Ruminal kinetics and degradability of energetic feedstuffs used in diets for ruminants

Mikael Neumann,Bruno José Venancio,Fernando Braga Cristo,Leslei Caroline Santos,Eloize Jaqueline Askel,Giovanna Bobato Pontarolo,Emylli Pereira E Silva,Daniel Corrêa Plodoviski

doi:10.1590/1809-6891v22e-68993

Abstract

Abstract This study aimed to evaluate energetic feedstuffs regarding chemical composition, in situ ruminal degradability of dry matter (DMD), ruminal kinetics and ruminal disappearance rate of dry matter. Seven feedstuffs (treatments) were evaluated: ground corn, ground oat, ground barley, wheat bran, soybean hull, malt root and corn germ, in a completely randomized design of four repetitions each. Two bovines ruminally cannulated were used for incubation, wherein each treatment was subjected to seven periods of exposure to the rumen (0, 3, 6, 9, 12, 18 and 24 hours). Among the evaluated feedstuffs, soybean hull had the highest neutral detergent fiber (NDF) content (68.91%) and the lowest DMD at 24 h (64.91%). Ground barley and ground corn contained the lowest content of soluble fraction (SF) (26.34 and 28.7%, respectively), among which ground barley had the highest DMD at 24 h (90.48%) and therefore showed the highest rumen disappearance rate (2.50%.h-1) by combining both parameters, while the ground oat presented the highest SF (47.75%) and the lowest rumen disappearance rate (1.09%.h-1).

Highlights

In ruminant nutrition, the mixture of feedstuffs that favor the synchronicity of carbohydrate and protein degradation in the rumen maximizes microbial efficiency, decreases nitrogen losses as ammonia and carbohydrate energy losses, and this represents the maximization of the use of nutrients and animal performance[1]
This study aimed to evaluate the rates of ruminal degradation of energy feedstuffs and tested the hypothesis that cereal grains have greater ruminal degradability at 24 hours when compared to industrial derivatives
Cereal grains have the lowest content of neutral detergent fiber (NDF) (Table 1) and the highest content of non-fiber carbohydrates (NFC) and, are used to increase the energy and starch content of diets

Summary

Introduction

The mixture of feedstuffs that favor the synchronicity of carbohydrate and protein degradation in the rumen maximizes microbial efficiency, decreases nitrogen losses as ammonia and carbohydrate energy losses, and this represents the maximization of the use of nutrients and animal performance[1]. Availability and degradability of nutrients can be determined using in situ, in vitro and in vivo techniques[3]. The nylon bag ruminal incubation technique (in situ)(4) is the most frequently used to determine the ruminal degradability of components such as dry matter and crude protein, and is used as a reference method for evaluating ruminal degradation of feedstuffs[5]. Starch is an important energy source for microbial growth, but in some situations it is desirable to control the inclusion and ruminal digestibility of starch[6]

Objectives

Methods

Results

Conclusion