Onderwerp scriptie

Effect of dry period length and milk production on lying and feeding behaviour of dairy cows - Brechtje de Schipper

The objective was to investigate if the changes in dry period length 0 (N=19) and 30 (N=10) days dry (dd) have effect on the lying and feeding behaviour of dairy cows and whether these consequences are correlated with the milk production. Behaviour of cows is an indicator for welfare and could indicate a degree of stress or discomfort of the cow. Shortening or omitting the dry period had no effect on lying behaviour and feeding time after calving.

A dry period (without milking) is necessary at the end of lactation to maximise the milk yield of cows in the next lactation. Dairy cows get a negative energy balance (NEB) after calving. They cannot eat enough energy to produce the increased amount of milk. An NEB increases the risk for metabolic health problems, disease incidence and a reduced fertility. As a result, cow welfare may be reduced. An approach to prevent an NEB is to reduce the energy output or increase the energy intake. It is difficult to establish a higher feed intake of cows. Shortening or omitting the dry period could result in a lower milk production. A shorter dry period induces a shift in milk gift from critical weeks after to the weeks before calving. In early lactation, cows need less energy to produce, because the amount of milk after calving is reduced. The objective was to investigate if the changes in dry period length 0 (N=19) and 30 (N=10) days dry (dd) have effect on the lying and feeding behaviour of dairy cows and whether these consequences are correlated with the milk production. Behaviour of cows is an indicator for welfare and could indicate a degree of stress or discomfort of the cow. Shortening or omitting the dry period had no effect on lying behaviour and feeding time after calving. There was a difference before calving. The 30dd cows were grouped separated from the 0dd cows with less space, different feeding ration and no milking moments which reduced the steps and feed intake. The 0dd cows were more active before calving, whereas the 30dd cows had a rest period. After calving the 0dd cows had a lower increase of milk production and their feed intake was higher than the 30dd cows. The changes in all indicators (except lying bouts) from before to after calving was more extreme for the 30dd cows than for the 0dd cows. This could mean that the 30dd cows had to cope harder than the 0dd cows to adapt from the dry period to early lactation, which might reduce the welfare and health of the 30dd cows.

Student: ACB de Schipper

Supervisor: A Kok, MSc

36 Ects