Effect of natural feed additives on meat quality and caecotrophic fatty acid profile of New Zealand rabbits

ABSTRACT The objectives of this research were to evaluate the effects of commercial probiotic and chitosan as food additives on the quality and meat composition of 36 New Zealand White rabbits (57 ± 8 days old and 1,648 ± 0.194 kg) and on the fatty acid profile of caecotrophs. The treatments were CT (diets without inclusion of additives), PRO (inclusion of 4 g / kg of commercial probiotic) and CHI (inclusion of 4 g / kg of chitosan). The additives increased triglycerides and decreased urea compared to the control group, as well as increased oleic and linoleic acids, Ʃ unsaturated, Ʃ monounsaturated and Ʃ polyunsaturated in caecotrophs. CHI animals showed a decrease in myristic and palmitic acids compared to PRO. CHI decreased the meat's crude protein and the meat's fat. In addition, there was a decrease in omega-3, omega-6 and the relationship unsaturated and saturated fatty acids for the CHI group and an increase in erucic acid and a decrease in the rate of hypocholesterolemic acids. As a conclusion, the data showed that the animals that ingested probiotic had better meat quality, for having better fatty acid profile and hypocholesterolemic index, compared to the treatment with chitosan. The additives improved the caecotrophs fatty acid profile.

摘要：本研究旨在评估商用益生菌与壳聚糖（chitosan）作为食品添加剂时，对36只57±8日龄、初始体重为1.648±0.194 kg的新西兰白兔的肉品质、肌肉组成，以及盲肠内容物（caecotrophs）脂肪酸谱的影响。实验设置3组处理：CT组（日粮不添加任何添加剂）、PRO组（日粮添加4 g/kg商用益生菌）、CHI组（日粮添加4 g/kg壳聚糖）。与对照组相比，两种添加剂均可提升血清甘油三酯（triglycerides）水平并降低尿素（urea）含量；同时可显著提高盲肠内容物中的油酸（oleic acid）、亚油酸（linoleic acid）、总不饱和脂肪酸、总单不饱和脂肪酸以及总多不饱和脂肪酸含量。与PRO组相比，CHI组兔肉中的肉豆蔻酸（myristic acid）与棕榈酸（palmitic acid）含量降低。CHI组兔肉的粗蛋白（crude protein）与粗脂肪（crude fat）含量均有所下降。此外，CHI组的Omega-3、Omega-6脂肪酸含量，以及不饱和脂肪酸与饱和脂肪酸的比值均出现下降，同时芥酸（erucic acid）含量上升，低胆固醇血症相关脂肪酸（hypocholesterolemic acids）占比降低。研究结论表明：与壳聚糖处理组相比，饲喂益生菌的新西兰白兔肉品质更优，其脂肪酸谱与低胆固醇血症指数更佳；两类添加剂均可改善盲肠内容物的脂肪酸谱。