On days 8 and 11, significant depressing effects due to extra walking on milk yield and composition were recorded. Milk yield was decreased (P<0.05 day 8), fat % increased (P<0.05 day 8) and protein % decreased (P<0.01 day 11) which resulted in a significant decrease (P<0.01 on day 8 and 11) in protein yield and milk solids yield (P<0.05) on day 8. No effect of walking on milk yield and composition were recorded on days 15 and 18. Total milk protein and milk solids production over the two week recording period was reduced (P<0.01 and P<0.05 respectively) for the 8km walk treatment.
Extra walking increased (P<0.05) somatic cell counts on day 11. A depressing effect on somatic cell counts was also observed on day 18 but differences were not significant. Cow condition score was lower (P<0.05) on the 8km extra walk treatment on day 8 and liveweight loss on days 8-16 was less (P<0.01) on the extra walking treatments.
No effect was observed on pasture herbage mass levels before or after grazing or on the rate of DM disappearance. DM intake as assessed by controlled release chromium capsules over days 8-18 also showed no treatment effect.
The effects of walking on milk production were significant in only one of a two week monitoring period and from this result it cannot be assumed the production differences and effects on milk quality recorded are repeatable.
Keywords: NZSAPAB; Walking; lactating cows; milk solids; somatic cell count.