EFFECTS ON MEAT QUALITY OF THE USE OF CLENBUTEROL IN VEAL CALVES

The objective of this study was to examine the effects of clenbuterol administration on meat quality traits of veal. Sixteen Holstein-Friesi an veal calves (male) were randomly assigned to one of four treatment groups; either control (n = 4) or elenbuterol-treated (.16 mug.kg BW-1 .d-1, 42 d) with a withdrawal period between clenbuterol treatment and slaughter of 8 d (n = 4), 4 d (n = 4), or 2 d (n = 4). All animals we re slaughtered at the same day at a commercial slaughterplant. At 30 m in postmortem the carcasses were split and the right carcass side was electrically stimulated. After 24 h of cooling the longissimus, semime mbranosus, triceps brachii, and psoas major muscles were excised and v acuum-packaged. After 1, 7, and 13 d of vacuum storage at 2 +/- 2-degr ees-C the muscles were sampled to determine tenderness, water-holding capacity, and color characteristics. Clenbuterol treatment resulted in a slower rate of pH decline in the unstimulated longissimus muscle bu t did not affect the ultimate pH. Clenbuterol treatment resulted in to ughening of the longissimus, semimembranosus, and triceps brachii musc les after 1 and(or) 7 d of storage (P < .05). It is suggested that thi s resulted from a decrease in postmortem proteolysis because both the intensity of a 30-kDa peptide and the myofibril fragmentation index we re lower in clenbuterol-treated muscles. Clenbuterol treatment resulte d in increased lightness (L-value) of longissimus and semimembranosus muscles (P < .05), coincident with a lower water-holding capacity. In a following experiment, the effect of clenbuterol administration (0 [ n = 5] and 1.0 [n = 5] mg/kg of feed for 27 d) on calpain and calpasta tin levels at 1 d postmortem in longissimus muscles of Friesian Pie No ire veal calves was investigated. Clenbuterol administration resulted in an increase in calpastatin levels (P < .05) and a trend (P < 0.1) t oward a decrease in mu-calpain activity at 1 d postmortem.