THE EFFECT OF PROTEIN-SOURCE ON LAMENESS AND SOLEAR LESION FORMATION IN DAIRY-CATTLE

Two groups of 16 cubicle-housed Holstein-Friesian cattle from weeks 3 to 27 of lactation were offered either a proprietary protein supplemen t of animal origin (P) or soya-bean meal (S) as the protein source in the concentrate in a continuous design experiment. Concentrates were o ffered mixed with grass silage as complete diets to give a forage : co ncentrate ratio of 41 : 59 and a crude protein content of 213 and 210 g/kg dry matter (DM) and a metabolizable energy content (MJ/kg DM) of 11.9 and 12.0 for P and S respectively. There teas no significant diff erence due to diet for mean locomotion score (1.75 v. 1.66 (s.e. 0.15) ), prevalence (0.1 v. 0.09 per cow per week) or incidence of lameness (0.04 v. 0.04) for P and S respectively. Similarly there was no effect on hoof growth, wear, hardness or conformation. Sole haemorrhages, in dicative of subclinical laminitis, were observed throughout the experi ment but were most severe at approximately 16 weeks after calving. Lev els of heel erosion remained constant throughout. There was no signifi cant effect of treatment on either heel or sole lesion formation. No s ignificant differences were observed between treatments for milk yield , live weight, condition score or blood metabolites. The conclusions f rom this study were that source of dietary protein has no effect on da iry cow lameness or the development of sole lesions indicative of subc linical laminitis.