Effect of dietary betaine supplementation on the performance, carcass yield, and intestinal morphometrics of broilers submitted to heat stress

Abstract

The objective of this study was to evaluate the effect of betaine in methionine-and choline-reduced diets fed to broilers submitted to heat stress. In total, 1,408 male broilers were randomly distributed into eight treatments, according to 2 x 4 (environment x diet) factorial arrangement, with eight replicates of 2 birds each. Birds were reared environmental chambers under controlled temperature (25-26 °C) or cyclic heat-stressing temperature (25-31 °C). The following diets were tested: positive control (PC), formulated to meet broiler nutritional requirements; negative control (NC), with reduced DL-methionine and choline chloride levels; and with two supplementation levels of natural betaine to the negative control diet (NC+NB1 and NC+NB2). Live performance, carcass traits, and intestinal morphometrics were evaluated when broilers were 45 days of age. The results showed that all evaluated parameters were influenced by the interaction between environment and diet, except for breast meat drip loss. The breakdown of the interactions showed that birds fed the PC diet and reared in the controlled environment had greater breast drip loss than those submitted to the cyclic heat-stress environment. Birds submitted to cyclic heat stress and fed the PC diet presented the lowest feed intake. Feed conversion ratio was influenced only by diet. The FCR of broilers fed the NC+NB2 diet was intermediate relative to those fed the PC and NC diets. The addition of betaine in the diet, with 11.18% digestible methionine and 24.73% total choline reductions, did not affect broiler live performance, carcass yield, or intestinal morphometrics.

An Elevated Dietary Cysteine to Methionine Ratio Does Not Impact on Dietary Methionine Efficiency and the Derived Optimal Methionine to Lysine Ratio in Diets for Meat Type Chicken

“…This observation is in line with several reports [49]- [55]. They observed no significant effect of added BET on growth of chicken when supplemented to marginally Met deficient and methyl donor-adequate diets, even when dietary choline supply was reduced [56] [57].…”

Effect of dietary supplementation with <i>Rhizopus oryzae</i> or <i>Chrysonilia crassa</i> on growth performance, blood profile, intestinal microbial population, and carcass traits in broilers exposed to heat stress

“…Concomitant with our finding, Sakomura et al (2013) reported no difference in carcass, leg and breast yield and drip loss in broilers reared under thermoneutral and HS conditions. Moreover, Hosseini-Vashan et al (2016) reported no effect of HS on the abdominal fat content of broilers.…”

Effects of supplementation of betaine hydrochloride on physiological performances of broilers exposed to thermal stress

“…37,38 Nevertheless, unlike some earlier reports, betaine supplementation at both the dose levels improved feed intake in this study. 21,39,40 Live weight improved by more than 3% over the PC and NC groups in the Bet 2.0 group, which suggests that at this level of inclusion betaine not only compensated for methionine but also contributed a substantial amount of energy to support this growth process. Feed conversion also improved over the PC group by 3.6 and 4.5 points, respectively, in the Bet 1.3 and Bet 2.0 groups.…”

“…20 Within the body, betaine is synthesized from choline. 21,22 Being a methylgroup donor, betaine is thought to spare methionine from this function, thus allowing methionine to be utilized more for growth and muscle development. 23 Choline presumably alleviates heat stress in broilers due to its ability to be oxidized readily to betaine, which is then used as a methyl-group donor to synthesize methionine.…”

“…This was in agreement with earlier observations indicating beneficial effects of betaine supplementation in thermally stressed broiler chickens. 21,35,36 However, during days 17-38, there was a subtle effect of supplemental betaine on feed consumption, indicating little effect of betaine on feed intake in older birds. 37,38 Nevertheless, unlike some earlier reports, betaine supplementation at both the dose levels improved feed intake in this study.…”