Digestion and nitrogen balance using swine diets containing increasing proportions of coproduct ingredients and formulated using the net energy system1

Abstract

Rising feed expenditures demand that our industry pursues strategies to lower the cost of production. One option is the adoption of the NE system, although many producers are hesitant to proceed without proof that NE estimates are reliable. The objective of this experiment was to compare the apparent total tract digestibility (ATTD) of energy and nutrients and the N retention (NR) of diets formulated using the NE system with increasing quantities of coproduct ingredients. The 5 dietary treatments included a control corn-soybean meal diet (CTL); the CTL plus 6% each of corn distiller's dried grains with solubles (DDGS), corn germ meal, and wheat middlings and NE equal to the CTL by adding soybean oil (CONS-18); the CONS-18 diet, without oil added, with NE content lower than the CTL (DECL-18); the CTL plus 12% each of corn DDGS, corn germ meal, and wheat middlings and NE equal to the CTL by adding soybean oil (CONS-36); and the CONS-36 diet, without oil added, with NE content lower than the CTL (DECL-36). Diets were formulated for both the growing period (GP; 40 to 70 kg) and the finishing period (FP; 70 to 110 kg). Forty gilts (PIC 337 × C22 or C29; 38.5 ± 0.4 kg initial BW) were randomly assigned to treatment and received feed and water ad libitum (8 pigs per treatment). For the last 13 d of the GP and FP, pigs were transferred to metabolism crates, where 2 total urine and fecal collections (d 4 to 6 and d 11 to 13) were performed. The GP fed diets with coproduct ingredients had lower ATTD of DM, N, and GE than those fed the CTL ( < 0.050). The ATTD of N and GE progressively decreased as coproduct inclusion increased from 0 to 18 to 36% in the FP ( < 0.010). In the GP and FP, there were no differences in ATTD of DM, N, or GE between CONS-18 and DECL-18 or between CONS-36 and DECL-36 ( > 0.050). The NR declined on all coproduct diets in the GP ( = 0.010) and tended to decline in the FP ( = 0.079). There were no differences in NR between CONS-18 and DECL-18 or between CONS-36 and DECL-36 ( > 0.050). In conclusion, digestion of diets containing up to 36% coproducts and formulated using NE resulted in expected DE and ME values; NR of diets with coproducts was lower than that of the simple CTL, which is not related to the accuracy of the energy estimations but rather to other factors such as imbalances in the AA concentrations or to postabsorptive energy metabolism, factors not accounted for by the current energy systems approach.

Modeling net energy requirements of 2 to 3-week-old Cherry Valley ducks

“…In the pig industry, a savings of 4.00 to 4.50 €/t of feed cost is possible, and the excretion of nitrogen is also reduced when the ME system is replaced by the NE system, without negative effects on production performance [5,6]. The nitrogen retained in diets with co-products is not affected when the imbalances in the amino acid concentrations or the post-absorptive energy metabolism of diets is taken into account [7]. In recent years, the ME or the DE systems have been substituted gradually by the NE system in pig husbandry of North America and Europe [8].…”

A dietary carbohydrase blend improved intestinal barrier function and growth rate in weaned pigs fed higher fiber diets1

“…Most coproducts in the United States, such as distillers dried grains with solubles ( DDGS ) and wheat middlings, originate from corn and wheat processing and contain high levels of insoluble fiber ( Gutierrez et al, 2014 ). A high inclusion rate of these coproducts may decrease nutrient digestibility ( Acosta et al, 2017 ), induce intestinal inflammation ( Weber et al, 2008 ), and depress subsequent growth performance in nursery pigs ( Tsai et al, 2017 ).…”

Insoluble dietary fiber does not affect the ability of phytase to release phosphorus from phytate in the diet of nursery pigs1

“…Although there was no effect of fiber on bone mineralization, results also suggest a strong effect of insoluble fiber on the digestibility of DM, NDF, and ADF. The effect of insoluble fiber on the digestibility of dry matter and insoluble fiber constituents is supported by the literature (Le Goff and Noblet, 2001;Liu et al, 2014;Acosta et al, 2017), including fiber of corn bran origin (Gutierrez et al, 2013). The decrease in fiber digestibility can be the result of a limited capacity of the pig to ferment insoluble fiber (Stanogias and Pearce, 1985), especially at early growth stages.…”