目的:本研究旨在评估低蛋白饮食对生长性能的影响,car体性状,营养素消化率,血液剖面,和生长肥育猪的气味排放。
方法:共126头平均体重(BW)为38.56±0.53kg的杂交猪([约克郡×长白猪]×杜洛克)进行了为期14周的喂养试验。在随机完全区组设计中,将实验猪分配给6个处理中的一个,每个围栏7个猪的3个重复。给猪饲喂不同水平的粗蛋白(CP)的每种处理饮食。第一阶段(早期生长):14%,15%,16%,17%,18%,19%;第二阶段(后期生长):13%,14%,15%,16%,17%,18%;第三阶段(早期完成):12%,13%,14%,15%,16%,17%;第四阶段(后期整理):11%,12%,13%,14%,15%,16%。每个阶段的所有实验饮食都含有相同浓度的赖氨酸(Lys),蛋氨酸(Met),苏氨酸(Thr),和色氨酸(Trp)。
结果:在整个实验期间,BW没有显着差异,平均日采食量,和所有处理的增料比(p>0.05),但是在D组中,平均日增重(ADG)在后期的平均日增重(ADG)中观察到二次效应(p=0.04)。血尿素氮浓度随饮食CP水平的增加而线性增加(p<0.01)。关于营养素消化率,随着CP水平的增加,尿液和粪便中的排泄氮和氮保留呈线性增加(p<0.01)。随着胺中CP水平的增加,观察到线性效应,氨,气味排放中的硫化氢(p<0.01)。在测量car体性状和肉特性时没有观察到显着影响(p>0.05)。
结论:在阶段喂养中,将早期生长猪的CP水平降低到14%,13%在生长后期的猪中,12%的早期肥育猪,建议在后期肥育猪中使用11%。
OBJECTIVE: This study was conducted to evaluate the effect of a low-protein diet on growth performance, carcass traits, nutrient digestibility, blood profiles, and odor emissions in growing-finishing pigs.
METHODS: A total of 126 crossbred pigs ([Yorkshire×Landrace]×Duroc) with an average body weight (BW) of 38.56±0.53 kg were used for a 14-week feeding trial. Experimental pigs were allotted to one of 6 treatments in 3 replicates of 7 pigs per pen in a randomized complete block design. Pigs were fed each treatment diet with different levels of crude protein (CP). Phase 1 (early growing): 14%, 15%, 16%, 17%, 18%, 19%; phase 2 (late growing): 13%, 14%, 15%, 16%, 17%, 18%; phase 3 (early finishing): 12%, 13%, 14%, 15%, 16%, 17%; phase 4 (late finishing): 11%, 12%, 13%, 14%, 15%, 16%. All experimental diets in each phase were contained the same concentration of lysine (Lys), methionine (Met), threonine (Thr), and tryptophan (Trp).
RESULTS: Over the entire experimental period, there was no significant difference in BW, average daily feed intake, and gain-to-feed ratio among all treatments (p>0.05), but a quadratic effect (p = 0.04) was observed in average daily gain (ADG) during the late finishing phase with higher ADG in Group D. Blood urea nitrogen concentration linearly increased with an increase in dietary CP levels (p<0.01). Regarding nutrient digestibility, excreted nitrogen in urine and feces and nitrogen retention linearly increased as the CP level increased (p<0.01). A linear effect was observed with increasing CP levels in amines, ammonia, and hydrogen sulfide in odor emissions (p<0.01). No significant effects were observed in the measurements of carcass traits and meat characteristics (p>0.05).
CONCLUSIONS: In phase feeding, reducing the CP level to 14% in early-growing pigs, 13% in late-growing pigs, 12% in early-finishing pigs, and 11% in late-finishing pigs is recommended.