Li Zengmin, Liang Huan, Xin Junping, Xu Lanjiao, Li Meifa, Yu Hanjing, Zhang Wenjing, Ge Yu, Li Yanjiao, Qu Mingren
Key Laboratory of Animal Nutrition in Jiangxi Province, Jiangxi Agricultural University, Nanchang, China.
Laboratory Animal Engineering Research Center of Ganzhou, Gannan Medical University, Ganzhou, China.
Front Vet Sci. 2021 Jul 9;8:684295. doi: 10.3389/fvets.2021.684295. eCollection 2021.
An experiment was conducted to determine the effects of supplementing the diet of bulls with guanidinoacetic acid (GAA) on their feed efficiency [feed efficiency were evaluated with feedlot average daily gain (ADG), average daily feed intake (ADFI), and feed-to-gain ratio (F:G)], blood measures, and meat quality. Forty-five bulls (24 ± 3 months old and 350.15 ± 30.39 kg by weight) were randomly distributed among five experimental groups (each = 9) and each group was randomly fed with one of five diets (concentrate: roughage ratio of 60:40): (1) control; (2) 0.05% GAA; (3) 0.1% GAA; (4) 0.2% GAA; and (5) 0.4% GAA, respectively. After a 52-days feeding trial, five bulls from the control group and five bulls from the optimal GAA supplementing group were randomly selected and slaughtered for collection of the (LT) and (SM) muscles to determine meat quality. The results showed that dietary GAA improved the ADG, decreased the value of F:G, and affected blood measures and antioxidant variables. Supplementing 0.2% GAA into the diet was optimal for feeding efficiency and most of the measured blood measures. Supplementing 0.2% GAA into the diet increased the a (redness) values, and b (yellowness) values, and the amount of creatine kinase (CK), muscle glycogen, creatinine (CRE), and laminin (LN) in LT muscles. However, it decreased the drip loss, L (lightness) value, and lactate dehydrogenase (LDH) content of LT muscles. Drip loss and shear force decreased in SM muscles, as did the amount of type IV collagen (CV-IV). In conclusion, supplementing 0.2% GAA into the diet could enhance feed efficiency to improve beef growth and meat quality.
进行了一项实验，以确定在公牛日粮中添加胍基乙酸（GAA）对其饲料效率[用育肥牛场平均日增重（ADG）、平均日采食量（ADFI）和料重比（F:G）评估饲料效率]、血液指标和肉质的影响。45头公牛（24±3月龄，体重350.15±30.39千克）被随机分配到五个实验组（每组 = 9头），每组随机饲喂五种日粮中的一种（精粗比为60:40）：（1）对照组；（2）0.05% GAA；（3）0.1% GAA；（4）0.2% GAA；和（5）0.4% GAA。经过52天的饲养试验，从对照组随机选取5头公牛，从最佳GAA添加组随机选取5头公牛进行屠宰，采集腰大肌（LT）和半膜肌（SM）用于肉质测定。结果表明，日粮中添加GAA可提高ADG，降低F:G值，并影响血液指标和抗氧化变量。日粮中添加0.2% GAA对饲料效率和大多数测定的血液指标最为适宜。日粮中添加0.2% GAA可提高LT肌肉的a*（红色度）值、b*（黄度）值以及肌酸激酶（CK）、肌肉糖原（muscle glycogen）、肌酐（CRE）和层粘连蛋白（LN）的含量。然而，它降低了LT肌肉的滴水损失、L*（亮度）值和乳酸脱氢酶（LDH）含量。SM肌肉的滴水损失和剪切力降低，IV型胶原蛋白（CV-IV）含量也降低。总之，日粮中添加0.2% GAA可提高饲料效率，促进牛肉生长并改善肉质。
