This study aimed to assess the bioeconomic performance and the qualitative
and quantitative characteristics, physical and chemical composition of the carcass
and components not included in the carcass of veal calves fed in confinement
exclusively with concentrated diet fed ad libitum or restrictively (2kg.100kg PV-1
), and
slaughtered at 8 or 10 months of age. We used twenty-eight uncastrated calves with
initial age of 3 months and initial body weight of 71.56 kg . The experimental design
was completely randomized with treatments in a 2x2 factorial arrangement (two
slaughter ages and two diet levels), using seven replicates. There was no difference
in ruminal pH according to feeding level with an average of 5.82. There was no
interaction between the factors for feed conversion. Animals slaughtered at 8 months of
age fed restrictively showed better feed conversion. Animals slaughtered at 10 months of
age had higher final weight and average daily weight gain, as well as those fed ad
libitum. The costs with corn grain, with calves 90 days of age, and with the same
price paid per kg of carcass for the veal calves as for the fat steers, made the
production of veal calves unfeasible in northern Tocantins. Calves slaughtered at 10
months of age had higher hot carcass yield (51.46 vs. 49.65 kg.100kg live weight-1
)
and cold carcass yield (50.04 vs. 48.52 kg.100kg live-weight-1
) than those
slaughtered at 8 months of age. Older calves had carcasses with higher
subcutaneous fat thickness (2.17 vs. 0.78mm) and mm/100 kg of cold carcass weight
(1.57 vs. 0.80), higher side cut (13.30 vs. 12.03 kg.100 kg-1
) and lower pistol cut
(46.62 vs. 48.92 kg.100kg-1
) than calves slaughtered with younger age. The supply
of food ad libitum and the slaughter of older animals increased the participation of
adipose tissue in the carcass. The increase in slaughter age and the level of food
supply in the diet promoted higher absolute weight of the small intestine and higher
absolute weights of internal and mesentery fat. The absolute weights of the contents
of the gastrointestinal tract, internal fat, total internal organs and empty body weight
were influenced by the supply levels of the diet and slaughter age of modified veal
calves. The use of ad libitum feeding and slaughtering of calves at 10 months of age
improves the quantitative carcass traits of calves benefitting the producer and beef
industry but the largest slaughter age worsens the primary attribute sought by the
consumer for this product type, which is the tenderness of the meat.
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