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Kedajany Senepol Stud-information page
Muscling in Senepol Cattle
Meat and Livestock Australia use muscle scores to describe the variation in muscularity of cattle. High muscle scores of (A, A+,A-) were the realm of European breeds such as Limousin, Charolais, Romagnola & Peidmontese. Low muscle scores (D, D+, D-) were the realm of dairy breeds such as Jersey and Holstein. The majority of Australian beef cattle sold in commercial saleyards have muscle scores of C. Brett Littler (DPI) stated that "muscling was four times more likely to influence price variation across classes of cattle than weight, and seven times more likely than fat score".
The effect of muscle scores on retail beef yield was examined in the NSW DPI Agfact on "Cutability of Beef Cattle". Two similar Angus steers weighing 375 kg liveweight, but differing in muscle scores (B vs D), were slaughtered and retail beef yields were determined. The carcase of the heavily muscled steer produced an extra 26.7 kg of saleable red meat, a 24% increase compared with the lightly muscled steer. A high muscle score is clearly a benefit to producers and retailers.
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Cattle tend to look better muscled when they are fat. "Many bulls that have been prepared for shows look better muscled; but are they infact well muscled, or are they just fat?"(NSW DPI Agfact Cutability). Also calves will increase their muscle score at puberty if they carry muscling genes. Muscularity in Senepol cattle is under genetic control. Both the sire and the dam contribute to the muscularity of the offspring. Substantial variability in muscle scores exist with the Senepol breed. At Kedajany Senepols, we have identified a number of bloodlines that exhibit high muscle scores. Some examples of high muscle Senepol sires include WC98N, WC850 & OLR9902J (see above photos L toR). We have been using these bulls in our breeding program. The effect of using high muscle score bulls on the appearance of heifers can also be seen in the photos below of Kedajany heifers (C-, B, A muscle scores from L to R).
High muscle scores are no longer just the realm of European cattle breeds and their crosses. Senepol cattle can deliver some of these advantages for producers in tropical environments.
Growth rate of Senepol Cattle
Senepol cattle can have a high growth rate compared to other breeds of cattle and perform well in the feedlot. Growth rates averaging 1.3 kg/day have regularly been recorded in Australia (Table 1). Yearling weights of over 500 kg have been measured in a number of bulls such as Kansas Kidman and CBN Outback.
Age (months) Growth rate(kg/day) Weight (kg) 13 1.30 590 11 1.30 474 15 1.24 510 15 1.10 534 27 1.02 856 16 1.18 468 23 1.09 804 21 1.22 768 13 1.37 570 17 1.35 722 24 1.16 874 Angus cattle have long been the benchmark by which other cattle are judged. Data available from the ABS Global 2010 catalogue for leading Angus bulls such as Androssan X5 (series 2), Rito Plus (series 3) Gar Authority (series 4) and Woodhill foresight (series 1) are plotted in the below graph. The line of best fit represents a growth rate of 1.14 kg/day. This growth rate compares favourably with data from elite Senepol sires.
Genetic variability in growth rate exists within all breeds. Presale data from the 2007 5 Star sale indicated Senepol cattle are no exception (growth rates varied from 0.8- 1.3 kg/day). Genes responsible for high growth rate of Angus cattle have been determined and tests are commercially available. It is likely that similar genes are responsible for high growth rates in Senepol cattle. The efficacy of their use in a breeding program needs to be evaluated. When data from Kansas Kidman (Excel genetics flyer) is examined, it reveals a progressive reduction in growth rate of this bull: from birth to 219 days the average growth rate was 1.5kg/day; from 219-390 days the growth rate was 1.3 kg/day; and from 390-510 days the growth rate was 0.95 kg/day. A high growth rate prior to weaning is to be expected due to the caloric value of the dam's milk. A declining growth rate in the paddock may be due to seasonal conditions (frosted pasture or drought) or alternatively due to animal health issues. Data from Kedajany Senepol Stud reveal the reduction in growth rate is associated with the early maturity of some bulls. Once frame size is fixed there is a limit to the growth of a bull. At Kedajany Senepol Stud we have identified a number of later maturing bloodlines and are in the process of evaluating their progeny.
Senepol cattle have also performed well in the feedlot. In 2009, Senepol-infused steers achieved a growth rate of 2.94 kg/day in the Callide-Dawson Beef Carcase competition. In 2010, Senepol infused steers achieved a growth rate of 3.21 kg/day after 45 days on feed in the Primex Beef Challange. These animals ate 13kg of ration per day and converted it to weight gain at less than 4( kg dry weight feed eaten) to 1(kg live weight gain) ratio.This is an astounding conversion ratio as figures as high as 7:1 have been reported in other trials.
Copyright Dr D.J. Flower - Kedajany Senepols - Last updated 24/3/11
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