Graduation date: 2007
An experiment was conducted with 27 multiparous Holstein and 27 multiparous
Jersey cows to determine if nicotinic acid (NA) supplementation during the prepartum
phase of the transition period decreases lipolysis and improves dry matter intake and
to determine if Holstein and Jersey cows respond similarly to NA supplementation.
Cows were blocked by expected calving date and assigned at random to one of three
prepartum dietary treatments which were 0, 49, and 98 mg of NA/kg of body weight
(BW). Cows were group housed in freestalls and fed individually via Calan® gates
from 30 d prepartum to 21 d postpartum. Cows were offered a dry cow total mixed
ration twice daily and NA was hand mixed in the morning feeding. Following
parturition all cows received the same lactation total mixed ration. Data were analyzed
as repeated measures using the MIXED procedure of SAS. Dry matter intake -3 wk
prepartum was used as a covariate for analysis of prepartum dry matter intake.
Prepartum and postpartum BW and body condition score (BCS) were similar for NA
treatments. Body weight was greater for Holsteins compared to Jerseys; however BCS
between breeds did not differ. Prepartum DMI was similar for NA treatments, but
cows supplemented with 49 mg NA/kg BW had greater DMI following parturition.
Prepartum DMI depression was greater for Holsteins compared with Jerseys, 32 and
14%, respectively. Prepartum NA treatment had no effect on prepartum or postpartum
nonesterfied fatty acids (NEFA), β-hydroxybutyrate, and glucose. The magnitude of
increase of NEFA as parturition approached was greater for Holsteins compared with
Jerseys. Further, plasma NEFA of Jersey cows were lower than Holstein cows during
the postpartum period (613 vs 862 µEq/L for Jerseys and Holsteins). Milk production differed between NA treatments, with increased production from cows supplemented
with 49 mg NA/kg body BW compared to other treatments. Milk composition was not
affected by the supplementation of NA. In summary, supplemental NA during the last
3 wk of gestation did not affect DMI or plasma metabolites during the transition
period. Lipid metabolism and prepartum feed intake depression does differ for the two
major breeds of dairy cattle.
Key Words: dairy breed, transition cow, nicotinic acid