Short communication: Reference intervals for claw dimensions of intensively finished Charolais and Limousin young bulls and heifers housed on different flooring systems

Abstract

This study aimed at calculating reference intervals for specific claws dimensions of healthy feet originating from intensively finished Charolais (CH) and Limousin (LIM) young bulls and heifers. Moreover, within a given breed × gender combination, measurements of healthy and affected claws were compared to investigate how claw conformation might change in relation to the housing on different types of floor. A total of 2237 CH feet (1324 bulls; 913 heifers) and 595 LIM feet (459 bulls; 136 heifers) were analyzed post-mortem during 20 sessions in three slaughterhouses in Northern Italy. Four measurements were performed on lateral claws of each hind foot: dorsal wall (DW) and total hoof (TH) lengths, heel height (HH) and toe angle (TA). Afterwards, a veterinarian trimmed the sole horn and assessed claw health condition by looking for specific disorders. A foot with no claw disorder was classified as -“healthy”, whereas when at least one claw disorder of different etiology was observed, the foot was classified as “affected”. A reduced dataset considering only healthy feet was used to calculate 95% reference intervals (RI) for each claw dimension according to breed (CH/LIM) × gender (bulls/heifers) combination. Relevant batch variance was detected for DW, TH and HH of CH heifers and for DW and TH of LIM heifers. These calculated RI might be used to assess claw condition and its predisposition to diseases in finishing beef cattle belonging to the tested beef categories. Affected claws belonging to both CH young bulls and heifers showed greater HH than healthy claws. In presence of claw disorders, CH young bulls and heifers housed on deep litter had longer DW and TH lengths, but only heifers showed shorter TA compared to healthy ones. Longer claws and higher heels of CH should be carefully monitored as indirect indicators of the presence of some disorders, particularly when housed on less-wearing surfaces. Claw health condition had no effect on conformation in LIM young bulls or heifers housed on different types of floor. The housing of young bulls, regardless of breed, on concrete slatted floor showed the highest occurrence of feet affected by any claw disorders, confirming the harmfulness of this type of floor for finishing beef cattle.