Growth of Broiler Chickens in Response to Feed Restriction Regimens to Reduce Ascites

Abstract

A trial was conducted to investigate the impact of early feed restriction on ascites induced by cold temperatures and the subsequent effect on the whole body and breast muscle growth of broilers. Two feed restriction regimens were tested, consisting of limiting daily feed intake of the birds to 75% of the ME required for normal growth from either 4 to 11 d or from 7 to 14 d. At 21 d, half of the birds were moved to a cold house (17.8 C) to induce ascites. Five birds from each pen were killed for the breast muscle growth, Pectoralis major and Pectoralis minor, and heart and abdominal fat pad weights at 4, 7, 11, 14, 21, 35, and 49 d of the experiment. Birds in the cold house were heavier and had better feed conversion than birds in the control house at 49 d of age. This could be attributed to the high ambient temperatures (27 to 33 C) in the control house. The ad libitum birds had a significantly greater percentage of P. major than the feed-restricted birds. Exposure to cold temperatures caused significantly higher percentage of ascites from 21 to 49 d. Cold temperatures also increased the percentage of total heart and the right ventricle weight relative to total heart weight ratio at 35 and 49 d of age, suggesting that the surviving birds were more likely to develop ascites. Although catch-up growth was observed, the final body weight of feed-restricted birds was not the same as ad libitum birds. Early feed restriction reduced the incidence of ascites, but at the cost of breast muscle growth.

Efeito da restrição alimentar qualitativa sobre o ganho compensatório em frangos de corte

“…Arce et al (1992), submetendo as aves a oito horas de acesso ao alimento por dia, ou 10% a menos do consumo à vontade, não obtiveram diferença significativa na conversão alimentar com relação as aves do tratamento-testemunha. Também Acar et al (1995) não registraram diferenças quanto à conversão alimentar (21-49 dias) entre as aves submetidas a restrição em 75% da EM exigida para o crescimento normal.…”

Cold-Induced Ascites in Broilers: Effects of Vitamin C and Coenzyme Q10

“…Cold environmental temperatures increase the levels of T 3 , which is required for the generation of additional metabolic heat to maintain body temperature in cooler environments. The subsequent increase in metabolic rate results in an increase in blood pressure as the heart attempts to maintain the oxygen supply to the organs and muscles, thus leading to pulmonary hypertension, right ventricular failure, and eventually ascites (Julian et al, 1989;Acar et al, 1995;Gupta, 2011).…”

The Effects of Different Eggshell Temperatures Between Embryonic Day 10 and 18 on Broiler Performance and Susceptibility to Ascites

“…It was previously assumed that the high susceptibility to ascites of modern broilers was linked to their high growth rate (Maxwell et al, 1990;Robinson et al, 1992;Acar et al, 1995;Balog et al, 2000). However, some authors suggest that the growth rate per se is not related to ascites (Balog et al, 2001).…”