The locus showed a statistically significant additive behavior along the whole lactation trajectory for all quality traits, whereas for milk yield the effect was not significant at later stages.
In the individual disease models, specific changes in the shape of the lactation curve were found for all MD except twinning.
The probability of developing mastitis for cow i can be expressed as (9) π i j k (H D ) = P f i (t + 1 ) (H D ) = 1 f i t (H D ) = 0 and was the same for cow i throughout the entire lactation, i.e. for all values of t, (t = 1,..., T i-1).
A lactation consultant was on-site for all recruitment efforts in Lowell and available by phone to all potential participants.
a The least square means are the adjusted means of the EBVs for the SCS for bulls which are grouped by genotype for each SNP and calculated for the respective lactation (over all, first, second or third lactations).
The EBVs for SCS at the first, second and third lactations and for over all lactations are reported according to the genotypes for SPP1c.-1301G>A, SPP1c.-430G>A SPP1c.-430G>A>andnd SPP1c.*40A>C (Table 2).
a EBV values from the Canadian Dairy Network database, evaluation published on August 2008 b EBVs are calculated for the respective lactation: over all (SCS), first (SCS1), second (SCS2), and third (SCS3) lactations.
The BLG genotype AA showed a greater performance than the BB genotype for all traits along the whole lactation curve, whereas the heterozygote showed an intermediate performance.
The objective of this experiment was to measure the milk yield and composition from cows offered a total mixed ration (TMR) compared with those grazing grass and offered different quantities of concentrates during the first 6 wk of lactation when the experimental diets were offered, and for the remainder of lactation when all animals were offered a similar diet.
As shown in figure 4, the udder consistency decreased over lactation from a score value of 4 to 3 for all 3 parity groups.
