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Meat quality comparisons were carried out on hams produced from pork legs showing evidence of PSE and normal pork legs. Quality measurements included drip loss, sliceability, cooking loss, TBARS analysis and colour evaluation (Hunter L, a, b). A total of 40 pork legs were selected from a commercial slaughtering plant, 20 from carcasses showing PSE and 20 from normal carcasses based on L, a, b, and pH values. Carcass pH taken between the third/fourth rib was measured 45 min, 90 min, and 24 h after slaughter. Using a Minolta colorimeter (Hunter L, a, b,), colour of the Longissimus dorsi muscle was measured 24 h after slaughter. PSE had an adverse effect on cooked hams in comparison to normal cooked hams with respect to driploss (P

The objective of this study was to assess the effect of feeding steam flaked wheat and maize in diets with high and low levels of dairy products and to examine the effect of sequence of feeding the processed cereals in diets for newly weaned pigs. In experiment 1, 96 pigs were weaned at 27 days of age, blocked on sex and weight and assigned as individually penned pigs to four dietary treatments as follows: (a) high dairy product diet (6 kg of starter diet containing 230 g/kg milk powder followed by a link diet containing 125 g/kg milk powder to 26 days) with uncooked cereal (HDP), (b) high dairy product diet with steam flaked cereal (HDPC), (c) low dairy product diet (6 kg of starter diet containing 125 g/kg milk powder followed by a link diet containing no milk powder to 26 days) with uncooked cereal (LDP) and (d) low dairy product diet with steam flaked cereal (LDPC). In experiment 2, 96 pigs were weaned at 19 to 24 days of age, blocked on sex and weight and assigned as individually penned pigs to four dietary treatments containing: (a) uncooked cereal for 26 days, (b) uncooked cereal for 14 days followed by cooked cereal to 26 days post weaning, (c) cooked cereal for 26 days and (d) cooked cereal for 14 days followed by uncooked cereal to 26 days post weaning. Steaming and flaking of wheat and maize did not significantly affect pig performance during the experimental period or at any subsequent period up to slaughter. Daily gain from day 0 to 26 post weaning was 415 and 453 g/day (s.e.13•5; P < 0•05) for low and high dairy product diets, respectively. Food conversion efficiency (FCE) from day 0 to 14 post weaning on the low and high dairy product diets was 1•86 and 1•33 g/g (s.e. 0•14; P < 0•05), respectively. Pigs given the high dairy product diets during the experimental post-weaning period reached final carcass weight 5 days earlier than pigs given the low dairy product post-weaning diets (P < 0•05). In experiment 2, treatment did not affect food intake (mean = 450 s.e. 13•2 g; P > 0•05), daily gain (mean = 382 s.e. 12•5 g; P > 0•05) or FCE (mean = 1•19 s.e. 0•02 g/g; P > 0•05). In conclusion, feeding steamed flaked wheat and maize in post-weaning diets failed to improve pig performance irrespective of dairy product or sequence of feeding cooked cereals.

The objective of this study was to determine if weight and age at weaning affect the response of pigs to inclusion of cooked cereal in their post-weaning diet. In experiment 1, pigs (no. = 116) weaned at 17 to 28 days of age and weighing between 4 and 10 kg were individually given for 28 days post weaning, diets based on: (1) uncooked cereal or (2) cooked cereal (steamed and flaked wheat and maize). The gelatinized starch proportion was 0•265, 0•838, 0•203 and 0•745 for uncooked maize, steam flaked maize, uncooked wheat and steam flaked wheat, respectively. Pigs were offered 2•5 kg of starter diet (16•1 MJ digestible energy (DE) per kg and 17•4 g/kg of lysine). This was followed in each case by link diet (15•2 MJ DE per kg and 16•2 g/kg of lysine) to 28 days post weaning. Thereafter, pigs were grouped and given a common weaner diet and a common finisher diet to slaughter. In experiment 2, pigs (no. = 408) were weaned at between 20 and 28 days of age. Pigs were allocated by weight to heavy (7 to 8 kg), medium (6 to 7 kg) and light (5 to 6 kg) groups (24 groups of 17 pigs) and assigned to treatments as in experiment 1 for 26 days. A common weaner diet was offered between day 26 and day 56. In experiment 1, pig weight, food intake, daily gain, food conversion efficiency and carcass measurements were not affected by cooking (P > 0•05). Regression analysis indicated that weight and age at weaning had a significant association with weight at 28 days post weaning for uncooked (R2 = 0•628; P < 0•001) and cooked (R2 = 0•579; P < 0•001) cereal diets. In experiment 2, there was no interaction between weaning weight and cooking (P > 0•05) and no performance benefit resulted from cooking (P > 0•05). In conclusion, steam flaking did not improve pig performance during the treatment period or at any subsequent period.

Antioxidant potential for previously identified optimum levels of aloe vera (AV), fenugreek (FGK), ginseng (G), mustard (M), rosemary (R), sage (S), soya protein (SPI), tea catechins (TC) and whey protein concentrate (WPC) were evaluated in raw and cooked patties manufactured from frozen pork. The optimum levels determined were: AV (0.25%), FGK (0.01%), G (0.25%), M (0.10%), R (0.10%), S (0.05%), SPI (0.10%), TC (0.25%) and WPC (4%). Test ingredients were evaluated against synthetic antioxidants butylated hydroxyanisole/butylated hydroxytoluene (BHA/BHT) (0.01%) and a supplemented meat containing natural antioxidant, α-tocopherol (1000 mg α-tocopheryl acetate/kg feed). Ranking the decreasing antioxidant effectiveness of added ingredients in raw patties on day 9 showed that: ControlGSPIFGKAVMWPCSα-tocopherolRTCBHA/BHT. Cooking resulted in a four-fold increase in TBARS values over raw patties with TC being the most effective antioxidant having significantly (P0.001) lower TBARS values than the cooked control on days 3, 6 and 9. Ranking of decreasing antioxidant effectiveness of added ingredients showed that: MSPIGFGKα-tocopherolAVcontrolSBHA/BHTRWPCTC. BHA/BHT had the most beneficial effect on cooked meat redness with Hunter 'a' values being significantly (P0.05) higher than the control on days 3, 6 and 9. Ranking of Hunter 'a' values for added test ingredients showed that FGKWPCcontrolRBHA/BHTα-tocopherolTCAVSPIMGS on day 9. Hunter 'L' and 'b' values showed no significant trend over the storage period in either raw or cooked patties. The pH values of both raw and cooked pork control patties and products containing added test antioxidants were variable and while a number of trends were observed, no significant differences were recorded between samples.

The objective of this study was to investigate the effect of reducing residual nitrite levels on the quality (oxidative and colour stability) of cured pork products manufactured from meat containing high and low levels of dietary α-tocopheryl acetate. Pigs were fed a basal (10 mg A-tocopheryl acetate kg feed −1 ) or a supplemented (500 mg α-tocopheryl acetate kg feed −1 ) diet for 10 weeks prior to slaughter. M. semimembranosus from both supplemented and control feed groups were used in the manufacture of bacon and cooked ham products. High and low residual nitrite levels of 100 and 50 mg nitrite kg meat −1 were used in meat processing. The influence of overwrap packaging of cooked ham and vacuum packaging of bacon stored (4°C) in a display cabinet, under fluorescent light was evaluated via oxidative stability (TBARS) and colour (Hunter ‘ a ’ values) changes over time. Results show that dietary supplementation with α-tocopheryl acetate improved the oxidative stability of all low nitrite products. Dietary supplementation with α-tocopheryl acetate also produced Hunter ‘ a ’ colour values in low-nitrite (50 mg nitrite kg meat −1 ) products similar to those obtained for basal meat containing high nitrite levels (100 mg nitrite kg meat −1 ).

The objective of this study was to examine the differences in sow metacarpal properties through various parities and to compare the incidence of locomotory problems between stalled and loose-housed sows. Metacarpals (n = 110) of sows from six farms were collected at slaughter and stored at -20°C. Bones from one forelimb of sows in stalls (n = 36) and loose-housed (n = 20) were collected and their articular surfaces examined for Osteochondrosis Dissecans (OCD), these sows were also scored for lameness pre-slaughter. Metacarpals were CT scanned for cross sectional area and moment of inertia. Cylindrical sections from the diaphysis were used for mechanical testing and calculating bone strength indices. The results show there was little change in bone mineral status throughout the range of parities examined and overall metacarpal integrity was not compromised by multiple production cycles. There were no differences detected in the incidence of lameness or joint pathology between housing systems.

The objective of this study was to examine the effects of production (the number and weight of pigs produced over a lifetime) on the physical and mechanical properties of the metacarpals of cull sows, the prevalence of osteochondrosis and conformation traits. Metacarpals (n=79) and forelimbs (n=36) from cull sows were collected at slaughter. Bones were CT scanned for cross-sectional area and moment of inertia. Cylindrical sections from the diaphysis were used for mechanical testing and for calculating bone strength indices. The value of elastic (Young's) modulus, dry bone ash percentage, apparent bone density and bone mineral density did not decrease with the parity of the sows. Osteochondrosis was found in all the sows. The most severe lesions were in the medial condyle of the humerus and the anconeal process of the ulna. No relationship was found between lameness and joint pathology.

The aim of this study was to compare the prevalence of Salmonella serotypes at two different sites on pig carcasses from herds classified as high-risk or low-risk and to elucidate the relationship between carcass contamination levels and serological status. Caecal samples and carcass surface swabs were cultured for Salmonella from a total of 210 pigs from low risk herds ( 32% of pigs in herd Salmonella seropositive) in three abattoirs. Meat juice samples were collected for analysis by ELISA. The prevalence of Salmonella in the caecal contents of "low-risk" pigs was 10%, which was significantly lower than the 19% prevalence in "high-risk" pigs (p < 0.01). The corresponding figures for skin samples collected immediately post-evisceration were 2% and 12%. The predominant Salmonella serotype in the caecal contents of both the low-risk and high-risk pigs was Salmonella Typhimurium. Salmonella Kentucky and Salmonella Derby were the most frequent isolates from the carcass surface swabs of low- and high-risk pigs respectively. There was a positive association between seropositivity of pigs from high-risk herds and caecal carriage (p < 0.05). Results showed that herd categorisation based on serological results was useful in predicting Salmonella isolation rates from caecal samples and surface swabs of slaughtered pigs.

Antioxidant activities of aloe vera, fenugreek, ginseng, mustard, rosemary, sage, soya protein, tea catechins and whey protein concentrate (35% protein) were evaluated in pork patties prepared from both fresh and previously frozen (−20°C) pork. Chemical analysis showed test ingredients to be more effective in reducing lipid oxidation in patties made from previously frozen pork. Tea catechins, rosemary and sage were identified as being the most effective antioxidants with potency decreasing in the following order: tea catechins>rosemary>sage. Optimum addition rates of these ingredients suggested levels of 0.25, 0.10, 0.05% for tea catechins, rosemary and sage, respectively. Soya protein (0.10%) increased meat redness in fresh pork patties producing significantly ( P a ’ values over the controls on days 0, 3 and 6. However, fenugreek (0.01%) was more effective in increasing Hunter ‘ a ’ values in patties manufactured from previously frozen pork. No significant ( P >0.05) differences in Hunter ‘ L ’ and ‘ b ’ values were found between test and control samples on storage. The pH values of tea catechins, sage and soya protein fluctuated over time. Fresh pork patties with mustard and ginseng caused an initial decrease followed by a subsequent increase in pH values. Fenugreek caused an initial increase in pH values followed by a decrease from day 3 onwards.

The objective of the present study was to determine the effects of dietary vitamin E supplementation and reduced nitrite levels on the colour stability of cooked hams. Large white × Landrace pigs (male n=6, female n=6) were each subdivided into two groups (n=3) and fed an α-tocopheryl acetate supplemented diet (1000 mg/kg feed) and a basal diet (10 mg/kg feed) for a period of 10 weeks. M. semitendinosus were removed from each pig, divided into light and dark pigmented fractions, vacuum packed and stored at 4°C for 24 h. Muscles were cured with input nitrite levels of 25 and 100 mg/kg meat and were tumbled and massaged for 17 h. Samples were cooked, sliced and overwrapped in a high oxygen permeable film for a storage period of 10 days. Surface colour of hams was measured and expressed as Hunter ‘a’ values. Concentrations of α-tocopherol were significantly (P

The effect of dietary α-tocopheryl acetate supplementation on the uptake of α-tocopherol in ewe plasma, lamb plasma, milk, organs and muscles was investigated. The oxidative stability and colour in fresh M. longissimus dorsi and frozen M. longissimus dorsi, M. psoas major and M. gluteus medius were also investigated. Ewes (n = 12) were selected and scanned to assess pregnancy. They were divided into two groups (n = 6). The control group was fed a diet containing 20 mg α-tocopheryl acetate/kg feed/day and the supplemented group fed a diet containing 1000 mg α-tocopheryl acetate/kg feed/day, for 9 weeks ante-parturition and 3 weeks post-parturition. The lambs were weaned at 3 weeks and fed supplemented or basal feed for 10 weeks before slaughter. Plasma α-tocopherol increased significantly (p < 0.01) in ewes in the 9 weeks ante-parturition, and lamb plasma taken just before slaughter was significantly (p < 0.01) higher for the supplemented group than the basal group, following 13 weeks of supplementation. Milk α-tocopherol levels were significantly (p < 0.01) higher from ewes fed the supplemented diet at parturition and for the three weeks of supplementation post-parturition (p < 0.05). Supplementation increased the α-tocopherol levels in all tissues sampled. The α-tocopherol concentrations in M. longissimus dorsi and M. psoas major were also determined after frozen storage at -20 °C for 34 weeks. Frozen storage resulted in a significant (p < 0.01) reduction in mean α-tocopherol levels for M. longissimus dorsi but not M. psoas major. Dietary supplementation with α-tocopheryl acetate significantly (p < 0.05) increased the oxidative stability of lamb muscle. Surface colour (Hunter L, a, b) was found to be negatively correlated with metmyoglobin content. Supplementation reduced surface discolouration in refrigerated display under fluorescent light over a 6-7 day storage period. The effect was more pronounced in frozen displayed muscles than in freshly displayed samples.

The effect of n−3 fatty acid-enriched diets (in the form of 0.5% linseed oil with either 1.5% sunflower oil or 1.5% olive oil) and α-tocopheryl acetate supplementation (200 mg/kg feed) on lipid oxidation (thiobarbituric acid-reactive substances, TBARS) and cholesterol oxide products (COPS) in cooked pork was investigated. Longissimus muscle was studied. Meat from pigs fed 0.5% linseed oil-enriched diets had a higher proportion of n−3 fatty acid than meat from pigs in other dietary groups in neutral (P < 0.0001) and polar lipids (P < 0.0001), and a 20% reduction in the n-6:n- 3 ratio was observed. α-Tocopheryl acetate supplemen- tation increased (P < 0.05) monounsaturated fatty acids in polar lipids and increased (P = 0.0001) α-tocopherol levels in muscle. α-Tocopherol concentration in muscle was affected by dietary fat (P < 0.05). Groups receiving diets enriched with sunflower oil had significantly higher α-tocopherol levels (P < 0.05) in muscle than those groups receiving olive oil-enriched diets. Num- bers of TBARS were significantly (P < 0.05) lower in the group fed supplemental olive oil than in those fed sunflower oil. Dietary linseed oil increased (P < 0.05) lipid oxidation principally at the initial period of storage in cooked pork. Overall, dietary α-tocopheryl acetate supplementation significantly increased (P < 0.001) lipid stability and decreased (P < 0.05) total COP pro- duction across the dietary groups. α-Tocopherol was a more effective antioxidant for decreasing TBARS val- ues in cooked meat when adding sunflower oil to the diets instead of olive oil.

Heat treated cereals whether steamed and flaked or extruded are widely used in pig starter diets despite the dearth of experimental information to support the view that cooking of cereals improves their utilisation by young pigs or improves growth performance of weaned pigs.McCone et al. (1991) showed that micronisation and flaking of cereals had no beneficial effect on pig performance. The objective in the present trial was to evaluate extruded and steamed-flaked wheat and steamed-flaked maize in diets for pigs immediately after weaning.

Vitamin E functions as an antioxidant in animal tissues. Deficiency has been associated with sudden deaths in suckling and growing pigs as well as impaired immune function and reduced fertility. Of the tocopherols and tocotrienols present in nature, only a-tocopherol (a-T) appears in appreciable amounts in pig blood and tissues. A previous trial (Monahan et al., 1990) had shown that feeding a diet containing a high level of a-tocopherol to sows from day 3 of lactation resulted in a significant increase in sow plasma, sow milk and piglet plasma a-T levels. The present trial was designed to study the effect of feeding high a-T from late pregnancy or from farrowing on milk a-T levels.

The objectives of this study were to determine the effect of dietary vitamin E supplementation on tissue α-tocopherol levels in muscles in the porcine carcass. Pigs (n = 9), were selected at random and divided into three groups (n = 3) and fed diets containing 0 (basal), 20, 160 mg dl-α-tocopheryl acetate/kg feed for a period of 130 days prior to slaughter. After slaughter carcasses were split centrally and chilled at 4 °C × 24 h. Muscles (n = 37) were identified and removed from the left side of each animal for each dietary group and stored at −20 °C until required. The mean α-tocopherol levels in pork muscle tissue were significantly (p < 0.05) higher in the high-supplemented group (160 mg α-tocopheryl acetate/kg of feed) compared with the low-supplemented (20 mg/kg of feed) and basal groups (unsupplemented). In the supplemented samples, the muscles of the thoracic limb (4.8–9.9 mg α-tocopherol/kg of tissue) and neck and thorax (3.7–9.2 mg/kg) contained the greatest levels of α-tocopherol compared the muscles of the pelvic limb (4–5.6 mg/kg) and back (2.5–3.5 mg/kg).