Effects of a specific blend of essential oils on apparent nutrient digestion, rumen fermentation and rumen microbial populations in sheep fed a 50:50 alfalfa hay:concentrate diet.

N Khateri,O Azizi,H Jahani-Azizabadi

doi:10.5713/ajas.15.0865

N Khateri, O Azizi + Show 1 more

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https://doi.org/10.5713/ajas.15.0865

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Abstract

ObjectiveAn experiment was conducted to investigate the effects of a specific mixture of essential oils (MEO), containing thyme, clove and cinnamon EO, on rumen microbial fermentation, nutrient apparent digestibility and blood metabolites in fistulated sheep.MethodsSix sheep fitted with ruminal fistulas were used in a repeated measurement design with two 24-d periods to investigate the effect of adding MEO at 0 (control), 0.8, and 1.6 mL/d on apparent nutrient digestibility, rumen fermentation characteristics, rumen microbial population and blood chemical metabolites. Animals were fed with a 50:50 alfalfa hay:concentrate diet.ResultsRuminal pH, total volatile fatty acids (VFA) concentration, molar proportion of individual VFA, acetate: propionate ratio and methane production were not affected with MEO. Relative to the control, Small peptides plus amino acid nitrogen and large peptides nitrogen concentration in rumen fluid were not affected with MEO supplementation; while, rumen fluid ammonia nitrogen concentration at 0 and 6 h after morning feeding in sheep fed with 1.6 mL/d of MEO was lower (p<0.05) compared to the control and 0.8 mL/d of MEO. At 0 h after morning feeding, ammonia nitrogen concentration was higher (p<0.05) in sheep fed 0.8 mL/d of MEO relative to 1.6 mL/d and control diet. Ruminal protozoa and hyper ammonia producing (HAP) bacteria counts were not affected by addition of MEO in the diet. Relative to the control, no changes were observed in the red and white blood cells, hemoglobin, hematocrit, glucose, beta-hydroxybutyric acid, cholesterol, total protein, albumin, blood urea nitrogen and aspartate aminotransferase and alanine aminotransferase concentration. Apparent total tract digestibility of dry matter, crude proten, organic matter, and neutral detergent fiber were not influenced by MEO supplementation.ConclusionThe results of the present study suggested that supplementation of MEO may have limited effects on apparent nutrient digestibility, ruminal fermentation and protozoa and HAP bacteria count, blood cells and metabolites.

Highlights

In response to the rising concern about the use of growth promoter antibiotics in animal pro duction systems due to an increase in the probability of antibiotic resistance, the use of growth promoting antibiotics in animal production is banned in most developed countries [1]
The results of the present study showed that ruminal protozoa and hyper ammonia producing (HAP) bacteria counts were not affected by addition of mixture of essential oils (EO) (MEO) in the diet (Table 7)
MEO, mixture of essential oils (50% thyme, 30% cinnamon, and 20% clove); SEM, standard error of mean; RBC, red blood cells; NS, non significant; white blood cells (WBC), White blood cells; HGB, hemoglobin; * significant

Summary

Introduction

In response to the rising concern about the use of growth promoter antibiotics in animal pro duction systems due to an increase in the probability of antibiotic resistance, the use of growth promoting antibiotics in animal production is banned in most developed countries [1]. From wide investi gation of plant EO, the results from clove, cinnamon and thyme EO were more favorable, due to their valuable effects on rumen fermentation such as decrease in methane emissions and ammonia nitrogen (N) concentration and an increase in propionate to acetate ratio [10,11,12,13,14]. The aim of the present study was to investigate the effects of a specific mixture of EO (MEO), containing thyme, clove and cinnamon essential oils, on rumen microbial fermentation and nutrient apparent digest ibility of a 50:50 forage:concentrate diet and blood metabolites in fistulated sheep

Methods

Results

Conclusion