Evaluation Of Digestible Energy Value Of Cottonseed Meal Feeds For Pigs And Prediction Of Digestible Energy Value Of Cottonseed Meal From Chemical Analysis

The objective of this study was to survey the proximate composition of cottonseed meal feeds in China, to measure the digestible energy of 9 cottonseed meal Sample Entities fed to growing pigs, and to predict of digestible energy value of cottonseed meal feeds for pigs from chemical analysis. Surveyed and collected 29 samples of cottonseed meal from 29 grease factories, which using the typical process of production of cottonseed meal in main cotton producing areas in China. The proximate composition of 29 cottonseed meal samples were analyzed. According to the proximate composition, production process and cotton varieties of cottonseed meal samples,9 cottonseed meal Sample Entities were formed with 29 cottonseed meal samples, each Sample Entity include 3 or 4 cottonseed meal samples. To determine energy digestibility in each cottonseed meal Sample Entity by the difference method.Eighteen growing barrows (initial BW:37.2±1.8 kg) were allotted to three 6×6 Latin square design with 6 periods and 6 diets in each square. Each 6×6 Latin square design diets including 3 cottonseed meal Sample Entities, each cottonseed meal Sample Entities have two replacement ratios of basis diet. Each period lasted 13 d, adaptation period:3d, pretest period:5d, and formal test:5d. On the basis of measured digestible energy value and analyzed proximate composition of cottonseed meal Sample Entity, established prediction equation of digestible energy value of cottonseed meal from chemical analysis. Results of the study showed that:1 The proximate composition(weighted mean, as-fed basis) of 29 cottonseed meal samples is:DM,89.57%; CP,43.96%; EE,0.78%; Ash,6.22%; ADF,18.13%; NDF,25.36%; FG,598.81mg/kg.2 The measured digestible energy values by the difference method with two replacement ratios have small differences. It shows that digestible energy in pig feeds has good additivity. The digestible energy value(the mean of two results, as-fed basis) of 9 cottonseed meal Sample Entities feed for pigs are:2416 kcal/kg,2347 kcal/kg,2288 kcal/kg,2102 kcal/kg,2244 kcal/kg,2164 kcal/kg,2226 kcal/kg,2611 kcal/kg,2464 kcal/kg, respectively. The weighted mean of digestible energy value(as-fed basis) of 9 cottonseed meal Sample Entities feed for pigs is 2376 kcal/kg.3 The correlation analysis and path analysis among analyzed composition of cottonseed meal showed that the content of CP, NDF, SCHO and ADF have greater influence on DE value. According to Regression Analysis and professional knowledge, prediction model of DE of cottonseed meal feeds for pigs from chemical analysis was selected out. The linear regression equation is:DE(kcal/kg)=-1964+ 98.85×CP%(R2=0.68); The multiple linear regression equation is:DE(kcal/kg)=-3438+0.557×GE+76.71×CP%-3.03×NDF%(R2= 0.72).