RESUMEN
Calpain system (µ- and m-calpain, calpastatin) and myofibril fragmentation index (MFI) were analysed on muscle longissimus thoracis et lumborum of 16 male fallow deer, half 18- and half 30-month-old, slaughtered after a 4-month feeding trial on pasture alone or with concentrate supplement. Diet did not produce any difference on the measured variables. The muscle of the elder deer had a higher calpastatin level 6 h post-mortem (136.0 vs. 99.7 units/50 g, for the 30- and 18-months-old, respectively), and a lower MFI value, particularly 24 h post-mortem (71.1 vs. 89.1). This is in agreement with previous data showing tougher meat from 30-month-old animals.
RESUMEN
Thirty-two male fallow deer, half 18- and half 30-month-old, were slaughtered after a 4-month feeding trial on pasture alone or with daily supplement of 500 g (dry matter) concentrate/head (eight each 18- and 30-month-old). Neither diet nor age produced significant effects on M. longissimus thoracis et lumborum (LM) and on M. semimembranosus (SM) pH and colour. Meat texture properties (Warner-Bratzler-WB Shear Force and compression), water loss and collagen content were unaffected by diet, while the older deer had higher LM WB peak force values (4.15 vs 4.88 kg) and lower collagen solubility (34.61 vs 22.58%). LM and M. semitendinosus (ST) of the supplemented deer had a higher content of fat (pasture vs concentrate feeding: 0.56 vs 0.72% in LM; 0.55 vs 0.78% in ST) and provided lower PUFA, particularly n-3 PUFA, and higher n-6/n-3 ratio (3.30 vs 4.76 in LM; 3.39 vs 4.63 in ST). Thirty-month-olds' LM and ST were fatter than 18-month-olds', and provided lower PUFA, both in the n-6 and n-3 fraction.
RESUMEN
Thirty-two male fallow deer, half 18- and half 30-month-old, were slaughtered after a 4-month feeding trial on pasture alone or with daily supplement of 500 g (dry matter) concentrate/head (eight each 18- and 30-month-old). The concentrate was composed of 40% maize, 25% sugar beet pulp, 20% alfalfa, 13% soy flakes, 2% minerals and vitamins. Supplemented deer were heavier (49.9 vs 45.0 kg) and their carcasses produced higher dressing proportions (61.5 vs 57.2%) and bigger amounts of first quality cuts. Supplemented feeding improved muscle development and fat deposition. Thirty-month-olds were heavier than 18-month-olds (53.3 vs 41.6 kg) and their carcasses produced higher dressing proportions (60.9 vs 57.7%) and bigger amounts of first quality cuts; older deer carcasses showed better conformation and bigger amounts of fat deposition.