Effects on animal performance and fat composition of two fat concentrates in diets for growing-fattening bulls

Abstract

Two experiments were carried out with growing-fattening bulls, offered a fattening diet based on concentrate and supplemented with soya oil or steam-flaked linseed. Soya oil (200 g/kg) was mixed with middlings (800 g/kg). Linseed (500 g/kg) and whole barley (500 g/kg) were steam flaked. The fat incorporation resulted in an increase of the ether extract content from 26·5 g/kg dry matter to about 45 g/kg. The incorporation of soya oil increased the average daily gain (P> 0·05). The saturated: unsaturated fatty acid ratio was reduced in perirenal fat due to an increase of oleic acid and a reduction of stearic acid. The inclusion of steam-treated linseed resulted in a lower slaughter weight (P< 0·05) and a shorter fattening period (P> 0·05). The fatty acid composition of perirenal fat was affected significantly: the concentrations of oleic, linoleic and linolenic acid were increased and the concentrations of myristic, palmitic and stearic acids were reduced. This resulted in a reduced saturated: unsaturated fatty acid ratio.In a third experiment, samples of the two fat concentrates were incubated in nylon bags in the rumen. The ether extract disappearance was high with both concentrates. Furthermore, the fatty acid composition was altered to a large extent for soya oil while large proportions of unsaturated fatty acids were still present with steam-flaked linseed.

Meat fatty acid composition as affected by fatness and genetic factors: a review

“…The lean nature of Belgian Blue meat and the accompanying high P/S ratio in the intramuscular fat has been shown in several studies [9,10,12,13,90]. In addition to the high ratio of phospholipids to triacylglycerols contributing to the high P/S ratio, the PUFA content of the phospholipid fraction also seems to be higher in double-muscled animals compared to other literature data (Tab.…”

Correlation between carcass conformation and fat cover degree, and muscle fatty acid profile of yearling bulls depending on breed and mh-genotype

“…In this sense, the better muscle development and carcass conformation were, the lower fat content was, being also reflected in the muscle FA composition (Raes et al, 2003;De Smet et al, 2004). Animal carcass conformation was positively correlated with unsaturated groups (PUFA, n-6, n-3, UFA), and negatively with SFA and MUFA as reported by Clinquart et al (1991Clinquart et al ( , 1994. While degree of fat cover showed positive correlations with SFA and MUFA, and negative correlations with unsaturated groups (PUFA, n-6, n-3, UFA), also found by Lo Fiego et al (2005) in pigs from different genotypes and Kosulwat et al (2003) in lambs from different carcass classification scores.…”

Meat lipids

“…93 The effectiveness of rumen hydrogenation depends upon the nature of the feed. Steam-flaked linseed allowed more linolenic acid to escape rumen hydrogenation in bulls than occurs when free oil or more processed seeds are used 94 but only increased the proportion in perirenal fat from 1.9 to 4.1. If, on the other hand, the rumen is functionally bypassed with protected lipid 95 or by use of the oesophageal groove reflex,96 dietary polyunsaturated fatty acids are readily incorporated into the tissues, as in non-ruminants.…”