Effect of Dietary Crude Protein, Lysine Level and Amino Acid Balance on Performance of Broilers 0 to 18 Days of Age

Interactive effect of amino acids balanced at ideal lysine ratio and exogenous protease supplemented to low CP diet on growth performance, carcass traits, gut morphology, and serum metabolites in broiler chicken

This study evaluated the effect of amino acids balanced at a specific lysine ratio with exogenous protease supplementation and reduced CP levels in the broiler diet. In total, 480 straight-run broiler chicks (Ross-308) were used for the study. A completely randomized design in the factorial arrangement was applied, with 4 treatments of 6 replicates with 20 birds each. Treatments consisted of 2 lysine ratios (100% and 110%; factor 1) without or with exogenous protease supplementation (200 g/ton; factor 2). Twenty percent reduction of CP from standard requirements of Ross-308 (18.4% vs 23% in starter and 17.2% vs 21.5% in grower phase) was made in all the treatment diets. Growth performance (feed intake, weight gain, feed conversion ratio, livability), carcass traits (live and carcass weight, carcass yield, heart, liver, gizzard, leg quarter, breast weight, and abdominal fat percentage), gut morphology (villus height, crypt depth, and villus height and crypt depth ratio), and serum metabolites (total protein, albumin, and uric acid) were evaluated. A significant interaction (p ≤ 0.05) for lysine ratio and protease was noted in body weight gain, feed conversion ratio, carcass traits, and gut morphology throughout the experimental period yet a non-significant (p > 0.05) influence was observed on serum metabolites. It was concluded that the broiler diet with a net reduction of 20% CP from Ross-308 standards, balanced for amino acids at lysine ratio 110% and supplemented with exogenous protease, could be used to improve growth performance, intestinal health, and carcass traits.

Effect of varying dietary concentrations of lysine on growth performance of the Pearl Grey guinea fowl

Lysine is the second limiting essential amino acid in poultry nutrition after methionine. Understanding the lysine requirement of poultry is necessary in guiding formulation of least cost diets that effectively meet the nutritional needs of individual birds. The lysine requirement of the Pearl Grey guinea fowl (PGGF) is not known. Therefore, the objective of this study was to assess the appropriate lysine levels required for optimal growth attributes of the PGGF. In a 12-week study, 512 one-day-old Pearl Grey guinea keets were weighed individually and randomly assigned to electrically heated battery brooders. Each battery contained 12 compartments housing 15 birds each. Eight diets fed to the experimental birds consisted of corn-soybean meal and contained 0.80 to 1.22 digestible lysine in 0.06% increments. Feed and water were provided at free choice and the diets were replicated twice. Experimental diets contained 3,100 Kcal metabolizable energy (ME)/kg diet and 23% crude protein (CP), 3,150 ME Kcal ME/kg diet and 21% CP, and 3,100 ME/kg and 17% CP, at zero to 4, 5 to 10, and 11 to 12 weeks of age (WOA), respectively. Birds were provided water ad libitum and a 23:1 and 8:16-hr (light:dark) regimen at zero to 8 and 9 to 12 WOA, respectively. Birds were weighed weekly, and body weight gain, feed consumption, and feed conversions were determined. Data were analyzed using the General Linear Model (GLM) procedures of SAS (2002) with dietary lysine as treatment effect. Females responded better to diets containing 1.04 and 0.8% lysine from hatch to 4 and 5 to 12 WOA, respectively. Males responded better to diets containing 1.10 and 0.8% lysine at hatch to 4 WOA and 5 to 12 WOA, respectively. Therefore, we recommend that PGGF females and males be fed diets containing 1.04 and 1.10%, respectively, at hatch to 4 WOA and 0.80% lysine at 5 to 12 WOA. The diets should be supplied in phases.

Desempenho e características de carcaça de três genótipos comerciais de frangos de corte alimentados com diferentes dietas

RESUMO Este estudo teve como objetivo avaliar o desempenho e as características de carcaça de frangos de corte de três genótipos comerciais do nascimento aos 35 dias de idade. Utilizou-se um total de 2.970 pintos de três genótipos de aves comerciais (Cobb 500, Hubbard Flex e Ross 308). Os programas nutricionais foram dieta basal, dieta com 10% mais e 10% menos de aminoácidos do que a dieta basal. As aves foram distribuídas em delineamento inteiramente ao acaso, em esquema fatorial 3x3x2 (genótipo x dieta x sexo), com cinco repetições e 33 aves por unidade experimental. Conversão alimentar, ganho de peso diário, ingestão da dieta e peso corporal aos 35 dias de idade foram registrados. Duas aves de cada unidade experimental foram amostradas e abatidas aos 35 dias de idade para avaliar as seguintes características de carcaça: peso corporal no momento do abate, peso da carcaça e rendimento, e peso e rendimento dos cortes (peito, pernas e asas). Houve uma interação significativa entre o genótipo e sexo para GPD e PC35. Os machos apresentaram melhores desempenhos e características de carcaças do que as fêmeas.