| The experiment was conducted, treating the improvement in meat quality of lambs as the starting point, to assess the effects of grape pomace extract(GPC) and linseed oil(LO) on growth performance, carcass performance, meat quality and nutrient digestive utilization of lambs fed diets with isoenergic and isonitrogenous by feeding, slaughter, metabolism trials, to provide a scientific basis and technical support for the production of high-grade meat.Fifty- four Hu lambs with same genetic background, growing in good condition and weaning at the age of 3 month were selected and the study used 2 × 3 factorial design with two levels of LO(0, 4%) and three levels of GPC(0, 0.36%, 0.72%), each treatment has nine replicates with one sheep per replicate. Trial period was 70 d, which including 10 d pre-trial and 60 d positive trial; Five lambs with body weight approaching group average weight were selected from each group at the end of the feeding trial for the digestion and metabolism test, feeding methods were same as feeding trial, the sheep alone placed in digestion and metabolism cage, pre-trial was 3 d and test period was 6 d. The results shown as follow:1. Dietary GPC supplementation had no significant effect on growth performance, carcass performance and visceral weight of lambs(P>0.05); Diet supplemented with LO had a significant red uction in the dry matter intake, average daily gain, dressing percentage, carcass weight and the content of perirenal fat(P<0.05), had a decreased trend on the final body weight(P=0.069), there was a significant interaction effect on the lungs weight(P<0.05).2. Diet containing 0.36% GPC brought a significant increase in NDF apparent digestibility and nitrogen retention rate(P<0.05), the group of 0.72% GPC adding significantly improved apparent digestibility of ether extract(P<0.05); Diet supplemented with 4% LO had a significant reduction in the apparent digestibility of dry matter, organic matter, neutral detergent fiber, acid detergent fiber and gross energy(P<0.05), but the reverse case for the apparent digestibility of ether extract and nitrogen(P<0.05). There was a significant interaction effect on the apparent digestibility of neutral detergent fiber, ether extract and gross energy(P<0.05).3. The molar ratio of propionic acid in 0.36% GPC group was significantly lower than that of no adding group(P<0.05), the molar ratio of butyric acid and acetic acid/propionic acid were significantly higher than those of no adding group(P<0.05), other acid molar ratio was significantly higher than that of 0.72% adding(P<0.05), the molar ratio of butyric acid and acetic acid/propionic acid in 0.72% adding group were significantly higher than those of no adding group(P<0.05); diet supplemented with 4% LO had a significantly reduction in the molar ratio of acetic acid, butyric acid, acetic acid/propionic acid and had a significantl increase on the molar ratio of propionic acid(P<0.05); GPC and LO produced a significant interaction on the molar ratio of acetic acid, butyric acid, acetic acid/propionic acid(P<0.05).4. Diet containing 0.36% GPC had a significant reduction in the rate of water loss and cooking loss than those of 0.72% group(P<0.05), the group of 0.72% had a siginificant reduction in b*, but the water loss was significant higher than other two groups(P<0.05), drip loss had a decreased trend with the improvement of GPC level(P=0.073), LO adding had an increased trend on a*(P=0.074).5. The group of 0.72% had a significant reduction in the content of C17:1, C18:1n9c and significantly increased the content of C18:2n6c, C LA-c9t11(P<0.05), GPC adding had an increased trend on the content of C18:2n6t(P=0.073); LO adding had a significant reduction in the content of C16:1, C18:1n9c(P<0.05) and significantly increased the content of C18:2n6t, C18:2n6c, CLA-c9t11, C18:3n3(P<0.05); there was a significant interaction effect on the content of C18:2n6t, C18:2n6c, C18:3n3(P<0.05).As above, the suggested levels of GPC and LO were 0.36% and 4%, respectively from the point of growth performance and the digestion and metabolism of nutrient, starting from the production of high- grade mutton recommended to add 0.72% GPC and 4% LO. |
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