Silage-concentrate finishing of bulls versus silage or fresh forage finishing of steers: Effects on fatty acids and meat tenderness

Abstract

The objective of this trial was to assess meat quality in terms of tenderness and fatty acid (FA) composition in M. longissimus dorsi and M. gluteus medius from bulls finished on ad lib silage-concentrates (SIL:CON) vs. steers fed ad lib silage (FF) or restricted silage and unrestricted grazing (RES-F). Warner-Brazler shear force value day 1 was lowest for the FF steers (pB0.05). Myofibril fragmentation index (MFI) values were similar after seven days of ageing, showing that ageing compensated for differences in meat tenderness associated with feeding programmes. Total monounsaturated FAs and 18:1c-9 levels were higher in the steer tissue (pB0.001). The SIL:CON bulls had higher polyunsaturated n-6 fatty acids and 18:2n-6 level (pB0.001). Polar lipid 18:2n-6 and n-6 levels were higher for FF than for RES-F steers, whereas the 18:3n-3 level was higher for RES-F than for FF steers (p B0.001). The n-6/n-3 ratio was lowest for the FF steers and highest for the SIL:CON bulls (pB0.001).

Fatty acid profile and intramuscular fat concentration ofMusculus longissimus thoracisin bulls fed grass silage harvested at one of three maturity stages, either with or without concentrate supplementation

“…The n-6/n-3 ratio at the C18 chain length was at the same level as found by Moloney et al (2013) in heifers finished at a similar diet, and the total n-6/n-3 ratio over all chain lengths (C18, C20 and C22) were at the same low level as found for pasture-derived label beef of calves, heifers and steers by Razminowicz et al (2006) and in forage-fed steers by Turner et al (2011). Significantly lower proportions of long-chain n-6 PUFA (P = 0.03), as well as long-chain n-3 PUFA (P = 0.01), with increasing IMF on muscle basis might be caused by the higher phospholipid proportions in IMF in leaner bulls (Wood et al, 2008).…”

Nutritional Indices for Assessing Fatty Acids: A Mini-Review

“…The results are shown in Table 1. [27][28][29], crops [30,31], plant oil [32,33], shellfish [34], fish [34][35][36][37][38][39][40], meat [41][42][43][44][45][46][47][48][49][50][51][52][53], and dairy products [54][55][56][57] 2 IA Index of atherogenicity [C12:0 + (4 × C14:0) + C16:0]/ΣUFA Seaweeds [27][28][29]58,59], crops [30,31,60,61], plant oil [33,62], shellfish [63], shrimp [64], fish [36][37][38][39][65]…”

Effects of dietary total non-structural carbohydrates and folic acid and vitamin B12 supplement on growth and meat quality of yearling steers in a forage-based beef production system

“…The carcasses lost on average 1.7% water during the 48 h of refrigeration, but no difference in chilling losses was found between treatments (P 0.10; Table 3). Turner et al (2011) reported no difference in final liveweight of steers fed barley supplements as a TNC source during the finishing period as opposed to steers finished on a silage diet. However, unlike the present study, Turner et al (2011) observed a difference in carcass yield, possibly due to the age at slaughter, which differed between the two studies (approximately 1 vs. 2 yr old).…”

“…Turner et al (2011) reported no difference in final liveweight of steers fed barley supplements as a TNC source during the finishing period as opposed to steers finished on a silage diet. However, unlike the present study, Turner et al (2011) observed a difference in carcass yield, possibly due to the age at slaughter, which differed between the two studies (approximately 1 vs. 2 yr old). Nevertheless, as far as the carcass cuts (LT and ST) weight is concerned, the present results are in agreement with those of del Campo et al (2008), who reported no differences in striploin, tenderloin and rump weights for steers fed either pasture or pasture and corn as a source of TNC.…”