Marginal dietary zinc concentration affects claw conformation measurements but not histological claw characteristics in weaned pigs.

The aim of the present study was to explore whether marginal dietary zinc (Zn) concentrations affect claw quality measurements in weaned pigs. Twenty-four weaned pigs were randomly assigned to two dietary treatment groups: (1) 42 mg Zn/kg diet from ingredients only (unsupplemented, marginal dietary Zn concentration below Zn requirements of 80 mg Zn/kg feed); and (2) 106 mg Zn/kg diet, where Zn was added as ZnO (common commercial dietary Zn concentration). Claw conformation characteristics were measured at the start (day 0, 4 weeks of age) and at the end (day 36) of the study, and the histological claw characteristics of horn wall and heel horn were examined on samples collected at 9 weeks of age. Non-supplemented pigs had narrower claw widths (P= 0.028) and lower toe heights (P= 0.010) at 9 weeks. The length of the dorsal border tended to be lower for the non-supplemented piglets (P= 0.092). Claw volume and claw horn size were lower (P= 0.003 and P < 0.001, respectively) for the non-supplemented pigs at 9 weeks of age. Horn growth and wear were lower for the non-supplemented pigs (P= 0.044 and P < 0.001, respectively), but net horn growth (horn growth minus wear) was not different (P= 0.406). No changes in the histological claw characteristics were observed. Differences in claw quality measurements were found between lateral and medial claw digits and between fore and hind claws. It was concluded that marginal dietary Zn concentration affected various claw quality measurements. Marginal dietary Zn concentrations may not be sufficient to maintain claw quality in pigs.

[Influence of floor surface and access to pasture on claw characteristics in dairy cows kept in cubicle housing systems].

This study aimed at investigating the effect of the floor type used in the walking area of cubicle housing systems and of access to pasture on claw dimensions and claw shape in dairy cows. Data were collected on 36 farms, 12 farms each fitted with mastic asphalt, slatted concrete or solid rubber flooring. With each floor type, cows on half of the farms had access to pasture in summer. The farms were visited three times at intervals of about 6 months and data were collected from 10 cows during each visit. Net growth of the claw horn was highest on rubber flooring and lowest on mastic asphalt. On all floor types, claw angles were larger after the winter period and smaller after the summer period. With regard to claw shape, floor type had an effect on the occurrence of flat, concave and overgrown claw soles. In conclusion, none of the investigated floor types was clearly superior to the others with regard to claw dimensions and claw shape, and access to pasture during summer (median 4 h per day) had only little influence on the investigated claw characteristics.

Cette étude avait pour but de déterminer l'influence du sol dans la zone de sortie ainsi que celle de la mise au pâturage sur les dimensions et la forme des onglons de vaches laitières. Le recueil des données s'est fait dans 36 exploitations avec une stabulation libre à logettes, 12 avec une zone de sortie en asphalte,12 en béton et 12 recouverte de matelas de caoutchouc fixés. Indépendamment de la qualité du sol, les vaches avaient, sur la moitié des exploitations, accès au pâturage durant l'été. On a recueilli sur chaque exploitation des données sur 10 vaches à trois reprises, avec un intervalle d'environ 6 mois. La croissance des onglons était maximale sur les sols en caoutchouc et minimale sur l'asphalte. Quel que soit le type de sol, l'angle de la paroi était plus grand à la fin de la période hivernale et plus petit à la fin de l'été. Le type de sol avait aussi une influence sur l'apparition d'onglons plats, concaves ou trop longs. Dans l'ensemble toutefois, aucun des types de sol ne se révélait nettement supérieur et la mise au pâturage (en moyenne 4 heures par jour) n'avait qu'une faible influence sur les dimensions et la taille des onglons.