R Bernard

Evaluation of a protocol for determining the effectiveness of pretreatment with local analgesics for reducing experimentally induced articular pain in domestic fowl.

An experimental paradigm based on the microcrystalline sodium urate-induced arthritis model was developed for determining the effectiveness and optimum dose of drugs with potential local analgesic properties for the diagnosis and alleviation of musculoskeletal pain in birds. The optimum intra-articular injection of sodium urate was 6 mg in 0.2 ml diluent in 12-week-old male domestic fowl of 1.5 kg live weight. The response criteria were changes in behavioural profiles over 60 minutes commencing one hour after intra-articular injection. The testing system was used to determine the optimum rate of intra-articular application of the local anaesthetic bupivacaine hydrochloride. The behavioural profile of treated birds was restored to that of the controls at a minimal injection of 3 mg in 0.3 ml saline. It was concluded that the optimum intra-articular dose of bupivacaine for the treatment of musculoskeletal pain in the domestic fowl was 3 mg bupivacaine in 0.3 ml saline.

Effects of the age of male and female broiler breeders on sexual behaviour, fertility and hatchability of eggs

1. The effects of the age of male and female broiler breeders on fertility, hatchability and sexual behaviour were determined in two 2 × 2 factorial experiments. In the 1st, male and female birds 27 to 29 and 35 to 37 weeks and in the 2nd at 35 to 37 and 55 to 57 weeks of age were compared. 2. Fertility was not affected by the age of the males or females. 3. Early embryo deaths were higher and hatchability of fertile eggs was lower in eggs from females aged 27 to 29 and 55 to 57 weeks compared with eggs from birds aged 35 to 37 weeks. 4. There were no differences in male display behaviours at any age. The number of observed matings were higher in young males 27 to 29 weeks old compared with males 35 to 37 and 55 to 57 weeks of age. There were no detectable differences in the responses of the females to the males at different ages. 5. Plasma testosterone concentration in males increased from 24 to 30 weeks of age and was relatively constant from 36 to 60 weeks. Plasma oestrogen in females was high at 24 and lowest at 30 weeks of age after which it increased. 6. The results suggest that there may be little difference in the fertility of male and female broiler breeders at different ages when body weight is adequately controlled to at least 60 weeks of age.

Evaluation of intraarticular opioid analgesia for the relief of articular pain in the domestic fowl.

An experimental paradigm, based on the microcrystalline sodium urate-induced arthritis pain model, was used to investigate the potential peripheral analgesic properties of a variety of opioid agonists. The response criteria were changes in behavioral profiles and pain-related behaviors over 60 min commencing 1 h after intraarticular injection. The testing system was used to determine the potential optimum dose of intraarticular application of morphine sulphate (1-3 mg), fentanyl citrate (0.5-3 mg), and buprenorphine hydrochloride (0.05-1 mg). None of the opioid analgesics used had any effect on pain behavior, and it was concluded that opioids with a high affinity for the mu receptor when injected intraarticularly were unlikely to be of use in the treatment or diagnosis of inflammatory arthritic pain in the strain of domestic fowl chosen.

Effects of dietary crude protein content and food intake on the production of semen in two lines of broiler breeder males

1. The effects of dietary crude protein (CP) concentration and feeding rate on semen production and quality from 21 to 66 weeks of age were assessed in a factorial experiment with 48 caged broiler breeder males from 2 strains. 2. The probability of obtaining semen and semen volume were lower in one of the two strains but the concentration and yield of spermatozoa were similar. 3. There was no evidence that males which were fed on an increasing quantity of food produced more semen or a greater concentration of spermatozoa than males on a fixed allocation of 120 g/d food. 4. The concentration of spermatozoa was lower in males fed on a diet containing 160 compared with 120 g CP/kg. On termination of the experiment, average testes size was small and testicular function was absent in a large proportion of the males on the high protein diet.

Effects of male body weight, strain and dietary protein content on fertility and musculo‐skeletal disease in naturally mated broiler breeder males

1. The effects of male body weight at mating and different rates of gain on overall fertility were studied in two strains of broiler breeder males fed on a diet containing 160 or 120 g crude protein/kg. Sexual activity, musculo-skeletal disease and culling were also assessed. 2. There were no differences in early fertility between males weighing 3.0 or 3.5 kg at the start of the mating period, or between males gaining 1.0 or 1.5 kg body weight from mating to 60 weeks of age. 3. There were no differences in fertility between males fed on the two diets differing in crude protein content. 4. One strain of male had lower fertility than the other and this was associated with a greater weight of breast muscle, lower frequency of observed copulations and a higher number of incompleted matings. 5. Sexual activity declined and the number of spermatozoa trapped on the perivitelline membrane increased with age. 6. There were no differences among the treatments in the prevalence of musculo-skeletal lesions (destructive cartilage loss). As a proportion destructive cartilage loss occurred in 0.67 of the males at 66 weeks of age. Degeneration of the antitrochanter was present in 3 of 50 females examined and a cartilage flap in the medial condyle of the tibiotarsus occurred in 15 of these birds. 7. Beak lesions were the most important cause of male culling which averaged 0.24 as a proportion of the males at the start of the experiment.

Plasma growth hormone and insulin‐like growth factor‐I (IGF‐I) concentrations at the onset of lay in ad libitum and restricted broiler breeder fowl

1. Plasma concentrations of growth hormone (GH) and insulin-like growth factor I(IGF-I) were determined in individually caged broiler breeder females from 17 to 30 weeks of age. The birds were fed ad libitum or restricted during rearing in a randomised block design. Restricted birds were fed ad libitum after laying an egg and egg production was recorded to 54 weeks. 2. GH concentrations were higher in restricted compared with ad libitum-fed birds at 17 to 21 weeks of age and were similar thereafter. Plasma IGF-I concentrations were higher in restricted compared with ad libitum-fed birds throughout the sampling period of the experiment. 3. The age at first egg was delayed by about two weeks in restricted birds. At 54 weeks of age they had laid 114 compared with 67 eggs in birds fed ad libitum throughout and had produced less than half the number of eggs with defective shells. 4. It was suggested that differences in egg production between ad libitum and restricted broiler breeder females could be related to changes in the pattern of GH and/or IGF-I secretion.

Interaction of age, strain, sex and food restriction on plasma creatine kinase activity in turkeys

1. Plasma creatine kinase activity was determined at 4, 8, 12, 16, 20, 24, 28, 38 and 48 weeks of age in male and female traditional turkeys fed ad libitum, in male and female turkeys of a sire-line fed ad libitum or restricted to 0.5 during rearing and subsequently to 0.8 of sex-specific ad libitum-fed body weight, and in sire-line males fed ad libitum to 18 weeks and 0.8 of ad libitum body weight thereafter. 2. Plasma creatine kinase activity was low in traditional turkeys and increased rapidly after 12 weeks of age in males and females of the sire-line of turkeys. 3. Food restriction decreased the activity of plasma creatine kinase. 4. There was no difference in plasma creatine kinase activity between the sexes during rearing. After the onset of lay, the activity in plasma from females decreased at 38 weeks of age and rose dramatically in restricted females at 48 weeks when the birds had ceased laying. 5. The changes in plasma creatine kinase activity in females were associated with concomitant changes in ovarian activity as reflected in altered plasma triglyceride concentrations.

Assessment of pain during locomotion and the welfare of adult male turkeys with destructive cartilege loss of the hip joint

1. An assessment was made of the potential pain and stress from musculo-skeletal disease at 54 weeks of age in large male-line turkeys fed ad libitum or on restricted amounts of food. Males from traditional turkey lines were used as a negative control. 2. Traditional turkeys were fed ad libitum and male-line turkeys were fed ad libitum or restricted to 0.5 during rearing and subsequently to 0.8 of sex-specific ad libitum-fed body weight or fed ad libitum to 18 weeks and 0.8 of ad libitum thereafter. 3. Pain was assessed at 54 weeks of age by the change in number of steps taken by turkeys with or without musculo-skeletal disease after a course of betamethasone, a steroid anti-inflammatory agent with analgesic properties. 4. The numbers of steps over 24 h were recorded using a pedometer and were similar in all 4 treatments before and after treatment with the analgesic. It was concluded that there was no evidence for pain associated with musculo-skeletal disease among the turkeys in this experiment. 5. Musculo-skeletal disease was not associated with raised heterophil-lymphocyte ratio, a recognised index of stress.

Comparative development of the ovary and production, fertility and hatchability of eggs from traditional turkeys and a contemporary male-line fed ad libitum or restricted.

1. Ovarian function was assessed at first egg and at 44 and 54 weeks of age in traditional turkeys and in a male-line fed ad libitum or restricted to 0.5 of ad libitum during rearing. Egg production was recorded daily and fertility and hatchability were determined at 2 ages. 2. Age at sexual maturity did not differ between the 3 treatments. 3. The number of follicles at first egg in the male line averaged 16.3 compared with 8.9 in traditional turkeys. Food restriction in the male line decreased the number of yellow follicles to 14.6 at first egg and restricted birds were largely in a non-reproductive state from 44 to 54 weeks of age. 4. The total number of recorded ovipositions to 54 weeks of age in male line fed ad libitum or restricted and traditional turkeys respectively were 40.1, 25.2 and 70.7; comparable productions of normal shelled eggs were 28, 20 and 66.3. 5. There were no differences between treatments in fertility after a single insemination at 2 different ages. Hatch of fertiles after the first inseminations were 71.4, 45.5 and 90.3 respectively for male line fed ad libitum or restricted and traditional turkeys.

Comparative development of the antitrochanter in three strains of domestic fowl

Lameness and musculoskeletal disease were more frequent in two strains of broilers (selected [S] and relaxed [R]) than in an unselected layer (J). Defective fibrocartilage accounted for 0.15 of the total area of antitrochanteric cartilage at 29 weeks of age in the S-strain birds. There was more retained hyaline cartilage in the R- and S-strain birds at 15 weeks, and at 22 and 29 weeks there was delayed ossification. Occluded blood vessels, death of chondrocytes and degenerate areas of fibrocartilage occurred only in the broiler strains; they were worse in the S-strain and degenerate fibrocartilage occurred more frequently and in larger amounts. The area, length and depth of cartilage were larger in the heavier strains but the differences were considerably smaller than the difference in their relative bodyweights. The degeneration of the antitrochanter appeared to be associated with a reduction in the blood supply to the underlying hyaline cartilage and with the death of chondrocytes and the degeneration of matrix within the fibrocartilage of the antirochanter.