Effect of Rumen-protected Choline Addition on Milk Performance and Blood Metabolic Parameters in Transition Dairy Cows

Guozhong Xu,Jun''An Ye,Jianxin Liu,Yueying Yu

doi:10.5713/ajas.2006.390

Abstract

This work was conducted to study the effect of rumen-protected choline (RPC) addition on milk performance and blood metabolic parameters in transition dairy cows. In Experiment 1, fourteen Chinese Holstein dairy cows were supplemented with 0 or 20 g/d of RPC from 7 d before expected calving to 21 d post partum. Feeding of RPC tended to increase milk yield and milk protein percentage, while milk fat and lactose percentage were not changed. Plasma concentrations of glucose tended to increase as cows consumed RPC, while plasma concentrations of triglycerides, very low density lipoproteins, cholesterol and nonesterified fatty acids were not significantly different between the two groups. In Experiment 2, thirty-six Chinese Holstein dairy cows were supplemented with 0, 30, 60 or 90 g/d RPC from 15 d before expected calving to 15 d post partum. Feeding of RPC tended to increase yield of milk and 4% fat-corrected milk for all the lactating cows, and milk composition was similar among the four groups. Plasma concentrations of glucose were remained at a higher level in 30 or 60 g/d RPC-supplemented groups, and nonesterified fatty acids were decreased in the 30 g/d group. Concentrations of triglycerides tended to reduce in 30 and 90 g/d RPC-supplemented animals, and cholesterol was reduced in 0 or 30 g/d group. 'these results suggest that RPC addition tended to increase milk yield and improve blood metabolic parameters during transition dairy cows, and feeding 30 g/d of RPC may be the optimal.

Highlights

Dairy cows experience a dramatic physiological and metabolic adaptation during the transition period accompanied by decreased dry matter intake, while the nutritional requirements for maintenance, pregnancy and milk production increase rapidly (Moe and Tyrrell, 1972; Bell, 1995), resulting in a state of negative energy balance
The objective of this study was to investigate the effects of rumenprotected choline (RPC) addition on milk performance and blood metabolic parameters in transition dairy cows
Milk yield and composition In Experiment 1, post-partum dry matter (DM) intake by cows was not affected by RPC addition (Table 2)

Summary

INTRODUCTION

Dairy cows experience a dramatic physiological and metabolic adaptation during the transition period accompanied by decreased dry matter intake, while the nutritional requirements for maintenance, pregnancy and milk production increase rapidly (Moe and Tyrrell, 1972; Bell, 1995), resulting in a state of negative energy balance. Dairy cows must mobilize more body fat to meet their nutritional requirements and may produce higher concentrations of non-esterified fatty acids (NEFA) in the blood plasma during the transition period (Rukkwamsuk et al, 1999). Piepenbrink et al (2003) observed that adding RPC at 45 and 75 g/d tended to increase the concentration of glycogen, and the rate of VLDL synthesis in and secretion of esterified lipid products from liver, whereas the milk yield and body condition were not affected. The objective of this study was to investigate the effects of RPC addition on milk performance and blood metabolic parameters in transition dairy cows

MATERIALS AND METHODS

RESULTS

DISCUSSION