The effect of a high or low fibre diet within two confinement housing systems on the production, health, and behaviour of primiparous dairy cows
The nutrient requirements and the behaviour of the dairy cow have been widely studied. The consequences of feeding a primiparous cow a low fibre diet or of a tie-stall housing system on production, health, and behaviour over a full lactation have been insufficiently determined. A gate was designed to individually confine the cows within the dimensions of a tie-stall system and a diet (high fibre:HF) was formulated specifically for the production potential of the primiparous animal. An experiment using a factorial arrangement having two diets (HF and conventional multiparous:LF) within two housing systems (Gate and conventional collar-chain:Chain) over one and a half lactations was conducted. Primiparous cows received the dietary treatment during the first 225 days postpartum, after which all animals were fed the same diet regimen. The HF diet designed using National Research Council (1989) recommended nutrient allowances for a 550 kg cow producing 27 kg of milk per day (3.44% fat) at 50 days postpartum, caused a reduction in dry matter intake. The primiparous cows in this experiment fed the HF diet spent more time eating than the animals on the LF treatment. The production of milk and milk components was not affected by dietary treatment. Growth as measured by body weight and body condition score was not affected by diet. There was no difference in the health parameters measured in this experiment between the animals receiving the two different diets. The diets fed in the first lactation did not significantly affect the production or health in the second lactation. There was no difference between the two housing systems in the production parameters measured with the exception of body condition scores which were higher for the primiparous cows housed in the Gate system. The animals housed in the Gate system had fewer teat and locomotion inhibiting injuries during lactation one. There was no difference in the time spent at the behaviour parameters measured between the two housing systems, with the exception of standing. The Chain housed animals spent significantly more time standing. The Gate housed cows spent a significant proportion of time out of their stalls unsupervised (roaming). The roaming performed by the Gate housed animals did not significantly affect the production or health parameters measured.