Does silage containing plantain affect the urination behaviour and urinary nitrogen of dry cows grazing diverse or conventional pasture?

Abstract

The objective of this study was to investigate the effect of diverse silage containing plantain on urination behaviour and urinary and faecal nitrogen (N) concentration of dairy cows when grazing standard ryegrass-white clover (RGWC) or diverse pasture containing plantain. Four groups of six non-lactating dairy cows were balanced and randomly assigned to one of four dietary treatments in a 2 × 2 factorial design: RGWC pasture plus RGWC silage; RGWC pasture plus diverse silage containing plantain; diverse pasture plus RGWC silage; diverse pasture plus diverse silage. Urination behaviour (frequency and volume) was continuously measured for a minimum of 24 hours on four cows per treatment using the Lincoln University PEETER V1.0 sensor. There was no silage or silage × pasture type interaction effects on urination behaviour, though diverse pasture regardless of silage increased daily urination frequency (p=0.046) and daily urine volume (p=0.003) of cows by 27% and 31% respectively, compared to RGWC. Spot urine N% concentration was similar among treatments, but faecal N% tended (p=0.07) to be higher in cows grazing diverse pasture compared to those grazing RGWC with no silage type effect. Unlike fresh plantain, silage containing plantain does not seem to alter urination behaviour or N excretion of dairy cattle.