Browsing by Author "Mtenga, L. A."

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Carcass and meat quality characteristics of indigenous cattle in Tanzania
(EGERTON UNIVERSITY, KENYA ., 2010) Mwilawa, A. J.; Kimambo, A. E.; Mtenga, L. A.; Laswai, G. H.; Madsen, J.; Hvelplund, T.; Weisbjerg, M. R.; Christensen, M.; Mgheni, D.M.
Seventy two Tanzania indigenous cattle (36 Boran steers; 2-3 years old; initial liveweight 225 kg and 36 Tanzania Short Horn Zebu (TSHZ); 3-4 years old; initial liveweight 117 kg) were randomly allocated to three dietary treatments to study the effects of breed, diet and ageing time on carcass and meat quality characteristics. Animals were fed three different diets: grazing alone (Diet 1: control), control + 50 % ad libitum concentrate intake (Diet 2) and ad libitum hay + ad libitum concentrate intake (Diet 3). The concentrate contained 126 g CP and 13 MJ ME per kg DM. The steers were fattened for 90 days, slaughtered, and carcass and meat quality assessed. Boran had heavier (P<0.05) empty body weight, carcass weight and greater rib area than TSHZ (242 vs. 192 kg; 132 vs. 108 kg and 56 vs. 47 cm2). Animals fed diet 3 had higher (P<0.05) dressing percentage, carcass fat thickness, conformation score and normal meat colour score (54%; 2 cm; 12; 2.9) followed by Diet 2 (51%; 0.9 cm; 9; 3.7 and lastly Diet 1 (47%; 0.6 cm; 7; 4.4). In addition, longissimus dorsi (LD) muscle from animals fed Diet 3 had the lowest (P<0.05) shear force (45 N) indicating very tender meat whereas LD from animals fed diet 1 had the highest value (60 N) indicating less tender meat. Increasing post-mortem storage time from 2 up to 20 days decreased (P<0.05) shear force by 65%. It is concluded that both Boran and TSHZ cattle obtained acceptable range of meat quality values and that tender meat can be produced from indigenous cattle through feedlot finishing and post-mortem storage at refrigerated temperatures
Effect of level of inclusion of Lablab meal in diet on Carcass Chanlcteristi of blackhead Persian Sheep
(Tanzania Journal of Agricultural Sciences, 1998) Muhikambele, V. R. M.; Mtenga, L. A.; Mafwere, W. D.
Twenty four Black Head Persian (BHP) castrate lambs weighing 14.1 ± 2.7 kg were randomly allotted to four dietary treatments . Animals on treatment A (control) were fed Rhodes (Chloris gayana) hay, ad libitum as basal diet, plus 3BO-g maize bran daily. Animals on treatments B, C and D were fed 'basal diet plus 3BO g of "maize bran and lablab meal" mixture at a ratio of 2.B:1, 0.9:1 and 0.27:1, respectively daily. Four animals from each treatment were selected for slaughter at the end of 99th day of feeding. The level of inclusion of lablab in the lambs' diet had no significant effect on all killing-out characteristics. However, the increase in dietary lablab level in supplement increased the hot carcass weight (HCW) and empty body weight (EBW). The mean HCWfortreatmentsA, B, C, andD were B.O, B.B, 9.2 and 9. 7 kg, respectively, while the respective mean EBWs were 15.3, 16.9, 17.B and 1B.2 kg. Dressing percentage showed no definite pattern. Regression of HCW on EBW and on slaughter weight showed high correlation coefficients (r = 0.91 and r = 0.90, respectively). Lean tissue weight increased with increasing lablab level in the supplement diet, while fat tissue decreased with increased dietary lablab levels (P < 0.10). Differences among treatments in carcass fat were however small and statistically non-significant. Although bone tissue did not show any defined trend, animals on treatment Chad heavier (B30 vs 716 g) carcass bone than animals on treatment A (P< 0.10). Expr,essed as percentages of the carcass, the weights of lean, fat and bone showed no significant treatment effects. However, the trend was an increase in percentage of lean tissue and a decrease in percentage offat tissue with increasing level of lablab in the supplement diet (60.9,51.3, 61.1 and 63% lean and 19.1,20.2, 1B.4and 17.5%fat,for treatments A, B, C and D, respectively).
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.
Empirical assessment of short-term preferences of tropical forages by crossbred bull calves
(Academic journals, 2007) Komwihangilo, D. M.; Lekule, F. P.; Mgheni, D. M.; Petersen, P. H.; Mtenga, L. A.; Kajembe, G. C.; Kurwijila, R. L.
Short-term preference studies were carried out with growing calves based on diets of local grass forages found in Turiani division, Morogoro, Tanzania. Four intact crossbred male calves aged 7 - 8 months and weighing 82.75 kg were used. Four grass species were provided either singly [Panicum maximum (T1), Panicum trichocladum (T2), Pennisetum purpureum (T3) and Rottboelia cochinchinensis (T4)] or in combinations of two forages in equal proportions [P. maximum + P. trichocladum (M1), P. maximum + R. cochinchinensis (M2), P. trichocladum + R. cochinchinensis (M3) and P. purpureum + P. trichocladum (M4)]. The single grass species and mixtures were respectively fed for four days. Animals were simultaneously observed while each animal was feeding on one of the four treatments in sequential periods of 15 min each in random orders (1, 2, 3 and 4) every test-day. The amounts of herbage eaten were estimated by differences between offered and left feed. The intake rate of 15.72 gDM/min, bite rate of 5.31 bites/min and bite mass of 3.11 g/bite for T3 was significantly higher (P < 0.05) than other single grass forages. There was no significant difference (P > 0.05) between intake rate of T1 (9.78 g/min) and T2 (9.36 g/min). Total DM intake of M3 and M4 of 224.54 and 232.52 g/15 min respectively were significantly (P < 0.05) higher than that of M1 and M2. All grass mixtures had bite mass significantly different (P < 0.05) from each other although that of 3.34 gDM/bite M4 was the highest thus suggesting that whether singly or in mixture P. purpureum was the most preferred grass forage in the study area. It is concluded that in order to optimize DM intake farmers should consider the type of grasses and their level of inclusion in grass mixture depending on their preference by cattle
The estimate of genetic correlation and heritability of various traits in small East African goats
(Tanzania Journal of Agricultural Sciences, 2002) Malole, J. I.; Kifaro, G. C.; Mtenga, L. A.; Chenyambuga, S. W.
This study was done on three strains of East African goats namely, Dodoma. Kigoma and Mtwara with the aim of estimating heritability for pre-weaning (4 months), post-weaning (8 months) and yearling (12 months) growth rates. Other heritability parameters measured were for weight at birth, 4, 8, and 12 months of age and helminth resistance traits (faecal egg count or FEC and packed cell volume or PCV) at six and twelve months of age. Genetic correlations were also determined between FEC. PCV and growth rate at six and twelve months of age. Genetic correlation and heritability were estimated using the Restricted Maximum likelihood (RFML) of the variance component (Var Comp) procedure of the Statistical Analysis System (SAS) package. Most of the traits were observed to have moderate heritability ranging from 0.32 to 0.39, with exception of weight at weaning (4 months). 8 months, one year of age and PCV, which had high heritability (0.4-0. 44) estimates. Negative genetic correlations were observed between FEC and growth rate at six months (rg = -0.69 ± 0.042), and twelve months of age (rg = -0.8 ± 0.011), whereas, PCV-showed positive genetic correlations with growth rate within the same periods rg = 0.59± 0.010 and rg = 0.45 ± 0.022, respectively. It was concluded that the moderate and high heritabilities obtained for growth rates, weights at different age FEC in this study indicate that improvement of growth rate, body size and genetic resistance to helminthosis could be improved through selection and manipulation of both the additive genetic action and non genetic (ienvironmental) components for tropical goat improvement. It was also recommended that genetic manipulation at molecular level should be employed in identifying and isolating quantitative and qualitative trait loci (QTL) linked to economic and desirable traits which will enable development of goats suitable for different ecological zones.
The influence of incentives in eliminating hypothetical bias: Evidence from a choice-based conjoint experiment for beef products in Iringa and Mbeya Regions in Tanzania
(2013) Nandonde, S. W.; Msuya, E. E.; Mtenga, L. A.; Kilima, F. T.; Alphonce, R.
Consumer responses were observed for a within-sample comparison of preference and willingness-to pay (WTP) estimates for tenderness, leanness, freshness and hygiene for beef products from finished cattle and non-finished cattle (status quo). This comparison was conducted through two sessions of repeated choice-based conjoint experiments (CBC), starting with a hypothetical choice-based conjoint (HCBC) experiment that involved cheap talk only followed by a real choice-based conjoint (RCBC) experiment that involved the actual purchase of experimental products with real money. Consumers prefer more tender, less fatty, chilled beef and clean retailing premises, regardless of the choice session; however, the estimated coefficients were not equal (p<0.001). The selection was motivated by alternatives in HCBC where finished beef constituted 76% of all choices made. The selection of finished beef dropped to 67% in RCBC where consumers were sensitive to the price and quality content of alternative products. Consumers overestimate the WTP for hygiene in HCBC (p=0.014); however, there are no significant differences in WTP estimates for other attributes. Therefore, it is concluded that monetary incentives can reduce hypothetical choice bias and provide more trustworthy WTP estimates for all attributes. Key words: Beef, fini
The influence of incentives in eliminating hypothetical bias: Evidence from a choice-based conjoint experiment for beef products in Iringa and Mbeya regions in Tanzania
(Journal of Agricultural Economics and Development, 2013) Nandonde, S. W.; Msuya, E. E.; Mtenga, L. A.; Kilima, F. T.; Alphonce, R.
Consumer responses were observed for a within-sample comparison of preference and willingness-to-pay (WTP) estimates for tenderness, leanness, freshness and hygiene for beef products from finished cattle and non-finished cattle (status quo). This comparison was conducted through two sessions of repeated choice-based conjoint experiments (CBC), starting with a hypothetical choice-based conjoint (HCBC) experiment that involved cheap talk only followed by a real choice-based conjoint (RCBC) experiment that involved the actual purchase of experimental products with real money. Consumers prefer more tender, less fatty, chilled beef and clean retailing premises, regardless of the choice session; however, the estimated coefficients were not equal (p<0.001). The selection was motivated by alternatives in HCBC where finished beef constituted 76% of all choices made. The selection of finished beef dropped to 67% in RCBC where consumers were sensitive to the price and quality content of alternative products. Consumers overestimate the WTP for hygiene in HCBC (p=0.014); however, there are no significant differences in WTP estimates for other attributes. Therefore, it is concluded that monetary incentives can reduce hypothetical choice bias and provide more trustworthy WTP estimates for all attributes.
Influence of sex, age and body condition score on carcass composition and tissue distribution in marketed small East African goats
(2002) Mushi, D. E.; Mtenga, L. A.; Kifaro, G. C.; Chenyambuga, S. W.
Twenty-four half carcasses of small East African goats (8 females 8 entire males and 8 castrated males) were jointed into seven joints namely: hind leg, chump, loin, rib, breast, neck and fore leg. These joints were further dissected into the separable components: muscle, bone and fat. The carcasses of these goats, were composed of 7.8, 16. 5% fat, 55.6-62, 7% muscle and 27.9- 29,5% bone. The proportions of muscle in carcasses of females (56%) and castrates (58%) were significantly (P<0.05) lower than in entire males, (63%). Fat content in the carcasses of females (16%) and castrates (12%) were signtficantly (P<0.05) higher than in entire males (9%). The neck of entire males had higher (P<0.001) percentage muscle weight (11%) than the neck of females (8%) and castrates (9%). The hind leg females had higher (P<0.05) percentage muscle weight (28%) than hind leg of males (25%) but castrates had values in between the two (27%). The fore leg off females had the least (P<0.001) percentage of muscle (21 %) compared wiith males (23%) and castrates (24%). The loin and fore legs of females had higher (17% vs. 12%) and lower (16% vs 20%), percentage of fat than those of castrates and entire males. The fore leg of females had lower (10% vs 12%) percentage of bone than that of entire males and castrates. The neck and fore leg of goats above 3 years old had higher (10% vs 9%) and lower, (22 vs 23%) percentage of muscles respectively than those of goats aged 2 to 3 years. The loin and hind legs of goats with body condition score of 4 had higher (12% vs 11%) and lower (25% vs 27%) muslce percentage respectively than those of goats with five score. The rib joint of goats with body condition score of 4 had higher (13% vs 11%) percentage of bone than those of goats with five score It is concluded that sex of the animal affects both the proportion and distribution of carcass tissue to a greater extent than age and body condition score. This means that where carcass quality is a major goal given the right market guidelines, farmer can make use of the sex differences in the proportion and distribution of carcass tissue to serve the consumer markets with meat goat of their preference.
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.
Muscle distribution in farm animals: comparison between goats and other farm animals
(1998) Mtenga, L. A.; Owen, E.; Muhikambele, V.R.M.
Eight,male goats w,ere 'slaf.lghtered at. 36 kg, live weight (approximately two thirds of mature weight) and dissected, into individual anatomic m'((s(;les. Weights of individual muscles were then grouped into 8 functional units and compared with published data on bulls, rams and boars.' There was a wide species d(tference;in "size index'~ musGles..· Abdominal wall index was highest !'n boars followed by goats, bulls and'rams, the values being 108, 1.00, 91 m:zd 90 resp.ectivety. 9,o(lts had. higher i!ldices ill four;functional units: agility, locomotion, supporting muscles 'and specialised funCtionai mu~cles.· Muscle data .. o/ goa~s indicated that goats are most aggressive followed by bulls, rams and pigs.
Preliminary evaluation of slaughter and carcass traits of castrates of Tanzanian long fat-tailed sheep slaughtered at different ages
(Global Researhers Journals, 2012) Shirima, E. J. M.; Mtenga, L. A.; Kimambo, A. E.; Laswai, G. H.; Mushi, D. E.; Mgheni, D. M.; Safari, J. G.; Shija, D. S.
The aim of this study was to evaluate the effect of age on slaughter and carcass traits of castrates of Tanzanian long fat-tailed sheep (TLS) purchased from the auction markets in Dodoma region, Tanzania. A total of 40 castrates aged 9, 12, 15 and 18 months old were slaughtered at Dodoma abattoir within one week of purchase. Slaughter body weight (SBW) was significantly different (P<0.01) among the slaughter age groups ranged from 15.1 to 22.9 kg live weight in 9 to 18 months, respectively. Cold carcass weight (as %SBW) did not differ (P>0.05) with increasing slaughter age while the proportional of gastro-intestinal tract (GIT) (as %SBW) increased with increasing slaughter age. Dressing percentage on empty body weight basis ranged from 50 to 54 and did not differ with slaughter age. Older animals (18 months old) had higher lean and low fat content and had significantly tough meat with 69.7 Ncm-2 shear forces. Gross margin ranged from USD 17.8 to 32.8 with realization of small net profit between 0.64 and 1.17 USD when animals are slaughtered direct from extensive
The' effect 'of feeding position,and body size on the capacity of small ruminants to reach, for fOOd when fed through balriers
(2000) Muhikambele, V.:R. M.; Massawe, N. F.; Mtenga, L. A.; Butler, E.A.; Owen, E.
Small ruminant systems, espedally with intensification in the tropics, are increasingly involving indoor stall-feeding. To facilitate manger design, there is a needfor iriformation on the ability of the animal to reachfor food, suchas that availablefor cattle fed through barriers. Thirty eight goats (20 Galla, mean weight 28.2 kg; 18 Small East African; mean weight 24. 6 kg) and 26 sheep (16 Blackhead Persian, mean weight 24.0 kg, 10 Red Maasai; mean weight 20.4 kg), were trained to reach for concentrate meal placed on a horizontal platform through a vertical tombstone barrier. The barrier allowed the neck to pass through, but not the shoulders. 1t was hypothesized that goats would have larger reach than sheep and thatforeach species, horizontal reachforwards, F, (distancefrom mid-point of barrier to uneaten meal) and sideways,S, (distances sidewaysjrom mid-point of barrier to uneaten meal adjacent to barrier) would be ajunction of height of platform above the floor (0, 15, 30 and 45 cm) and body size (weight and linear measurements, e.g. body length). Goats had significantly larger F and S values than sheep. Mean values for Fat platform heights 0, 15, 30 and 45 cm were 37.9,41.8, 44.7 and 39.4 em respe;ctively for sheep and 45:4, 46.6, 47.2 and 43.0 cm respectively for goats. Values for S were smaller, but followed a similar pattern. Linear correlation coefficients between For S and dimensions in sheep were all low (0-0.5), but in goats, especially for F, correlations were generally high (0.4-0.8). Exceptfor the low correlation between reach and size in sheep, the results supported the hypotheses. The data will facilitate manger design for small'ruminants of similar breeds, having dimensions in the range of those used in the study.