Link to this article: http://journals.cambridge.org/abstract_S0003356100018973How to cite this article: A. J. Kempster, G. L. Cook and J. R. Southgate (1988). Evaluation of British Friesian, Canadian Holstein and beef breed × British Friesian steers slaughtered over a commercial range of fatness from 16-month and 24month beef production systems 2. Carcass characteristics, and rate and efciency of lean gain. Animal Production, 46, pp 365-378 ABSTRACT Carcass characteristics, and the rate and efficiency of lean gain of purebred British Friesian and Canadian Holstein steers and of crossbred steers out of British Friesian dams by Charolais, Hereford, Limousin, Lincoln Red, Simmental, South Devon and Sussex sires were examined in two beef production systems. One was similar to the commercial 18-month grass/cereal system (16-month) and the other to a commercial 2-year system (24-month). The cattle were serially slaughtered at three pre-determined fatness levels, estimated by the Scanogram ultrasonic machine. The trial extended over 4 years and involved a total of 650 cattle, 398 of which had their left sides separated into tissues. Breeds were compared at equal carcass subcutaneous fat proportion determined by visual carcass assessment (SF e ). Data for the two production systems were analysed separately.Sire breed differences were not detected in the regression on SF e for most characteristics (P > 0-05). Sire breeds differed in killing out and visual conformation score in both production systems (P < 0-001): Charolais and Limousin crosses had the highest values and purebred Canadian Holsteins the lowest. The overall range between sire breeds was 30 g carcass weight per kg live weight and five points on a 15-point conformation scale.Breeds with the higher conformation scores generally had higher carcass lean proportions and higher lean : bone ratios. Canadian Holsteins had a 20 g/kg lower carcass lean proportion than the British Friesians (P < 0-05).Breed crosses with larger adult body size tended to have higher lean tissue growth rates: the difference between mean values for Charolais crosses and Hereford crosses was 49 g/day (16-month) and 38 g/day (24-month). The lean tissue growth rates of the British Friesians and especially the Canadian Holsteins were low in relation to their adult body size.Limousin and Charolais crosses had the highest efficiency of lean gain (g lean per kg digestible organic matter intake). These and the other crosses were significantly more efficient than the purebred Canadian Holsteins (P < 0-05). The overall range between breeds was 20 g/kg.

Carcass characteristics of purebred British Friesian steers and crossbred steers by eight sire breeds out of British Friesian dams, in 16-month and 24-month beef production systems, were compared. Sire breeds included Charolais, Simmental and the main traditional British beef breeds. A total of 579 cattle were involved.The cattle were slaughtered at a fixed level of fatness and the carcasses evaluated using a standardized commercial cutting technique. Data were adjusted to equal carcass subcutaneous fat concentration.Sire breed differences were similar in both feeding systems. Charolais crosses killed-out best and Aberdeen- Angus and Devon crosses poorest; the range was 25 g/kg live weight.Significant differences were recorded between breeds in the proportion of saleable meat in the carcass (P<0·001): Charolais, Sussex and Aberdeen-Angus crosses had the highest values, on average being 15g/kg carcass weight better than purebred Friesians. Breed differences were detected in the proportion of total saleable meat occurring in the higher-priced joints, Simmental and Charolais crosses ranking highest, but the range across sire breeds was only 10 g/kg carcass weight. There were important differences between sire breeds in rate of meat weight gain that were related to mature size.Purebred Friesians were less efficient than either Charolais or Hereford crosses in converting food into meat in the 24-month system. Friesians also had the lowest efficiency and Hereford crosses the highest efficiency in the 16-month system, although the differences were not statistically significant.

Link to this article: http://journals.cambridge.org/abstract_S0003356100000635How to cite this article: J. R. Southgate, G. L. Cook and A. J. Kempster (1982). A comparison of the progeny of British Friesian dams and different sire breeds in 16-and 24-month beef production systems 1. Live-weight gain and efciency of food utilization. ABSTRACTThe live-weight gain and efficiency of food utilization of purebred British Friesian steers and of crossbred steers out of British Friesian dams by Aberdeen-Angus, Charolais, Devon, Hereford, Lincoln Red, Simmental, South Devon and Sussex sires were examined in two beef production systems. One system was similar to the commercial 18-month grass/cereal system (16-month system) and the other to a commercial 2-year system (24month system). The cattle were slaughtered at a standard level of fatness, determined by the use of the Scanogram ultrasonic machine.The trial extended over 3 years and a total of 579 cattle were involved. Data for the two production systems were analysed separately. Adjustment was made to equal age at the beginning of the test and to equal carcass subcutaneous fat concentration.There were important differences between sire breeds in daily live-weight gain (P<005), the order of performance for the different sire breeds being similar in the two systems. Charolais and Simmental crosses grew fastest, followed by South Devon crosses, and then by the purebred British Friesian and the other native breed crosses. Faster growing sire-breed crosses were generally heavier and older at slaughter; they ate more, and there was no obvious relationship between sire-breed means for growth rate and efficiency. The range in efficiency between sire breeds was 27 g and 17 g live-weight gain per kg digestible organic matter intake for the 16-and 24month systems respectively. In both systems, Hereford crosses ranked highest and the purebred British Friesian among the lowest. Probability levels for sire breed differences were P < 0 1 (16 month) and / ) <001 (24 month). 155 >-005 J 1 > 0-05 J I r 9 J 1 r 19 J ] r 21 O c /-\ > Pi o 8 > Pi H rd t/3 O c o 5 o o o > Ed en

The live-weight gain (LWG) and efficiency of food utilization of purebred British Friesian and Canadian Holstein steers and of crossbred steers out of British Friesian dams by Charolais, Hereford, Limousin, Lincoln Red, Simmental, South Devon and Sussex sires were examined in two beef production systems. One was similar to the commercial 18-month grass/cereal system (16-month) and the other to a commercial 2-year system (24-month). The cattle were serially slaughtered at three levels of fatness covering the commercial range and determined by the use of the Scanogram ultrasonic machine. The trial extended over 4 years and involved a total of 650 cattle. Data for the two production systems were analysed separately. Changes in growth performance were examined relative to estimated carcass subcutaneous fat content (g/kg; SFC) and sire breed crosses compared at the mean fatness level within system: 65 g/kg SFe for 16-month and 74 g/kg SFe for 24-month.Sire breed differences were not detected (P > 0·05) in the regressions on SFe of age and live weight at slaughter, overall daily LWG and overall efficiency of weight gain. Pooled within sire breed, live at slaughter and age at slaughter increased by 2·5 kg and 2·8 days (16-month) and 2·2 kg and 2·1 days (24-month) for each g/kg increase in SFe.Charolais crosses and Canadian Holsteins were heaviest at equal SFC in both systems, but the latter were 63 days older (16-month) and 42 days older (24-month): Hereford, Lincoln Red and Sussex crosses were lightest and among the youngest in both systems.Sire breed crosses differed significantly in daily LWG: Charolais crosses grew fastest in both systems; the relative growth rate of other sire breed crosses was less consistent between the two although the Hereford crosses and British Friesians grew slowly in both systems. Overall efficiency of LWG (g gain per kg digestible organic matter intake) ranged from 164 to 205 (16-month) and 146 to 171 (24-month). Canadian Holsteins and British Friesians had the lowest efficiency of LWG in both systems of production; differences between the other breeds were not statistically significant (P > 0·05).

A comparison was made of the carcass characteristics of purebred Galloway, Luing and Welsh Black steers, and crossbred steers out of Blue-Grey and Hereford × Friesian dams by Aberdeen-Angus, Charolais, Devon, Hereford, Limousin, Lincoln Red, Simmental, South Devon and Sussex sires, in winter and summer fattening systems. A total of 1430 cattle were involved and the trial extended over 6 years.The cattle were slaughtered when their fatness was estimated, using the Scanogram ultrasonic machine, to be in fat class 3L of the Meat and Livestock Commission Beef Carcase Classification Scheme. Carcasses were evaluated using a standardized commercial cutting technique.The data for crossbred and purebred cattle were analysed separately within the fattening system using leastsquares models, which included effects for year, sire breed and dam breed, and with regression on age at the beginning of the trial and carcass subcutaneous fat concentration estimated by visual appraisal.Limousin and Charolais crosses killed out best. Their carcass weights were, on average, 20g/kg live weight heavier than those of Aberdeen-Angus, Devon, Hereford and Lincoln Red crosses. There was a range of 20 to 30 g/kg carcass weight between sire breeds in carcass saleable meat yield: the highest values were recorded for the Limousin crosses (evaluated on winter fattening only) followed by Charolais and Aberdeen-Angus crosses; Lincoln Red crosses had the lowest values among the crossbreds and Luing cattle among the purebreds. These differences were more a reflexion of differences in fat trim than of differences in meat to bone ratio.Continental sire breeds had significantly more of their total saleable meat in the higher-priced cuts (P<0·05), although the range between sire breeds was only 15 g/kg.