Farm Animal Metabolism and Nutrition

Grouping of primiparous cows

When practical, heifers within several
weeks of parturition should be grouped
separately and adapted to the early post-
partum environment (Grant and Albright,
1995). Cows that undergo abrupt environ-
mental and social changes during the
periparturient period often exhibit aberrant
feeding behaviour and are more susceptible
to metabolic disorders (Grant and Albright,
1995).
Primiparous cows can benefit from
separate grouping (Fig. 17.3). Phelps (1992)
reported the response to grouping older
dairy cows separately from younger,
smaller primiparous cows. When separated,
primiparous cows produced significantly
more milk. Competition with older cows
resulted in less feed intake and milk
production for the primiparous animals.
The difference in performance was propor-
tional to the difference in body size
between young and mature cows. Other
research summarized by Grant and
Albright (1997) showed that when heifers
were separated from older cows, eating
time increased by 11.4%, meals per day
increased by 8.5%, silage dry matter intake
increased by 11.8%, lying time increased

by 8.8% and lying periods increased by

19% day^1.

Due to constraints of limited cattle

numbers and facilities at most research

farms, very few data exist regarding the

interaction between group size and feeding

activity. Data from lambs, however,

indicated that as the number of lambs per

pen increased, feed consumption per visit

to a feeding station increased linearly.

However, total feed consumption was

greatest for an intermediate number of

lambs. One possible explanation for these

observations could be that social facilita-

tion increased feeding activity to a point,

and then excessive competition resulted in

a subsequent decline in feed intake.

Similarly, some researchers have observed

that beef cattle eat less when fed indivi-

dually versus when group-fed, perhaps

because of increased anxiety due to isola-

tion and lack of social facilitation from

group mates (Kidwell et al., 1954).

Feeding Area Design and

Feeding Behaviour

Facility design plays an important role in

facilitating aggressive feeding behaviour. In

Feeding Behaviour 373

Fig. 17.2.Feeding activity in large group of dairy cows following delivery of fresh feed.