LAUSR

Abstract This study analysed potential associations between the prevalence of rumen, abomasum, liver, and claw disorders detected in 26 batches of Holstein veal calves through a post-mortem inspection at the slaughterhouse, and on-farm mortality and feeding management data. Organs of 15–16 calves per batch (16.5 rumens, 15.9 abomasa, 15.1 livers, and 31.1 claws) were inspected by 3 veterinarians in the slaughter-line. ‘Batch’ refers to group of calves belonging to the same farm and slaughter group. Hyperkeratosis and plaques were detected in over 60% of rumens per batch, and some cases, in all rumens. More than 85% of abomasa showed ulcerations. Sole haemorrhages were detected in 64 to 97% of claws. During fattening, calves received on average 312 kg of milk-replacer (MR) and 162 kg of solid feed (SF), composed mainly of corn grain (85–93% as-fed basis). Rumens with hyperkeratosis were positively correlated to the percentage of corn grain. Abomasa with large-sized-lesions in the pyloric area were positively correlated to the SF amount. Ulcerated abomasa were positively correlated to calves’ mortality reported by farmers. Cluster analysis identified 3 feeding plans. The first, based on MR administration and moderate SF amount, produced lighter carcasses and low-developed rumens, but reduced the prevalence of rumen hyperkeratosis and sole haemorrhages; the other two, more ‘aggressive’ by increasing the amount of SF or both SF and MR, produced heavier carcasses but worsened rumen and claw conditions. This study suggests the existence of different feeding practices used by veal producers that should be reviewed to improve calves’ welfare. Highlights Feeding plans based on moderate amount of solid feed together with the liquid diet reduce the prevalence of rumen alterations and sole haemorrhages The provision of greater amount of high-grain solid feed throughout the fattening rises the prevalence of rumen hyperkeratosis and sole haemorrhages None of the feeding plans were capable of decreasing the occurrence of abomasal ulcerations, which were positively associated with on-farm mortality