Compensatory growth and fat parameters on broiler fasted in early life

The experiment was carried out to investigate the effect of feed withholding in the very early life of bird on its compensatory growth capacity and fat parameters. a total of 60 mixed-sexes of one day old ross chicks were used in the experiment conducted with completely randomized design of 2 different feeding times after hatching,i.e.: t1: given access to feed and water ad libitum immediately after hatching until 35d of age; and t2: withheld from feed (fasted) but not from water for 48h after hatching and then fed ad libitum until d35. the birds were weighed at the start of experiment and weekly thereafter,and dwg was then calculated. feed intakes and fcr were also recorded weekly. at d36,abdominal fat was taken out from 2 birds per pen and was weighed. breast meat (skinless) from the same birds was also sampled for total fa analysis. final bw (d35) and total feed consumption of earlyfasted birds were 1935.17±43.90 kg and 2745.55±47.48 kg and those of unfasted birds were 2019.00±50.85 kg and 2910.84±128.10 kg,respectively. fcr of early-fasted and unfasted birds at d35 were 1.42±0.03 and 1.45±0.07. the magnitude difference of dwg between early-fasted and unfasted birds was 27% at d7,whereas at d35 the difference was only 4.5%. abdominal fat percentage to live bw of early-fasted birds was 1.65±0.09% (male) and 1.60±0.10% (female) and that of unfasted birds was 2.00±0.19% (male) and 1.89±0.38% (female). total fa contained in meat of early-fasted and unfasted birds were 0.82±0.10 and 0.85±0.10 g/100gdm. overall,bw and feed consumption of early-fasted birds were significantly lower (p>0.05) than unfasted birds. dwg,fcr,abdominal fat and total fa contained in meat were not significantly different (p<0.05) between early-fasted and unfasted birds. in conclusion,holding birds without feed following hatch (under practical conditions) may limit the compensatory growth capacity of birds in the later age. fasting applied in the very early life of broiler leads to impairment of cell hyperplasia resulting in permanent stunting. abdominal fat and total fa contained in meat might not be affected by fasting for 48h after hatching. the degree or duration of feed withholding (for 48h after hatching) might not sufficient to reduce adipocyte proliferation or the number of precursor adipocytes. © 2010 de gruyter open ltd. all rights reserved.