Carcass and Meat Characteristics of Bulls from Arsi, Boran, Harar and Holstein Frisian Crosses Cattle Breeds Finished under Similar Level of Concentrate Supplementation

A study was conducted to evaluate the effect of age and breeds (Arsi, Borana, HF-Cross and Harar) on carcass and meat characteristics of bulls finished under similar feeding conditions. The feeding experiment was conducted for 90 days at Beef farm of Haramaya University. In this experiment, 24 bulls were fed with roughage (60%) which contained grass hay and wheat straw and concentrate (40%) which contained wheat bran, noug (gucia abysica) cake, maize grain, limestone, salt and ruminant premix. The bulls were transported to Bishoftu ELFORA export abattoir for slaughter following the procedure of the abattoir. The result of the study revealed that the average slaughter weight, hot carcass weight, cold carcass weight, shrink loss, commercial dressing and true dressing percentage were 179.1 kg, 86.8 kg, 82.7 kg 4.7%, 48.8% and 78.3%, respectively. Total edible and nonedible offal were significantly (P < 0.01) influenced by breed and age. Pelvic fat was significantly (P < 0.01) influenced by breeds. Meat yield percentages of Arsi, Boran, Harar, and HF-crossbred were 78.1%, 77%, 72.8% and 77.2% respectively. Meat yield was predicted from fat thickness and ribeye area with 61% accuracy. Arsi bulls attained the highest (78%) meat yield at early age but decreased by 0.713 rate as age of animals advanced by one digit whereas the meat yield from other breeds showed increment in meat yield percentage with the rate of 1.98, 1.1 and 0.1 for cross, Borana and Harar breed bulls, respectively as age advanced. Yield from fore shank, sirloin, top and bottom sirloin primal cuts were affected by breed. Arsi breed had higher meat bone ration than cross breed. Retailed meat yield was significantly (P < 0.001) predicted from rib area and subcutaneous fat thickness (P < 0.001) with a coefficient of determination 61%, from live animal trait and primal cuts with a coefficient of determination 89.56% and 94.78% respectively. Arsi bulls can be used for beef purpose at 2 - 3 years, as the meat percentage decreases thereafter;while bulls from Boran, cross breed and Harar breeds can be used up to 5 years of age. Meat to bone ratio indicated that HF-Crossbred was less appropriate for beef purpose than other breed bulls in this study. The rate of pH decline was not influence (P > 0.05) by age and breed in the current study.

Growth Performance of Arsi, Borana, Harar and HF-Crossbred Bulls Finished under Similar Feeding Condition

The study was conducted to evaluate the fattening performance of Arsi, Borana, Harar and Holstein Friesian crossbred bulls finished under a similar feeding condition at the beef farm in Haramaya University. The average daily weight gain of the four breeds ranges from 0.49 to 0.71 kg. Feed conversion efficiency also ranges from 0.11 - 0.15. Simple linear regression models were used to explore the relationship between live body weight change and change in body condition score as well as seven linear body measurements for all age groups. An average change for a unite of body condition score was equivalent to 20.3, 20.61, 22.42 and 27.78 kg for Borana, Arsi, Harar and Holstein Friesian crossbred bulls respectively. Body condition score was significantly influenced by breeds. There was a significant breed by age interaction effect on the initial body condition score of the four breeds. There was a significant and positive strong association between change in body weight and body condition score. There was a significant and strong correlation between change in body weight and change in Total topline, neck length, heart girth, flank circumference and rump length having correlation coefficients ranges from 0.57 to 0.97. A higher net profit of 7380.47 ETB per head was recorded by Borana bulls followed by Harar bulls, Arsi and Holstein Friesian crossbred with net profit of 5406.86, 5193.29 and 3384.98 ETB per head respectively. Borana bulls are more superior in weight gain and net profit. Bodyweight change could be predicted based on body condition score change during the fattening period.