Effect of milking frequency and nutritional level on hoof health, locomotion score and lying behaviour of dairy cows

摘要

This study evaluated the effect of milking frequency (MF; once a day (OAD) versus twice a day (TAD)) at two nutritional levels (NL) on hoof health, locomotion and lying behaviour of dairy cows. Cows (n =72) were randomly assigned to one of four treatments from calving in a 2c2 factorial design for an entire lactation: OAD or TAD milking at a high (30.9kg DM/c/d) or low (18.8kg DM/c/d) herbage allowance NL. Hoof health (sole lesions, heel erosion, digital dermatitis and white line disease) and locomotory ability (including overall locomotion, ab/adduction, tracking, speed, head carriage and spine curvature scores) were assessed on 6 occasions between calving in the spring and housing the following autumn. Udder firmness was recorded in the milking parlour prior to milking at approximately 57, 93 and 132days in milk (DIM). Standing/lying behaviour was recorded using modified voltage dataloggers over 2c24h periods at approximately 157 and 208DIM. Cows milked OAD had lower sole lesion (P <0.05) and white line disease (P <0.01) scores, but higher heel erosion scores (P <0.05) than cows milked TAD. There was an interaction between time of examination and MF (P <0.05) for locomotion scores; although in early lactation cows milked OAD had higher overall locomotion scores than TAD cows, this was reversed later in lactation. OAD cows had higher ab/adduction scores in early lactation (P <0.05). On the other hand, speed and head carriage scores were all higher for TAD compared to OAD cows. High NL cows had higher overall ab/adduction (P <0.01) scores, and at 57DIM had higher udder tension scores than low NL cows (P <0.001). Neither MF nor NL had an effect on total lying times. However cows on the high NL and OAD treatments spent less time standing after morning milking (P <0.05), and spent more time per hour lying between 0900 and 1200. Cows milked OAD also spent more time than TAD cows lying between 1530 and 1830. High abduction scores in the OAD cows in early lactation may be related to discomfort in the udder. In general however, OAD milking resulted in improvements to hoof health and locomotion ability. Moreover, cows milked OAD use the extra time at pasture in the afternoon to rest, an option that is not available to TAD milked cows. Fewer disruptions to the diurnal pattern of OAD cows are an indication of improved welfare.