96 results on '"Hoffman, L C"'
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2. CONSUMER MEAT SAFETY KNOWLEDGE AND HYGIENE PRACTICES IN A VETERINARY DISEASE-CONTROLLED AREA OF SOUTH AFRICA.
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Nkosi, D. V., Bekker, J. L., and Hoffman, L. C.
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HYGIENE ,CONSUMERS ,SAFETY education ,ANIMAL mechanics ,MEAT - Abstract
Consumers' practices and knowledge play a significant role in ensuring meat safety and hygiene application. This is important in an environment where the slaughter and release of such meat is restricted and not always controlled and monitored. This could have been contributed by the lack of slaughter facilities; the controlled movement of live animal restrictions applicable in a typical veterinary diseases-controlled area. The aim of this investigation was to identify meat hygiene practices and general meat safety knowledge applied by consumers of central Bushbuckridge, South Africa. Structured interviews (n=81) were conducted with consumers observed purchasing meat from local meat supply centres. Data analysis was achieved by SAS Statistical software (Version 26) SAS and graphs were drawn using MS Excel 2020. The majority (84.2%, s=29.4) of the consumers indicated that meat supplied in the region were from registered facilities. The general belief amongst the consumers was that routine hygiene inspection was conducted by authorities at all meat distributing or butchery facilities (74.1%, s=39.7). None of the facilities or/and butcheries in the study area was registered and therefore, no formal regulated practices could have been conducted. Slaughter and distribution of meat within the area were seen as a good business by 78.6%, s=18.9 of the consumers, and as a result, the consumers did not have a problem with widespread slaughter and release of this meat to the public outside of those facilities. The extent of hygiene application practices at household level varied. These included the assurance that perishable products were properly handled after purchase (84.1%, s=8.3), and the handling or transportation of sourced meat did not comply with cold chain management prescripts (39.9%, s=44.9). The likelihood of consumers feeling the same about meat hygiene concerns and practices is undoubtedly low as represented by a high standard deviation (s) of the responses. These results show that consumers were relying on authorities for meat safety assurances. This ought to caution authorities on consumer practices and needed interventions such as animal movement policies enforcement. The adoption of such policies by consumers lies with the development and rollout of consumer awareness and meat safety assurances training programs. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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3. Precision finishing of South African lambs in feedlots: a review.
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Van Der Merwe, D. A., Brand, T. S., and Hoffman, L. C.
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In the intensification of sheep production systems, feedlot finishing plays a fundamental role in preparing lambs for slaughter, as well as relieving the grazing pressure on pasture. The profit margins in feedlot operations are often narrow and require the economics of scale to generate a sufficient income. In order to minimise expenses, intensive management and precision rearing of lambs to an ideal slaughter weight is needed to obtain premium carcass prices. The South African sheep industry is made up of wool, dual-purpose as well as meat type breeds, which also vary in terms of maturity. In order to implement precision finishing of South African lamb, a complete understanding of the growth, intake and fat deposition trends of growing lambs of different breed types is needed. This review outlines feedlot lamb production within the Southern African context for the major commercial breeds, while also providing insight in the considerations necessary to develop a decision support system for lamb rearing. Integrating such a decision support system into a lamb feedlot operation can then be used for precision finishing of lambs by predicting the optimal length of the feeding period and ideal slaughter weights of lambs. [ABSTRACT FROM AUTHOR]
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- 2020
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4. Extending the interval between second vaccination and slaughter: II. Changes in the reproductive capacity of immunocastrated ram lambs.
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Needham, T., Lambrechts, H., and Hoffman, L. C.
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Immunocastration improves the welfare of castrated commercial slaughter lambs; however, the time-point at which this technique influences semen quality and sperm production has not yet been established for various vaccination schedules. Furthermore, the effect of extended intervals between second vaccination and slaughter needs to be investigated regarding continued testosterone suppression in immunocastrated lambs. The effect of extending the interval between second immunocastration vaccination and slaughter from four to six weeks on the reproductive capacity of Dohne Merino lambs was examined. A total of 40 Dohne Merino lambs were stratified according to initial weight (45.4±3.68 kg) and randomly assigned to four treatments that included intact control rams (R), Burdizzo-castrated lambs (B) and lambs immunocastrated with either four (ICS4) or six (ICS6) weeks between second vaccination and slaughter. Blood and semen samples were collected throughout the study period to determine serum testosterone concentrations, evaluate semen quality and assess sperm viability. Semen samples from R showed improvement over the trial. Throughout the collection period, B lambs had low serum testosterone concentrations, poor sperm motility and sperm viability, as expected. However, a slight increase in the percentage of live sperm in semen samples from B lambs towards the end of the collection period indicated poor success rates of the technique in some lambs. Burdizzo-castration also caused testes tissue necrosis and abscessing, indicating physiological stress. Semen appearance scores varied for both immunocastrated treatments, but the mass motility scores decreased over time. The ICS6 lambs showed a consistent and continuous decline in serum testosterone concentrations and sperm viability, with an increased percentage of dead abnormal sperm in the semen samples at the end of the study. The ICS4 treatment was successful in interrupting serum testosterone production and reducing semen quality; however, not as consistently as the ICS6 treatment. Primary immunocastration vaccination influenced serum testosterone concentrations but consistently low levels were only realised for both treatments after secondary vaccination. Although all castration treatments influenced testes size and colour, the six-week vaccination-to-slaughter interval caused a greater decrease in testes cut surface L * (lightness) colour values and in seminiferous tubule circumference. Extending the interval between second immunocastration vaccination and slaughter resulted in a more consistent and reliable influence on reproductive capacity of immunocastrated lambs. Thus, immunocastration is a suitable alternative to Burdizzo-castration regarding the interruption of testosterone production and testis functioning. [ABSTRACT FROM AUTHOR]
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- 2019
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5. Extending the interval between second vaccination and slaughter: I. Effects on growth, scrotal size and stress responses of immunocastrated ram lambs.
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Needham, T., Lambrechts, H., and Hoffman, L. C.
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Immunocastration provides a less invasive means of castrating lambs. Considering increasing consumer awareness, the efficacy of this technique on commercial slaughter lambs needs to be further investigated and its effects on growth and stress responses need to be established. This study compared the growth rate, testes size and stress responses of immunocastrated lambs with that of lambs physically castrated with a Burdizzo clamp, as well as intact rams. A total of 40 Dohne Merino ram lambs (average live weight = 45.4±3.68 kg) were randomly allocated to the following four treatment groups: control (intact; R), Burdizzo-castrated (on day 2; B), immunocastrated with a 4-week (ICS4), or a 6-week (ICS6) interval between the second immunocastration vaccination and slaughter. Within the immunocastration treatments, the reaction to vaccination was assessed through injection site scoring, recording the local injection site surface temperature and assigning a walking score. The response to Burdizzo castration was assessed by scoring the reaction during the procedure, testes palpation reaction, walking gait and measuring testis temperature. Additional parameters recorded included BW, serum cortisol concentration, scrotal circumference and rectal temperature. Pain behaviours were described for the short-, medium- and long-term effects after the two methods of castration. Predominantly, tissue-hardening and bruising occurred at the injection sites of immunocastrates, but little effect was observed on walking comfort and no effect on injection site temperature or rectal temperatures. After Burdizzo castration, lambs spent more time in abnormal postures, and from day 3 (D3) to D8 of the trial, discomfort was observed during testes palpation and walking in B lambs. Serum cortisol concentrations were elevated in B lambs on D3 and D15, indicating physiological stress. Thus, immunocastration improved the welfare of castrated lambs as assessed by cortisol secretion, scrotal swelling and pain behaviours, without influencing growth rate. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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6. Artificial diets for neonatal black soldier fly (Hermetia illucens) larvae.
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Woods, M. J., Hoffman, L. C., and Pieterse, E.
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- 2019
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7. Hermetia illucens larvae reared on different substrates in broiler quail diets: effect on apparent digestibility, feed-choice and growth performance.
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Woods, M. J., Cullere, M., Van Emmenes, L., Vincenzi, S., Pieterse, E., Hoffman, L. C., and Zotte, A. Dalle
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- 2019
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8. Structure in Vitreous Silicate Fibers as Shown by Small-Angle Scattering of X-Rays.
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Statton, W. O. and Hoffman, L. C.
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- 1960
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9. Growth responses of entire and immunocastrated male pigs to dietary protein with and without ractopamine hydrochloride.
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Needham, T., Hoffman, L. C., and Gous, R. M.
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The interaction between dietary balanced protein, ractopamine (RAC) and Improvac (IMP) on the growth response of 120 individually penned male PIC© pigs was evaluated. The pigs entered the trial at 16 weeks of age and were assigned to 12 treatments using a 2×2×3 factorial design. Three balanced protein diets, formulated with standard illeal digestible lysine levels of 7.50 (low), 9.79 (medium) and 12.07 g/kg (high), were fed from 20 weeks. Improvac was administered at 16 and 20 weeks, the booster being given 4 weeks before slaughter. Ractopamine was supplemented at 10 mg/kg to the applicable treatments from 20 weeks. Live weight, backfat depth and food intake were measured on a weekly basis. Primary vaccination had no influence on the parameters measured. Immunocastration, RAC and higher protein diet treatments increased weight gain, but food intake was increased only with the use of IMP. Although weight gain increased in IMP-treated males, the increased feed intake resulted in their feed conversion efficiencies (FCE) being inferior to the intact controls. Feeding RAC only benefitted FCE when a high or medium protein diet was fed. Immunocastrates deposited more backfat after the booster vaccination than did entire males. Thus the cost of using RAC, IMP and of increasing dietary protein content needs to be weighed up against the additional revenue generated through the use of these interventions. [ABSTRACT FROM PUBLISHER]
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- 2017
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10. Proximate composition and variation in colour, drip loss and pH of breast meat from broilers supplemented with Moringa oleifera leaf meal over time.
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Nkukwana, T. T., Muchenje, V., Masika, P. J., Pieterse, E., Hoffman, L. C., and Dzama, K.
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This study investigated the breast meat proximate composition and quality indicators in relation to response of broilers to the following dietary treatments (T): positive control (+C; with 668 mg salinomycin and 500 mg zinc bacitracin per kg of feed); Moringa oleifera leaf meal (MOLM) was fed at a low level (ML; 1-5 g/kg feed, depending on growth stage), a medium level (MM, 3 times the low level) or a high level (MH, 5 times the low level); and a negative control (-C; without supplementation) for 35 days. At postmortem, the carcass weight, and breast musclepHat 45 min (pH45) and 24 h (pH24) were recorded. At 36 h postmortem, breast muscles were excised, weighed and stored in a refrigerator at 4°C to measure pH, colour (CIE-L*, lightness; a*, redness; and b*, yellowness) and cumulative drip loss over eight consecutive days. Chroma (C*) and hue angle (h) were calculated. The -C had the highest (P > 0.05) dressing percentage and chilled carcass weight, and ML had the lowest. Breast meat fat and energy contents were highest (P < 0.05) in +C and MOLM supplemented diets, and lowest in -C. Dietary treatments had no effect on pH at postmortem and during storage over time. Cumulative drip loss increased with each day of storage, and it was highest (P < 0.05) in +C and lowest in MH. Dietary supplementation of MOLM significantly (P < 0.05) reduced lightness, but increased redness, yellowness, chroma and the hue angle during storage over time. In conclusion, dietary supplementation of M. oleifera leaf meal had positive effects on proximate composition and shelf-life quality indicators of broiler breast meat. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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11. The effect of slaughter weight on the carcass characteristics of pork with sex type as co-variable.
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Pieterse, E., Hoffman, L. C., Siebrits, F. K., Gloy, E. L., and Polawska, E.
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SWINE carcasses , *WEIGHT of swine , *SLAUGHTERING - Abstract
A study was conducted with 192 pigs of three sex types with treatments according to slaughter weight (65 kg to 144 kg). The main statistical differences observed were for slaughter weight with significant (P < 0.05) and highly significant (P < 0.01) differences describing more than 10% of variance observed for all characteristics (liveweight, warm carcass weight, dressing percentage, eye muscle area, subcutaneous fat thickness, intramuscular fat area, subcutaneous fat : eye muscle area, intramuscular fat : eye muscle area, fat thickness, muscle depth, carcass length, ham circumference, ham length and chest depth) measured. Sex differences (P < 0.05) were also observed for dressing percentage, fat measurements and muscle depth measured between the 5th and 6th lumbar vertebrae. Sex type differences, in all instances, accounted for 10% or less variance except for subcutaneous fat : eye muscle area ratio (18.47%). It was shown that although significant sex type differences (P < 0.05) existed; slaughter weight had the largest effect on carcass characteristics in the given circumstances accounting for most of the observed variance. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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12. Carcass traits and cutting yields of entire and immunocastrated pigs fed increasing protein levels with and without ractopamine hydrochloride supplementation.
- Author
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Needham, T. and Hoffman, L. C.
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SWINE carcasses , *SWINE nutrition , *RACTOPAMINE , *SLAUGHTERING , *LOW-protein diet - Abstract
The objective of this study was to determine the effects of increasing balanced protein, with and without ractopamine hydrochloride (RAC), in the finisher diets of immunocastrates on their carcass cutting yields and respective muscle, fat, and bone proportions. Carcass traits and yields of 120 individually housed entire male pigs and immunocastrates were evaluated following a 2 × 2 × 3 factorial design. Vaccination occurred at 16 and 20 wk of age and slaughtering at 24 wk. Up until 20 wk of age, all pigs received a commercial grower diet. Low-, medium-, and high-protein (7.50, 9.79, and 12.07 g standardized ileal digestible [SID] lysine/kg, respectively) diets were then fed for the last 28 d with RAC supplemented at 0 or 10 mg/kg. Immunocastration and RAC supplementation increased (P = 0.003 and P = 0.017, respectively) the live weight at slaughter. The interaction between sex and protein (P = 0.039) for caliper backfat depths showed greater backfat depths in immunocastrates fed medium protein whereas RAC decreased (P = 0.027) the caliper backfat depth. Feeding RAC increased the trotters (P = 0.040), tenderloins (fillets; P < 0.001), shoulder (P = 0.002), hindquarter (P = 0.026), loin (P = 0.028), and belly (P = 0.044) percentages. The shoulder (P < 0.001), hindquarter (P < 0.001), and loin (P = 0.005) muscle percentages were increased and the hindquarter fat percentages were decreased (P = 0.032) with RAC supplementation. Immunocastration increased the belly cut (P = 0.006), loin fat (P < 0.001), and belly fat (P < 0.001) percentages. Therefore, carcass cutting and lean yields can be improved by RAC supplementation while decreasing the backfat depth, and the increase in backfat due to immunocastration could be avoided with the correct dietary protein level. [ABSTRACT FROM AUTHOR]
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- 2015
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13. The effect of dietary energy concentrations on production variables of ostrich chicks ( Struthio camelus var. domesticus ).
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Brand, T. S., Carstens, P. D., and Hoffman, L. C.
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OSTRICH farming ,CALORIC content of foods ,OSTRICHES ,BIRD growth ,FOOD consumption ,ANIMAL carcasses ,SLAUGHTERING ,PHYSIOLOGY - Abstract
The effects of different dietary energy concentrations on ostrich production variables were examined in two separate trials. The first trial tracked changes in production variables from the pre-starter phase through the starter phase and grower phase. The second trial was based on the finisher phase per se. In both trials, the influence of dietary energy on feed intake, feed conversion ratio (FCR) and growth variables was investigated. Additionally, basic abattoir weights were recorded, and measurements of the feathers and skin were performed.In both trials, three diets with different concentrations of dietary energy were given during each phase where the low-, medium- and high-energy concentrations for each phase were as follows: 13.5, 14.5 and 15.5 MJ ME/kg feed pre-starter; 12.5, 13.5 and 14.5 MJ ME/kg feed starter; 10.5, 11.5 and 12.5 MJ ME/kg feed grower and 9.5, 10.5 and 11.5 MJ ME/kg feed finisher. Feed and water were available ad libitum in both trials.Overall, it was found that the best performance for growth, FCR, skin size and grade, live weight, carcass weight and thigh weight were obtained on the medium-energy diet during the pre-starter, starter and grower phases.During the finisher phase, improved growth rate and tanned skin size was found in birds given the diet with the highest energy concentration (11.5 MJ ME/kg feed). Carcass weight, growth rate and certain feather variables were also significantly influenced by gender. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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14. The carcass quality, meat quality and sensory characteristics of broilers raised on diets containing either Musca domestica larvae meal, fish meal or soya bean meal as the main protein source.
- Author
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Pieterse, E., Pretorius, Q., Hoffman, L. C., and Drew, D. W.
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The effects of Musca domestica (common house fly) larvae meal (magmeal) on the meat quality of broiler chickens were investigated in a trial consisting of three isonitrogenous and isoenergetic treatment diets containing either 10% fish meal, 10% M. domestica larvae meal or a control diet with soya bean meal as the protein source. Chicks that received either the 10% M. domestica larvae meal or 10% fish meal produced significantly heavier carcasses and had a higher breast-meat yield than did the control chicks. Sensory attributes evaluated by a trained sensory panel included chicken aroma, metallic aroma, initial juiciness, chicken flavour, sustained juiciness, metallic aftertaste, toughness and mealiness. The samples were judged to have a prominent chicken aroma but a less prominent chicken flavour. Although the samples had a moderate initial juiciness, they did not have a sustained juiciness except for the larvae-fed samples, which had higher sustained juiciness values; all samples were perceived as tender; fishmeal-fed samples were judged more mealy than larvae-fed samples, with the control being intermediary; larvae-fed samples had higher metallic aroma and aftertaste values, although these values were low and unlikely to be detected by consumers. Comparison of meat-quality characteristics showed no treatment differences for breast- and thigh-muscle colour, pH, water holding capacity or cooking losses. Significant differences were observed for drip loss, with the lowest drip loss reported for the larvae meal-fed samples, followed by the control diet and the highest for fish meal-fed samples. It is concluded that the inclusion of larvae meal into the diets of broilers will have positive rather than any detrimental effects on most carcass, meat and sensory characteristics. Presently, the worldwide poultry industry is experiencing difficulties in maintaining production costs, especially pertaining to energy and protein sources.The effects of Musca domestica (common house fly) larvae meal on the meat quality of broiler chickens were investigated. It was concluded that the inclusion of larvae meal into the diets of broilers will have positive rather than any detrimental effects on most carcass, meat and sensory characteristics. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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15. Carcass composition of Namaqua Afrikaner, Dorper and SA Mutton Merino ram lambs reared under extensive conditions.
- Author
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Burger, A., Hoffman, L. C., Cloete, J. J. E., Muller, M., and Cloete, S. W. P.
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ANIMAL carcasses , *LEAST squares , *CATTLE industry , *ANIMAL products , *MEAT , *MEAT industry , *COOKING - Abstract
This study evaluated the differences in the muscle-fat-bone yield of Namaqua Afrikaner (NA), Dorper (D) and SA Mutton Merino (SAMM) ram lambs. The breeds constituted an indigenous, hardy and late maturing, fat-tailed breed (NA), an early maturing, commercial meat breed (D) and a late maturing commercial dual-purpose breed (SAMM). Lambs were slaughtered at 35 (± 8) days post weaning. Carcasses were cooled for 24 h, separated into retail cuts (leg, loin, rib, and shoulder), weighed and deboned. Meat and fat were separated after deboning and weighed to calculate the muscle-fat-bone yield per cut. Least-square means were computed for the respective breeds, using slaughter age as covariate. Results for percentage meat indicate that, with exception of the rib, retail cuts from the NA breed contained a lower percentage of meat than D and SAMM breeds, particularly in the valuable loin and leg cuts. The shoulder of the NA had a lower percentage meat than that of the D. The percentage fat in retail cuts did not differ between breeds for any of the cuts. In comparison with both D and SAMM, NA contained a higher percentage bone in all cuts. Dorper and SAMM carcasses did not differ in terms of the percentage of bone, fat or muscle for any of the retail cuts. The lower meat yield, particularly in the more expensive loin and leg of the NA, when compared to the commercial meat breed (D) could make the former less preferred for meat production. However, the NA compared more favourably than the dual-purpose SAMM. Differences in carcass composition could be attributed to the fact that the NA is an unimproved and late maturing sheep breed. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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16. Effect of transportation on ostrich (Struthio camelus) weight loss and meat quality.
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Hoffman, L. C., Wolmarans, W. J., Smith, C., and Brand, T. S.
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OSTRICHES , *WEIGHT loss , *STUFFING (Cooking) , *THERAPEUTICS , *MEAT - Abstract
The purpose of this study was to compare the effect of different transport distances on ostrich meat quality parameters, weight loss, and dressing percentage. Twenty-four ostriches were transported for 0 (T0), 60 (T60) and 600 (T600) km before being slaughtered. There was a significant difference (P = 0.038) in the percentage liveweight loss during transport and lairage between T60 km (2.4 ± 2.185%) and T600 km (8.13 ± 1.156%), respectively. There was also a significant difference (P = 0.003) in dressing percentage (farm weight to cold carcass weight) between the two abovementioned groups (T60 = 49.77%; T600 = 46.86%). Treatments also had a significant effect (P < 0.05) on ultimate pH (pH[sub u]), with the ostriches that did not travel exhibiting the lowest average pH[sub u] (5.77 ± 0.053) and the birds that travelled 600 km having the highest average pH[sub u] (6.11 ± 0.053). No differences (P > 0.05) were found in shear force and percentage cooking loss between the treatments, although all three treatments differed significantly (P < 0.05) from each other in drip loss (T0 km = 0.40%; T60 km = 1.36%; T600 km = 0.97%). Significant differences (P < 0.05) were found for L*, b* and hue-angle colour ordinates between the three treatments, while there were no differences (P > 0.05) in a* and chroma values. A significant correlation was found between hue angle (r = 0.528; P = 0.008) and pH[sub u]. The results of this study indicate that ostrich transport distance influences liveweight loss and meat quality. Little is known of the effect of transport distance on the meat quality of ostriches. Ostriches travelled 60 or 600 km to quantify the effect of transport distance on their meat quality. It was shown that the longer the distance ostriches travel, the more negative the effect on the meat yield and quality. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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17. Physical and chemical properties of selected beef muscles infused with a phosphate and lactate blend.
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Hoffman, L. C., Vermaak, A., and Muller, N.
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PHOSPHATES , *LACTATES , *MEAT industry , *BEEF products , *BICEPS femoris , *RECTUS femoris muscles , *INFUSION therapy - Abstract
The consumer demands a beef product of consistent and acceptable tenderness. The infusion of beef muscles with a blend containing sodium and potassium salts, various phosphates and lactates has the potential to improve the current status of low meat consumption and inconsistent tenderness of fresh beef products in South Africa. In the present investigation, the biceps femoris (BF, silverside), rectus femoris muscle (RF), semitendinosus muscle (ST, eye of the silverside), supraspinatus muscle (SS, scotch fillet) and longissimus et lumborum muscles from the left side of beef carcasses were infused, 3 d post mortem, with a blend consisting of various sodium and potassium salts, di- and triphosphates and lactates, while the corresponding muscles from the right side were untreated and served as the control. The changes in beef quality over a 19-d period and the initial proximate and mineral composition of the muscles were also determined. The general findings suggest that an increase in tenderness concurrent with an acceptable beef colour resulted from the infusion with this blend. The chemical composition of the treated muscles was not negatively affected by the infusion and the mineral content of the treated muscles was increased, accordingly. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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18. It takes two to tango: The use of social network theory in explaining knowledge production through research networks.
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Frick, B. L. and Hoffman, L. C.
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SOCIAL networks ,KNOWLEDGE base ,MODERN society ,COOPERATIVE inquiry ,PROBLEM solving ,EDUCATION policy - Abstract
Contemporary society presents researchers with complex problems that often demand collaborative inquiry to extend the existing knowledge boundaries. Research networks give researchers access to a wider pool of expertise in solving such complex problems. This article uses social network theory to explore the different ways in which such networks are formed. Network formation is based on ties that are belonging, bonding or binding, which may influence how resources become accessible and distributed. We argue that research networks can be formed in all three these ways, and that universities exist amidst such multiple networks. An ecological understanding of the multiplicity of network formation may enable universities and academics to foster a variety of approaches to establishing and supporting knowledge production through research networks -- implying a functional relationship akin to the delicate balance between tango dancers and the music. [ABSTRACT FROM AUTHOR]
- Published
- 2012
19. The fatty acid composition of muscles and fat depots of ostriches as influenced by genotype.
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Hoffman, L. C., Brand, M. M., Cloete, S. W. P., and Muller, M.
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MUSCLE physiology , *FATTY acids , *OSTRICHES , *GENOTYPE-environment interaction , *CROSSBREEDING , *POLYENES - Abstract
Three genotypes of ostrich (South African Black, Zimbabwean Blue Necks and crosses between Zimbabwean Blue Neck males x South African Black females) were used to investigate the influence of genotype on the fatty acid composition of the musculus gastrocnemius and musculus ilioflbularis, and abdominal and breast fat depots. Total saturated fatty acids in both the m. gastrocnemius and m. ilioflbularis were higher in crosses (36.4% and 35.9%) than in South African Black ostriches (32.9% and 30.4%), whereas mono-unsaturated fatty acids were highest in South African Black ostriches. Total polyunsaturated fatty acids in the m. gastrocnemius were lowest in South African Black ostriches (26.5%) compared with the Zimbabwean Blue Necks (33.2%). Neither the ratio of polyunsaturated to saturated (0.73 to 0.99) nor n-6 to n-3 (1.6 to 2.2) fatty acids were influenced by genotype, although the ratio of polyunsaturated to saturated fatty acids in Zimbabwean Blue Necks was higher in the m. gastrocnemius (0.99) than in the m. ilioflbularis (0.73). Differences in individual fatty acids were prominent in the breast fat, and total saturated and monounsaturated fatty acids differed between genotypes in both breast and abdominal fat. Only the ratio of polyunsaturated to saturated fatty acids in the fat depots differed between South African Black (0.48) and Zimbabwean Blue Neck ostriches (0.42). The latter ratio was higher in the breast (0.50) than abdominal (0.42) fat in Zimbabwean Blue Necks. These results indicate that crossbreeding of different genotypes of ostriches reared under similar conditions does influence the overall fatty acid profiles of meat and fat. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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20. Quality characteristics of blue wildebeest (Connochaetes taurinus) meat.
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Hoffman, L. C., van Schalkwyk, S., and Muller, M.
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BRINDLED gnu , *MEAT , *GNUS , *NATURE reserves , *BIOCHEMISTRY , *BLESBOK , *IMPALA - Abstract
The Muscularis Iongissimus dorsi of eight blue wildebeest (Connochaetus taurinus), collected at Sandveld Nature Reserve, South Africa, were analysed for biochemical and physical characteristics and chemical composition. The initial (6.60) and final (5.41) pH, drip loss (4.91%), cooking loss (39.42%) and maximum Warner-Bratzler shear force (4.91 kg/ 1.27 cmo) were comparable to values found in meat from several other African game species (black wildebeest, blesbok, duiker, impala, red hartebeest, reedbuck, springbok, warthog). Like other wild ungulates, blue wildebeest meat had a higher crude protein (22.28%) and lower lipid (1.06%) content compared to beef, which makes it a healthy alternative to traditional red meat. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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21. Comparison of the effects of different transport conditions and lairage times in a Mediterranean climate in South Africa on the meat quality of commercially crossbred Large white × Landrace pigs.
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Hoffman, L. C. and Fisher, P.
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- *
AUTOMOTIVE transportation , *MEAT quality , *GLYCOGEN , *LANDRACE swine , *SUMMER , *POWER resources - Abstract
Information on the effect of road transportation conditions and lairage times on the meat quality of pork under South African conditions is very sparse. In this investigation, the effects of 2 road conditions (rough road with frequent stops - A; smooth road, few stops - B) and 2 tairage holding periods (2 h and 24 h) on the physical meat quality attributes of commercially produced pigs during summer (ambient temperatures >30 °C) in the Western Cape (South Africa) were investigated. Pig meat from pigs transported on a road that caused more stress (A), had lower pH4s (measured 45 nun post mortem) values after 2 h lairage than pigs transported over a smoother road. Pigs B had a lower muscle pH24 (measured 24 h post mortem) than group A, indicating that they had more glycogen reserves available for post mortem glycolysis. Road conditions A were more stressful resulting in a higher incidence of PSE pork, as shown by the percentage drip loss and the L* values. When the lairage period was increased to 24 h prior to slaughter, pigs transported under road conditions A had time to replenish their energy reserves and the pH45, drip loss and L values were within an acceptable range. However, pigs transported under road conditions B had lower pH45 and higher pH24 values, indicating that the lairage period was too long and that energy reserves were depleted in order to adapt to the stressful conditions. Results from this investigation indicate that improvement of the transport/road conditions will result in better pork quality. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
22. Prevalent organisms on ostrich carcasses found in a commercial abattoir.
- Author
-
Hoffman, L. C., Britz, T. J., and Schnetler, D. C.
- Subjects
- *
MICROBIAL growth , *CATTLE carcasses , *SLAUGHTERING , *OSTRICHES as food , *MEAT quality , *SHELF-life dating of food , *GRAM-negative bacteria , *PSEUDOMONAS - Abstract
The prevalent microbial growth on carcasses before and after overnight cooling in an ostrich abattoir and de-boning plant was investigated. The effect of warm or cold trimming of the carcasses was examined together with possible causes of contamination along the processing line. An attempt was made to link the prevalent microorganisms that were identified from carcasses to those from specific external contamination sources. Samples of carcasses and possible contaminants were collected in the plant, plated out and selected organisms were typed using a commercial rapid identification system. It was indicated that the cold trim (mainly of bruises) of carcasses was advantageous in terms of microbiological meat quality. Results indicated pooled water in the abattoir as the most hazardous vector for carcass contamination and that contaminants from this source are mostly Gram-negative pathogens. Pseudomonas and Shigella were frequently isolated from surface and air samples and indicated that the control of total plant hygiene is a requirement for producing ostrich meat that is safe to consume and has an acceptable shelf-life. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
23. Effect of bleeding method and low voltage electrical stimulation on meat quality of ostriches.
- Author
-
Hoffman, L. C., Cloete, S. W. P., van Schalkwyk, S. J., and Botha, S. St. C.
- Subjects
- *
OSTRICH farms , *THORACIC arteries , *AORTIC aneurysms , *THROAT , *MEAT quality - Abstract
The effect on ostrich muscle quality of an additional thoracic stick (TS) to the normal ventral throat slit to bleed ostriches after electrical stunning was evaluated. The additional TS had no negative or positive effect on the drip loss, cooking loss, colour or pH and temperature readings of the fillet (Muscularis iliofibularis), big drum (M. gastrocnemius, pars interna) and inside loin (M. iliotibialis cranialis). None the less, personal observations would recommend the use of TS due to ethical considerations. An early post mortem low voltage electrical stimulation (ES) of the carcasses also had no influence on the cooking loss, drip loss and colour of these muscles. Electrical stimulation did result in a lower pH45 in both the fillet and big drum muscles. However, after 24 h the pH of the muscles did not differ. Electrical stimulation also caused elevated initial muscle temperatures, although this effect was only temporary due to the efficient cooling mechanism used in the abattoir. Electrical stimulation also had no effect on the Warner Bratzler shear force values in the fillet. It can be concluded that low voltage ES has no advantage pertaining to physical quality characteristics of importance in an ostrich abattoir. [ABSTRACT FROM AUTHOR]
- Published
- 2009
24. Carcass characteristics and meat quality of progeny of five Merino dam lines, crossed with Dormer and Suffolk sires.
- Author
-
Cloete, J. J. E., Hoffman, L. C., and Cloete, S. W. P.
- Subjects
- *
MEAT quality , *LIVESTOCK carcasses , *ANIMAL genetics , *ANIMAL breeding , *ANIMAL genetic engineering , *MERINO sheep - Abstract
This study details the slaughter traits of lambs born from a terminal crossbreeding experiment that involved five Merino type dam lines crossed with Dormer and Suffolk sires. Dam lines included dual purpose types; South African Mutton Merino (SAMM), Dohne Merino, SAMM rams crossed to commercial Merino ewes (SAMM cross) and specialist Merino lines selected either for clean fleece weight (FW+) or for an increased fertility (Rep+). Data include between 228 and 483 individual records, depending on the trait. The unadjusted fat depth 25 mm from the midline at the 13th rib of lambs from dual-purpose ewes was between 22 and 32% greater than that of lambs from FW+ Merino ewes. Progeny from Rep+ Merino ewes showed a closer resemblance to the progeny of dual-purpose breeds than to those of FW+ Merino ewes in this instance. Adjustment for slaughter weight eliminated these differences. The initial pH of meat from progeny of FW+ Merino ewes was lower than that from progeny of dual-purpose ewes, and Rep+ Merino ewes. No differences in Warner-Bratzler shear values of the meat were found between the different crosses. Crossbred progeny of the Merino lines performed satisfactorily for all the traits considered, and will not be discriminated against in the market. No conclusive differences in favour of either sire breed were found. [ABSTRACT FROM AUTHOR]
- Published
- 2008
25. Effects of post mortem temperature on rigor tension, shortening and pH in ostrich muscle.
- Author
-
Botha, S. St C., Hoffman, L. C., and Britz, T. J.
- Subjects
- *
OSTRICHES , *MUSCLES , *RIGOR mortis , *POSTMORTEM changes , *TEMPERATURE - Abstract
Fully developed rigor mortis in muscle is characterised by maximum loss of extensibility. The course of post mortem changes in ostrich muscle was studied by following isometric tension, shortening and change in pH during the first 24 h post mortem within muscle strips from the muscularis gastrocnemius, pars interna at constant temperatures of 7 °C and 37 °C. Maximum shortening was significantly higher at 37 °C (33.4 ± 3.57%) than at 7 °C (10.7 ± 2.63%). The rate of rigor development was temperature dependent, reaching a maximum tension at 4.08 ± 3.89 h post mortem in muscle strips at 37 °C; while at 7 °C maximum tension was reached at 10.5 ± 6.47 h post mortem. It was concluded that the completion of rigor occurred at the point of minimum pH. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
26. Carcass and muscle yields of ostriches as influenced by genotype.
- Author
-
Hoffman, L. C., Brand, M. M., Muller, M., and Cloete, S. W. P.
- Subjects
- *
ANIMAL carcasses , *OSTRICHES , *GENOTYPE-environment interaction , *WEIGHT (Physics) , *GENETIC polymorphisms - Abstract
Live, carcass, leg and muscle weight (kg) as well as dressing percentage were compared between South African Black (Struthio camelus var. domesticus) ostriches, purebred Zimbabwean Blue Neck (Struthio camelus australis) ostriches and the progeny of Zimbabwean Blue Neck males crossed with South African Black females, commercially slaughtered at 14 months of age. South African Black ostriches had the lowest live (84.9 kg) and carcass (43.3 kg) weights, compared to Zimbabwean Blue Necks (100.9 and 51.2 kg, respectively). In general, crossbred birds resembled Zimbabwean Blue Necks more closely for the quantitative meat traits. However, dressing percentage (51.1%) and yields of different carcass components (bone, leg) did not differ between genotypes. Six of the major muscles present in the ostrich leg (M. gastrocnemius, M. femorotibialis accessorius, M. iliotibialis cranialis, M. iliotibialis lateralis, M. iliofibularis and M. iliofemoralis) showed significant weight differences between genotypes, with South African Black ostriches yielding the lowest values. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
27. Effect of slaughter age and breed on the carcass traits and meat quality of beef steers finished on natural pastures in the arid subtropics of South Africa.
- Author
-
Du Plessis, I. and Hoffman, L. C.
- Subjects
- *
BEEF cattle , *CATTLE breeds , *CATTLE carcasses , *MEAT quality , *PASTURES - Abstract
Simmentaler cross (SX), Bonsmara cross (BX) and Nguni (NG) steers were raised on natural sweet veld pastures and slaughtered at 18 or 30 months of age. Slaughtering occurred at the end of the wet summer season. Live weight and carcass traits were significantly influenced by breed and slaughter age. The amount as well as percentage kidney and omental fat differed significantly between the respective slaughtering ages, but only between breeds at 30 months of age. Breed and slaughter age affected back-fat thickness. All fat parameters were lower at 18 months than at 30 months of age. Breed did not have a large influence on meat quality attributes, but age did. Drip loss was similar for the breeds and slaughter age groups. The meat was darker and more red at 30 months than at 18 months of age. The pH24 of the longissimus muscle was 5.51 and 5.67 at 18 and 30 months of age, respectively. No breed differences were detected for sensory panel attributes or Warner-Bratzler shear force values. Sensory panel tenderness and Warner-Bratzler shear force values indicated tougher meat from 30-month old steers than from 18-month old steers. Differences in meat quality were probably due to the combined effects of fatness, pH and collagen characteristics. It is concluded that in sweet veld areas steers from small- to medium-framed breeds can be raised successfully and slaughtered at 30 months of age without supplementation of natural pastures. Slaughtering steers at younger ages may require supplementary feeding or feedlot finishing. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
28. Effect of hot-deboning on the physical quality characteristics of ostrich meat.
- Author
-
Botha, S. St. C., Hoffman, L. C., and Britz, T. J.
- Subjects
- *
ZOOLOGICAL research , *OSTRICHES , *MICROBIAL contamination , *DEBONING of meat , *FOOD production - Abstract
The effects of hot-deboning on the physical meat quality characteristics and shelf-life of ostrich m. gastrocnemius, pars interna (gastroc) and m. iliofibularis (iliof) were investigated during 42 days (d) of refrigeration. The hot-deboned gastroc was initially tougher than the cold-deboned muscles, while hot-deboning had no significant effect on the shear force of the iliof. After 14 d of refrigerated storage, there was no difference in tenderness between the hot- and the cold-deboned muscles. Hot-deboning caused significantly more purge (3.4 ± 2.33%) compared to cold-deboning (2.1 ± 2.06%) throughout the 42-day storage period. All muscle samples were acceptable in terms of Aerobic Plate Counts (APC < 104 cfu/g) and E. coli (E. coli < 10¹ cfu/g), based on the South African Standards for the microbiological monitoring of meat for refrigerated export. It was concluded that hot-deboning did not influence the shelf-life of ostrich muscles negatively. [ABSTRACT FROM AUTHOR]
- Published
- 2006
29. Consumer expectations, perceptions and purchasing of South African game meat.
- Author
-
Hoffman, L. C., Muller, M., Schutte, De. W., Calitz, F. J., and Crafford, K.
- Subjects
- *
WILDLIFE as food , *PURCHASING , *CONSUMER behavior , *CONSUMERS , *MEAT industry - Abstract
The expectations, perceptions and purchasing behaviour of consumers of game meat were researched by a survey method using a structured, self-administered questionnaire. The sample consisted of 300 South African consumers and included 100 white, 100 coloured and 100 black consumers. It is evident that South African consumers perceive game meat differently than they do the 'traditional' meat types such as beef, mutton/lamb, chicken and pork. They do not consider game meat as a 'regular' type of meat, but rather as an exotic, seasonal product. Furthermore, South African consumers indicated that they are not willing to pay more for game meat than other types of meat. South African consumers indicated that they consider the fat content of meat as an important quality when they purchase meat, as they aspire towards consuming lean meat. This research not only shows that South African consumers are ill-informed regarding the positive attributes of game meat, but also that producers and marketers of game meat are not doing enough to promote game meat. This provides an excellent opportunity for game meat producers and marketers, as game meat is lower in fat than pork, lamb or beef. [ABSTRACT FROM AUTHOR]
- Published
- 2005
30. The retail of South African game meat: current trade and marketing trends.
- Author
-
Hoffman, L. C., Muller, M., Schutte, De W., and Crafford, K.
- Subjects
- *
SUPERMARKETS , *WILDLIFE as food , *FOOD , *CATTLE industry - Abstract
The purchasing and marketing of game meat by supermarkets and butcheries in the Western Cape Province of South Africa was researched by the survey method. Two supermarket groups in South Africa indicated that they do market game meat, and springbok (Antidorcas marsupialis) was the species that most supermarkets sold. Both supermarket groups indicated that they would sell more game meat if available. They also mentioned that a central marketing structure would facilitate the sale of game meat and ensure consistent quality. Thirteen of the twenty butcheries that sell game meat were also in favour of a central marketing structure. The butcheries indicated that consumers are not adequately informed about the health benefits and cooking methods of game meat. Some of the meat buyers at butcheries were ignorant of the qualities of meat that are important when purchasing game meat. It is evident that game meat marketers should exercise stricter control over the quality of game meat, and that supermarkets and butcheries are not promoting game meat extensively enough. [ABSTRACT FROM AUTHOR]
- Published
- 2004
31. A comparison between the body composition, carcass characteristics and retail cuts of South African Mutton Merino and Dormer sheep.
- Author
-
Cloete, J. J. E., Hoffman, L. C., Cloete, S. W. P., and Fourie, J. E.
- Subjects
- *
CATTLE carcasses , *SHEEP , *FATTY acids , *EWES , *MONOUNSATURATED fatty acids - Abstract
The body composition, carcass characteristics and retail cuts of 61 Dormers (21 rams and 40 ewes) and 35 South African Mutton Merinos (SAMM) (17 rams and 18 ewes) were determined. A range of carcass measurements was recorded. Since there was no sex x breed interaction, only main effects of breed and sex were considered. There were no differences in slaughter weight between Dormer and SAMM sheep at 18 months of age. Dormers had a 2.7% point higher dressing percentage and a 6.2% higher carcass weight than the SAMM. The Dormer had a higher fat content (kidney fat, back-fat depth) than the SAMM. The eyemuscle area of the Dormers was 13% larger than that of the SAMM sheep. Rams were heavier than the ewes at slaughter. All the traits measured, indicated advantages in favour of rams. Only the saturated, monounsaturated fatty acids and polyunsaturated fatty acids to saturated fatty acids ratio differed significantly between the Dormer and SAMM sheep. Based on the fatty acid profile, SAMM meat is slightly healthier than that of Dormer sheep. The higher retail cut weights of Dormers suggested that they were superior to the SAMM as far as meat production was concerned. [ABSTRACT FROM AUTHOR]
- Published
- 2004
32. Effect of chronological age of beef steers of different maturity types on their growth and carcass characteristics when finished on natural pastures in the arid sub-tropics of South Africa.
- Author
-
Du Plessis, I. and Hoffman, L. C.
- Subjects
- *
BEEF cattle , *CATTLE carcasses , *BEEF , *GRAZING - Abstract
In the arid sweetveld regions of South Africa producers are marketing beef steers increasingly as long weaners (ca. 12 months of age) or finishing them on the natural grazing to a ready-to-slaughter stage at between 18 and 30 months of age. Limited production norms in this regard are available since most growth and carcass studies have been conducted in the sourveld regions of the country. In this study steers from four different beef maturity types which differ in body frame size were used, viz. Simmentaler crosses (large, >500 kg mature weight), Bonsmara crosses (large-medium, 450-500 kg mature weight), the Afrikaner (small-medium, 400-450 kg mature weight) and the Nguni (small, <400 kg mature weight). After weaning the steers in each type were randomly allocated to three groups, viz. groups slaughtered at 18, 24 or 30 months of age after raising them on natural sweetveld pasture. Live weight, cold carcass weight, carcass fat classification code and number of visible incisors were recorded. Growth rates from weaning to 24 months of age were similar for the different maturity types, though the Afrikaner steers gained significantly less than the Bonsmara crossbreds. Periods where high growth rates occurred (at 12 to 18 months of age and 24 to 30 months of age) coincided with the rainy season. Relatively low dressing percentages were noted and could be attributed to the fact that all internal organs and fat were removed at slaughtering, as well as a possible high level of gut fill. Due to genetic variation within maturity types it was not possible to predict the market readiness of a particular individual from its live weight. The carcass weights were heavier for steers slaughtered at 24 months of age than those at 18 months of age, but had a lower fat classification code. This seems to be due to the fact that these steers were slaughtered at the end of the winter period when the quality of the grazing was at its lowest. The carcasses of all maturity types... [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
33. A comparison between the effects of two cropping methods on the meat quality of impala (Aepyceros melampus).
- Author
-
Kritzinger, B., Hoffman, L. C., and Ferreira, A. V.
- Subjects
- *
IMPALA , *BIG game animals , *AEPYCEROS , *ANIMAL products , *MEAT quality - Abstract
Impala (Aepyceros melampus) constitute one of the most commercially important species in game farming in South Africa. The purpose of this study was to compare the effects of day and night cropping on the meat quality characteristics of impala. Emphasis was placed on the influence of the cropping method on muscle pH[sub45] (45 minutes post mortem), pH[subu] (ultimate pH), pH decline, and the related influence on drip loss, cooking loss, toughness and colour of the meat in the M. longissimus lumborum. Measurements taken from 16 animals cropped at night were compared to those taken from 24 animals cropped in daytime. A mean pH[sub45] of 6.67 ± 0.11 was recorded for the night cropped animals compared to a mean pH[sub45] of 6.55 ± 0.23 for the day cropped animals. A mean pH[subu] of 5.39 ± 0.08 for animals cropped at night was recorded compared to a mean pH[subu] of 5.45 ± 0.11 for the animals cropped in the day. Regression analysis showed the rate of pH decline to be slower in the night cropped animals compared to those cropped in the day. This persisted when the pH values were adjusted to correct for ambient temperature. The cooling rate of the M. longissimus lumborum was twice as fast in the night cropped group. Shear force values and drip losses respectively, for the night-cropped animals were 19.11 ± 5.68 g/mm² and 2.93 ± 1.59%, whereas for the day cropped animals the values were 23.42 ± 8.13 g/mm² and 4.15 ± 2.34%. The results of this study indicate that night-time cropping does have a beneficial effect on certain meat quality parameters. [ABSTRACT FROM AUTHOR]
- Published
- 2003
34. Effects of various dietary n-3/n-6 fatty acid ratios on the performance and body composition of broilers.
- Author
-
Coetzee, G. J. M. and Hoffman, L. C.
- Subjects
- *
FATTY acids , *BROILER chickens , *BODY composition of poultry - Abstract
Presents a study which examined the effects of various dietary n-3/n-6 fatty acid ratios on the performance and body composition of broilers. Materials and methods; Results and discussion; Conclusion.
- Published
- 2002
35. A chemical comparison between the golden and normal coloured strains of the African sharptooth catfish, Clarias gariepinus (Burchell 1822).
- Author
-
Hoffman, L. C., Prinsloo, J. F., Theron, J., and Casey, N. H.
- Published
- 1995
- Full Text
- View/download PDF
36. A COMPARISON OF ALLOZYME HETEROZYGOSITY AND LIFE HISTORY VARIABLES IN FOUR STRAINS OF AFRICAN CATFISH (CLARIAS GARIEPINUS).
- Author
-
Grobler, J. P., Hoffman, L. C., and Prinsloo, J. F.
- Published
- 1997
- Full Text
- View/download PDF
37. COMPARISON OF FISH GONADS AND FISH MEAL AS MAJOR COMPONENTS IN THE DIETS OF YOUNG AFRICAN SHARPTOOTH CATFISH, CLARIAS GARIEPINUS (BURCHELL).
- Author
-
Hoffman, L. C., Prinsloo, J. F., and Theron, J.
- Published
- 1994
- Full Text
- View/download PDF
38. Post-mortem changes in the physical meat quality characteristics of refrigerated impala M. longissimus dorsi.
- Author
-
Hoffman, L. C.
- Subjects
- *
AGING , *ANIMALS , *MEAT industry , *ANIMAL industry , *QUADRATIC equations - Abstract
The effect of aging the M. longissimus dorsi of 13 impala at 4°C over a ten-day period was investigated. Large variation between animals was observed for the percentages drip and cooking loss as well as for the CIELab colour (L*, a*, b*) values. No trend could be observed for these physical characteristics over time. Means for all traits correspond to that reported in the literature for this species. Similarly, the tenderness of the muscle varied between the animals. However, the tenderness (as measured by a Warner Bratzler shear apparatus) of the muscle generally improved with time. The quadratic equation y = -0.0817x⊃2 + 0.4468x + 10.477 best described (R ⊃2 = 0.32) this improvement in tenderness. The implications of this result is that fresh game meat producers can de-bone carcasses after 24 hours post mortem and leave the primal cuts to age in vacuum bags in the chiller, thereby utilizing the available chiller space more efficiently. [ABSTRACT FROM AUTHOR]
- Published
- 2004
39. Wool production in Dohne Merino, Dormer, Merino and South African Mutton Merino lambs.
- Author
-
Van der Merwe, D. A., Brand, T. S., and Hoffman, L. C.
- Subjects
- *
WOOL , *LAMBS , *MERINO sheep , *SHEEP , *GROWTH rate , *SHEEP diseases - Abstract
In this study, the wool growth of Dohne Merino, Dormer, Merino and South African Mutton Merino (SAMM) lambs reared on a feedlot diet (10.62 MJ ME/kg feed, 20.7% crude protein) was monitored from about two months old until the lambs were shorn as yearlings. The 100 cm2 patches on the left sides of the lambs were sheared monthly and the clippings were weighed to determine the wool growth rate. At approximately one year old, the lambs were shorn and the fleeces were weighed. A mid rib fleece sample was also retrieved from each lamb for quality analysis. Merino lambs presented the highest wool growth rates (12.943 g/day) and fleece weights (6.140 kg), whereas Dormer lambs exhibited the lowest values for these traits (8.487 g/day and 3.330 kg, respectively (P <0.05)). The lack of differences between Dohne Merino (9.720 g/day and 4.671 kg) and SAMM (10.553 g/day and 4.158 kg) lambs for these wool growth rate and fleece weight traits was attributed to disparities in live weight (86.8 kg and 105.2 kg, respectively (P <0.05), with heavier SAMM lambs offsetting the expected variations in fleece weight. Wool from Dohne Merino and Merino sheep had the finest fibre diameters (<21 µm), followed by SAMM wool (22-23 µm), with Dormers producing coarse wool (>27 µm). These results could be used as guidelines in sheep production to predict the income contribution of wool from these breeds. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
40. Effect of including canola meal in diets of slaughter ostriches (Struthio camelus var. domesticus).
- Author
-
Brand, T. S., van der Merwe, J., and Hoffman, L. C.
- Subjects
- *
OSTRICHES , *SOYBEAN meal , *ANIMAL nutrition , *SLAUGHTERING , *THYROID gland , *CANOLA , *ERECTOR spinae muscles - Abstract
Canola meal (CM) is a locally produced protein source that may be less expensive than soybean meal (SBM). This study evaluated the effects of replacing 0%, 25%, 50%, 75%, and 100% SBM with CM in diets for slaughter ostriches. The CM was added at the expense of SBM and other concentrates, with minor changes in other ingredients. Birds (n = 15 per treatment) were reared from 77 to 337 days old on the trial diets, which were supplied ad libitum for starter, grower, and finisher phases. Bodyweights and feed intake were measured during these phases. No differences (P >0.05) were found between treatments for live weight at the end of each phase, dry matter intake (DMI), average daily gain (ADG) and feed conversion ratio (FCR) over all the growth phases. Although no differences were observed in live weight at the end of each phase, the birds reared on the diet with 50% CM were heaviest at slaughter, and birds reared with 100% CM were lightest (P <0.05). Differences (P <0.05) between diets were observed for the weight at slaughter, weights of the liver and thyroid glands and the pH of the cold carcass. However, no differences (P >0.05) were observed between diets for fat pad weight, dressing percentage, and weights of thighs and Muscularis gastrocnemius. The results indicate that CM could replace SBM in the diets of slaughter ostriches without affecting production traits and slaughter yields. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
41. Premium lamb production of South African sheep breed types under feedlot conditions.
- Author
-
van der Merwe, D. A., Brand, T. S., and Hoffman, L. C.
- Subjects
- *
FEEDLOTS , *LAMBS , *SHEEP breeds , *METABOLIZABLE energy values , *BODY weight , *EWES - Abstract
An increasing number of producers opt to finish their lambs in on-farm feedlots. Therefore, detailed production information is required to implement precision finishing of lambs of different genotypes. Precision finishing monitors growth, feed intake and efficiency to optimize management. In this study, feedlot production characteristics of Dohne Merino, Dormer, Dorper, Meatmaster, Merino, Namaqua Afrikaner, and South African Mutton Merino (SAMM) lambs were evaluated. The lambs were reared in a feedlot and fed a diet with 10.41 MJ metabolizable energy (ME)/kg feed and 19.06% crude protein. Feed intake and body weight were recorded weekly from an initial weight of 30 kg until they had the subcutaneous fat cover needed to produce an A2 carcass. Subcutaneous fat was measured on the Longissimus lumborum muscle with an ultrasound scanner. Dorper, Meatmaster and Namaqua Afrikaner had the shortest rearing periods in the feedlot, and were market ready at a lower live weight (P <0.05). As a result, these lambs consumed less feed in the feedlot. Namaqua Afrikaner and Merino lambs were least efficient: 7.08 and 5.63 kg feed/kg gain, respectively. Dohne Merino, Dormer, Dorper, and Meatmaster rams and Dorper ewes were more efficient; approximately 3.58 kg feed/kg gain. Dohne Merino and Dormer rams had the highest growth rates: approximately 465 g/day. The end weights described in this study could be used as an indication for producers of the ideal slaughter weights for breeds of different maturity types. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
42. Correlations between PORCUS classification and androstenone in boars, and effects of cooking methods thereon.
- Author
-
Needham, T., van Zyl, K., and Hoffman, L. C.
- Subjects
- *
FRENCH fries , *BOARS , *MEAT quality , *MEAT analysis , *CLASSIFICATION , *ERECTOR spinae muscles , *FAT , *SLAUGHTERING - Abstract
The aim of this research was to evaluate relationships between the PORCUS classification system and factors affecting boar taint in pork. Intact male pork carcasses (n = 176) were randomly selected in a South African commercial abattoir from three PORCUS carcass classification groups (P, O and R) and samples from their Longissimus lumborum (LL) were obtained at 24 hours post mortem. Correlations between carcass weight, backfat depth, intramuscular fat percentage and subcutaneous fat androstenone concentrations were estimated. A sub-sample of O carcasses (n = 12) with high levels of androstenone levels were used to determine the influence of pan-frying, oven-roasting and sous vide cooking methods on meat proximate composition and fat androstenone concentration. Although O carcasses were heaviest, backfat depth increased over the carcass classifications. Intramuscular fat percentages were lowest in O carcasses, and crude protein percentages were higher in O compared with R carcasses. The correlation between percentages of backfat depth and LL intramuscular fat was insignificant. No differences were observed between classifications in androstenone concentration, which had a weak positive correlation with carcass weight. All cooked samples exceeded the established sensory threshold for androstenone (>0.45 µg/g). Cooking methods were ineffective in decreasing the potential for consumers to experience boar taint. Therefore, alternative processing methods should be considered for these carcasses. In addition, the PORCUS classification system cannot be used reliably to estimate the intramuscular fat content or androstenone concentration of a carcass. These findings are interpreted to suggest a revision of the application of the current classification system is required. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
43. Growth, carcass and meat quality traits of two South African meat rabbit breeds.
- Author
-
North, M. K., Zotte, A. Dalle, and Hoffman, L. C.
- Subjects
- *
MEAT quality , *RABBIT meat , *RABBIT breeding , *FAT content of meat , *SOUTH Africans - Abstract
Rabbits could contribute to meat production in South Africa. However, little research has been done on rabbit farming in the country, including on the performance of locally available meat breeds. This study examined the meat production of the New Zealand White (NZW) and Phendula rabbit breeds. The live weights (LW) and average daily gains (ADG) of 80 (44 male, 36 female) NZW and 40 (22 male, 18 female) Phendula rabbits, housed in single-sex groups of three, were recorded from weaning (5 weeks) until slaughter (11 weeks). The slaughter weight, and carcass, organ, and carcass portion weights were recorded for 10 male rabbits and 10 females of each breed, and the physical and proximate chemical quality of the loin meat was determined. The breeds differed for the reference carcass (RC) yield (NZW: 85.3 ± 0.14%; Phendula: 84.9 ± 0.24%) and the proportions of the low-value fore (NZW: 38.6 ± 0.26%; Phendula: 37.6 ± 0.28%) and high-value intermediate (NZW: 19.6 ± 0.16%; Phendula: 20.4 ± 0.28%) parts. Females had greater LW and ADG at 11 weeks old, and reduced dressing percentages, but greater RC yields owing to lighter heads and red offal. Females also had smaller proportions of the fore part. Meat quality did not differ between the breeds or sexes. Overall, both breeds compared well to previous reports. However, they appeared to mature relatively early, as indicated by the significant sex differences, and the high carcass and meat fat content. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
44. pH decline of the M. logissimus thoracis of night-cropped Grey Duiker (Sylvicapra grimmia).
- Author
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Hoffman, L. C. and Ferreria, A. V.
- Subjects
- *
DUIKERS , *PHYSIOLOGICAL effects of hydrogen-ion concentration - Abstract
The effect of night cropping (shooting the animal in the head with a light calibre rifle) on the pH[sub 45], pH[sub 24] and rate of pH decline in the M. longissimus thoracis of ten Grey duiker was investigated. A mean pH[sub 45] of 6.28 +/-0.3895 and a mean pH[sub 24] of 5.55 +/- 0.0803 was recorded. The change in pH with time was fitted to the exponential function y = a + b e[sup (ct)] for the pooled data, and values of 5.5156 +/- 0.06294, 0.8387 +/- 0.11184 and -0.2281 +/- 0.07311 were realised for the constants a, b and c, respectively. This exponential function indicates that the pH of duiker meat reaches an asymptotic pH of 5.52 after 24 hrs under these cropping conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2000
- Full Text
- View/download PDF
45. Performance, water intake, carcass characteristics and intestinal histomorphology of broilers supplemented with phytase.
- Author
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van Emmenes, L., Pieterse, E., and Hoffman, L. C.
- Subjects
- *
PHYTASES , *DRINKING (Physiology) , *BONE ash , *BROILER chickens , *DIETARY supplements , *BIRDCAGES , *INTESTINES - Abstract
A 32-day experiment was conducted to study the effects of supplementation of phytase enzyme, Ronozyme® HiPhos (DSM Nutritional Products, Basel, Switzerland), on the production parameters, water intake, intestinal histomorphology, carcass characteristics and bone mineralization of broiler chickens. A total of 1920 one-day-old Cobb 500 broilers were randomly allocated to one of three treatments, each comprising eight replicate cages (eight replications per treatment) with 80 birds per cage. Dietary treatments were created using a standard commercial diet as the positive control (CON); reducing the nutrient content of the CON diet with values similar to the matrix values of 1500 FYT (phytase units) Ronozyme® HiPhos to create the negative control diet (NEG); and supplementing the NEG diet with 1500 FYT/kg Ronozyme HiPhos to create the phytase diet (HiPhos). Supplementation of the NEG diet with HiPhos significantly improved average daily gain (ADG), feed conversion ratio (FCR), bodyweight (BW) at slaughter and the European production efficiency factor (EPEF) of broilers compared with those in the NEG treatment group, but had no effect on total feed intake, water intake, villi height, crypt depth, dressing percentage, portion yields, pH of the meat or colour of the meat. Fat-free bone ash percentage and tibia breaking strength of broilers in the HiPhos treatment group were intermediate to broilers in the NEG and CON treatment groups. Results from the study proved that broilers could be supplemented with HiPhos phytase without detrimental effects on growth parameters, bone mineralization, carcass characteristics and water intake. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
46. Importance and implications of antibiotic resistance development in livestock and wildlife farming in South Africa: A Review.
- Author
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van den Honert, M. S., Gouws, P. A., and Hoffman, L. C.
- Subjects
- *
DRUG resistance in microorganisms , *ANTIBIOTICS , *VETERINARY medicine , *LIVESTOCK , *AGRICULTURE , *FOODBORNE diseases , *WILDLIFE as food - Abstract
Antibiotic resistance (ABR) is regarded as one of today's major global health challenges. The development of ABR in nature is a complex phenomenon with many influencing factors, of which the farming industry is labelled a significant contributor. The transfer of ABR to humans, which usually occurs via the food chain, is of concern for human health. A food source that is increasing in popularity is game meat, which is farmed widely in South Africa. The natural environment, including wildlife, is not isolated from the rest of the farm, and thus could be a source of ABR or possibly a transfer vector. It is therefore important to assess the ABR situation in wildlife species and the factors that influence its emergence and transfer. Elements that play a part in the development of ABR in game species include certain harvesting and slaughtering and other farming practices and closer contact with humans and other farm animals. Additionally, natural transfer vectors include wind, water, manure, crops and animals. Worryingly, there is lack of knowledge of this situation owing to inadequate monitoring, documentation and control of antibiotics in the farming industry. The objective of this review was to gain better understanding of this situation, which would aid in the development of surveillance systems and methods to prevent or hinder the development of ABR in wildlife species. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
47. Structure in Vitreous Silicates as shown by Low-angle Scattering of X-Rays.
- Author
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HOFFMAN, L. C. and STATTON, W. O.
- Published
- 1955
- Full Text
- View/download PDF
48. Castration of male livestock and the potential of immunocastration to improve animal welfare and production traits: Invited Review.
- Author
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Needham, T., Lambrechts, H., and Hoffman, L. C.
- Subjects
- *
MALE livestock , *CASTRATION , *ANIMAL welfare , *AGRICULTURE , *MEAT quality - Abstract
Growing consumer awareness about animal welfare has led to the assessment of the impact of common farming practices, such as physical castration, on animal well-being under production conditions. Physical castration is used in livestock industries to prevent indiscriminate breeding, control aggression, and improve meat and carcass quality. In terms of animal welfare, physical castration causes pain, decreased growth performance, infection, and mortality. An alternative approach to castration is thus warranted that will ensure optimal growth without compromising the castrated animal's wellbeing. Immunocastration has proved to be an effective method of suppressing the development and functioning of the reproductive system in various domesticated and wildlife species. The effect of immunocastration on production performance is welldocumented for both swine and cattle. Although ram lambs used for meat production are often physically castrated, information regarding the potential application of immunocastration in sheep is limited. However, immunocastration may potentially improve the welfare, performance, and meat quality of ram lambs used in commercial meat production systems. The purpose of this review is to compare the application and the effects of immunocastration on male livestock to highlight and motivate the need for further research into its use on ram lambs. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
49. The effect of different dietary vitamin and mineral levels on certain production parameters, including egg shell characteristics of breeding ostriches.
- Author
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Brand, T. S., Tesselaar, G. A., Hoffman, L. C., and Brand, Z.
- Subjects
- *
OSTRICHES , *BIRD breeding , *DIETARY supplements , *PHYSIOLOGICAL effects of minerals , *PHYSIOLOGICAL effects of vitamins , *FOOD consumption , *NUTRITIONAL requirements , *REPRODUCTION - Abstract
Earlier studies on breeding birds indicated no effect of dietary energy-content on feed intake. This observation is contradictory to results for other animals and/or poultry where feed intake decreases with an increase in dietary energy level. Literature revealed that a lack of certain nutrients may cause animals to consume more feed than necessary to satisfy their nutrient requirements for these limiting nutrients. In this study eight diet groups were evaluated. A standard commercial diet plus one of the following supplements: (i) Standard diet without a vitamin and mineral premix pack (control diet), (ii) with a normal premix pack, (iii) with normal vitamin and 2 x trace elements (M x 2), (iv) with normal trace elements and 2 x vitamins, (v) with a normal premix pack and limestone added as calcium source; (vi) with a normal premix pack and monocalcium phosphate added as phosphorus source, (vii) with a normal premix pack and soybean oilcake added as crude protein source, (viii) with a normal premix pack and linseed added as a fatty acid source. Significant differences were recorded in the quantity of feed ingested by birds between the diet with surplus minerals (M x 2) (Group 3) (2.3 ± 0.3 kg/bird/day), the diet with no vitamins and minerals added (Group 1) (2.7 ± 0.3 kg/bird/day) and the diet with added fatty acids in the form of linseed (Group 5) (2.9 ± 0.5 kg/bird/day). This indicates the possibility that ostriches may adjust feed intake to satisfy their mineral requirements. No statistically significant relationship was found between the thickness and strength of the shell. Significant differences in shell strength (mean value of 154.7, 109.9, 140.4, 142.7, 153.0, 143.4, 138.4 and 151.1 N/cm², respectively) were found between all treatments, but no specific pattern could be identified. Results further revealed no effect of dietary treatment on egg production, dead-in-shell eggs (DIS), infertile eggs or chick production. Further experiments that include certain dietary treatments during the five months rest period are currently being done to quantify the effect of the addition of minerals and vitamins during this period on the production of breeding ostriches. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
50. Physico-chemical shelf-life indicators of meat from broilers given Moringa oleifera leaf meal.
- Author
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Wapi, C., Nkukwana, T. T., Hoffman, L. C., Dzama, K., Pieterse, E., Mabusela, T., and Muchenje, V.
- Subjects
- *
SHELF-life dating of food , *MEAT , *ANIMAL products , *BROILER chickens , *MORINGA oleifera , *CATTLE industry - Abstract
The objective of the study was to determine the effect of using Moringa oleifera leaf meal (MOLM) as an additive on physico-chemical shelf life indicators of meat from broilers. A total of 432 1-day-old chicks were randomly allocated to four treatments (TRT's). Water and feed was provided ad libitum. The feeding phases were pre-starter (0 to 7 days), starter (8 to 18 days), grower (19 to 28 days) and finisher (29 to 35 days).The four TRT's contained graded levels of the MOLM at 1000 g/ton, 750 g/ton, 500 g/ton and 0 g/ton (control), respectively. The birds were slaughtered at 35 days of age and the breast muscle was sampled for meat pH, colour and drip loss measurements over 7 days. The pH levels in all the TRT's were constant from Day 1 to Day 5, peaking on Day 6, and then declining on Day 7. Using MOLM as an additive had a significant effect on chickens, with TRT1 having the highest lightness (L*) values. The redness (a*) values were the highest in TRT2. Using MOLM as an additive had an effect on yellowness (b*) values. Drip loss was not affected by the dietary treatments. Using MOLM as an additive in broiler feeds produced chicken breast with a light (L*) appearance while shelf life indicators generally remained constant in the first 5-days of storage. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
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