µg/L) or natural mating (10.8 ± 1.9 µg/L). Values remained high for about 20 minutes and had returned to pre-collection values by 40 minutes. Our data suggest that when natural mating is not possible, semen collection using an AV is less stressful than EEJ.
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Table 10.
Estimated progeny differences for faecal worm egg count and temperament score. Note: the methodology for temperament testing needs further development so these EPD values need verification.
Sire DYNR205_1847 MTAY40 DYNB50_4800 KDCGZ158 ATJ113 UWA2002A272 KABB39 DMR131 BRB102 ATJU084 MACA005 RBGZ26 DIA377 ATJW052 HTE23 BRB301 UWA2002A078 Y1584
Faecal worm egg count (epg) -815 -652 -542 -179 -3 0 0 0 0 0 15 27 87 137 169 346 380 1030
Sire DMR131 KABB39 UWA2002A078 BRB301 ATJ113 MTAY40 HTE23 ATJW052 MACA005 BRB102 RBGZ26 Y1584 UWA2002A272 DIA377 KDCGZ158 DYNR205_1847 DYNB50_4800 ATJU084
Temperament score -0.030 -0.021 -0.021 -0.017 -0.016 -0.014 -0.012 -0.009 -0.004 0.000 0.002 0.004 0.005 0.018 0.019 0.020 0.022 0.055
Stress and Insemination Procedure An initial analysis of data from adult and maiden does provides evidence that stress is worse with laparoscopy than with trans-cervical artificial insemination. In adults, the plasma cortisol peak did not differ between methods but the trans-cervical group appeared to return to baseline values sooner. This seems to reflect the duration of the stressor (P < 0.01) with the trans-cervical procedure taking 64 ± 9 seconds whereas the laparoscopic procedure took 105 ± 10 seconds. In addition, adult does were less vocal, with fewer bleats and a lower overall bleat intensity, with trans-cervical compared to laparoscopic AI. However, no differences were seen in the number of struggles during the procedure. In maiden does, there was no difference in the duration of the method (trans-cervical 102 ± 10 seconds; laparoscopic 99 ± 12 seconds). Stressful bleats (open mouth) were more frequent for laparoscopic (5.1 ± 1.2) than trans-cervical AI (1.8 ± 0.7; P < 0.05). No differences were seen in the number of struggles or low pitch bleats (closed mouth). The plasma cortisol peak response was higher for laparoscopy than trans-cervical AI (83.1 ± 5.3 µg/L vs. 50.4 ± 7.1 µg/L; P < 0.05) and returned to baseline levels later (by 60 minutes compared to 15 minutes). Due to a national veterinary requirement to sedate goats undergoing commercial laparoscopic AI, a comparison was also made between methods with and without sedation. No behavioural or physiological differences were seen when animals were under sedation, but trans-cervical AI does not require sedation on-farm and the stress data suggest that it is not necessary.
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6. Implications The Australian cashmere industry can now choose superior sires for economically import traits: down fibre diameter, down fleece weight (or the McGregor Index), birth weight and growth rate to 12 months in kids, and worm resistance to drench. In addition, there appears to be useful scope for selection on the basis of temperament but the test used in the present study had been developed for sheep. Should the industry decide to pursue this concept, a focussed project will be needed. Cashmere producers can use these EPDs to increase the production of cashmere to the quality standards specified by manufacturers. This should lead to increased demand that, in turn, will directly benefit the entire industry by improving production and economic returns for Australian cashmere growers. Because this process is based on genetic improvement, the benefits will accumulate and for many years into the future. The availability of a website for the Australian Cashmere Growers Association will improve the profile of the industry nationally and internationally, and provide a new avenue for communication among growers. This, in combination with the process of generating EPDs, has helped fosters a national approach for Australian production, a first step towards re-establishing Australia as a supplier of elite cashmere. The supplementary project has shown that industry should change to transcervical AI. This reduces stress in the does and appears to greatly improve reproductive efficiency as reflected in pregnancy rates. In addition to the benefit in productivity, costs can be reduced because the process is faster in adults and because sedation is not necessary. There is also good evidence to justify the use of artificial vagina for semen collection rather than electro-ejaculation. Importantly for the long term, the adoption of ‘animal-friendly’ practices will give the industry a positive image in the eyes of society and thus the customers.
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7. Recommendations The Australian cashmere industry needs to adopt methods for choosing superior sires from across the entire national herd. The industry needs very high selection differentials so it can make rapid gains in productivity. Further investment in this concept is essential. There appears to be useful scope for selection on the basis of temperament because poor behaviour is one issue that appears to be preventing the expansion of the cashmere goat industry. Temperament is a moderately heritable trait in sheep and there is no reason to think goats would be different. However, in order to progress, we need first to develop a temperament test specific for goats. The industry should consider investing in R&D in this area. The availability of a website for the Australian Cashmere Growers Association will improve the profile of the industry nationally and internationally, and provide a new avenue for communication among growers. This is only a first step in fostering national coordination of the Australian cashmere industry. Without a national approach, the industry cannot develop. In the long term, all animal industries in developed countries will need to be seen as ‘clean, green and ethical’ in the eyes of society and thus the customers. This type of image is especially important for modern high-price markets driven by discretionary spending – the only markets within which Australia can profit. Cashmere is a luxury product so it falls directly into this category. To become ‘clean, green and ethical’, we need to develop management practices that minimise the use of hormones, drugs and chemicals, that have a minimal environmental footprint, and that are mindful of animal ethics and welfare (Martin et al. 2004). The supplementary project described in this report has shown that this is neither expensive nor difficult … on the contrary, it can make the enterprise more profitable by reducing costs and increasing efficiency. Greater profitability and long-term prospects should flow from catering to high-price markets with a high-quality product.
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Appendices Appendix 1. Flyer of project for growers
School of Animal Biology Allandale Research Farm PO Box 29 WUNDOWIE WA 6560
Ph: (08) 9573 6219 Fax (08)9572 7033 Mb: 0400 207 773 Email:
[email protected]
Dear Cashmere Grower Low production per head of fibre from Cashmere goats is one of the major factors limiting the profitability of running Cashmeres on farms in Australia. The ACGA sees the identification of superior genetics for fibre production (quantity & quality) in the Australian herd as a very important issue that could have a huge influence on making running Cashmere goats a very profitable part of your farming enterprise. The University of WA has been granted funds by RIRDC to conduct a sire referencing scheme for the evaluation of cashmere bucks at Allandale Research Farm, 70km to the east of Perth. This project will determine the genetic worth of individual bucks independently of environmental effects and will present the results as estimated breeding values for all important production traits. It is then hoped that growers will be able to use this information to make truly informed decisions on which bucks or semen to source that will maximise the rate of genetic gain for fibre production for their herds. This leads to the reason for this letter. We are now seeking nominations from growers of bucks that they feel may be worthy of evaluation in this scheme. Due to restrictions on doe numbers at Allandale only six bucks per year will be able to be tested. Link sires will be used to make valid between year comparisons. Matings will be conducted over three years and progeny carried through to adults. All matings will be by inter-uterine AI using frozen semen. The project will fund the cost of collection, freezing and storage of semen and associated health checks etc. Depending on the location of the growers properties whose bucks are to be tested I will try to organise the semen collection to be done on farm. If this cant be arranged then growers will be required to transport their buck to their closest artificial breeding centre for semen collection. The selection process will give preference to white bucks, with the final selection of nominated bucks to be conducted by a committee of growers drawn from industry and chaired by Bruce Mc Gregor. For this project to be successful and have a positive impact on increasing the performance of the cashmere herd in Australia it will be a requirement of growers who have bucks evaluated in the scheme to make available (at a commercial cost) to the wider industry the genetics from these bucks, be it live animals or semen. A nomination form is attached and any inquiries please contact me on the above numbers. Yours sincerely
Steve Gray Manager
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References Martin, G.B., Milton, J.T.B., Davidson, R.H., Banchero Hunzicker, G.E., Lindsay, D.R. & Blache, D. (2004). Natural methods of increasing reproductive efficiency in sheep and goats. Animal Reproduction Science 82-83, 231-246.
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National Evaluation of Sires for the Production of Quality Cashmere by Stephen Gray, Graeme Martin, Aprille Chadwick, John Milton and Johan Greeff Publication No. 10/153 This report describes a 5-year project that has produced a genetic tool for the Australian cashmere industry. A 3-year controlled breeding program was used to provide estimated progeny differences (EPDs) that can help accelerate genetic progress in the national herd an thus address the stagnation of cashmere production. The EPD values were published on a web site and growers can use them to choose superior sires for down fibre diameter, down fleece weight (or the McGregor Index), birth weight and growth rate to 12 months in kids, and worm resistance to drench.
RIRDC is a partnership between government and industry to invest in R&D for more productive and sustainable rural industries. We invest in new and emerging rural industries, a suite of established rural industries and national rural issues. Most of the information we produce can be downloaded for free or purchased from our website . RIRDC books can also be purchased by phoning 1300 634 313 for a local call fee.
The primary target audience is the cashmere growers of Australia.
Cover photo: Top: Pregnant does in fox-proof kidding paddocks sown with Saia grazing oats (left), weighing of kids at birth (right) Bottom: releasing a doe kid from the isolation box during temperament testing (left), shearing an adult doe (right)
Most RIRDC publications can be viewed and purchased at our website:
www.rirdc.gov.au
Contact RIRDC: Level 2 15 National Circuit Barton ACT 2600 PO Box 4776 Kingston ACT 2604
RIRDC
Ph: 02 6271 4100 Fax: 02 6271 4199 Email:
[email protected] web: www.rirdc.gov.au Bookshop: 1300 634 313
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