Evaluating the ability of the NE system to predict growth performance and energy utilization of growing pigs

Abstract

The net energy (NE) system describes the useful energy for growth better than the metabolizable energy (ME) system. This NE system should maintain growth performance and carcass parameters when diverse ingredients are used. However, this statement needs to be demonstrated in practice. This study compared the pig growth performance, carcass characteristics and caloric efficiency on diet programs formulated using either the ME or NE systems. A total of 944 gilts and 1,110 castrates (initial BW=40.8±2.0 kg) were allotted to separate pens and assigned to one of 5 different feeding programs. A simple corn-soybean meal control (Ctl) served as the basis to establish baseline levels of ME and NE concentrations. One set of two treatments added DDGS to the Ctl diet formulated using the ME or the NE system (ME-D and NE-D; respectively) and another set of diets that added both DDGS and corn germ meal and was formulated using the ME or the NE system (ME-DC and NE-DC; respectively).

Analysis of Growth Performance in Swine Based on Machine Learning

“…It is worth noting that the effective temperature is generally higher than the comfort temperature in our dataset due to the characteristics of pig farms that are taken into account in this work, which do not have windows. 8 As can be observed from the figure, the growth performance is likely to be high, i.e., DG ≥ 0.8 kg, FI ≤ 3 kg, GP ≤ 170 days, and MSY ≥ 95%, when the difference between effective temperature and comfort temperature is small. This result also aligns with our intuition that the heat stress affects the growth performance of livestock, adversely [30].…”

“…Especially, we can find that the temperature difference in the early stage of growing period has a larger impact on the growth performance because young pigs are more vulnerable to the heat stress. However, we can find that the temperature difference itself is insufficient to predict the 8 Although pig farms without windows require higher initial installation cost, they are beneficial in view of reducing bad odor caused by the farms and maintaining the environmental conditions of pig farms, e.g., the temperature and humidity, using the ventilation facility and the air conditioning system, unlike pig farms with windows whose environmental conditions are heavily affected by the outdoor temperature. As a consequence, the pig farms without windows are likely to be used more widely in the near future, e.g., the Government of South Korea plans to change all pig farms to farms-withoutwindows by 2023.…”

“…Furthermore, the generation of synthetic data on the growth of swine based on the analytical growth curve and measured data, was taken into account in [7]. In addition, Net Energy (NE) model which takes into account the metabolism of pig was also used to characterize the growth of swine [1], [8]- [11], where the DG of swine is estimated by calculating the excess of energy taken by the pig. Although the growth of swine has been investigated extensively by means of hand-crafted mathematical models, it has a limitation to model more complicated interactions between the growth performance and various environmental conditions, especially when multiple components have to be taken into account jointly and it is hard to capture the hidden dynamics in the growth of pig.…”