Effects Of Encapsulated Niacin On Metabolism And Production Of Periparturient Dairy Cows

Background

The objective was to determine if a relatively high dose of encapsulated niacin (EN) alters lipid metabolism and productivity of transition cows.

What

Primiparous (n = 9) and multiparous (n = 13) cows (BCS 3.63 ± 0.08) entered the study 21 days prior to expected calving and were sequentially assigned within parity to EN (24 g/d, provided with ration twice daily) or control treatments through 21 d postpartum.

Parameters Monitored

Throughout the study, liver biopsies were collected for triglyceride (TG) analysis and blood samples were collected for nonesterified fatty acid (NEFA) and ß-hydroxybutyrate (BHBA) analyses. On d 22-23 postpartum, blood samples were collected every 8 h to monitor post-treatment NEFA responses.

Key Results

There were no prepartum treatment effects on plasma parameters.
There was a treatment x time x parity effect on prepartum dry matter intake (DMI, p < 0.07) caused by a 4 kg/d decrease in DMI of EN-treated cows compared to control cows during the final 5 d prepartum.
There were no treatment effects on postpartum DMI.
Treatment x time x parity effects were detected for NEFA (p = 0.09) and BHBA concentrations (p = 0.03) during the postpartum period. Plasma NEFA peaked at 1.7 and 1.3 mEq/L for control heifers and cows, respectively, compared to 0.7 and 0.8 mEq/L for EN-treated heifers and cows.
EN treatment also suppressed peak BHBA concentrations in both parity groups.
After treatments ended on d 21, there was a treatment x time x parity effect (p < 0.09) on plasma NEFA; however, treatment means showed a continued suppression of plasma NEFA by EN in cows, with no evidence of a rebound in either parity group.
No treatment effects were observed for liver TG concentration, BCS, BW, or milk or milk component production.

Implications

These results indicate that a high dose of EN can decrease postpartum plasma NEFA and BHBA.

Abstract

Effects of encapsulated niacin on metabolism and production of periparturient dairy cows

D. Morey, B. J. Bradford*, L. K. Mamedova, and D. E. Anderson, Kansas State University, Manhattan.

Nicotinic acid (niacin) can suppress lipolysis, but responses to dietary niacin have been inconsistent in cattle. Our aim was to determine if a relatively high dose of encapsulated niacin (EN) alters lipid metabolism and productivity of transition cows. Primiparous (n = 9) and multiparous (n = 13) cows (BCS 3.63 ± 0.08) entered the study 21 days prior to expected calving and were sequentially assigned within parity to EN (24 g/d, provided with ration twice daily) or control treatments through 21 d postpartum. Throughout the study, liver biopsies were collected for triglyceride (TG) analysis and blood samples were collected for nonesterified fatty acid (NEFA) and ß-hydroxybutyrate (BHBA) analyses. On d 22-23 postpartum, blood samples were collected every 8 h to monitor post-treatment NEFA responses. Data were analyzed using mixed models with repeated measures over time. There were no prepartum treatment effects on plasma parameters; however, there was a treatment x time x parity effect on prepartum dry matter intake (DMI, p < 0.07) caused by a 4 kg/d decrease in DMI of EN-treated cows compared to control cows during the final 5 d prepartum. There were no treatment effects on postpartum DMI. Treatment x time x parity effects were detected for NEFA (p = 0.09) and BHBA concentrations (p = 0.03) during the postpartum period. Plasma NEFA peaked at 1.7 and 1.3 mEq/L for control heifers and cows, respectively, compared to 0.7 and 0.8 mEq/L for EN-treated heifers and cows. EN treatment also suppressed peak BHBA concentrations in both parity groups. After treatments ended on d 21, there was a treatment x time x parity effect (p < 0.09) on plasma NEFA; however, treatment means showed a continued suppression of plasma NEFA by EN in cows, with no evidence of a rebound in either parity group. No treatment effects were observed for liver TG concentration, BCS, BW, or milk or milk component production. These results indicate that a high dose of EN can decrease postpartum plasma NEFA and BHBA, but may also decrease prepartum DMI.