Effects of Soybean Oil or Rumen Protected Conjugated Linoleic Acid Supplementation on Accumulation of Conjugated Linoleic Acid in Dairy Cows’ Milk

Wisitiporn Suksombat,Khukhuan Chullanandana

doi:10.5713/ajas.2008.80046

Abstract

The effects of feeding soybean oil (SBO) or rumen protected conjugated linoleic acid (RP-CLA) on CLA accumulation in milk, and performance of lactating dairy cows were studied. Twenty four Holstein Friesian crossbred lactating dairy cows, averaging 126±45 days in milk, 15.6±2.43 kg of milk and 452±51 kg body weight were stratified randomly and assigned in a randomized complete block design (RCBD) to three treatments of 8 cows each. The treatments were control, 150 g of SBO and 150 g of RP-CLA supplementation. Performance parameters showed that DM intake, NE LP intake and body weight change were similar across treatments, while CP intake was decreased by SBO and RP-CLA supplementation. Milk yield and milk composition were not significantly different among treatments, except for milk fat percentage and fat yield which were significantly decreased by 27% (p<0.05) and by 28% (p<0.01), respectively, by RP-CLA supplements compared with control treatment. Feeding RP-CLA reduced 3.5% FCM compared with the other treatments (p<0.003). Both SBO and RP-CLA supplementation reduced <C16:0 fatty acids but increased ≥C18:0 and CLA concentration in milk tat.

Highlights

Conjugated linoleic acids (CLA), a mixture of positional and geometric isomers of octadecadienoic acid with conjugated double bonds, have a range of potent health effects, including suppression of carcinogenesis (Ip et al, 1999; Belury, 2002; Corl et al, 2003), antiobese effect (Park et al, 1997), modulation of the immune system (Cook et al, 1993), reduction in atherosclerosis (Nicolosi et al, 1997), diabetes (Houseknecht et al, 1998) and decreased body fat mass in humans (Blankson et al, 2000; Gaullier et al, 2005)
It is accepted that CLA are intermediates in the biohydrogenation of linoleic acid, which originate from the incomplete biohydrogenation of unsaturated fat by rumen function (Bauman et al, 1999)
Chemical and fatty acid compositions of feeds used in the experiment are presented in Table 1 and 2, respectively

Summary

Introduction

Conjugated linoleic acids (CLA), a mixture of positional and geometric isomers of octadecadienoic acid with conjugated double bonds, have a range of potent health effects, including suppression of carcinogenesis (Ip et al, 1999; Belury, 2002; Corl et al, 2003), antiobese effect (Park et al, 1997), modulation of the immune system (Cook et al, 1993), reduction in atherosclerosis (Nicolosi et al, 1997), diabetes (Houseknecht et al, 1998) and decreased body fat mass in humans (Blankson et al, 2000; Gaullier et al, 2005). It is accepted that CLA are intermediates in the biohydrogenation of linoleic acid, which originate from the incomplete biohydrogenation of unsaturated fat by rumen function (Bauman et al, 1999). Research work has found that cows can synthesis CLA from trans-11 octadecadienoic acid, another intermediate in the rumen. Comparison between oils and RP-CLA supplementation in dairy cows is very limited. The aim of the present study was to compare soybean oil and RP-CLA supplementation on CLA accumulation in milk fat and performance of lactating dairy cows

Objectives

Methods

Results