Evaluation of carcass performance of Matebele goats managed extensively based on the eruption of permanent incisors teeth

Abstract

Matebele goats were slaughtered at different state of permanent incisors eruption 1st pair (I1 )(237records), 2nd pair (I2 )(312 records), 3rd pair (I3 )(237records), 4th pair (I4)(232 ), Broken Mouth (BM)(214) and Smooth Mouth (SM)(218) over a period of 15 years (1989- 2004) and analysed for carcass performance. Performance parameters and weight of organs as a percentage of empty body weight (EBW) containing the effects of number of permanent incisors at I1, I2, I3, I4,, BM and SM were analysed using the General Linear Models. Live weight averaged 21.57 kg ± 0.02, 27.01± 0.02 kg, 28.40± 0.02 kg, 28.88± 0.02 kg, 36.92± 0.02 kg and 37.33± 0.02 kg for goats slaughtered at I1, I2, I3, I4,,, BM and SM, respectively. There was a significant (p<0.01) difference in slaughter weight at different periods of permanent incisors teeth eruptions. The goats slaughtered at I1 and I2 had significantly heavier hot carcass mass,
cold carcass mass and rib barrel than those slaughtered I3, I4,, BM and SM. The goats slaughtered at I3 had the highest dressing percentage and goats slaughtered at BM had the lowest dressing percentage (DP). For external noncarcass components, the proportion of the head did not change but it was the feet proportion that increased markedly from I1 to I3 which coincided with the decrease in pelt. The proportion of hind barrel, head and kidney fat seemed to be constant. There was a significant (p< 0.01) difference between mesenteric fat amongst teeth groups, which increased with increasing number of permanent incisors eruption representing age increase. The lower proportion of noncarcass components in I3 may have contributed to a higher DP.