Browsing by Author "Hozza, W. A."

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Effects of days in feedlot on physico-chemical properties and meat tenderness from Tanzanian long fat-tailed sheep
(J. Anim. Prod. Adv., 2013) Shirima, E. J. M.; Mtenga, L. A.; Kimambo, A. E.; Laswai, G. H.; Mgheni, D. M.; Mushi, D. E.; Shija, D. S.; Safari, J. G.; Hozza, W. A.
The objective of this study was to evaluate the effects of days in feedlot (DF) on physico-chemical properties and meat tenderness of Tanzanian long fat-tailed sheep (TLS) of Tanzania. Seventy castrated TLS (12 months old and mean live weight of 21.1 0.6 kg) were randomly assigned to seven treatment periods of DF in a completely random design experiment. The periods were 0, 14, 28, 42, 56, 70 and 84 days, designated as DF0, DF14, DF28, DF42, DF56, DF70 and DF84, respectively. Each treatment period had 10 experimental animals. Immediately after purchase, DF0 animals were slaughtered and their meat quality characteristics were determined. DF14, DF28, DF42, DF56, DF70 and DF84 groups were fed Cenchrus ciliaris hay as basal diet and molasses-based concentrate diet (160 g CP and 10.9 MJ ME/kgDM) and water on ad-libitum basis. At each period of stay, 10 experimental animals were randomly selected and slaughtered until the end of the feedlot period of 84-d was reached when the last group was slaughtered. Carcass pH and temperature were measured at 45 min, 6 h, 24 h and 48 h post mortem at the m. longissimus thoracis et lumborum (LL) muscle. The m. longissimus thoracis et lumborum (LL), semimembranosus (SM) and supraspinosus (SP) muscles were then dissected from the carcass and evaluated for drip loss (%), cooking loss (%) and Warner-Bratzler shear force (WBSF) values, after zero and nine days of aging. The results from this study revealed that there was a significant (P<0.001) decrease of pH values at 6 h post mortem (pH6) as the DF increased. The pH at 24 h post mortem (pH24) ranged from 5.72 to 5.79 and was not significantly (P>0.05) affected by period of stay. Cooking losses decreased (P<0.05) with increasing DF and aging duration from 0 to 9 days. The WBSF values of cooked muscles were highest (P<0.05) in SP followed by SM and lastly LL and their overall tenderness increased with increasing DF. There was an interaction effects between DF and post mortem aging time on tenderness such that castrates under DF56, DF70 and DF84 showed the lowest shear force values in LL and SMmuscles after nine days of aging. The results indicated that 42 days was optimal DF for production of high quality meat in Tanzanian long fat-tailed sheep.
Meat quality characteristics of small East African goats and Norwegian crosses finished under small scale farming conditions
(Asian-Australasian Journal of Animal Sciences, 2014-12) Hozza, W. A.; Mtenga, L. A.; Kifaro, G. C.; Shija, D. S. N.; Mushi, D. E.; Safari, J. G.; Shirima, E. J. M.
The aim of the experiment was to study the effect of feeding system on meat quality characteristics of Small East African (SEA) goats and their crosses with Norwegian (SEA×N) goats finished under small scale farming conditions. Twenty four castrated goats at the age of 18 months with live body weight of 16.7±0.54 kg from each breed (SEA and SEA×N) were distributed in a completely randomized design in a 2×3 factorial arrangement (two breed, and three dietary treatments). The dietary treatments were; no access to concentrate (T0), 66% access to ad libitum concentrate allowance (T66) and 100% access to ad libitum concentrate allowance with 20% refusal (T100) and the experimental period was for 84 days. In addition, all goats were allowed to graze for 2 hours daily and later fed grass hay on ad libitum basis. Daily feed intakes were recorded for all 84-days of experiment after which the animals were slaughtered. Feed intake of T100 animals was 536 g/d, which was 183 g/d higher than that of T66 group. Supplemented goats had significantly (p<0.05) better feed conversion efficiency. The SEA had higher (p<0.05) hot carcass weight (8.2 vs 7.9 kg), true dressing percentage (54.5 vs 53.3) and commercial dressing percentage (43.3 vs 41.6) compared to SEA×N. There was no significant difference (p>0.05) for dressing percentage and carcass conformation among supplemented goats except fatness score, total fat depots and carcass fat which increased (p<0.05) with increasing concentrate levels in the diet. Increasing level of concentrate on offer increased meat dry matter with subsequent increase of fat in the meat. Muscle pH of goats fed concentrate declined rapidly and reached below 6 at 6 h post- mortem but temperature remained at 28°C. Cooking loss and meat tenderness improved (p<0.05) and thawing loss increased (p<0.05) with ageing period. Similarly, meat tenderness improved (p<0.05) with concentrate supplementation. Shear force of muscles varied from 36 to 66, the high values been associated with Semimembranosus and Gluteobiceps muscles. The present study demonstrates that there are differences in meat quality characteristics of meat from SEA goats and their crosses with Norwegian breeds finished under small scale farming conditions in rural areas. Therefore, concentrate supplementation of goats of both breeds improves meat quality attributes.