Mineral and glycerol concentrations in drinking water on body weight loss and acid-base balance in feed-deprived Holstein bulls

Situations in which cattle are feed-deprived over extensive periods of time are common in the context of transport and is an animal welfare concern which may also compromise growth and carcass yield grade. This study investigated how the main components of an oral rehydration solution would affect BW loss and blood parameters in feed-deprived bulls. Three dose-response experiments were performed with 24 bulls each (n = 6 per treatment) to study the effect of mineral concentration in Study I (0, 100, 200 and 300 mOsm/kg), the K⁺ to Na⁺ ratio in Study II (25:75, 40:60, 60:40 and 75:25), and glycerol concentration in Study III (0%, 1%, 2% and 4% of the final solution). The blocking factor was initial BW and treatments were randomly assigned within each block. Measurements included fluid intakes, BW, and blood parameters at 0, 24 and 48 h relative to the start of feed deprivation. In Study I, increasing mineral concentration in solution linearly decreased BW losses at 48 h. At 24 and 48 h, serum urea linearly decreased with increasing mineral concentration. At 48 h, blood K⁺ and Na⁺ linearly increased, resulting in increased blood osmolarity. Additionally, at 24 h feed deprivation, blood pH linearly increased with increasing osmolality. In Study II, BW losses decreased with increasing K⁺ to Na⁺ ratio at 24 h, but not at 48 h. No effect of the K⁺ to Na⁺ ratio was found on blood parameters, apart from a trend for a linear decrease of blood osmolarity at 48 h. In Study III, serum urea tended to linearly decrease with increasing glycerol inclusion at 24 h, while blood glucose linearly increased with glycerol inclusion at 24 and 48 h. These combined results indicated that a solution with an osmolality of 200 mOsm/kg and a high K⁺ to Na⁺ ratio would effectively mitigate BW losses and maintain blood acid-base balance, whereas high glycerol inclusion sustained blood glucose in feed-deprived bulls.

Balancing consumer and societal requirements for sheep meat production: an Australasian perspective

Although there has been a decline in sheep numbers in Australia and New Zealand, both countries remain significant producers and exporters of sheep meat. The ongoing demand for more sustainable and ethical animal farming systems and practices requires sheep production industries to be both vigilant and responsive to consumer and the broader societal needs. Demonstration of continuous improvement in animal welfare is paramount and the welfare risks and challenges confronting Australasian sheep industries now and into the future are discussed.

Effect of lairage on lamb welfare and meat quality

The study analysed the effect of lairage on some indicators of welfare and meat quality in lambs. Forty-eight lambs were divided into two treatments: T1 without lairage and T2 with 12 h of lairage. Blood samples were collected at slaughter to analyse cortisol, lactate, glucose, creatinine kinase, non-esterified fatty acid, white blood cells, red blood cells, haematocrit and ratio of neutrophil : lymphocytes. Meat from the M. longissimus was analysed in terms of pH 24 h post-mortem, water-holding capacity, texture and colour. Sensory analyses were performed by a trained panel. Lairage had a significant effect on stress response, but had no effect on haematological variables. The lambs with a lairage period before slaughter (T2) had significantly (P ≤ 0.001) lower values of cortisol at the time of slaughter. A similar result was observed for lactate and glucose, with T1 lambs showing significantly (P ≤ 0.05) higher values than T2 lambs. The creatinine kinase activity and non-esterified fatty acid concentrations were highest in T2 lambs (P ≤ 0.05). Instrumental and sensory meat quality were not affected, with the exception of water-holding capacity and some meat colour indicators. The water-holding capacity was significantly higher for T2 (P ≤ 0.05), while T1 lambs had a higher yellow index (P ≤ 0.05) and hue (P ≤ 0.05). The results obtained in this study suggest that animals will be less stressed at the time of slaughter with an overnight lairage compared with slaughter on arrival at the abattoir. While stress at the time of slaughter can influence meat quality, these changes were small and always within the normal commercial range.