磷酸脲添加量对羔羊生长性能、屠宰性能和肉品质的影响

本试验旨在研究磷酸脲添加量对羔羊生长性能、屠宰性能和肉品质的影响,并对磷酸脲在肉羊生产中的安全使用剂量进行评价。试验选用80只杜寒杂交F1代平均体重(25.86±1.06)kg的公羔羊,随机分为5组,每组8个重复,每个重复2只,在精粗比为1∶1的饲粮中分别以0(对照)、0.5%、1%、2%、4%的磷酸脲替代部分豆粕类饲料。预试期为12 d,正试期为60 d。结果表明:1%组的羔羊在各时期平均日增重、宰前活重、胴体重、屠宰率均达到最高值;4%组的羔羊在各时期平均日增重、宰前活重、胴体重均极显著低于其他各组(P0.01);与对照组相比,磷酸脲添加量对肉色红度值、p H、滴水损失无显著影响(P0.05);2%组的黄度值显著高于其他各组(P0.05);在剪切力方面,1%组(5.16 kg/cm2)显著高于0.5%组(4.47 kg/cm2)、4%组(3.69 kg/cm2)和对照组(4.21 kg/cm2)(P0.05)。结果提示:磷酸脲可以作为氮磷添加剂用于肉羊饲粮中。羔羊饲粮中的磷酸脲添加量为1%时,羔羊达到最佳生长性能和屠宰性能;当磷酸脲替代比例达到4%时,极显著降低羔羊的平均日增重、胴体重,增加肌肉的亮度值;当磷酸脲替代比例为2%时,为有效安全水平,对羔羊生长性能、屠宰性能和肉品质除肌肉黄度值外无显著影响。因此,饲粮中磷酸脲适宜添加量为1%。

Effects of Urea Phosphate Supplemental Level on Growth Performance,Slaughter Performance and Meat Quality of Lambs

This experiment aimed to investigate the effects of urea phosphate supplemental level on growth per-formance, slaughter performance and meat quality of lambs, and to evaluate the safety dosage of urea phos-phate used in lambs ’ diet. Eighty F1 Dorper × thin-tailed Han crossbred male lambs with an average body weight of (25.86±1.06) kg were used and randomly divided into 5 groups with 8 replicates per group and 2 lambs per replicate. Urea phosphate was added into each group to partly replace soybean meal and other ingre-dients of a basal diet, which had an equal proportion of forage and concentrate. Urea phosphate level in diets of each group was 0 ( control) , 0.5%, 1%, 2% and 4%, respectively. The adaptation period was 12 d, and ex-perimental period was 60 d. The results showed as follows:1% group had largest values of average daily gain ( ADG) in each period, live weight before slaughter, carcass weight and slaughter rate; while ADG in each period, live weight before slaughter and carcass weight of 4% group were significantly lower than those of oth-er groups ( P<0.01);compared with control group, the supplementation of urea phosphate had little effects on the lamb meat redness, pH and drip loss ( P>0.05) , and 2% group had a highest value of yellowness occurred (P<0.05); in addition, share force of 1% group (5.16 kg/cm2) was significantly higher than that of 0.5%group (4.47 kg/cm2), 4% group (3.69 kg/cm2) and control group (4.21 kg/cm2) (P<0.05). In conclu-sion, urea phosphate can be used as an additive for nitrogen and phosphorus in diets for fattening lambs. Lambs supplemented with 1% urea phosphate have the best growth and slaughter performance. Supplementation of 4%urea phosphate significantly decreases ADG and carcass weight, but muscle redness and brightness are im-proved. It is safe to add 2% urea phosphate in lambs’ diet with detrimental effects on growth, slaughter per-formance and meat quality, and it can significantly improve brightness value of muscle. Therefore, supplemen-tation of 1% urea phosphate is beneficial for growth performance of fattening lambs to reach an optimal level.