Effects of different lipid levels on protozoa population, microbial protein synthesis and rumen degradability in cattle

Juliana Duarte Messana,Roberta Carrilho Canesin,Andressa Ferreira Ribeiro,Telma Teresinha Berchielli,Giovani Fiorentini,Pedro Braga Arcuri

doi:10.4025/actascianimsci.v34i3.12729

Abstract

Protozoa population, microbial synthesis efficiency and rumen degradability of dry matter and neutral detergent fiber in cattle fed on diets with different lipid rates were evaluated. Nine 16-month- old Nelore young bulls, cannulated in the rumen and duodenum, weighing 232 ± 35 kg, were used in the trial. Experimental design consisted of a 3 x 3 square in triplicate, comprising the following treatments: 2, 4 and 6% lipid in diet. In situ degradability was assessed by rumen incubation of corn silage, soybean, soybean meal and citrus pulp during 0, 3, 6, 12, 24, 48, 72 and 96h. The flow of microbial nitrogen and microbial efficiency were not influenced (p > 0.05) by the inclusion of lipid levels in the diet. When the animals received diet with 4% lipid, there was a reduction (p < 0.05) in the potential and effective degradation of dry matter of corn silage (64.10 and 55.04%, respectively), soybean meal (94.55 and 60.83%, respectively) and soybeans (98.45 and 76.44%, respectively). Since the degradability of neutral detergent fiber was not affected, 4 and 6% lipid levels in the diet may be used without altering the parameters of rumen degradation of fiber.

Highlights

Lipid supplementation in the diet has become a promising strategy to increase the efficiency in animal production by an increase in the diet’s energetic density (HESS et al, 2008)
An increase in the number of gram negative bacteria and a decrease in ammonia concentration occur (JOUANY, 1996), with a possible increase in the flow rate of rumen solids (CZERKAWSKI et al, 1975). These effects contribute towards an increase in the efficiency of microbial protein synthesis when lipids are supplemented for ruminants (DOREAU; FERLAY, 1995)
High coefficients of variation (CV) in the experiment are intrinsic to the method used (DEHORITY et al, 1989) since growth has not been reported in some counts, whereas a relatively large number of protozoa was observed in others (ORPIN, 1984)

Summary

Introduction

Lipid supplementation in the diet has become a promising strategy to increase the efficiency in animal production by an increase in the diet’s energetic density (HESS et al, 2008). An increase in the number of gram negative bacteria and a decrease in ammonia concentration occur (JOUANY, 1996), with a possible increase in the flow rate of rumen solids (CZERKAWSKI et al, 1975). These effects contribute towards an increase in the efficiency of microbial protein synthesis when lipids are supplemented for ruminants (DOREAU; FERLAY, 1995). Diets with higher rates of ether extract are evaluated with regard to rumen protozoa, microbial protein synthesis and diet degradability

Material and methods

Results and discussion

Conclusion