Edmonds M S, Baker D H
Nutrition and Product Development, Kent Feeds, Inc., Muscatine, IA 52761, USA.
J Anim Sci. 2003 Nov;81(11):2783-91. doi: 10.2527/2003.81112783x.
Two trials with growing-finishing pigs were conducted to evaluate the effects of fluctuating dietary CP levels and/or space allocation on performance and carcass traits. In Trial 1, three CP regimens were used with 216 growing-finishing pigs (mixed sex). Average initial and final weights of pigs were 31 and 103 kg, respectively. The CP regimens consisted of: 1) control (18% CP from wk 0 to 4; 15% CP from wk 4 to 12); 2) moderate CP variations (MCPV = 19.5% CP from wk 0 to 2, 16.5% CP from wk 2 to 6, 13.5% CP from wk 6 to 8, 16.5% CP from wk 8 to 10, 13.5% CP from wk 10 to 12); and 3) extreme CP variations (ECPV = 21% CP from wk 0 to 2, 15% CP from wk 2 to 4, 18% CP from wk 4 to 6, 12% CP from wk 6 to 8, 18% CP from wk 8 to 10, 12% CP from wk 10 to 12). Overall (wk 0 to 12), treatment differences were not observed (P > 0.05) for gain, feed intake, CP intake, gain:feed ratio, or gain/CP intake. Trial 2 involved 360 finishing pigs (mixed sex) in a 3 x 2 factorial arrangement (three dietary CP regimens, two floor space allowances). The diets consisted of: 1) control (16% CP from wk 0 to 4, 15% CP from wk 4 to 8; 14% CP from wk 8 to 12); 2) MCPV (17.5% CP from wk 0 to 2, 14.5% CP from wk 2 to 4, 16.5% CP from wk 4 to 6, 13.5% CP from wk 6 to 8, 15.5% CP from wk 8 to 10, 12.5% CP from wk 10 to 12); and 3) ECPV (19% CP from wk 0 to 2, 13% CP from wk 2 to 4, 18% CP from wk 4 to 6, 12% CP from wk 6 to 8, 17% CP from wk 8 to 10 wk, 11% CP from wk 10 to 12). Pigs were provided with either 1.12 m2 (uncrowded; five pigs/pen) or 0.56 m2 (crowded; 10 pigs/pen). Average initial weight was 49 kg and final weights were 126 kg (uncrowded) and 118 kg (crowded). Overall (0 to 12 wk), crowded pigs had lower (P < 0.05) ADG (822 vs. 916 g) and feed (as-fed) intakes (2,633 vs. 2,876 g) than uncrowded pigs. At the end of the 12-wk trial, a control vs. ECPV x space interaction (P < 0.05) occurred for weight gain, fat depth, and percentage of lean. Thus, uncrowded pigs fed ECPV gained faster (933 vs. 887 g) but had a lower percentage of lean (53.5 vs. 54.5) than controls, whereas crowded pigs on the ECPV regimen gained more slowly (812 vs. 842 g) but were leaner (54.8 vs. 54.6%) than those on the control CP regimen. Despite the wide dietary CP fluctuations, pigs in both trials consumed about the same quantity of CP during the 12-wk feeding periods. These data suggest that uncrowded pigs respond differently than crowded pigs to fluctuating levels of dietary CP.
进行了两项针对生长育肥猪的试验，以评估波动的日粮粗蛋白（CP）水平和/或空间分配对生产性能和胴体性状的影响。在试验1中，对216头生长育肥猪（混合性别）采用了三种CP方案。猪的初始平均体重和终末平均体重分别为31千克和103千克。CP方案包括：1）对照组（第0至4周为18% CP；第4至12周为15% CP）；2）适度CP变化组（MCPV = 第0至2周为19.5% CP，第2至6周为16.5% CP，第6至8周为13.5% CP，第8至10周为16.5% CP，第10至12周为13.5% CP）；3）极端CP变化组（ECPV = 第0至2周为21% CP，第2至4周为15% CP，第4至6周为18% CP，第6至8周为12% CP，第8至10周为18% CP，第10至12周为12% CP）。总体而言（第0至12周），在增重、采食量、CP摄入量、增重/采食量或增重/CP摄入量方面未观察到处理差异（P > 0.05）。试验2采用3×2析因设计（三种日粮CP方案，两种地面空间面积），涉及360头育肥猪（混合性别）。日粮包括：1）对照组（第0至4周为16% CP，第4至8周为15% CP；第8至12周为14% CP）；2）MCPV组（第0至2周为17.5% CP，第2至4周为14.5% CP，第4至6周为16.5% CP，第6至8周为13.5% CP，第8至10周为15.5% CP，第10至12周为12.5% CP）；3）ECPV组（第0至2周为19% CP，第2至4周为13% CP，第4至6周为18% CP，第6至8周为12% CP，第8至10周为17% CP，第10至12周为11% CP）。为猪提供1.12平方米（不拥挤；每栏5头猪）或0.56平方米（拥挤；每栏10头猪）的空间。初始平均体重为49千克，终末体重分别为126千克（不拥挤）和118千克（拥挤）。总体而言（0至12周），拥挤猪的平均日增重（ADG）（822对916克）和采食量（风干基础）（2633对2876克）低于不拥挤猪（P < 0.05）。在12周试验结束时，在体重增加、背膘厚度和瘦肉率方面出现了对照组与ECPV×空间的交互作用（P < 0.05）。因此，饲喂ECPV的不拥挤猪增重更快（933对887克），但瘦肉率低于对照组（53.5对54.5），而采用ECPV方案的拥挤猪增重较慢（812对842克），但比采用对照CP方案的猪更瘦（分别为54.8对54.6%）。尽管日粮CP波动很大，但两项试验中的猪在12周饲喂期内消耗的CP量大致相同。这些数据表明，不拥挤猪和拥挤猪对日粮CP水平波动的反应不同。
