Daily Production Traits

Lactation Curves

Fixed lactation curves for milk, fat, protein, and SCS, computed by Jarmila Bohmanova from Canadian data for lactations up to 365 days in milk are used. Five parameters per curve. Curves are based on age groups (1::less than 25 mo, 2::25 mo, ... , 7:30 mo, 8::greater than 30 mo) within first parity, (1::less than 37 mo, 2::37 mo, 3::38 mo, 4::39 mo, 5::40 to 43 mo, 6::greater than 43 mo) for second parity, and (1::less than 51 mo, 2::51-52 mo, 3::53-54 mo, 4::55-56 mo, and 5::greater than 56 mo) for third and later parities. Two seasons are 1::April to October, 2::November to March.

There should also be curves for Lactose, Milk-Urea-Nitrogen, and Omega 3 fatty acids, but not found yet.

Legendre polynomials from day 1 to day 365 in milk, of order 4 are used. Residual variances of each trait for each day in milk are stored in a table for quick retrieval.

Two production values are produced. One is the amount of milk actually sold, and the other is an amount used to derive feed intake and the effects of production on other traits. For example, an animal being treated for a disease with antibiotics may produce 25 kg of milk, but none of it could be sold. However, dry matter intake would depend on the actual amount produced.

Adjustments are made for diseases, and cold and heat stress.

Effects of Pregnancy

Adjustment of yields for days pregnant use factors developed by Bohmanova et al.(2008), and are applied after 4 months pregnant.

Days PregnantMilkFatProtein