双低菜籽粕生长猪净能值测定及实验方法对能值的影响

J W Kim, B Koo, C M Nyachoti

翻译：李平 校对： 上海亘泰实业集团

本试验测定了双低菜籽粕（CM）的消化能（DE）、代谢能（ME）和净能（NE）含量，并且研究了基础日粮[玉米日粮和玉米-豆粕（SBM）日粮]，及不同测定方法（替代法和回归法）对双低菜籽粕能值的影响。

将36头生长期去势公猪（初始体重20.8±1.0kg）单独饲养在代谢笼中，并随机分配到6种日粮处理中，每个处理6个重复。6种试验日粮包括玉米日粮，玉米-豆粕日粮，含15％或30％双低菜籽粕的玉米日粮，和含15％或30％双低菜籽粕的玉米-豆粕日粮。双低菜籽粕的DE、ME和NE由玉米日粮或玉米-豆粕日粮作为基础日粮来测定。在每种基础日粮中配制2种包含15％或30％双低菜籽粕的日粮，以通过替代法和回归法来测定和估算能值。饲喂水平设定为每天550 kcal ME/kg BW^0.6。猪饲喂试验日粮共16天，包括10天适应期和6天全部粪便和尿液收集期。 然后将猪移入间接测热室以测定24小时产热量（HP），和12小时禁食产热量。

无论采用何种基础日粮，替代法测定双低菜籽粕的DE、ME和NE均在回归法测定DE、ME和NE估计的95％置信区间内，这表明替代法和回归法可以得出基本相同的双低菜籽粕DE、ME和NE值。 然而，当比较线性模型的拟合优度时，玉米-豆粕日粮回归分析的相关系数r²（0.78）相对于玉米日粮的（0.40）更高。根据玉米日粮和玉米-豆粕日粮做出的预测方程，所得到双低菜籽粕的预测NE值分别为2,096 kcal/kg和1,960kcal/kg（饲喂基础），而用替代法测定的NE值分别为2,233kcal/kg和2,106 kcal/kg（饲喂基础）。

总之，在此次研究中测定的双低菜籽粕的NE值平均为2,099 kcal/kg（饲喂基础）。在生长猪阶段，使用替代法和回归法来测定双低菜籽粕的NE值，并没有得出明显不同的结果。虽然使用玉米日粮或玉米-豆粕日粮测定的双低菜籽粕的NE值没有差异，但玉米-豆粕日粮回归分析的相关系数r²比玉米日粮中的r²值更大，这表明玉米-豆粕日粮是用于NE测定更合适的基础日粮。

关键词：双低菜粕，产热量，间接测热，净能，猪

Net energy content of canola meal fed to growing pigs and effect of experimental methodology on energy values

J W Kim, B Koo, C M Nyachoti

An experiment was conducted to determine the digestible energy (DE), metabolizable energy (ME), and netenergy (NE) contents of canola meal (CM) and to investigate the effects of basal diet [corn diet vs. corn-soybean meal (SBM) diet] and methodology (difference method vs. regression method) on energy values of CM. Thirty-six growing barrows (20.8 ± 1.0 kg initial body weight [BW]) were individually housed in metabolism crates and randomly allotted to one of six dietary treatments to give six replicates per treatment. The six experimental diets included a corn diet, a corn-SBM diet, a corn diet with 15 or 30% of CM, and acorn-SBM diet with 15 or 30% of CM. The DE, ME, and NE of CM were determined using the corn diet or the corn-SBM diet as a basal diet. In each basal diet, two additional diets containing 15 or 30% of CM were formulated to compare the determined energy values by the difference method and estimated energy values from the regression method. Feeding level was set at 550 kcal ME/kg BW^0.6 per day. Pigs were fed experimental diets for 16 d including 10 d for adaptation and 6 d for total collection of feces and urine. Pigs were then moved into indirect calorimetry chambers to determine 24 h heat production (HP) and 12 h fasting HP. The DE, ME, and NE of CM determined by the difference method were within the 95% confidence intervals estimated for the DE, ME, and NE of CM by the regression method regardless of the basal diets used, which indicates that the difference and regression methods give equivalent DE, ME, and NE of CM. However, when the goodness of fit for the linear model was compared, the r² of the regression analysis from the corn-SBM diet (0.78) was relatively greater than that from corn diet (0.40). The estimated NE of CM by the prediction equations generated by either the corndiet or corn-SBM diets were 2,096 kcal/kg and 1,960 kcal/kg (as-fed basis), respectively, whereas those values determined by the difference method were 2,233 kcal/kg and 2,106 kcal/kg (as-fed basis), respectively. In conclusion,the NE of CM determined in the current study was, on average, 2,099 kcal/kg (as-fed basis). The difference and regression methods do not give different NE value of CM fed to growing pigs. Although the NE values of CM determined using either the corn diet or the corn-SBM diet were not different, the greater r² of the regression analysis from the corn-SBM diet than that from the corn diet suggests that the corn-SBM diet is a more appropriate basal diet for NE determination of ingredients.

Key words: canola meal, heat production, indirectcalorimetry, net energy, pig