Effects of a High-Protein Corn Product on Nutrient Digestibility and Production Responses in Mid-Lactation Dairy Cows

W E Brown,B J Bradford

doi:10.4148/2378-5977.7876

Abstract

Effects of a High-Protein Corn Product on Nutrient Digestibility and Production Responses in Mid-Lactation Dairy Cows

Highlights

Corn grain is a useful feed ingredient in lactating dairy cow diets, serving as a readily available energy substrate; it is low in crude protein
The soybean meal (SBM) diet was formulated to provide 5.7% rumen-undegradable protein (RUP), while soybean meal with bypass protein (SBMBP) and canola meal with rumen-bypass soy protein (CANBP) diets were formulated for 6.8% RUP to match high-protein corn product (HPCP)
As SBMBP and CANBP increased yield compared with SBM, but HPCP decreased milk yield compared to all treatments

Summary

An experiment was conducted to assess the effects of a high-protein corn product (56% crude protein; CP) relative to other sources of protein on the lactation performance of dairy cows. Cows were individually fed one of four diets with a different protein concentrate source during each 28-day period, including: soybean meal (SBM), high-protein corn product (HPCP), soybean meal with rumen-bypass soy protein (SBMBP), and canola meal with rumen-bypass soy protein (CANBP). As SBMBP and CANBP increased yield compared with SBM, but HPCP decreased milk yield compared to all treatments. HPCP decreased apparent total tract CP digestibility, leading to less urine nitrogen excretion and greater fecal nitrogen output. The HPCP diet reduced milk yield, milk component yields, urine nitrogen excretion, and increased fecal nitrogen excretion due to lesser total tract CP digestibility

Introduction

Experimental Procedures

Results and Discussion

Conclusions