Comparison between Analyze and Reference Starch and Sugar Contents Influencing on Feeding Value of Net Energy in Swine Diets

Abstract

A 33-day feeding trial was conducted wherein a total of 360 starter pigs (initial weight 17.70 ± 0.53 kg) were allotted to 4 dietary treatments with 3 replicates (30 pigs/pen) arranged in a 2x2 factorial design. For the main treatment, reference (CVB) and analyzed starch and sugar values were used to predict NE of feed ingredients using NE equation from the Dutch system. Furthermore, diets were designed with different NE concentrations and feed forms and were used as sub-treatment. Pellet forms were 30 kcal/kg lower NE compared to mash, then diets were fed to starter pigs from 55d to 87d to evaluate pig growth responses and implication on feed cost. Starch contents of ingredients except in barley were higher in the analyzed treatment compared to those in the reference which consequently resulted in higher predicted NE value of the analyzed. For sugar, analyzed and reference values also varied but unlike starch, its effect on predicted NE is minimal due to its relatively small concentration except in soybean meal. These results indicated that using NE from reference values without analyzing nutrient compositions of ingredients can result in inaccurate energy contents of swine diets because such compositions can vary, which consequently affect predicted NE values. In the growth trial, results showed that pigs fed different dietary treatments had relatively similar ADG (p>0.05). Starch and sugar values (reference or analyzed) also had no significant difference (p>0.05) in ADFI. However, considering feed forms and energy concentrations, pigs fed mash consumed significantly higher (p<0.05) compared to those fed pellets. This lower ADFI with similar ADG of pigs fed pellets resulted to their significantly better feed efficiency (p<0.05). In terms of cost, diets formulated using analyzed values had considerably lower cost/kg feed which can be attributed to its higher starch which supplied the major energy in the experiment diets. In conclusion, the present study suggests that accurate estimation of dietary energy contents in swine diets by analyzing the nutritional compositions including starch and sugar of ingredients can minimize diet cost without compromising animal performance. Additionally, it also demonstrated that in general, pelleting can positively affect feed efficiency potentially due to improved energy digestibility and/or nutrient utilization by the animals.