Studies on growth rate, carcass quality and helminth resistance of three strains of Tanzania local Goats
| dc.contributor.author | Malole,Julius Luhende | |
| dc.date.accessioned | 2024-07-31T05:32:23Z | |
| dc.date.available | 2024-07-31T05:32:23Z | |
| dc.date.issued | 2002 | |
| dc.description | Dissertation | |
| dc.description.abstract | This study was conducted on three strains (Kigoma, Dodoma and Mtwara) of Tanzanian local goats with the aim of estimating heritability for pre weaning (birth-4 months), post weaning (4-8 months) and yearling (8-12 months) growth rates. Other heritability parameters estimated were for weight at birth, 4, 8, and 12 months of age and helminth resistance traits i.e. Faecal egg count (FEC) and packed cell volume (PCV). Data accumulated between 1997 and 2000 was used to estimate heritability. The same data set was used to evaluate the effect of sex, birth type, strain, year of birth on growth rate at four, eight and twelve months of age. This formed part I of the study. In part II of the study, the effect of worm burden on growth rate was done only on goats that had available information on PCV and FEC at six and twelve months of age. This study also evaluated the effect of strain on killing out characteristics, carcass quality and composition as well as development of prediction equations/models for carcass weight and carcass tissues. Most of the traits considered were observed to have (0.32-0.39) moderate heritability, with exception of weight at weaning, 8 months, one year of age and PCV, which had high (0.4-0.44) heritability. Strain had a significant influence (P<0.05) on growth rate at four, eight and twelve months of age. The Dodoma strain had highest daily gain at four months (40.0g), eight months (37.6g) and twelve months (32.6g) of age compared to that of Kigoma (34.6g, 35.2g, 31.4g) and Mtwara (32.3g, 29.4g, 26.1g), respectively. Sex had a significant influence on growth rate only at four months of age. Male kids had higher daily gain than females. There was a significant effect of worm burden on growth rate at six and twelve months of age. Dodoma strain showed lowest FEC and highest PCV and growth rate. Mtwara strain showed highest level of FEC and the lowestiii PCV and growth rate. Kigoma strain was in between the other two strains. Susceptibility to helminth infection measured by FEC and PCV indicated that Dodoma strain did not differ significantly (P>0.05) from that of Kigoma strain, and that both of them were more resistant than Mtwara strain. Further more, results indicated a negative correlation between FEC and PCV at both ages. FEC also had a negative relationship with growth rate at six and twelve months of age, whereas PCV showed a positive relationship with growth rate. There were significant differences between strains in dressing percentage (DP), slaughter weight, empty body weight and carcass weight. Dodoma strain had the highest weights followed by Mtwara and Kigoma. Dressing percentage was 49.3% in Dodoma strain, 45.5% in Mtwara strain and 44.8% in Kigoma strain. Strain effects were also observed for edible non-carcass components when expressed as percentage of slaughter weight. Dodoma strain had the highest weight of kidney, head, feet, and gut fat compared to Mtwara and Kigoma. Other edible non-carcass components such as pluck, spleen, liver, and gut were heavier for Dodoma strain than those of others trains albeit the differences were not significant. Carcass composition consisted of 70.3, 69.8, and 68.4% for lean; 17.8, 18.8 and 19.7% for bone; 12.5, 15.5, and 15.5% for fat in Dodoma, Mtwara and Kigoma strains, respectively. Strain effect was also evident in carcass tissue ratios, with Dodoma goats showing better proportions than Mtwara and Kigoma. Strain also had significant effect (P<0.05) on carcass joint weights. The Dodoma strain exhibited heaviest weights of ribs, breasts, loin and feet than the other two strains. Heart girth was the best independent variable in predicting carcass weight (P<0.002, R2 = 82.4%). Foreleg joint was the best predictor of lean (P<0.001, R2 = 92%), while rib joint was the best predictor of both carcass bone (P<0.001, R2= 87%) and fat (P<0.001, R2= 80%). Of theiv the three independent variables namely slaughter weight, carcass weight and empty body weight, carcass weight was the best predictor of lean (P<0.001, R2= 98%) and fat (P<0.001, R2 =87%), whereas slaughter weight was the best predictor of bone (P<0.001, R2 = 89%). It was generally concluded that of the threes trains, the Dodoma strain was superior to the rest in terms of growth rate, helminth resistance and carcass quality. Selection, bio-molecular techniques and cross breeding could be employed to improve these traits because they have moderate heritability. | |
| dc.identifier.uri | https://www.suaire.sua.ac.tz/handle/123456789/6349 | |
| dc.language.iso | en | |
| dc.publisher | Sokoine University of Agriculture | |
| dc.subject | Carcass quality | |
| dc.subject | Helminth | |
| dc.subject | Local Goats | |
| dc.title | Studies on growth rate, carcass quality and helminth resistance of three strains of Tanzania local Goats | |
| dc.type | Thesis |