Sc Kestin

EFFECT OF CARPROFEN ON LAMENESS IN BROILER CHICKENS

Lameness is prevalent among broiler chickens and there is concern that it is chronically painful. The administration of an analgesic has been frequently used to identify pain in lame farm animals. Therefore, in this study the ability of lame and normal broiler chickens to traverse an obstacle course was tested after treatment with the analgesic, carprofen, a placebo saline injection or a control handling procedure. Sound birds traversed the course in approximately 11 seconds, irrespective of treatment. Lame birds took approximately 34 seconds to traverse the course, unless they received carprofen, which reduced their completion time to 18 seconds. Thus, carprofen substantially increased the speed of lame birds, providing evidence that birds with moderate lameness suffer pain when they walk.

Factors affecting the prevalence of foot pad dermatitis, hock burn and breast burn in broiler chicken

1. Standardised data on flock husbandry were recorded on 149 broiler farms during the 4 d prior to slaughter. 2. Birds were examined at the slaughterhouse for contact dermatitis lesions. Foot pad dermatitis score (FPDS) and hock burn score (HBS) were measured on five point scales. Carcase rejection data were also collected. 3. The mean percentage of birds in each flock with: moderate or severe foot lesions was 11·1% (range 0–71·5%); moderate or severe hock burn was 1·3% (range 0–33·3%); and, breast burn was 0·02%. 4. A general linear model was developed to examine factors associated with mean flock FPDS. Assuming a linear relationship, within the range of data collected and with all other factors remaining the same, every 1% increase in the proportion of Genotype A birds in the flock was associated with an increase in mean FPDS of 0·003, every one-point increase in litter score was associated with a 0·326 increase in mean FPDS and every one-point increase in flock mean HBS was associated with a 0·411 increase in mean FPDS. Flock mean FPDS was associated with feed supplier and was higher in winter. 5. The general linear model developed for flock mean HBS, found that every one-point increase in mean FPDS increased mean HBS by 0·090, every one-point increase in litter score increased HBS by 0·119 and, every 1% increase in small/emaciated birds decreased mean HBS by 0·333. Reduced HBS was also associated with increased final litter depth, younger slaughter age and an increased percentage of dietary wheat. For every 1% increase in Genotype A birds, a decrease in flock mean HBS of 0·003 would be expected. 6. An effect of hatchery was also identified.

Muscle lipid content determines the eating quality of smoked and cooked Atlantic salmon (Salmo salar)

The importance of muscle lipid content on the eating quality of smoked and cooked Atlantic salmon was investigated. Eighty fish with muscle lipid content ranging from 2.9% to 10.7% were filleted and one fillet smoked and the second fillet cooked. The fillets were presented to a trained taste panel and texture and flavour attributes rated. Hedonic ratings for overall flavour and overall liking were also expressed. The lipid content had a highly significant effect (P<0.001) on many of the texture and flavour attributes of the smoked fish. A significant effect (P<0.05) was also found on texture and flavour attributes of the cooked fish. This showed the importance of muscle lipid content on the eating quality and its potential to affect sensory studies on Atlantic salmon. The hedonic ratings also showed an increased preference of the smoked salmon at the higher lipid levels over the range studied (P<0.001). This result potentially has commercial implications for the targeting of fish towards certain products.

Depletion of glycogen reserves in fasting broiler chickens

1. Male broiler chickens were killed at various times up to 36 h after withdrawal of food; hepatic and muscle glycogen concentrations and pH were compared with those of control birds given continuous access to food and water. 2. Liver glycogen was reduced to negligible concentrations (less than 1 mg/g) within 6 h of food deprivation and the initial pH was elevated. 3. Withdrawal of food had no effect on glycogen concentrations in the m. pectoralis superficialis (PS) but reduced them in the m. biceps femoris (BF); the reduction was significant after 12 h. Ultimate pH was elevated by fasting in the BF, but not the PS.

Protocol for assessing brain function in fish and the effectiveness of methods used to stun and kill them.

A method for the evaluation of brain function in fish has been developed which is based on assessments of self-initiated behaviours, responses to stimulation, and reflexes. These assessments were validated in several freshwater and marine species and applied to evaluate the brain function of fish while they were anaesthetised and while they were being killed by a variety of methods. The results of these investigations were compared with published neurophysiological observations and it is concluded that some of the tests can be used to identify, with reasonable confidence, the state of awareness, and thus the capacity to experience suffering of several species of fish.

Electric stunning: a humane slaughter method for trout

Abstract The most common commercial slaughter method for portion-sized rainbow trout is asphyxiation in ice slurry. This method is however widely believed to expose the fish to unnecessary pain and suffering. The industry is consequently seeking an alternative method, which offers improved welfare of the fish at slaughter. Electric stunning of fish in water is identified as a suitable method. Parameters of an electric field that stuns trout beyond the point of recovery without causing carcass damage have been identified. A 60-s exposure to a 1000-Hz sinusoidal electric field of 250 V/m r.m.s. is recommended. Several practical options for implementing this method on commercial trout farms are identified and equipment for one of these approaches has been built and tested. The UK trout industry appears to be moving towards electric stunning as its preferred slaughter method.

The depletion of glycogen stores and indices of dehydration in transported broilers

Broilers were either not transported or were transported for 2, 4 or 6 hours after having been subjected to food withdrawal times of less than one hour or of ten hours. The birds were then slaughtered using normal commercial practices. The longer period of food deprivation reduced liver weight and glycogen content, and circulating glucose concentrations. It also elevated the ultimate pH value (pHu) in the biceps muscle and by implication, therefore, reduced its glycogen content. With longer journey times, liver weight and glycogen content decreased. Transport had an inconsistent effect on glycogen concentration in the pectoral muscle but progressively reduced its pHu. In contrast, pHu in the biceps progressively increased, by implication because transport depleted muscle glycogen levels. Birds transported further had higher concentrations of total protein in their plasma which, though this was not significant, also had a higher osmolality. This suggests that transported birds became dehydrated. Additionally, the depletion of body glycogen stores might be associated with the perception of fatigue.

Mercury in UK imported fish and shellfish and UK-farmed fish and their products

Total mercury concentrations were measured in fish and shellfish and their products imported into the UK and also in UK-produced farmed salmon and trout. Three hundred and thirty-six samples were collected using a two-stage sampling plan. The sample plan was weighted to reflect consumption, but with some bias towards fish that might accumulate higher levels of mercury, such as large predatory fish at the top of the food chain. The highest levels of total mercury were found in billfish (swordfish and marlin) and shark. Mercury concentrations in the five samples of fresh/frozen shark ranged from 1.006 to 2.200 mg kg−1, all above the European Commission limit for the species, and concentrations in 20 samples of fresh/frozen billfish ranged from 0.153 to 2.706 mg kg −1 with 13 samples above the 1.0 mgkg−1 limit for the species. One sample of Antarctic ice fish was collected and had a mercury concentration of 0.664 mgkg−1. The limit for this species was 0.5 mgkg−1. One sample of fresh/frozen tuna out of the 20 collected had a mercury concentration above the limit of 1.0 mgkg−1 (1.5 mg kg−1), but all other fresh tuna samples were well within the regulatory limit (average 0.4 mg kg−1). Mercury concentrations in canned tuna were lower with concentrations on average half that measured in fresh/frozen tuna. Mercury concentrations in UK-farmed salmon and trout were relatively low. The maximum concentration found in 46 samples of fresh/frozen or smoked trout and salmon was 0.103 mgkg−1.

Effects of feeding, watering and resting intervals on lambs transported by road and ferry to France

Three lorry loads, each of approximately 530 lambs, were monitored during August 1994 while they were transported from the Midlands to France. Each lorry underwent a similar journey, designed to study the effects of a) 22 hours on a lorry broken by two hours of feed, water and rest after 15 hours, b) 34 hours on a lorry broken by eight hours of feed, water and rest after 24 hours and c) 24 hours on a lorry and lairage for the following 48 hours. Measurements were made on 180 lambs in each load, of liveweight, plasma betahydroxybutyrate (BHB), non-esterified fatty acids (NEFA), urea, total protein, albumin, osmolality, creatine kinase (CK), cortisol and glucose, before, during and after transport. Twenty-four hours of transport resulted in changes in some of the variables measured that were little different from those observed after 24 hours of feed and water deprivation; however, the high ambient temperatures during the transport resulted in a greater degree of dehydration. For journeys longer than 15 hours a two-hour rest in lairage with access to water and a palatable food source was beneficial in allowing some slight recovery. Although all the differences were in the direction that would be expected with recovery, they were often small and, within the sensitivity of the study, were only significant for NEFA and CK. For journeys longer than 24 hours, an eighthour rest in lairage with access to water and a palatable food source was beneficial and allowed material realimentation and rehydration before further transport for up to 10 hours. After 24 hours of transport, however, liveweight, plasma urea, total protein and albumin had only returned to basal levels after 24 hours in lairage and plasma BHB, CK and osmolality after 48 hours of lairage.

Prevalence and factors associated with it, of birds dead on arrival at the slaughterhouse and other rejection conditions in broiler chickens

1. Standardised data on husbandry were recorded for a flock of birds in one house on each of 150 broiler farms in the UK during the 4 d prior to slaughter. 2. For each flock, the incidence of birds found dead on arrival (DoAs) and the Meat Hygiene Service carcase rejection records were recorded at the slaughterhouse. 3. The mean percentage of birds in each flock found DoA was 0·12% (range 0–0·64%) and the mean percentage of Total Carcase Rejects (TCRs) for each flock was 1·23% (range 0·07–5·51%). 4. A general linear model was developed to examine factors associated with flock percentage DoAs. Assuming a linear relationship, all other factors remaining the same, a one percentage point (PP) increase in small/emaciated birds will result in a 0·155 PP increase in DoAs and a 1 PP increase in wheat in diet 4 will result in a 0·003 PP decrease. An increase by one in the total number of vaccines administered will cause a 0·029 PP decrease in DoAs, a 1 g increase in live weight at slaughter will be associated with a 0·000043 PP increase and a 1 PP increase in mortality on farm would be associated with a 0·000044 PP increase. A 1 PP increase in Ross birds decreases DoAs by 0·0004 PPS: there is also a seasonal effect. 5. The model developed for flock percentage TCRs found that a 1 PP increase in wheat in diet 3 will result in a 0·052 PP decrease in TCRs and a 1 PP increase in Ross birds will cause a 0·009 PP decrease. A 1 PP increase in birds culled on farm will be associated with a 0·03 PP increase in TCRs and the diagnosis of disease during the flock cycle increases TCRs by 0·397 PPs. A one day increase in age at slaughter will result in a 0·046 PP increase in TCRs.