Influence of Com Processing and Rumen Undegradable Protein Levels on Performance of Holstein Cows during the Transitional Period

摘要

This study examined the effect of corn processing with varying rumen undegradable protein (RUP) on feed intake, milk yield, its composition and, blood characteristics in Holstein cows during the transitional period (21 days pre partum to 21 days postpartum). Twenty Holstein cows were randomly assigned to four diets (five cows/diet), ground com with 30 % RUP (GCR30), ground corn with 40 % RUP (GCR40), flaked corn with 30 % RUP (FCR30), and flaked com with 40 % RUP (FCR40). The processed corn with varying RUP was fed in total mixed rations (TMR) to cows. Dry matter intake (DMI) was higher with 40 % RUP diet than with 30 % RUP diet, resulting in higher protein and energy intake by cows during pre and post partum (p<0.05). However, it was not affectedby corn processing during pre and post partum. Similarly milk yield was higher with 40 % RUP diet than with 30 % RUP diet, and milk yield was affected by corn processing at RUP 30 % level. Corn processing did not affected the milk fat and protein contents in dairy cows. The concentration of blood non esterified fatty acid (NEFA) were effected by RUP level with flaked cohi, however, it was non-significant with RUP levels when given with ground corn. It is concluded that increasing RUP from 30 % to 40 % in iso-nitrogenous diet could increase milk yield in dairy cows during the transitional phase.