Determining Nutritive Values of Alfalfa Cuts Using in situ and Gas Production Techniques

Taghizadeh Taghizadeh

doi:10.3844/ajavsp.2008.85.89

Abstract

In order to determine of nutritive value of alfalfa in different cuts using in situ and gas production technique, this study was carried out. Three wethers (49Â±2.6 kg) were used in in situ method. The gas production was measured at 2,4,6,8,12,16,24,36,48,72 and 96 h and ruminal dry matter and crude protein disappearance were measured at 0,4,8,12,16,24,36,48,72 and 96 h. Dry matter degradability’s in first, second and third cuts of alfalfa at 96 h were 60.47, 64.71 and 64.36%, respectively. Crude protein degradability’s of mentioned cuts were 60.47, 63.08 and 58.07%, respectively. The gas productions of them at 96 h were 322.54, 295.21 and 300.32 mL gâ1 DM respectively. The relationship between dry matter and gas production values for alfalfa cuts obtained about 0.89, 0.85 and 0.84 and for crude protein and gas production data achieved 0.87, 0.88 and 0.84, respectively. High correlation between in situ and gas production techniques indicated that in situ degradability’s values can be predicted from gas production data.

Highlights

Balancing rations for ruminants requires knowledge of the proportion of feed protein that escapes ruminal degradation[25]
The Dacron polyester or nylon bag technique has been used widely for estimating ruminal nutrient degradation because it is a relatively simple, low-cost method compared with methods in volving intestinally annulated animal[19]
Nylon-bag technique provides a useful means to estimate rates of disappearance and potential degradability of feedstuffs and feed constituents[30].The in vitro gas production system helps to better quantify nutrient utilization and its accuracy in describing digestibility in animals has been validated in numerous experiments

Summary

Introduction

Balancing rations for ruminants requires knowledge of the proportion of feed protein that escapes ruminal degradation[25]. Fermentation characteristics of feedstuffs in rumen fluid can be studied using in vivo, in situ and in vitro techniques[7]. The Dacron polyester or nylon bag technique has been used widely for estimating ruminal nutrient degradation because it is a relatively simple, low-cost method compared with methods in volving intestinally annulated animal[19]. The in situ nylon-bag technique is widely used to characterize the disappearance of feeds from the rumen. Nylon-bag technique provides a useful means to estimate rates of disappearance and potential degradability of feedstuffs and feed constituents[30].The in vitro gas production system helps to better quantify nutrient utilization and its accuracy in describing digestibility in animals has been validated in numerous experiments. Ruminants require adequate dietary fiber intake for normal rumen function and dairy animals, in particular, need fiber to maintain a normal milk fat content[32].Primary factors in the conversion of forage to animal product are intake of dry matter (DMI) or energy (IE), digestibility, efficiency of converting digested energy to metabolizable energy and efficiency of converting metabolizable energy to net energy in animal product[39]

Objectives

Methods

Results