Effect of corn supplementation of grass finishing of Holstein bulls on fatty acid composition of meat lipids1

Abstract

Finishing Holstein young bulls exclusively on pasture generally results in very lean carcass and meat, but corn supplementation is expected to simultaneously improve carcass traits and intramuscular lipids (IML). The expected increase in IML would allow for a larger 18:2c9,t11 (CLA) deposition in meat without affecting the n-3 PUFA present in LM phospholipids (PL). Holstein bulls (n = 33) with initial BW of 423 ± 52.4 kg reared exclusively on pasture were assigned to 1 of 3 finishing period (85 d) diets: finished exclusively on pasture (P0) or finished on pasture and individually supplemented with 4 (P4) or 8 kg/d (P8) of ground corn. Final BW (546 ± 56.3 kg) was not affected (P> 0.05) by corn supplementation, but ADG increased (P < 0.01) with the increasing corn supplementation level from 1.23 kg/d for P0 to 1.44 kg/d for P4 and to 1.67 kg/d for P8. Subcutaneous fat depth in P0 bulls was 0.8 mm and increased (P < 0.001) in both P4 (2.9 mm) and P8 (2.7 mm) bulls, but no difference (P = 0.73) was observed between P4 and P8 bulls. Similarly, the IML increased with corn supplementation, from 1.84 g/100 g muscle in P0 to 2.96 in P4 and to 3.24 in P8, but no difference (P = 0.55) was found between P4 and P8 bulls. Corn supplementation decreased (P < 0.01) 18:1t11 in neutral lipids (NL) but not 18:2c9,t11 (P > 0.34). The 18:1t10 (mg/g total NL fatty acid [FA] ± SEM) were 2.5 ± 0.13 in P0, 5.5 ± 1.68 in P4, and 14.8 ± 3.18 in P8 bulls, being greater in P8 compared with P4 (P = 0.02). Total FA in muscle PL and SFA were unaffected, but increasing corn supplementation resulted (P < 0.001) in an increase of 18:2n-6 in PL by replacement of mostly the 18:1c9 and 18:3n-3. Notably, the total number of cis double bonds present in FA of PL remained constant (P = 0.74) with corn supplementation. Compared with P0, corn supplementation maintained (P > 0.05) the high n-3 PUFA content in meat (mg/100 g meat) and increased the 18:2c9,t11 (P = 0.028) and 18:1c9 (P < 0.001). However, increasing corn supplementation from 4 to 8 kg/d increased the 18:1t10 (P = 0.031) and had no effect on 18:2c9,t11. Therefore, supplementing grass-finished Holstein bulls with moderate amounts of ground corn (4 kg/d) increased carcass fat cover and IML, maintained n-3 PUFA, and increased 18:2c9,t11 content in meat, whereas greater corn supplementation (8 kg/d; P8) resulted in no further improvements.

Effect of feeding lambs with a tanniferous shrub (rockrose) and a vegetable oil blend on fatty acid composition of meat lipids

“…Consistently to this, increasing oil in the diet resulted in an extensive replacement of c9-18:1 by both 18:2n-6 and 18:3n-3. The biohydrogenation intermediates were incorporated in much less extent in PL than in NL although the same general pattern found in NL can also be recognized in PL, which confirms previous observations (Jerónimo et al, 2011;Rosa et al, 2014).…”

“…The FA composition of PL is under strong regulatory control in order to maintain the functionality of cellular membranes but even so, changing dietary PUFA supply induce an extensive remodeling of PUFA in PL (Jerónimo et al, 2011;Rosa et al, 2014). Consistently to this, increasing oil in the diet resulted in an extensive replacement of c9-18:1 by both 18:2n-6 and 18:3n-3.…”

“…The reason for that were the changes in biohydrogenation pathways, resulting in the replacement of t11-18:1 by t10-18:1 as the major biohydrogenation intermediate (hereafter t10-shift), observed when the Cistus and oil increased in the diet. The occurrence of the t10-shift has been frequently reported in ruminants fed low-forage, high-oil diets (Aldai et al, 2013) and in growing ruminants raised on pasture and supplemented with ground corn (Rosa et al, 2014). Polyunsaturated FA intake has a profound and well established effect on the accumulation of biohydrogenation intermediates in rumen and tissues (Shingfield et al, 2013;Shingfield and Wallace, 2014).…”

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

“…In general, meat from beef cattle finished on pasture has a more desirable fatty acid profile than when finishing is with grain (French et al 2000;Alfaia et al 2009;Daley et al 2010;Rossato et al 2010;Bressan et al 2011;Rosa et al 2014). 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.…”

Caracterización comercial y nutricional de la grasa subcutánea de terneros y vacas de desvieje sacrificados en la Comunidad Autónoma del País Vasco

“…Algunas investigaciones indican preferencia de substrato de la esteroil-CoA desaturasa sobre los AG sintetizados de novo, lo cual podría explicar los mayores porcentajes de 9c-18:1 en la grasa SC de los animales alimentados a base de concentrado (Collins et al, 2010). Los resultados de un estudio previo llevado a cabo por Rosa et al (2014) refuerzan esta teoría ya que se observó que, a medida que aumentaba el contenido de cereal en la ración de machos jóvenes de raza Frisona, aumentaba la proporción de 9c-18:1 y de AG trans, mientras que el contenido de los ácidos esteárico (18:0) y vaccénico (AV, 11t-18:1) disminuía. En el presente estudio, estos resultados se ven reflejados en la grasa SC procedente de los terneros (tabla II, figura 1) que posiblemente fueron cebados a base de pienso concentrado, práctica muy habitual en la producción de terneros en la CAPV.…”