Everton Luis Krabbe

Efeito da Energia, Relação Energia: Proteína e Fase de Crescimento Sobre o Desempenho e Composição de Carcaça de Frangos de Corte

Two experiments (EXP) were carried out to investigate the effects of crude protein (CP) levels reduction in high-energy (H) (3.200kcal ME/kg) and low-energy (L) (2.900kcal ME/kg) diets, on the performance and carcass composition of male broiler chickens. The CP levels were decreased to meet the following energy: protein (E:PB) ratios: 139, 146, 153 and 160 (kcal/%) for starter diets (EXP 1) and 160, 167, 174 and 181 (kcal/%) for grower diets (EXP 2), in both energy levels, keeping MET + CIS and LYS levels at the same concentration. All birds received a same diet before (EXP 2) or after (EXP 1) feeding the experimental diets. Feeding H diets resulted in better performance, but also in higher carcass fat deposition. In EXP 1, birds fed with L diets during the starter period had similar body weight gain (BWG), in the total period (1 to 42 days), than those H diets, however with better caloric conversion (kcal/kg) (CC). Also, the best CC was obtained with E:PB of 139. Lower BWG, sometimes occurred with lower levels of dietary CP, but in all experiments the CC was decreased with wider E:PB ration. In both EXP, protein utilization was improved with higher levels of dietary energy and with lower levels of dietary CP.

Suplementação de Treonina em Dietas de Frangos de Corte, Variando a Energia e as Relações Energia: Proteína

Dois experimentos (EXP 1 e 2) foram conduzidos para avaliar relacoes energia metabolizavel:proteina bruta (EM:PB) e a adicao de treonina (Thr) em dietas com alta (A) (3.200kcal EM/kg) e baixa (B) (2.900kcal EM/kg) energia, sobre desempenho e composicao de carcacas de frangos de corte machos. As relacoes energia:proteina foram 139 e 160 kcal/%, para as dietas iniciais (1 a 21 dias) (EXP 1) e 160 e 181kcal/%, para as de crescimento (22 a 40 dias) (EXP 2), nos dois niveis de energia. As dietas com ampla relacao EM:PB foram suplementadas, ou nao, com Thr a fim de iguala-las as dietas com menor EM:PB. Os niveis de Met+Cys e de Lys foram constantes. As aves receberam uma dieta unica apos (EXP1), ou antes (EXP2) do fornecimento das dietas experimentais. Nos dois EXP as dietas A proporcionaram melhor desempenho: ganho de peso (GP),consumo de racao e conversao alimentar (CA) (p<0,01), ao final de cada periodo experimental. Porem, no EXP 1, as aves que receberam dietas B tiveram melhor conversao calorica (CC, kcal/kg,) (p<0,01) no periodo total (1 a 40 dias), indicando um periodo de crescimento acelerado. Os niveis de Thr (0,74 e 0,69% para A e B respectivamente) das dietas com relacao EM:PB ampla nao foram limitantes no desempenho das aves. No EXP 2, a EM:PB 181 deprimiu o GP (p<0,08) e piorou a CA (p<0,01), nas energias A e B. Portanto, em dietas praticas iniciais, Thr nao foi um aminoacido (AA) limitante. Porem, de 22 a 40 dias, a adicao de Thr foi necessaria, em dietas com EM:PB 181kcal/%(EXP 2). A suplementacao de Thr nao influenciou a composicao das carcacas nos dois EXP.

Effect of chick weight, geometric mean diameter and sodium level in prestarter diets (1 to 7 days) on broiler perfomance up to 21 days of age

Seven hundred and twenty Ross 308 chicks were raised in a controlled environment room, distributed in a factorial design with 3 hatching chick weights (37, 40 and 44 g), 3 geometric mean diameter (GMD) (0.561; 0.783 and 0.997 mm) and 4 total sodium levels (Na) (0.12; 0.24; 0.36 and 0.48%) in the pre-starter diet (1 to 7 days). From 8 to 21 days (d) one single basal diet was used for all treatments. The thirty seven-gram chicks had the smallest yolk sack weight at 4d, smallest body weight (BW) and feed intake (FI) at 7d and 21d, but the same feed conversion (FC) than the other groups of hatching weight. Chicks receiving diet with intermediate GMD had the greatest BW and FI at 7d, but at 21d this effect was no longer seen. The diet with finest particle size resulted in birds with the smallest gizzard weight at 7d. The 0.12%Na diet was statistically different from the other Na levels, resulting in chicks at 7d with the worst FC and lowest body weights. At 21d, BW still was the lowest for this group of chicks. Birds with 0.48%Na produced more watery excreta and less dry matter in the carcass at 7d. Water consumption (C H2O ) was influenced linearly by chick weight up to 0.36%Na level. In the 0.48%Na level, 40 and 44 g chicks had similar C H2O , which was different from 37-g chicks. For best performance, Na values were set from 0.31 to 0.48%. The three studied factors influenced quality of pre-starter diet and consequently chick performance.

Avaliação da monensina no desempenho e rendimento de carcaça e partes de frangos de corte

Three experiments were conducted to evaluate the performance and carcass yield of broilers, receiving or not monensin (MON), at different levels (100,110 and 120 ppm) according to the growth phase (GP) (1 to 21; 22 at 40 and 41 to 45/46 days of age). The Experiment 1 was performed at metabolic cages and the AME, dry matter digestibility (DDM.) and nitrogen retention (NR) were determined. The Experiments 2 and 3 were performed at floor pens. In the Experiment 3, feed:gain ratio (F/G) was improved with MON, mainly from 22 to 40 days. The 100 and 110-ppm levels better responded than 120 ppm, mainly without drug withdrawal in the last GP. In the Experiment 3, birds without MON had higher feed intake (FI). No differences were observed in DMD, ME or NR. In the Experiments 1 and 2, the maintenance of the drug up to the last week positively influenced the carcass yield and 110-ppm dose showed higher breast yield than other levels. Abdominal fat was not affected by the MON levels in the diets. The use of MON positively affected the broiler F/G. The birds weight gain was not affected, even with reduced CR.