Characteristics of steers of six beef breeds fattened from eight months of age and slaughtered at a target level of intramuscular fat – I. Growth Performance and carcass quality

Abstract

SummaryGrowth Performance and carcass quality of 132 steers originating from six beef breeds, Angus (AN), Simmental (SI), Charolais (CH), Limousin (LI), Blonde d'Aquitaine (BL), and Piedmontese (PI), fattened under the same conditions on the same diet, were compared at a target level of 3.5 % intramuscular fat (IMF) in the M. longissimus dorsi. This target level was set on basis ofthe results ofa preliminary study investigating, with 784 persons, the Visual preference of marbling using photographs. The total mix ration, provided at ad libitum access, consisted of maize silage, grass silage and concentrate (52 %, 26 % and 22 % of DM, resp.). Series 1 was performed in a tie-stall bam while a loose-housing system with straw bedding was used in series 2. The animals were assigned to slaughter either when the target IMF content was reached aecording to the estimation with a real-time ultrasound system applied in the live animals or when 15 months of fattening had passed. AN, SI, CH and LI reached 3.5 % IMF on average at final weights of 501 ± 43, 628 ± 60, 693 ± 117 and 668 ± 65 kg, respectively. BL and PI did not reach this target, although the average fattening period was about three times longer for BL and PI than for AN and the final weights were 758 ± 93 and 647 ± 64 kg, respectively. Under the conditions of this experimental approach, daily gains were highest in AN, followed by CH, SI, LI and BL and lowest in PI. The daily feed intake was significantly lower for PI than for CH, SI and AN. The AN expressed the best feed conversion efficiency in terms of DM expenditure per kg gain over the complete fattening period while this efficiency was lowest in the PI group followed by BL. Among the four breeds, which reached the target IMF content, LI steers showed the greatest proportion of premium cuts and the highest lean to fat and lean to bone ratio in the sirloin, followed, in descending order, by CH, SI and AN. However all four groups were graded around 4 in fatness score (high to very high). The present results revealed for all breeds the difficulty to reach the desired extent of marbling and at the same time favourable carcass conformation, carcass size (except AN) and fat cover which meet market demands.

Effect of breed on growth performance and carcass composition of Aberdeen Angus, Charolais,Herefordand Simmental bulls

“…On the contrary, medium framed HE steers gained more than large framed SI steers when fed to a common backfat endpoint presumably due to a shorter time on feed and higher efficiency for maintenance and gain (Mandell et al, 1998). Similarly, Chambaz et al (2001) reported higher gains of AA compared to SI and CH slaughtered at a common target level of intramuscular fat also probably resulting from lower age at slaughter and days of fattening in AA.…”

“…Hereford gained more rapidly and more efficiently in this study while Simmental had heavier and leaner carcasses. Growth performance and carcass quality of steers from six beef breeds were compared at a target level of 3.5% intramuscular fat by Chambaz et al (2001).…”

Slaughter and carcass characteristics, chemical composition and physical properties of <i>longissimus lumborum</i> muscle of heifers as related to marbling class

“…In turn, IMF is the chemically estimated fat content of meat; the terms marbling and IMF are commonly used alternatively. This characteristic presents considerable variability both between (Chambaz et al, 2001;Šurbt et al, 2006) and within breed populations (Węglarz, 2010a) and among muscle types depending on their anatomy and the physiological role played (Rhee et al, 2004, Searls et al, 2005.…”

Growth curve analysis for body weight and dry matter intake in Friesian, Limousin x Friesian and Piemontese x Friesian cattle

“…Although there are several reports on growth curve parameters of cattle related to live weight of animal, there have been few reports on curve parameters related to feed intake. However, CHAMBAZ et al (2001) andGOYACHE et al (2003) suggest that considering only the BW of animal seems to be highly controversial to discuss improved biological efficiency. A genotype with high growth rate may not necessarily provide an improvement in biological efficiency over a slower growing animal with the same mature size.…”

“…In Turkey, meat producers prefer rapid maturing beef breeds for crossing on dairy cows in beef production. As well known, rapid growth until slaughter weight is an important goal for increased meat production (CARRIJO and DUARTE, 1999;CHAMBAZ et al, 2001). However, a genotype with high growth rate may not necessarily provide an improvement in biological efficiency (lean tissue produced / food consumed) over a slower growing animal with the same mature size, as it may have higher feed intake at maturity than the slower growing animal .…”