Effect of feeding level, grazing and finishing on growth and carcass quality of young Friesian bulls

The Effect of Beef Production System on the Health, Performance, Carcass Characteristics, and Meat Quality of Holstein Bulls

The aim of this study was to evaluate the effect of production system on the health, performance, carcass characteristics, and meat quality of autumn born (AB) and spring born (SB) Holstein bulls. The study involved a total of 224 Holstein bulls and was conducted over two years (2017/18, 2018/19). The four production system treatments differed during the grower period and consisted of: (i) grazed with no concentrate supplementation (G), (ii) grazed with 2 kg concentrate supplementation per day (G2), (iii) grazed with ad libitum access to concentrates (GA) and (iv) housed with ad libitum access to concentrates and grass silage (HA). All bulls were finished on ad libitum concentrates and grass silage and were slaughtered at a mean age of 15.5 months. Total grower dry matter intake (DMI) (p < 0.001) and total finishing DMI (p < 0.001) differed between production systems for both AB and SB bulls, with that of GA bulls being the greatest in both cases. Average daily gain (ADG) during the grower period was greatest (p < 0.001) for the HA production system in the AB bulls and the GA and HA production systems for the SB bulls. However, during the finishing period, G bulls had the greatest (p < 0.001) ADG of the AB bulls, while that of the SB bulls was from the G2 production system (p < 0.001). For both AB and SB, bulls on the GA and HA production systems produced heavier cold carcass weights than the G and G2 bulls (p < 0.001). There was no significant difference (p > 0.05) in health, carcass conformation, fat classification, or meat quality between production systems.

Effect of growth rate on tenderness development and final tenderness of meat from Friesian calves

The present study was conducted to determine the effect of growth rate of calves on the activity of the calpain system post mortem, post mortem desmin degradation, myofibrillar fragmentation index and meat tenderness of m. longissimus lumborum (LL) and m. supraspinatus (SS). Twenty-four Friesian heifer calves were allocated to two treatment groups: MM and HH. The MM calves were given food to achieve a moderate growth rate (678 g/day from 5 days of age to 90 kg body weight (BW) (period I) and 770 g/day from 90 kg BW to slaughter at 250 kg BW (period II)) and the HH calves were given food to achieve a high growth rate (period I: 895 g/day and period II: 1204 g/day). The myofibril fragmentation index (MFI), desmin degradation and the activity of µ-calpain, m-calpain and calpastatin were measured in LL and SS at slaughter, and 1 and 7 days post mortem. Shear force was measured in LL and SS after 1 and 7 days of ageing and a sensory panel evaluated the eating quality of the loin aged 7 days. MFI (P < 0·01) and tenderness (P < 0·01) were higher and shear force was lower (P < 0·001) in meat from HH calves compared with meat from MM calves. However, growth rate did not affect the activity of µ-calpain, m-calpain or calpastatin or the degradation pattern of desmin at any time post mortem. Besides growth rate and MFI at day 7 post mortem, which both correlated positively with meat tenderness (P < 0·001 and P < 0·01, respectively), fibre type traits and DNA or RNA concentrations were not generally related to final tenderness. Thus, it was concluded that increased growth rate of calves before slaughter increased the ease of fragmentation (MFI) of the meat and improved the tenderness but these findings could not be related to any changes in the activity of the calpain system.

Influence of feeding intensity, grazing and finishing feeding on meat and eating quality of young bulls and the relationship between muscle fibre characteristics, fibre fragmentation and meat tenderness

Forty-one autumn-born Friesian bull calves were allocated to two production systems (Extensive='E'and Intensive='I'). In the E-system, animals were loose-housed and fed a roughage-based diet from October to May, followed by a grazing period from May to October. Ten animals were slaughtered directly from pasture in October [360 kg body weight (BW)] and 11 after a 10-week finishing period in tie-stalls (460 kg). The E-bulls were compared with intensively-fed tie-stall-housed young bulls (I) slaughtered at comparable weights (360 kg, n=11 and 460 kg, n=9). The myofibril fragmentation index (MFI) was measured 24 h post mortem in semitendinosus (ST), longissimus dorsi (LD), and supraspinatus (SU) muscles, and meat quality characteristics and sensory evaluation of LD were performed on aged meat. Intramuscular fat content was lower (P<0.001) in all three muscles of E- compared with I-bulls. MFI of ST and LD was lower in E-bulls compared with I-bulls, but only at 360 kg. In contrast, MFI of SU was higher in E- compared with I-bulls at 360 kg. In E- compared with I-bulls, shear force value of ST was higher (P<0.003) at 360 kg, but not at 460 kg. Panel scores for tenderness, taste and juiciness were all lower (P<0.006 to 0.001) and remarks for off-flavour higher in E- compared with I-bulls, the effects being most pronounced at 360 kg. A 10-week finishing period improved all meat and eating quality characteristics of E-bulls. In LD, the correlation between MFI and tenderness was 0.79 (P<0.001), which indicates a potential of MFI as an early predictor of tenderness.

Consequences of two or four months of finishing feeding of culled dry dairy cows on carcass characteristics and technological and sensory meat quality

Finishing feeding was evaluated as a way to improve carcass-, meat- and eating quality of culled dairy cows. In total, 125 Danish Friesian cows were purchased from commercial dairy herds. Cows were culled for various typical reasons at different stages of lactation, were non-pregnant and had milk yield at culling ranging from 1 to 25kg/d and had LW varying from 330 to 778kg. Cows were housed in tie-stalls and had free access to barley straw and water during a 7-d drying-off period. Cows were allocated to three equal treatment groups based on parity, LW, BCS, and culling reason. A control group (C) was slaughtered immediately after drying-off (n=43), a group (F2) was finishing-fed for 63 days (n=41), and a group (F4) was finishing-fed for 126 days (n=41). In the finishing period, cows had free access to a TMR (10.6 MJ ME and 130g CP per kg of DM). Cows on treatment, F2 and F4 gained 1.16±0.05kg/d in the finishing period. Compared with C-cows, F2- and F4-cows had 56 and 97kg higher carcass weight, 10% and 21% larger Longissimus muscle area, and 14 and 70% more backfat, respectively, at time of slaughter. EUROP conformation scores were 2.2 (C), 3.4 (F2) and 4.4 (F4) and EUROP fat scores were 1.9, 3.0 and 3.7. Finishing feeding increased IMF, improved meat flavour and colour, and tended to reduce shear force value and improve tenderness and juiciness. The F4 cows also had higher fat trim than C- and F2-cows. Cows were divided into two parity groups (1st parity and older cows). Compared with 1st parity cows, older cows ate 12% more feed, had similar daily gain, were heavier, and had higher BCS and fatness including IMF. The results show that it is possible to dry-off and finish-feed culled dairy cows resulting in larger muscles, increased fatness, improved overall carcass quality and better technological as well as sensory quality characteristics.