|Dozier Iii, William|
Submitted to: Journal of Applied Poultry Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/15/2007
Publication Date: 12/15/2007
Citation: Corzo, A., Kidd, M., Dozier III, W.A., Vieira, S. 2007. Marginality and needs of dietary valine for broilers fed certain all-vegetable diets. Journal of Applied Poultry Research. 16:546-554.
Interpretive Summary: Feed cost represents 65% of the total live production cost for broiler chickens that supports an industry that produces 8 billion birds annually. Feed cost approximates 65% of the total cost for producing broilers. Large percentage of the cost of the diet is protein/amino acid contributing ingredients. Valine is the fourth limiting amino acid for broiler chickens fed corn-soybean meal based diets. The valine requirement was evaluated with Ross × Ross 708 broilers from 21 to 42 days of age. Digestible valine requirement based on growth and meat yield parameters was 0.74% and with a ratio to digestible lysine of 78.
Technical Abstract: Valine is likely the fourth limiting amino acid in most diets based of corn and soybean meal. However, its exact needs are not well known, and information regarding it is sparse. A series of studies were conducted to validate valine’s limitation in all-vegetable diets fed to broilers, and subsequently quantify an adequate ratio to lysine, in high-yield late-developing broilers (Ross x Ross 708) from 21 to 42 d. A preliminary study was designed to evaluate the supplementation of different amino acids likely to be fourth limiting on a corn-soybean meal (C/SBM) based diet, where Lys, TSAA and Thr were supplemented but no other critical amino acids were given minimums in formulation. Results obtained for BW gain, abdominal fat weight and abdominal fat percentage showed that birds were more responsive (P<0.05) to L-Val supplementation. A follow-up study using a corn-peanut meal (C/PM) based diet formulated to be deficient in Val, validated (P<0.05) a Val deficiency based on poor growth performance, and resulted in an immediate return to good performance when this amino acid was supplemented. Furthermore, the C/PM diet was compared to nutritionally similar C/SBM diet, and no difference was observed in the performance of broilers when fed these diets, thus validating the C/PM based diet’s ability to support adequate growth of these broilers. This C/PM based diet was used to feed gradual concentrations of Val, from levels that would be considered deficient (0.59% dig.) up to adequate (0.84% dig. Val). Results indicate that a ratio to Lys of 78, or a minimum dietary value of 0.74% dig. Val (0.82% total Val), should be adequate for this high-yield broiler grown from 21 to 42 d of age.