Effects of pasture and high‐concentrate diets on the performance of beef cattle, carcass composition at equal growth rates, and the fatty acid composition of beef

Abstract

Two experiments were carried out to examine the effects of high quality pasture and high-concentrate diets on liveweight and carcass gain of beef cattle, carcass composition at equal carcass gain, and the fatty acid composition of beef. Heifers of late-maturing breed type (406 kg initial liveweight; Experiment 1) and steers of latematuring breed type (460 kg initial liveweight; Experiment 2) were finished on a ryegrass pasture or a high-concentrate diet at either (1) ad libitum, (2) 85% of ad libitum intake or (3) 70% of ad libitum intake. The high-concentrate diet consisted of 95% barley-based concentrate and 5% barley straw. Carcass gain of the animals finished at pasture (648 g day -1 ) was 0.78 in Experiment 1 (P < 0.001) and 0.88 in Experiment 2 (P > 0.1) of that of the animals given the high-concentrate diet ad libitum. Gains in lean meat were similar for animals finished at pasture and those given concentrates ad libitum, whereas daily fat gains were 39% lower for the animals finished at pasture (P < 0.001). At an equal rate of carcass gain, animals finished at pasture produced carcasses with a higher lean content (P = 0.03) and a lower fat content (P = 0.03) than those produced from the high-concentrate diet. Muscle from pasture-finished cattle had higher concentrations of omega-3 polyunsaturated fatty acids (PUFA) (141 versus 49 ± 8.2 mg 100 g -1 muscle) and long-chain omega-3 PUFA (58 versus 27 ± 3.8 mg 100 g -1 muscle) than muscle from concentrate-fed cattle. These results highlight the potential of high quality ryegrass pasture for finishing cattle, and meat from pasturefinished cattle as a source of omega-3 PUFA.

Fattening heifers on continuous pasture in mountainous regions - implications for productivity and meat quality

“…Throughout the whole experiment, the average daily gain (ADG) of the Pasture and Indoor heifers was 1000 g/day ( Table 2). The ADG was high and in accordance with the results of Schwarz et al (1998), Steen et al (2003), Noci et al (2005), Keane andMoloney (2009), andVelik et al (2013) for semi-intensive beef fattening systems. Noci et al (2005) fed Charolais crossbred heifers on a perennial ryegrass sward without concentrates for five months prior to slaughter and found an ADG of 996 g/day.…”

“…Within the last decade, several studies have examined the suitability of heifers and steers for low input grassland-based fattening systems and have found contradictory results concerning animal performance and product quality (French et al, 2000b;Steen et al, 2003;Realini et al, 2004;Sami et al, 2004;Noci et al, 2005;Nürnberg et al, 2005;Razminowicz et al, 2006;Keane and Moloney, 2009). Yet, the literature reporting experiments in less favoured agricultural areas such as mountainous regions is limited.…”

Carcass- and meat quality of pasture &lt;i&gt;vs&lt;/i&gt; concentrate fed German Simmental and German Holstein bulls

“…Forages such as grass and wilted silage contain a high proportion of linolenic acid (C18:3n-3), typically 50 -75 %, in the lipids. Despite the biohydrogenation of C18:3n-3 in the rumen, the linolenic acid was deposited at higher concentrations in muscle of bulls on the grass-based diet (FRENCH et al, 2001;SCOLLAN et al, 2003;STEEN et al, 2003). Pasture feeding resulted in a significant increase in the concentration of n-3 fatty acids up to a factor of 2.8 in longissimus muscle of German Holstein and German Simmental bulls compared with the concentrate feeding system (Table 4).…”

“…Animal production practices, particularly the nutrient composition of the diet, can change the carcass-and meat quality, and fatty acid profile of meat (KREUTZER et al, 1995;LEIBETSEDER, 1996;FRENCH et al, 2001;REICHARDT et al, 2002;SCOLLAN et al, 2003;RAES et al, 2003;STOCKDALE et al, 2003;DEWHURST et al, 2003;DANNENBERGER et al, 2004;HOLLO et al, 2005;. Grass feeding has been reported to affect several meat quality characteristics of beef, in particular colour, flavour and fatty acid composition compared to concentrate diet systems PRIOLO et al, 2001;REICHARDT et al, 2002;STEEN et al, 2003;WOOD et al, 2003;VARELA et al, 2004;REALINI et al, 2004;KNOWLES et al, 2004;HOLLO et al, 2004;NUERNBERG et al, 2005). A pasture-based feeding system, including fresh and conserved forages and also occasional dietary supplements, leads to improved nutritional quality of meat from cattle to the consumers (KNOWLES et al, 2004).…”

“…A pasture-based feeding system, including fresh and conserved forages and also occasional dietary supplements, leads to improved nutritional quality of meat from cattle to the consumers (KNOWLES et al, 2004). Pasture feeding and diets containing proportionally high level of linolenic acid in the fat, such as fresh grass and grass silage resulted in increased deposition of n-3 fatty acids in the muscles (FRENCH et al, 2001;SCOLLAN et al, 2003;STEEN et al, 2003;DANNENBERGER et al, 2004;NUERNBERG et al, 2005). The objective of this study was to investigate the effect of different cattle breeds and different keeping systems to improve the meat quality for the consumer and enhance the contents of beneficial fatty acids in beef.…”