Heterosis for meat quality and fatty acid profiles in crosses among Bos indicus and Bos taurus finished on pasture or grain

Abstract

Physicochemical properties and fatty acid profiles of meat from Bos indicus, Bos taurus and crossbred B. taurus×B. indicus bullocks (n=216), finished on pasture or grain, were used to estimate the effects of heterosis. Meat quality and fatty acid profiles generally benefited with crossbreeding, but the advantages from heterosis differed among finishing systems. The Warner-Bratzler shear-force in fresh and aged meat was reduced due to heterosis in pasture-finishing, but the effect was minor under grain-finishing. With pasture-finishing, heterosis caused an increase of 5% in CLA concentration, but few other changes in fatty acid profiles. In grain-finishing, heterosis caused a reduction in intramuscular fat and cholesterol, increased amounts of PUFA, n-6 fatty acids and PUFA/SFA ratio, and a decline in atherogenic index. The Δ(9) desaturase estimated activity in crossbreds showed a behavior close to B. indicus, suggesting the existence of few loci and a dominance genetic effect on enzymes involved in fatty acid synthesis and metabolism.

Incomplete Dominance of Deleterious Alleles Contributes Substantially to Trait Variation and Heterosis in Maize

“…We observed substantial heterosis for a number of traits in our diallel (Fig 1), including high levels of heterosis for grain yield consistent with reports in other maize diallel populations [70]. Heterosis has been observed across many species, from yeast [71] to plants [72] and vertebrates [73], and a number of hypotheses have been put forth to explain the phenomenon [11,21]. Of all these explanations, complementation of recessive deleterious alleles [12,21] remains the simplest genetic explanation and is supported by considerable empirical evidence [22,23,74].…”

Differences in intramuscular fatty acid profiles amongBos indicusand crossbredBos taurus × Bos indicusbulls finished on pasture or with concentrate feed in Brazil

“…The impact of finishing system and breed on FA profiles of cattle meat has been investigated by various authors (French et al 2000;Garcia et al 2008;Gatellier et al 2005;Rossato et al 2010), and there are indications that important interactions exist between the two factors (Nuernberg et al 2005), such that B. indicus cattle tend to accumulate higher amounts of SFA than B. taurus, especially when they are finished intensively (Bressan et al 2011). On the other hand, heterosis for FA profiles has been shown to exist in crosses between B. taurus and B. indicus, but it also depends on the finishing system considered (Gama et al 2013). These results indicate that dealing with genotype  environment interactions for FA profiles is an important but unresolved issue.…”

“…On the other hand, genetic effects play an important role in fatty acid profiles of ruminant tissues and products (Pitchford et al 2002;De Smet et al 2004), e.g. by influencing the activity of enzymes involved in lipid metabolism, including elongase, D 9 desaturase and D 6 , D 5 and D 4 desaturase (Oosterveer et al 2009;Gama et al 2013;Gruffat et al 2013). Also, cattle breeds with lower levels of IMF are expected to produce meat with a higher amount of PUFA, given the negative association of these two variables .…”

Nellore meat quality and genomics

“…Identified fatty acids (Table 1) shows high variability concentration among those previously reported for Nellore breed or crossbreed animals (ANDRADE et al, 2014;GAMA et al, 2013;PADRE et al, 2006;SAN VITO et al, 2015). However, palmitic (C16:0), stearic (C18:0) and oleic (C18:1 cis-9) fatty acids, that account for more than 70% of all beef lipid composition, presented high degree of consistency among those results.…”

“…Several factors appear to influence the quantity, quality and lipid distribution in both animals and its byproducts, such as age, weight, sex, breed, genetics, nutritional status and castration, as well as external factors such as temperature, feeding (ALFAIA et al, 2006;KOUBA;MOUROT, 2011), animal handling and finishing systems (GAMA et al, 2013;RAES et al, 2003). Nevertheless, ruminants feed type has low effect over some fat components, since polyunsaturated fatty acids obtained through diet are partially or at some extent entirely, bio-hydrogenated in the rumen (ENSER et al, 1996;KOUBA;MOUROT, 2011;PADRE et al, 2006).…”