HETEROSIS LEVELS IN MEAT GOAT KIDS PRODUCED BY A THREEBREED DIALLEL MATING SCHEME.

*William C. Hendrixson, R. Browning, Jr., P. Pandya, T. Payton, M. Byars. Advisor:

Richard Browning, Jr., Institute of Agricultural and Environmental Research.

This work was done to assess heterosis levels generated in meat goat kids produced in a three-breed diallel mating scheme. Heterosis is an increase in animal performance derived through the practice of crossbreeding. The meat goat breeds involved were the Boer, Kiko, and Spanish. The Boer goat (B) is a meat goat developed in South Africa and imported to the U.S. in the mid-1990s. The Kiko goat (K) is a meat goat developed in New Zealand and also imported to the U.S. in the mid-1990s. The Spanish goat (S) is a common U.S. feral goat type that has evolved in the southern and southwestern states over the last few centuries. In the spring of 2004, the TSU meat goat breed evaluation project produced 29 BB, 31 KK, 27 SS, 18 BK, 29 KB, 30 KS, 25 SK, 18 SB, and 32 BS kids (The first letter designates the paternal breed, the second letter represents the maternal breed). Heterosis was determined on the following economically important traits; birth weight, preweaning average daily gain, weaning weight (3 months of age), and preweaning survival rate. Birth weight showed little to no heterosis among the breed pairings. Preweaning average daily gain shows 5.52% heterosis between B and S, 2.22% heterosis between B and K, and no heterosis was expressed between K and S. For weaning weight, B and S generated 6.42% heterosis, B and K expressed 3.16% heterosis and no heterosis was shown between K and S. For preweaning survival rate, B and S had 7.43% heterosis, whereas no heterosis was expressed between B and K or between K and S. In summary, kids produced by crossing Boer with Spanish experienced the highest levels of heterosis for three significant preweaning performance traits. Kiko crosses generated lower heterosis levels. Heterosis allowed Boer-Spanish reciprocal crosses to outperform both parental genotypes for growth traits; however, they did not outperform the purebred KK kids. This first year of data indicates that levels of heterosis vary among meat goat breed crosses.