Breed evaluation for health , reproductive , and carcass traits in meat goats : observations from the southeastern US

Commercial meat goat producers have a somewhat limited variety of breeds to consider when developing a breeding program compared to other livestock industries. Nevertheless, it is still important to provide these producers with objective, research-based information on the strengths and weaknesses of different breeds for economically important traits (e.g., reproduction, growth, and carcass merit). Most goats raised for meat production are managed under lowto moderate input systems. Breed evaluations should similarly be conducted under conditions reflective of limited-resource production systems. Reproductive performance is arguably the production trait with the greatest impact on profitability in a commercial meat goat enterprise. However, reproduction and survivability (both measures of fitness) are often overlooked when evaluating a new breed in a unique production environment. Little research attention has been given to variation among meat goat breeds for health and reproduction as compared to growth (Shrestha and Fahmy, 2007). In the United States, three primary breeds are represented in the commercial herd. The Boer is a meat breed developed in the semi-arid region South Africa (Casey and Van Niekerk, 1988). Boer is the predominant meat goat genotype in the U.S. today. The Kiko is a composite meat goat breed developed in humid New Zealand (Batten, 1987). The Spanish is a non-descript landrace breed-type that evolved in the semi-arid region of south-central Texas from stock brought by Spanish explorers to the western hemisphere in the 1500s (Shelton, 1978; Mason, 1981). Spanish goats were the main meat goat genotype in the US before the arrival of Boer and Kiko goats in the mid-1990s. The widespread use of Boer genetics was based on claims that growth rates and carcass traits would be improved over those of the Spanish goat base population. A pilot project preceding the present study suggested that substantial differences in fitness and performance may exist between Kiko and Boer goats (Browning et al., 2004). Warm, humid pasture conditions optimal for gastrointestinal parasites and hoof pathogens make efficient meat goat production in the southeastern US difficult. Internal parasites represent the greatest threat to goat health, survival, and productivity (Kaplan et al., 2004). Internal parasites and lameness lead to added inputs in terms of time, labor, and supplies used for prevention and (or) treatment. Research at this station has focused on evaluating performance and health indicators of Boer, Kiko, and Spanish goats under semi-intensive, pasture management conditions of the southeastern United States.