Effect of Full Feed and Early Feed Restriction on Broiler Performance, Abdominal Fat Level, Cellularity, and Fat Metabolism in Broiler Chickens

Abstract

Three hundred sixty Peterson x Arbor Acres chicks were fed two feed regimens to compare their effects on adipose cellularity, adipocyte lipolysis, hepatic glucose oxidation, adipocyte lipogenesis, bird performance, and abdominal fat level. Broilers in the first regimen had ad libitum access to feed throughout the 7-wk experiment, whereas broilers in the second regimen consumed feed at will throughout the experiment except that they were subjected to feed restriction (1.49 kcal/g BW2/3 daily) from 7 to 12 d of age (DOA). No differences in mean body weights were observed between the full-fed and restricted males and combined sex broilers at 49 DOA. Feed conversion and abdominal fat levels of female and combined sex were lower (P < .05) for the restricted than full-fed broilers. No differences in adipocyte numbers based either on whole abdominal fat pads at 28 and 42 DOA or per gram fat at 42 DOA were observed between broilers fed the two feed regimens. However, the adipocyte numbers per gram fat at 28 DOA were greater (P < .05) for the restricted broiler than for the broilers that ate freely. Lipolysis based per million adipocytes was not different between the treatments at 28 and 42 DOA; however, lipolysis based on per gram adipose tissue was increased (P < .05) with the addition of isoproterenol and theophylline for the restricted broilers compared to the full-fed broilers at 28 DOA. No difference was observed between the feed regimens at 42 DOA with hormone addition. Lipogenesis of the restricted broilers was lower (P < .05) than that of the full-fed broilers at 14 and 56 DOA. No difference in glucose oxidation was found between chickens fed the two regimens. Reduced abdominal fat in the restricted broilers is attributed to the reduction of adipocyte volume, which may be due to decreased lipogenesis.

Effects of the level and duration of feeding restriction on carcass components of broilers

“…However, there are conflicting reports on this issue, since some studies extrapolated the event observed in 42-day-old chicks back to a state that may have be present at an earlier age. Looking at 42-day-old broilers, Zhong et al (1995) did not observe that feed restriction reduced the amount of abdominal fat cells. However, they reported that lipocytes had become smaller.…”

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

“…Na maioria dos trabalhos, a eficiência alimentar foi incrementada durante o período de realimentação (Plavnik & Hurwitz, 1985;Fontana et al, 1992;Robinson et al, 1992;Zubair & Leeson, 1994;Palo et al, 1995;Zhong et al, 1995).…”

Early Diet Dilution with 40% Rice Hull Induces Lower Body Fat and Lipid Metabolic Programming in Peking Ducks

“…In avian species, the liver is the major site for lipogenesis and bone marrow, and adipose tissue and skin make minor contributions (Zhong et al, 1995). It has been reported that hepatic lipogenesis is highly responsive to nutrient changes in diets, the nutritional state of the bird as well as the amount and composition of feed consumed (Hillgartner et al, 1995).…”

“…Many investigators had attributed such results to lipogenic responses (Rosebrough et al, 1986), and control of hyperplasia and/or hypertrophy of adipocytes (Zhong et al, 1995;Zubair and Leeson, 1996). Metabolic programming may be defined as a physiological process whereby early adaptation to a nutritional stress permanently changes the physiology and metabolism of the organism and continues to be expressed even in the absence of the stress that initiates it (Lucas, 1998;Patel and Srinivasan, 2002).…”