Effect of low-protein diets and single sex on production performance, plasma metabolites, digestibility, and nitrogen excretion in 1- to 48-day-old broilers

Abstract

Two experiments were conducted to investigate the effect of low-CP diets supplemented with crystalline amino acids, according to an ideal amino acid ratio, on the performance, plasma metabolites, nutrient digestibility, nitrogen balance, and water intake in male and female chickens from 1 to 48 d of age using a 4-phase feeding program: prestarter (1-7 d), starter (8-21 d), grower (22-35 d), and finisher (36-48 d). Three experimental diets were formulated for each phase: a control diet with a CP level of 24.5, 23.0, 21.5, and 20.5%, respectively, and medium- and low-CP diets containing 1.5 and 3% less than that of the control, respectively, but the same ME and digestible lysine levels. In experiment 1, in males, the reduction in dietary protein content by 3% increased the feed conversion ratio (P < 0.05) in the starter, grower, and finisher phases, and plasma albumin levels were reduced (P < 0.05) during the prestarter, starter, and finisher phases. In females, the same effect on plasma album levels was observed (P < 0.05) only in the starter phase. Sex affected plasma albumin levels during the prestarter, starter, and finisher phases, being higher in females. In experiment 2, the reduction in dietary protein content linearly decreased water consumption in both sexes (P < 0.05). The reduction of dietary protein by 1.5 or 3% reduced nitrogen excretion to the environment by 9.5 and 17% in males and by 11.8 and 14.6% in females, respectively. In summary, the low-CP 4-phase feeding reduced water intake and nitrogen excretion with an adverse effect on the feed conversion ratio in males but not in females. So, single-sex rearing could be used to reduce the environmental impact of chicken farms.

Amino Acids Fortification of Low-protein Diet for Broilers Under Tropical Climate. 2. Nonessential Amino Acids and Increasing Essential Amino Acids

“…This result is in agreement with that reported by (Waldroup et al, 1976;Leeson, 1986;Cheng et al, 1997Cheng et al, , 1999) who emphasised the importance of maintaining optimal amino acid balance under hot weather conditions. The present findings support those of Swennen et al (2006) and Hernández et al (2012) who showed that birds fed unfortified low-CP diets had lower serum UA. This is expected because UA is the end product of protein catabolism in chickens.…”

“…There is no clear explanation for the discrepancies. However, the inconsistencies could be associated with factors such as CP level in the control diet, and concentration of supplemented AA (McGill et al, 2012b), energy level (Sklan and Plavnik, 2002), gender (Hernández et al, 2012), and age of chickens (Deschepper and DeGroote, 1995). Interestingly, in our study birds fed NC+EAA+NEAA diet had significantly poorer FCR comparable with those provided Amino acids profile for tropical climate NC+NEAA diet.…”

Comparison between linear and nonlinear systems of feed formulation for broilers

“…On the other hand, Kamran et al (2008), observed that BW and FCR linearly worsed and feed intake increased when dietary energy and protein were reduced. These results are in agreement with those of Nguyen et al (2012), who showed that high energy and protein levels resulted in better FCR; and with results by Hernández et al (2012), who verified that low protein levels led to worse FCR. In the present experiment, the BW of male broilers fed LF and housed at high density was reduced, consistently with the results of Tong et al (2012).…”

Effect of Sauropus Androgynus Leaves Extract (Sale) on Fat Deposition in Broiler Fed Low Protein Diets

“…On the one hand, feeding low protein diets on broiler is important, because it will reduce production costs and pollution levels caused by excessive nitrogen excretion (El-Hakim et al, 2009;Hernandez et al, 2012), lower levels of air and water pollution, lower the conversion of nitrogen to ammonia gas and increase nitrogen digestibility efficiency (El-Hakim et al, 2009;Nahm, 2007) and lower levels of stress caused by heat stress (Furlan et al, 2004). Hernandez et al (2012) found that the reduction of protein levels by 1.5% or 3.0% decrease nitrogen excretion into the environment of 9.5 and 17% in male broilers, and 11.8 and 14.6% in females. On the other hand, feeding low protein diets increased fat deposition in broiler chickens (Farahdiba et al, 2011;Jlali et al, 2012;Labussiere et al, 2008: Pesti, 2009Wood et al, 2004) .…”