Study On Fattening Performance And Meat Quality In Macheng Black Goats And Its Crossbred Progenies

Macheng black goats and its crossbred progenies as the research object were divided into fivegroups in this experiment, which were Macheng black goats group (Ⅰ for short), Boer×Macheng blackgoats group (Ⅱ), BMF1×BMF1group (Ⅲ), Boer×BMF1group (Ⅳ), Macheng black goats×BMF1group(Ⅴ). Body weights of0-12month-old goats were measured for five different time points in the grazingand complemental feeding situation. After rearing of90days for4-6month-old goats, slaughter andmeat quality were determined. In order for the rational use of local goats and cultivate new breeds forhigh-quality mutton goats, the growth-development law, meat performance and meat quality traits wereanalyzed in each group. The results are as follows:1) The growth-development law of Macheng black goats and its crossbred progeniesThe Logistic model, Gompertz model and Von Bertalanffy model, respectively, fit growth lawabout body weight of goats, all indicators are highest in the fitted values of the Von Bertalanffymodel.The estimated parameters to further estimate from Ⅰ to Ⅳgroup inflection point weight were8.84kg,12.94kg,10.08kg,13.89kg and9.23kg, weight inflection point days were115.82d,146.12d,103.06d,149.56d and105.02d, maximum daily gain were198.41g,223.40g,226.96g,228.24g and204.56g. The model can more response to the growth lawof0-12month-old goats in each group, andprovide evidence for fattening management of Macheng black goats and its crossbred progenies.2) The fattening and slaughter performance of Macheng black goats and its crossbred progenies4-6month-old goats in each group were slaughtered only after rearing of90days, the results showthat the initial body weight difference is not significant (P>0.05) among each finishing groups. Afterthe end of the fattening, the average body weight increased from10.60kg-13.25kg to17.03kg-23.13kg, group Ⅰ and group Ⅱ,Ⅳ were extremely significant(P<0.01), and differences in group III reached asignificant level(P<0.05), meanwhile the differences of the crossbred progenies groups were notsignificant (P>0.05);the size order of daily gain between the groups was Ⅱ> Ⅳ> Ⅴ> Ⅲ> Ⅰ, and averagedaily gain of groupⅠ w as lower than those of II, IV and Ⅴ group(P<0.01).Slaughter rate and meatpercentage of group Ⅰ compared withⅣgroup, the difference was extremely significant(P<0.01),compared with groups II, III, Ⅴ, the differences were significant(P<0.05), while crossbred progeniesexcept group Ⅲ and Ⅳwere significant(P<0.05), the other group difference was not significant(P>0.05); meat weight and eye muscle area of group Ⅰwere significantly lower than that of group II,Ⅳ(P<0.01). The results showed that the fattening and carcass performance of the crossbred progeniesare better than that of group I, and has a significant heterosis.3) The meat performance analysis of Macheng black goats and its crossbred progeniesCrossbred progenies of the crude fat content (7.10%-9.30%) have a slight increase, compared whitthat of group Ⅰ(7.00%), moisture content(67.85%-70.50%) was slightly lower than that in groupⅠ(70.60%), muscle moisture, crude protein, crude fat and ash content in each group were no significantdifferences(P>0.05). The content of tyrosine, glycine and proline in each group were significantlydifferent (P<0.05, P<0.01); the content order of total amino acids and umami amino acids was Ⅳ> Ⅲ> Ⅴ> Ⅱ>Ⅰ, although the contentdiffrence of the essential amino acids, umami amino acids,amino acids among these groups, was not significant(P>0.05); fatty acid composition was analyzed andthe results showed that: linoleic Acid(C18:2) content was decreased, palmitoleic acid (C16:1) and oleicacid(C18:1) content were increased, the meat quality of the crossbred progenies remained on Machengblack goats.In summary, crossbred progenies show both its own features, group Ⅱ with rapid weight gain,higher fattening performance is the ideal commodity goat cross combination; group IV with the largesteye muscle area, the highest dressing percentage and meat percentage among these groups.Simultaneous the content of the flavor amino acid contents and17amino acids were highest than thoseof the other groups, group IV can produce more high-quality lamb in the same feeding situation, and canbe used to further cultivate new varieties of Macheng black goats.