Final report for LS13-254
Project Information
LS13-254: Improving Fitness in Meat Goat Herds through Better Genetic Management
$230,000
PI: R. Browning, Jr. - Tennessee State University
Co-PI: M.L. Leite-Browning – Alabama A&M University
Co-PI: R.N.B. Lobo – EMBRAPA
Summary
Fitness problems in meat goat herds may be associated with unsuitable animal genetics for a given production environment. Moderate to low management inputs are important for meat goat enterprise profitability. Better genetic management under limited resource conditions may enhance meat goat herd performance. Findings of this project were that crossbreeding with Boer or Savanna did not improve on base Kiko or Spanish doe performance. Indications were that Boer or Savanna does had higher parasite burdens than Kiko or Spanish does. A substantial proportion of producer trainees indicated making changes in herd genetic management with positive outcomes.
Objectives/Performance Targets
Boer crossbred and Savanna crossbred does were compared to parental Kiko and Spanish purebred does for fitness traits on pasture typical of small farms in this region. An outreach effort was conducted to stimulate on-farm performance testing and enhance genetic evaluation in meat goat seedstock herds using a web-based management tool using best linear unbiased prediction to generate breeding values for growth and fitness traits.
Cooperators
Research
Research methodology. Boer F1 (Boer x Kiko and Boer x Spanish; n = 250) and Savanna F1 (n = 75) crossbred does and Kiko (n = 217), Spanish (n = 207) purebred does were managed on the TSU farm in Nashville, Tennessee over the three years of this project and the earlier years for the Boer F1, Kiko, and Spanish cohorts. The comparison of Boer F1 with Kiko and Spanish does (2009-2010, 2012-2015) was independent of the comparison of Savanna F1 with Kiko and Spanish (2015-2017). Except for the 45-day mating period, all does within each are managed together as one heterogeneous herd. Nutritional management for the doe herd includes grazing pastures with mixed grass and browse species, water and minerals for ad libitum consumption. In the winter, orchardgrass hay was provided and supplemented with either whole cottonseed or self-feeding molasses tubs.
All does were born as products of the TSU breeding program. Replacement doelings were developed to be first bred to kid as two-year-olds. Doelings were further evaluated to determine how their breed-type, rank based on performance-based relative weaning weight, and litter size type at weaning affected first opportunity reproductive rates. It was determined that one area lacking in research and producer education was doeling selection protocols and breed effects on doeling development. Doelings were classified by breed type, weaning weight ratio (high, moderately high, moderately low, and low) and weaning litter type (single or multiple type).
Each fall, Kiko, Boer x Kiko, and Savanna x Kiko does were bred to Savanna and Kiko bucks on a rotational basis in single-sire breeding paddocks. The same occurred for breeding Spanish, Boer x Spanish, and Savannah x Spanish does to Savanna and Spanish bucks. All Savanna bucks serviced both Kiko and Spanish type does to connect the groupings. Groupings allowed for doe comparisons balanced across service sire breed and comparative Savanna sire evaluations balanced across doe genotypes within Kiko or Spanish groupings. Body weights were recorded for does and kids within 24 hours after kidding and when kids were weaned at 3 months of age. Does were also weighed at the start of each breeding season. Doe reproductive performance was assessed by recording kidding rates and litter sizes at birth and weaning.
Routine health care of the doe herd included annual CD/T and pneumonia vaccinations and strategic deworming of the doe herd at spring kidding. Anthelmintic treatment was also administered to individual animals presenting clinical signs of internal parasitism in spite of strategic deworming. When does were weighed at breeding, kidding and weaning, fecal samples and blood samples were collected from does with fecal samples processed to determine nematode egg cell counts by the modified McMaster technique. Fecal egg counts is an indicator of internal parasite burden in goats (Baker et al., 1998; Costa et al., 2000; Zajac and Gipson, 2000) routinely performed in this laboratory. Blood samples will be processed for packed cell volume as an indicator of internal parasite tolerance when associated with egg counts. Annual doe mortality and project stayability was assessed as does were culled after second failure to wean a kid or because of chronic health problems.
Analysis of variance techniques was used to statistically process the data using procedures of SAS (SAS Institute, Cary, NC). Models included breed of sire and breed of dam as the fixed main effect. Sire and dam within breed will be included as random effects to test the breed of sire and dam of herd does. Year of record was included as a random effect. Response variables included kidding and weaning rates, animal weights, litter size, kid mortality rates, packed cell volumes, and log-transformed fecal parasite egg counts. Continuous data were tested using mixed models (PROC MIXED). Frequency data and count data were tested using general linear mixed models (PROC GLIMMIX). Measures of production efficiency assessed included litter size weaned per doe exposed. Breeding herd does and replacement doeling development to first kidding were similarly evaluated.
Outreach Methodology. Training workshops included providing hands-on exercises in reproductive and internal parasite management. The genetic components of the research effort were presented and producers were educated on the broader biological and economic implications genetic management decisions in commercial meat goat enterprises. It was stressed that each producer assess his or her enterprise situation and goals to customize a unique set of genetic and reproductive protocols. Fact sheets geared towards southeastern meat goat production were planned to assist producers in the understanding and selection of breeds by providing some insight into breed strengths and weaknesses as well as potential contributions to crossbreeding plans. A key component of the outreach effort was the introduction of an EPD program in cooperation with the Brazilian National Goat Research Center, a component of the Federal Agricultural Research Agency of Brazil (EMBRAPA). A web-based program was set up so that producers can go into the password-protected program to enter animal data and view summary reports.
Boer crossbred does. Cumulative production data indicates that Boer crossbred does were of similar for body weight and whole-herd performance values for reproductive traits and survival rates compared to parental Kiko and Spanish straightbred does (Table 1). As with the whole-herd values that include all does fall-exposed to bucks, Boer-cross does were similar to Kiko and Spanish base straightbred does within kidding and weaning populations. A smaller population of straightbred Boer does (n = 20) managed with the study herd has lower (P < 0.05) values for weaning rate (7 ± 5% does), and kid crop weaned (13 ± 7% kids/doe). One notable point of divergence was that Boer-Kiko does had higher (P < 0.05) fecal egg counts than Kiko straightbred does (Table 1).
A separate evaluation of replacement doeling development was conducted to assess doeling development from own weaning until weaning of their first kids. In this assessment, Boer-cross doelings were superior to Boer straightbred doelings, but no different than Kiko or Spanish straightbred doelings (Table 2). It was also revealed that low weaning weight ratio doelings (weaning weight less than 87% of contemporary group average) generally performed at levels lower (P < 0.05) than the other three groups, but high weaning weight ratio doelings (weaning weight greater than 112% of contemporary group average) were not better that moderately high or moderately low weight ratio doelings for survivability or first year reproductive performance.
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Table 1. Effect of doe breed on body weight and fitness traits. |
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|
Trait |
Kiko |
Boer x Kiko |
Spanish |
Boer x Spanish |
|
Doe weight at breeding, kg |
38.8 ± 1.3ab |
39.5 ± 1.4a |
34.4 ± 1.3c |
36.5 ± 1.4bc |
|
Weaning rate, % does/year |
55 ± 7 |
46 ± 7 |
60 ± 7 |
46 ± 7 |
|
Kid crop weaned, % kids/doe |
79 ± 11 |
68 ± 10 |
79 ± 11 |
61 ± 10 |
|
FEC, eggs/g |
1258a |
1949b |
1345ab |
1349ab |
|
Endoparasitism, % does/year |
21 ± 5 |
34 ± 7 |
30 ± 6 |
38 ± 7 |
|
Survival rate, % does/year |
83 ± 3 |
76 ± 4 |
79 ± 4 |
78 ± 4 |
|
abcLSMeans (± se) in row with different superscripts differ (P < 0.05). |
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Table 2. Effect of replacement doeling breed on post-weaning development. |
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|
Trait |
Boer |
Boer-cross |
Kiko |
Spanish |
|
Survival to 1st breeding, % |
52 ± 10b |
87 ± 5a |
90 ± 4a |
90 ± 4a |
|
Survival to 1st weaning, % |
38 ± 7b |
77 ± 5a |
79 ± 5a |
78 ± 5a |
|
Weaning rate, % does/year |
20 ± 9b |
57 ± 11a |
71 ± 9a |
74 ± 9a |
|
Kid crop weaned, % kids/doelings weaned |
35 ± 9b |
84 ± 16a |
104 ± 19a |
118 ± 22a |
|
abLSMeans (± se) in row with different superscripts differ (P < 0.05). |
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These data are derived from a Master’s thesis that was developed as part of this project (Khanal, 2016). One journal article is currently under peer-review and a second is being written. Boer goats were imported to cross on Spanish goats with the expectation of improving herd performance. The findings of this work generally showed that crossing with Boer germplasm did not represent fitness improvements over the base Kiko or heritage Spanish populations. A recent 9-yr study in semi-arid Texas also revealed that Boer x Spanish cross does did not differ from straight Spanish does for reproductive performance (Rhone et al., 2013). The results of the current project indicate that straightbred Boer populations would benefit from crossing with Kiko or Spanish germplasm to improve doe herd performance under conditions of low- to moderate-input production conditions.
Savanna crossbred does. Unlike the Boer-cross study, reciprocal crosses were not made because no straightbred Savanna does have been added to the TSU herd. Therefore, evaluations on this phase of the project were essentially treated as sire breed-daughter comparisons. In other words, doelings/does were evaluated based on their sire breed. In the case of Kiko and Spanish sires (as well as Myotonic sire), daughters included crossbred and straightbred daughters. All of the Savanna daughters were crosses with the base doe breeds. As part of a related study on anthelmintic resistance over one summer, is was demonstrated that young daughters of Savanna sires had higher (P < 0.05) fecal egg counts that daughters of Kiko and Myotonic sires (Goolsby et al., 2017; Figure 1). These data represent the first published of a comparative nature involving Savanna germplasm and provide some early indication of what commercial producers should be considering when contemplating the addition of Savanna influence into their doe herd gene pool.
A longer-term project in larger group of older breeding does produced by the same sire breed is also revealing some Savanna deficiencies within the conditions of this study. After 4 years, Savanna sires have been similar or inferior to the other three sire breeds for daughter fitness traits (Table 3). This evaluation of Savanna-influenced does will continue for another 3-4 years as additional external funding was recently secured from USDA to continue the work initiated on this SARE project. Preliminary reports on these sire-daughter data are currently being peer-reviewed for presentation at an upcoming livestock genetic conference. Similar to the findings on the Boer goat influence, these novel early results are suggesting that Savanna crossing would not be advantageous to enhancing doe herd fitness (i.e., health or reproductive) traits. The positive profile of Myotonic-sired does suggest that they receive additional research attention.
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Table 3. Effect of meat goat sire breed on daughter weight and whole-herd fitness1. |
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|
Trait |
Kiko |
Myotonic |
Savanna |
Spanish |
|
Doe weight, kg |
34.4 (1.2)a |
30.9 (1.7)ab |
33.4 (1.3)ab |
30.7 (1.3)b |
|
FEC2, eggs/g |
406 (-)bc |
262 (-)c |
691 (-)a |
602 (-)ab |
|
Weaning rate, % does |
53.9 (7.0)ab |
79.0 (3.8)a |
36.2 (5.5)b |
61.1 (6.6)ab |
|
Kid crop weaned, % kids |
75.0 (10.3)ab |
96.1 (13.2)a |
54.7 (8.0)b |
71.7 (9.7)ab |
|
Survival rate, % does |
67.4 (1.2)a |
87.1 (5.2)a |
44.0 (8.0)b |
67.6 (5.2)a |
|
1Least squares means (± se) 2Fecal egg count, geometric (i.e., back-transformed) means a-cMeans within a row not sharing a common superscript differ (P < 0.05)
|
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These breed evaluation results involving Boer and Savanna genetics were at the heart of the outreach activities involving genetic management for improved reproductive performance and internal parasite profiles in commercial meat goat herds. Producers were educated on how breed selection affects herd performance and economic status. These breed discussions fit well with the hands-on demonstrations on how to assess and manage internal parasitism in meat goat herds and how to use caution when disseminating germplasm via artificial insemination in the absence of within-breed or between-breed performance data. A dozen Kiko and Savanna producers enrolled in the online system for across-herd genetic evaluation. Unfortunately, continued fracturing within the various breeder groups stymied this component of the outreach program. A key component of a BLUP genetic evaluation system is the entry of pedigree data that is consistent across herds. The emergence of multiple registries and movement of animals and breeders among the various registries was difficult to overcome. However, the potential value of breeding values was presented as part of the outreach effort by using the internal sire summaries generated for the TSU research herd in cooperation with EMBRAPA-Brazil.
Educational & Outreach Activities
Participation Summary:
Over the course of this project, research updates and training exercises associated with this project have been conducted at various venues. Events included extension programs and industry events in multiple states in the southern region and beyond. The list of 48 outreach activities associated with this project is not all-inclusive, but provides most of the educational venues. At some events, multiple presentations/demonstrations were provided. As the latter event dates indicate, educational opportunities resulting from this project will extend beyond the formal timeframe of the project.
Learning Outcomes
Project Outcomes
Impacts
Impacts and Contributions/Outcomes
Information provided helped producers make better genetic management decisions in their herds. Many of the input costs associated with meat goat management are inflated to compensate for unfit genetics that are a poor match with the prevailing production environment. Over the course of the project, over 2,100 participants attended the various workshops and seminars conducted. A producer survey was completed by 825 participants representing 16 states to indicate their responses to our training programs. As a result of past TSU-AAMU workshops on herd health and genetic management, producers have expressed positive outcomes. Most attendees (76%, 82%, and 77%, respectively) indicated increased production efficiency by 5% to over 20%, decreased animal illnesses and deaths by 5% to over 20%, and increased herd profitability by 5% to over 20%. This laboratory has received positive feedback on including McMaster FEC wet-lab training along with the discussion of FAMACHA. For example, one producer indicated that her costs of WORM control in her Kiko herd has dropped from $727 in 2005 to $180 dollars in 2015 as a result of the combined FAMACHA and McMaster FEC trainings.
Past educational contacts over the course of this project also affected genetic management as 61% of respondents indicated approach to breed selection was affected or changed, 56% of producers started or modified performance recording activities, and 53% of the producer attendees modified their within-herd selection and culling procedures. Similar impacts were found after a series of minority producer workshops (Leite-Browning et al. 2016). In terms of the breed selection approach response, the vast majority of producers moved away from using Boer genetics in their maternal gene pool and began favoring Kiko- or Spanish-influenced does. Data from this project and related efforts at this research station have changed attitudes and behaviors towards genetic management and internal parasite control. Meat goat herd productivity and sustainability would be enhanced by better genetic management.
Accomplishments
Economic Analysis.
A direct economic analysis on the crossbred doe evaluation was not conducted. However, in 2016 a couple of related economic assessments were conducted on the source genetics used in the Boer-crossbred does evaluation. Gross returns were determined based on matings to produce purebred and crossbred kids using market kid prices applied to litter weaning weights (Figure 2). The matings were those resulting in the Boer-crossbred does and Boer, Kiko, and Spanish straightbred does used in the current project. The primary feature was that the matings that did not include Boer genetics or the applied Boer-influence market premium (KK, KS, SK, SS) generated cash receipts similar to or greater than Boer-influenced matings with a $0.20/lb premium applied. These cash values did not demonstrate a need for Boer crossbreeding to enhance financial returns on a per herd doe basis.
A follow-up 6-year enterprise budget outcome were determined in 2016 from the research data published the Boer, Kiko, and Spanish foundation stock (Browning et al., 2011; Browning and Leite-Browning, 2011) and using information on general TSU herd management costs (Table 4). It was revealed that Boer does suffered annual losses whereas Kiko and heritage Spanish does posted annual profits. Profits were realized despite the lack of a focused effort on herd economics or a profit motive in the research herd. Returns over variable and total doe costs for Kiko (13%, 6%, respectively) and Spanish (8%, 1%, respectively) were modest. The primary input costs was associated with feed and hay. A uniform feed cost was applied across all does based on the homogeneous nutritional management plan. Spanish does are generally lighter than Kiko does, so the actual feed intake was likely lower for Spanish does than for Kiko does. In turn, the Spanish net monetary returns are probably closer to the Kiko returns than reflected in this table.
Publications.
Peer-reviewed articles.
Goolsby, M. K., M. L. Leite-Browning, and R. Browning, Jr. 2017. Evaluation of parasite resistance to commonly used commercial anthelmintics in meat goats on humid subtropical pasture. Small Ruminant Research, 146:37-40.
Khanal, P. and R. Browning, Jr. 2017. Effect of doeling traits at weaning on subsequent replacement doe fitness traits in a multi-breed meat goat herd. Small Ruminant Research, Rumin-D-17-9110 (under review).
Browning, R. Jr., M. L. Leite-Browning, and E. G. Hayes. 2017. Fitness of meat goat does sired by Kiko, Myotonic, Savanna, and Spanish bucks in the southeastern United States. World Congress of Genetics Applied to Livestock Production. (under review).
Khanal, P. Browning, M. L., Byars, M., & Browning, R. Jr. 2017. Meat goat performance among Boer F1 crossbred and Kiko and Spanish base straightbred does in the Southeastern United States. (in preparation).
Research abstracts.
Hayes, E. G., P. Khanal, R. V. Lourencon, and R. Browning, Jr. 2016. 041 Evaluations of Savanna Sires Compared with Kiko and Spanish Sires for Birth to Weaning Meat Goat Kid Traits. Journal of Animal Science, 94(Supplement 1), 20-20. Southern Section, American Society of Animal Science. San Antonio, TX, February 6-9.
Khanal, P., M. L. Browning, M. Byars, and R. Browning, Jr. 2016. 026 Effect of doeling traits at weaning on doe survival and reproductive rates through their first production year in the southeastern United States. Journal of Animal Science, 94(Supplement 1), 13-13. Southern Section, American Society of Animal Science. San Antonio, TX, February 6-9.
Browning, M. L., T. Cook, and R. Browning, Jr. 2016. 019 Improving Enterprise Outcomes and Increasing Minority Participation within the Meat Goat Industry through Outreach Activities in the Southeast. Journal of Animal Science, 94(Supplement 2), 9-10. Southern Section, American Society of Animal Science. San Antonio, TX, February 6-9.
Goolsby, M. K., M. L. Leite-Browning, and R. Browning, Jr.. 2016. 405 Evaluation of parasite resistance to commonly used commercial anthelmintics in meat goats. Journal of Animal Science, 94(Supplement 2), 189-190. Midwestern Section, American Society of Animal Science. Des Moines, IA, March 12-16.
Browning, R. Jr. and M. L. Leite-Browning. 2016. 1728 Contribution of newer goat breeds to small ruminant profitability. Journal of Animal Science 94(E-Supplement. 5), 828. National Meeting of the American Society of Animal Science. Salt Lake City, UT, July 19-23.
Thesis Submissions.
Khanal, Piush. 2016. Influence of crossbreeding and non-genetic factors on doe fitness traits of Boer F1 and foundation breeds in southeastern United States. MS Thesis (August), Tennessee State University (R. Browning, Advisor).
Hayes, Emily. 2017. Influence of creep feeding on kid growth and dam health in multiple meat goat breeds and their crosses. MS Thesis (in preparation), Tennessee State University (R. Browning, Advisor).
Stevens, Lauren. 2017. Savanna sire effect on birth to weaning kid traits and doe reproductive health under subtropical conditions. MS Thesis (in preparation), Tennessee State University (R. Browning, Advisor).
Farmer Adoption.
Some of these particulars are addressed in the section on Impact. The 2,100 producer contacts value was based on those events where attendance was recorded. There were many of the outreach activities we were invited to where registrations or attendance was not recorded or surveys were not distributed. The TSU lab website used to provide documents and updates on this and related projects logged 1,019 visitors (or 2.8 visitors per day on average) over the last 12 months of this project. The total direct and indirect contacts over the 3.5 years of this project were probably well over 2,100 producers recorded. A couple of general recommendations offered to producers that have been augmented by this project include 1) do not rely solely on FAMACHA scoring as an internal parasite indicator; implement a plan for routine fecal egg counting, 2) avoid adding Boer genetics to the doe herd whenever possible; rely on Kiko and Spanish genetics for the doe herd and restrict Boer genetics to terminal sire use for market kid production.
Areas needing additional study.
There is a continued need to study meat goat breeds and their management in the context of limited-input, commercial production. The breeds need to be assessed to better determine how they should be used to meet the profit and sustainability objectives of commercial producers. Genetic management will likely play a more prominent role in overcoming internal parasitism in meat goats as anthelmintic resistance becomes more widespread and problematic.