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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]

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]

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]

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]

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]

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]

Eighteen F1 crossbred (commercial-type terminal crosses) pigs (boars, barrows and gilts) with an initial weight of 27.2 ± 2 kg were used to investigate the effect of porcine somatotropin (pST) administered for six weeks prior to slaughter on production parameters and tissue yield in the South African scenario. Pigs were grown to 135 kg live weight, which is heavier than the average weight at slaughter in South Africa of 80 - 100 kg. Porcine somatotropin had no significant effect on average daily gain or feed intake. However, pST administration caused a significant increase in feed conversion ratio (kg feed/kg gain) of treated boars, indicating that boars converted their feed less efficiently when treated with pST. This contradicts most of the findings in the literature. The effect of pST on the different carcass cuts was not significant, except for the percentage loin back, which was higher for pST-treated animals and percentage middle back of boars and barrows, which was slightly higher. No significant pST effects were found for live weight, carcass weight, % bone, % fat or % lean meat, but a significant increase in percentage skin was found. [ABSTRACT FROM AUTHOR]

Ostrich skins (n = 214) were assessed by 28 participants involved in the ostrich leather production and marketing chain. The participants were from various sectors in the ostrich industry, including producers, skin graders, leather marketers, agents and process managers. Skins were evaluated during two occasions, firstly without any knowledge of slaughter age and thereafter with prior knowledge of slaughter age. Nodule acceptability and distribution for each skin were scored on a linear scale of 1 to 10. Slaughter age, as estimated by the participants during the first evaluation, was regressed on the actual age of the birds at slaughter. The derived regression indicated that actual slaughter age accounted for approximately 46% of the variation found in estimated slaughter age. Nodule acceptability scores generally increased with slaughter age. Average scores of at least moderately acceptability were found only in skins from birds slaughtered at 11 months of age and older. A corresponding trend with increase in slaughter age was found for nodule distribution scores. Between skin variance ratios were comparatively low for nodule acceptability (0.09-0.10, depending on prior knowledge of slaughter age or not) and nodule distribution (0.05-0.06). The between scorer variance ratio was generally higher, exceeding 0.35. Scores for nodule acceptability with or without prior knowledge of the age of individual skins at slaughter were essentially the same, as judged from a near unity covariance ratio between individual skins. A similar trend was observed for nodule distribution score. The need for practical methods for the objective assessment of the acceptability of nodules and ostrich leather quality was expressed. [ABSTRACT FROM AUTHOR]

The authors investigated the effects of breed (Brahman, Bonsmara, Simbrah and Simmental crosses) and post-mortem ageing on meat tenderness, purge, cooking loss and ultimate pH of the longissimus muscle under commercial production and slaughter conditions of the Namibian beef export industry. Fifty steers of each breed cross, at an average age of 2 1/2 years and with an average subcutaneous fat cover of 2 mm over the 9th-10th thoracic vertebrae, were included in this study. The Brahman (BRX) differed significantly (P < 0.05) from all other breed crosses in all ageing treatments, recording higher Warner-Bratzler shear force values. The Bonsmara (BNX) steers showed the highest rate of tenderization and maintained this advantage up to day 30 post mortem. Purge and cooking loss increased initially and then tapered off over ageing time. BNX steers recorded the highest cooking loss. [ABSTRACT FROM AUTHOR]

The response of Namaqua Afrikaner, Dorper and South African Mutton Merino lambs, of approximately four months of age, towards a human being situated between them and their flock mates was studied in an arena test. The objective of the study was to determine whether the unimproved Namaqua Afrikaner, with an arguably shorter history of selection, would react differently to humans in an arena test compared to commercial breeds. A total number of 305 animals, born in 2010 and 2011 and raised under extensive veld conditions, were assessed in a modified arena test when the lambs born in each year were approximately four months old. From the test results it was possible to calculate the following parameters of the behaviour of the sheep: (i) The mean distance from the human operator, (ii) the time a lamb spent in a specific zone situated either close to or far from the human, and (iii) the total number of boundaries crossed, which gives an indication of the total distance travelled by an individual lamb. Other data recorded were the number of bleats and the number of times an animal urinated or defecated. There were no significant sex and birth type differences for any of the behaviour traits. No conclusive breed differences were found for any of the traits describing the behaviour of the lambs, except for the number of bleats. Namaqua Afrikaner lambs bleated significantly (24.0 ± 1.2) more in the three minute testing period than Dorper (8.2 ± 0.9) and South African Mutton Merino lambs (11.9 ± 2.5). Further research is necessary to see if this slight indication of anxiety could be related to other traits such as lamb survival or product quality. [ABSTRACT FROM AUTHOR]