Effect of preslaughter feeding system on weight loss, gut bacteria, and the physico-chemical properties of digesta in cattle

The effects of four preslaughter feeding systems on gut microflora, digesta consistency, soiling of the hide with faeces, liveweight loss, dehydration, meat stickiness, and plasma cortisol were examined in 60 Angus steers. The feeding systems were: feeding hay for 48 or 24 hours before transport to slaughter, transporting cattle directly off pasture, and fasting for 24 hours before transport. Cattle were held overnight at the processing plant after 2 hours transport. At slaughter, pasture-fed cattle were carrying approximately 75 x 10(9) aerobic bacteria and 86 x 10(9) facultative anaerobes in their gastro-intestinal tracts. The number and type of bacteria were strongly influenced by the preslaughter feeding system. Rumen contents of the fasted animals were less acidic and more moist than the other treatments. Fasted animals had more E. coli, Enterobacter, and facultative anaerobes throughout the gut. The 48-h hay-fed steers had higher numbers of Enterococci and fewer E. coli. The pasture groups had runnier faeces, and were dirtier after holding overnight at the processing plant. Treatments did not affect dehydration, but urinary sodium was negatively correlated with meat stickiness, suggesting that some individuals were sufficiently dehydrated to influence this meat quality feature. It was concluded that feeding cattle hay for 48 hours before despatch for slaughter provided several advantages over other preslaughter feeding systems.