Effect of starch content in the diet of lactating cows fed corn silage with high levels of indigestible neutral detergent fiber (iNDF).

Abstract

Indigestible Neutral Detergent Fiber (iNDF) is composed of cellulose and hemicellulose fractions bound to lignin. The iNDF content of the diet affects dry matter intake, nutrient digestion, and productive performance of lactating cows. Similarly, the starch concentration in diets influences nutrient intake and digestion, potentially affecting the productive performance of lactating cows. Recently, we evaluated the impact of different iNDF levels in the diet of dairy cows and observed that corn silage in Brazil has iNDF concentrations 60 to 100% higher than in temperate climate countries. Thus, intake, nutrient digestion, and productive performance are positively affected when silage with lower iNDF content is offered to lactating cows. Several studies have analyzed the interaction between starch and fiber in dairy cow diets, but they used corn silage and forages with iNDF levels different from those common in Brazil. The recommendations for starch inclusion in lactating cow diets from temperate countries may not reflect the reality of Brazilian farms. So far, there are no recommendations in the literature for diets with high iNDF corn silage in Brazil. In this research project, an experiment will be conducted to evaluate the effect of starch content in the diet of lactating cows fed with high iNDF corn silage on aspects of nutrient intake and digestibility, as well as the performance of lactating cows. The hypothesis of this project is that higher starch content in diets with high iNDF increases nutrient intake, positively influencing the productive performance of lactating cows.