OMASAL MORPHOLOGY OF DAIRY COWS FED WITH HIGH OR LOW GRAIN CONTENT DIET PRIOR PARTURITION

Danilo De Oliveira Rocha Bhering Santoro,João Luiz Pratti Daniel,Suely De Fátima Costa,João Chrysostomo Resende Júnior,Matheus Balduíno Moreira,Ronaldo Francisco De Lima

doi:10.1590/s1413-70542015000600005

Abstract

ABSTRACT Little is known about the morphological response of the omasum in dairy cows that consume a high-energy diet pre-partum. The aim of this study was to investigate whether a transitional diet with high grain content is able to induce changes in omasum morphology. Six weeks before the expected calving, four Holstein cows were fed a standardization diet, and four weeks before delivery, the cows were fed a diet with high grain content (HGC) or low (LGC) grain content. After calving, all of the cows were fed a high energy lactation diet. The cows that were fed the HGC diet pre-partum had higher dry matter and nutrient intake than the cows that were fed the LGC diet. The mitotic index of the omasum epithelium was higher than the mitotic index in the rumen, but apparently the response to the diet stimuli was slower. In the cows that were fed the HGC diet, the omasum papillae were taller one week before parturition and two weeks post-partum. Cows that were fed the HGC diet had a thinner epithelium due to thinner non-keratinized layers of the omasum epithelium. We conclude that the omasum mucosa of dairy cows responds to the stimuli of a pre-partum HGC diet, which was indicated by the greater height of the omasum papillae and by the reduced thickness of the omasum epithelium. It seems that the mitotic index responds a little more slowly, but the response to the diet stimuli is stronger in the omasum epithelium than in the rumen.

Highlights

In dairy cows, metabolic disturbances are common during the period between three weeks before and three weeks after parturition and achieving productive performance potential becomes difficult (Grummer, 1995)
These dairy cows receive a high calorie lactation diet after calving. These diets are rich in carbohydrates that are quickly fermentable in the reticulorumen and lead to rapid production of volatile fatty acids (VFAs)
Higher DMI/kg of body weight (DMIBW) led to higher intake of all nutrients/kg of body weight by the cows that were fed the high grain content (HGC) diet pre-partum compared to cows that were fed the low grain content (LGC) diet, which supports the theory of better health for those animals (Table 2)

Summary

Introduction

Metabolic disturbances are common during the period between three weeks before and three weeks after parturition and achieving productive performance potential becomes difficult (Grummer, 1995). Increasing the grain content of the diet during the last three weeks of gestation in highly productive dairy cows as a way to prepare them for lactation has been accepted for more than eighty years. These dairy cows receive a high calorie lactation diet after calving. These diets are rich in carbohydrates that are quickly fermentable in the reticulorumen and lead to rapid production of volatile fatty acids (VFAs). Agrotec., Lavras, v. 39, n. 6, p. 583-592, nov./dez., 2015

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