Nutritional feasibility of l-valine inclusion in commercial broiler diets

Abstract

Ingredient prices and availability have fluctuated during the last few years. Often, the industry has found itself with high ingredient prices and with few options to reduce diet cost effectively. When the spread of corn, soybean meal, and fat is wide, a reduction in CP via l-Thr is an effective formulation strategy that can maintain broiler performance, can alleviate diet costs, and does not interfere with feed milling logistics and throughput. Roughly a decade ago, the industry began implementing the inclusion of l-Thr as an alternative to diet cost reduction, successfully reducing the amounts of soybean meal and animal by-products in commercial di- SUMMARYResearch addressing the application of crystalline l-Val as a feed-grade amino acid to commercial broiler diets has not been known. An experiment was conducted to assess whether l-Val would adequately support growth if included in practical broiler diets, and if so, to pinpoint a recommended level of inclusion for l-Val. Male broilers were fed common diets up to 28 d of age, and were then fed one of various l-Val inclusion levels ranging from 0 to 1.3 kg/ metric ton until 42 d of age. This was accomplished by blending a diet with no l-Val with one that contained 1.3 kg of l-Val. As a result, equal levels of dietary Val were present in all diets, concomitant with decreases in other limiting dietary amino acids (Ile, Arg, or both). After data were analyzed, linear decreases for BW gain, feed intake, carcass weight, breast meat weight, and breast meat yield were observed as levels of l-Val were increased in the diet. For live performance and carcass traits, we observed that an l-Val inclusion level of 0.52 kg/metric ton supported adequate growth and meat yield when compared with a diet devoid of l-Val. Inclusion levels of l-Val greater than 0.52 kg/ton resulted in poorer feed conversion, breast meat weight, and breast meat yield. Based on these results, l-Val supplementation at levels below 0.52 kg/ metric ton showed the ability to support good production and could potentially offer a useful diet cost reduction alternative.

Performance of Broiler Chickens Fed Low Protein, Limiting Amino Acid Supplemented Diets Formulated Either on Total or Standardized Ileal Digestible Amino Acid Basis

“…The deficiencies of various amino acid viz ., valine (Corzo et al, 2011), valine and isoleucine (Corzo et al, 2009) and valine, isoleucine and tryptophan on DORB based rations (Basavanta Kumar et al, 2015) have been shown to depress feed efficiency similar to present study. The protein factor with a reduction of 1.5% unit protein and supplementation of limiting amino acids resulted in significant depression of FCR at all production phases, while, 0.75% unit protein reduction significantly reduced FCR only during pre-starter phase.…”

“…Among amino acid, methionine is primarily required for initiation of protein synthesis and has been revealed to influence myogenic gene expression in broilers (Wen et al, 2014) and moreover, lysine, methionine, threonine, valine and isoleucine are components of muscle protein and their deficiency invariably reduced the BWG. The growth retardation as a result of deficiency of either individual or various combinations of limiting amino acids lysine, methionine, threonine, valine, isoleucine and tryptophan is well noticed in previous studies (Corzo et al, 2009; Corzo et al, 2011; Basavanta Kumar et. al., 2015).…”

Impact of second line limiting amino acids’ deficiency in broilers fed low protein diets with rapeseed meal and de-oiled rice bran

“…The deficiency of SLAA resulted in significantly lower absolute intake of valine and isoleucine (in T 2 ) and additionally tryptophan (in T 3 ; Table-6 ) which perhaps impeded protein accretion and hence the growth performance of broilers, since AA have been revealed to influence the myogenic gene expression in broilers [ 16 ]. The growth retardation as a consequence to SLAA deficiency is well noticed in previous studies with deficiencies of valine alone in young broilers [ 17 , 18 ], valine and isoleucine [ 1 , 19 ], isoleucine, tryptophan and arginine [ 20 ], isoleucine alone [ 21 , 22 ] and arginine, valine, isoleucine and tryptophan [ 23 ]. With marginal SLAA deficiency in the finisher phase, birds could compensate to the SLAA intake at this time period (data not shown) and as a consequence, birds could grow on par with control which is suggestive of the compensatory growth during this period due to moderate but not for high SLAA deficiency.…”

Digestible Valine Requirements in Low-Protein Diets for Broilers Chicks

“…According to Jiang et al (2005), the EAA:NEAA recommended ratio is 46:54 in reduced-protein diets with for broilers. Corzo et al (2011) evaluated valine supplementation to conventional or reduced-protein diets (17.6% CP) fed to 28-to 42-d-old broilers found worse feed conversion ration when birds fed the low CP diet, and attributed this result to arginine and isoleucine deficiency. Considering that in the present study, arginine and isoleucine levels did not differ between the experimental diets, the worse feed conversion ratio may be attributed to inadequate EAA:NEAA ratios.…”