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

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

Investigation of Direct and Maternal Effects on 24 Months Weight in Indigenous Matebele Goats in Zimbabwe

This study investigated the importance of direct and maternal effects as well as the most appropriate model of analysis for 24 months weight (24MW) of indigenous Matebele goats. Records of 2110 (1245 males and 865 females) indigenous Matebele goat kids raised over the period 1996 - 2006 from 67 sires and 512 dams for 24MW were analyzed. Direct additive and maternal genetic effects were also investigated. The data originated from Matopos Research Station, Bulawayo, Zimabwe and variance components were estimated using restricted maximum likelihood, fitting five animal models, by including or excluding maternal effects. The maternal heritability decreased from 0.52 to 0.20 when maternal genetic effects were included in the model. Maternal heritability was zero when only maternal genetic effects were included in the model and was 0.04 when permanent environmental effects of the dam were added. On the other hand, permanent environmental effects of the dam were negligible. A negative and positive genetic covariance between direct and maternal genetic effects was observed. The results showed that maternal effects were not important for 24MW and could be neglected from the model. Therefore the inclusion of maternal effects into the model for mentioned trait is unnecessary

Weight at Slaughter and Carcass Characteristics of Indigenous Castrated Matebele Goats Reared On Range in Zimbabwe

A study was conducted to demonstrate that dimensions of carcass parameters and carcass compositions are influenced by adult mature weight at slaughter in castrated indigenous Matebele goats kept on range at Matopos Research Station, Bulawayo, Zimbabwe. Records of carcass parameters of indigenous  Matebele goats from selected mature adults at slaughter, 20 - 24 kg (378 records), 25 - 29 kg (292 records), 30 - 34 kg (283 records), 35 - 39 kg (292 records), 40 - 44 kg (257 records) and >45 kg  (237 records)  were obtained over a period of 15 years (1989 - 2004) and analysed for carcass performance. The goats  reached the selected adult mature weight ranges of 20 - 24, 25 - 29, 30 - 34, 35 - 39, 40 - 44 and >45 kg at 2.03, 2.44, 3.45, 4.50, 4.72 and 6 years of age respectively. Data on performance parameters and weight of organs as a percentage of empty body weight (EBW) containing the effects of the studied adult mature weight ranges were analysed using the General Linear Models (GLM) procedure of the Statistical Analysis System (SAS 1999-2000). The highest hot carcass mass (HCM) averaged 19.50± 0.38 kg for goats slaughtered at >45 kg. There was a significant difference (p<0.01) in cold carcass mass for different adult mature weights at slaughter. The goats slaughtered at weights above 25-29 kg had significantly heavier leg length (LGL), front barrel (FBL) and deep side (DPS) than those slaughtered at 20-24 kg, however there were no differences (p>0.01) amongst adult mature weight at heavier slaughter weights. The goats slaughtered at >45 kg weight had the highest (p<0.01) dressing percentage (DP) and goats slaughtered at 20 - 24 kg of weight had the lowest (p<0.01) DP. The proportion of pelt, kidneys, heart and mesenteric fat were constant. There was a significant (p<0.01) difference between kidney fat amongst groups, which increased with increasing weight. Optimal point of slaughter for castrated Matebele goat on range may be attainable between 25 and 35 kg of adult mature weight at slaughter under range management

Phenotypic Variation and Correlation of Some Carcass Traits in Indigenous Matebele Goats Kept on Range in Zimbabwe

Slaughter data on 619 castrated males and 423 does of three year of age were analyzed to evaluate the variabilities in heart girth measurement and carcass traits in local Matebele goats. There was a significant (p<0.01) difference between heart girth in does and castrated males. The does had lower (p<0.01) mean (13.64 kg) hot carcass mass and the castrated males had the higher (p<0.01) mean (16.16 kg) hot carcass mass, however there were no difference (p<0.01) between does and castrated males in condition score. Castrated males had a higher proportion of non-carcass components such as head, feet, empty gut, etc. It was found that heart girth was positively correlated with most carcass traits. The correlation of heart girth with fat score and front barrel was low, positive and non-significant in castrated males, while correlation of heart girth with fat score was negative and significant in does.  The correlation of hot carcass mass with empty gut, cold carcass mass with fat score and hearth girth with fat score were negative and reason for the negative association remained unclear. It was evident that major carcass parameters were more highly correlated in does than castrated males

Effects on Carcass Parameters in Indigenous Castrated Goats Managed on Range

Data on age at slaughter of indigenous Matebele goats collected over a period of 15 years (1989 - 2004) from Matopos Research Station, Bulawayo, Zimbabwe were analyzed after being grouped into different categories (early <1.5 years = 397 records, 1.5-2.5 years = 269, 3-4.5 years = 201 records and late slaughter >5 years=189 records). The goats slaughtered at the ages of 1.5-2.5, 3- 4.5 and >5 years had significantly heavier hot carcass mass, cold carcass mass and rib barrel than those slaughtered at <1.5 years of age. The highest (p<0.01) mean dressing percentage (DP) were observed at >5 years of age and goats slaughtered at 1.5-2.5 years of age had the lowest (p<0.01) mean DP. The proportion of heart, empty gut and the skin seemed to be constant among groups. There was a significant (p<0.01) difference between kidney fat amongst age groups, which increased with increasing age. The lower proportion of non-carcass components in the ages above 1.5-2.5 years may have contributed to higher DP and the proportion of fat increased in relation to increase in EBW