The mechanical properties and lesion score of the sole and white line horn of front and hind claws of heifers prior to and during first lactation

摘要

The aim of this experiment was to study the incidence of lameness and the pattern of lesion formation in the sole horn during the pre- and post-partum period of first lactation Holstein Friesian heifers and to compare these to mechanical testing of the hoof horn strength and with the breed society (Holstein Friesian) index of classification for conformation (HUKI) to compare heifers susceptibility to lameness. Samples of sole hoof horn were taken from all claws of 20 heifers at 144 and 40 days pre-partum and 50, 100 and 150 days post-partum. Simultaneously, all claws were assessed for the lesion score in the sole horn. Locomotion score was assessed weekly and heifers were conformation scored for the Holstein UK Index (HUKI). Hoof samples were analysed for elastic modulus and punch resistance. Punch resistance of the sole horn was significantly greater in front claws when compared to hind claws. The punch resistance, elastic modulus, lesion score and locomotion score increased significantly during the post-partum compared with the pre-partum period, post-partum elastic modulus and punch resistance were significantly negatively correlated to increase in lesion score and locomotion score between measurement periods and positively correlated to the breed society conformation index (HUKI) score for legs and feet. Mechanical tests reflected the changes in housing and in haemorrhage levels that occurred between 144, 40 pre- and 100 days post-partum and there may be a potential to select animals for increased hoof horn quality and reduce wear rates during lactation.