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This study aimed to assess preslaughter factors responsible for the occurrence of bruises to front, rib, loin, hip, and round sites of cattle carcasses. Data from the slaughter of 148 loads of cattle were assessed, totaling 4,611 carcasses. Evaluated bruising factor variables were animal gender, journey distance (km), vehicle type (m²), journey time (hours), load density (kg/m 2 ), handling and facilities conditions (optimal, acceptable, and unacceptable), and unloading waiting time (min). Gender had the strongest influence on carcass bruising, being the first variable to enter in the majority of models related to the carcass sites. Female carcasses displayed higher bruising in all sites. Densities above 401 kg/m² caused more bruising. With the exception of the loin, unacceptable, and acceptable conditions assigned to farm facilities and handling resulted in higher average bruising. Articulated vehicles with a greater load capacity were more likely to cause bruising. The effects of variables causing bruises act differently in the various carcass sites. In this sense, the results of this study suggested possible management practices for specific problems during the preslaughter period to minimize losses by bruising to different carcass sites., (© 2018 Japanese Society of Animal Science.)

Bruises in pigs inflicted by blunt trauma are a significant animal welfare problem, and affected skin and underlying muscle are regularly submitted for forensic investigation. Central to the evaluation is an assessment of the age of the bruises. This paper presents cases of bruises in pigs sent for forensic investigation that were collected retrospectively. Data comprised photographs of the gross lesions, slides for histology, and written reports. The time from collecting the animals at the farms and delivery to the slaughterhouse was recorded together with the time of slaughter. Since 2005 there has been an increase in cases, with a peak in 2008 and 2009 of 40 cases for each year. At gross examination, the pattern of bruises often reflected the type of object which caused them. Histologically, haemorrhage and cellular infiltrations were frequently present. Currently, the age of bruises may be estimated to be more or less than four hours based on a porcine bruise model. In bruises more than four hours old, estimations of two-hour intervals are used based on studies of wound healing. The time from collecting the pigs at the farms until slaughter was between one and four hours in 44.1 per cent of cases, during which time the pigs had been handled by several people. In addition, in 22.0 per cent of cases of bruising an inflammatory response was absent, making it impossible to estimate the age of the bruise.

The movements of cattle at 12 livestock auction markets were observed to determine the possible causes of trauma leading to carcase bruising. Design faults included right-angled bends in races, dead ends, flooring with insufficient slope or grip, and steps. Sliding gates were often misused for goading cattle. Projecting fittings and square-edged corners were potentially injurious; conversely, rounded posts and curved races assisted the flow of cattle with minimal impacts. At all the markets, some cattle were hit directly and poked with wooden sticks, and the variations in their use could partially explain the differences between the markets in the prevalence of carcase bruising. Most harder hits were directed at less valuable parts of the body, such as the spine, hips and shoulders, and a survey of bruising at the abattoir showed that these were the areas with most bruising. In this survey of 48,926 carcases, the overall level of commercially significant bruising of 4.1 per cent was lower than the 6.5 per cent found in a previous survey. Carcases of cattle from markets had a greater incidence and severity of bruising (P<0.001) than those arriving directly from farms or dealers. Carcase bruising in young bulls was less (P<0.001) than in heifers and steers.

A total of 356 piglets from one farm were examined for foot and skin lesions every day for the first 10 days after birth, and then on alternate days until they were weaned. Over a period of 24 days 100 per cent of the piglets examined developed sole bruising, and 49.1 per cent developed sole erosions. Sole bruising lasted for an average of 13 days and sole erosions for seven days. At the beginning of the study, a higher proportion of piglets had mild sole bruising; from three to nine days of age piglets had moderate sole bruising but from days 10 to 20 mild bruising was again observed more frequently. Skin lesions were observed on the carpal aspect of the front limbs; 60.9 per cent of the piglets developed skin abrasions, 70.7 per cent developed healed wounds and 90 per cent developed hairless patches. The skin abrasions lasted on average for six days, the healed wounds for five days and the hairless patches for eight days. Piglets which developed sole bruising and/or sole erosions on the first day of life were significantly heavier than those which did not. Continuous observations of the piglets' behaviour during the first six days of life showed that sole bruising increased as the total time spent in the creep area or lying near the sow on the solid floor increased. During the first three days of life skin abrasions increased as the total time spent lying in the creep area increased. There was a positive correlation between the total time piglets spent suckling and the incidence of carpal skin abrasions between four and six days of age. Piglets with sole bruising, sole erosions or carpal skin abrasions spent less time during the day in 'other' activities such as walking, playing or fighting.

In two surveys of a total of over 16,000 cattle carcases, animals from live auctions had more bruising and more meat rejected for bruising than animals from dealers and farms. The proportion of carcases with stick-markings was higher in market cattle (2.5 per cent) than in cattle from farms (0.9 per cent). The amount of bruising was much higher in animals which were stick-marked (35 per cent) than in the whole population surveyed (6.5 per cent). Young bulls had the lowest percentage of bruising and the least amount of meat rejected of all the categories of animals surveyed. There was less "important' bruising in animals travelling less than 50 miles from markets, but over 50 miles the amount of "important' bruising did not increase. However, the incidence of all bruising increased with the distance travelled and with the time the animal spent in the lairage. More than half the carcases surveyed (59 per cent) had some degree of bruising caused by preslaughter handling. The areas most frequently bruised were the butt and hip, loin, shoulder/foreleg and neck, hind leg and flank/brisket. The number of carcases with an ultimate pH (pHu) of over 5-8 and the average pHu of the muscle increased with the amount of carcase bruising.

The effects on bruising and muscle pH of mixing cows and steers at loading, and 96 hours before loading, for transport to slaughter were examined. A second experiment investigated the effect on bruising of mixing two strange groups of steers at loading, 24 and 96 hours before loading. All cattle were hornless Bos indicus crossbreds from the same property in north Queensland. The bruise score, bruise trim weight and muscle pH of mixed cows and steers did not differ significantly from that of those transported separately. Mixing of two strange groups of steers did not significantly affect bruising. Time of mixing had no noteworthy effect on bruising. Cows bruised significantly (P less than 0.01) more than steers. These results have important implications for low cost beef management.

The relative susceptibility of cattle of different sexes to bruising was examined in five trials. In each trial there were three groups of cattle--bullocks, cows and mixed (bullocks and cows). The weight of bruised tissue trimmed from the carcases of the cows was significantly greater than that trimmed from the carcases of bullocks. The amount of bruising in cows, but not in bullocks, increased with increase in duration of journey. There was no evidence to suggest that differences in carcase weight or temperament, or "riding" of cows in oestrus were major contributing factors to the different levels of bruising.

Six trials in Queensland compared the bruising of 960 cattle with untipped, tipped and no horns. In three of the trials the treatment groups were kept separate during transit to the abattoir. In the other trials all cattle were handled as the one group. Tipped and untipped cattle had similar bruising, whether sent for slaughter as separate groups or together. Thus tipping was ineffective in preventing bruising. Hornless cattle had significantly (P less than 0.05) less bruising than horned cattle when consigned as separate groups. However, this advantage was lost when hornless cattle were mixed with tipped or untipped animals.