Marking to weaning production aspects of lambs provided with NSAID analgesia compared with lambs receiving no analgesia at the time of elastrator ring marking.

The provision of analgesia at the time of marking has been adopted by the Australian sheep industry, but data on production benefits are lacking. In the current study, alternate lambs were provided with either meloxicam (non-steroidal anti-inflammatory drug [NSAID], n = 781) or no analgesia (NONE, n = 822) at the time of ring castration and tail docking. Six distinct management groups of lambs were studied. Lambs were weighed immediately before marking and then again at weaning. There was no significant effect of treatment on average daily gain between marking and weaning in cross-bred lambs. In Merino lambs, average daily gain was 5 g/day lower (P < 0.005) in lambs receiving NSAID, but this may not be biologically significant. Lamb losses were significantly (P < 0.05) lower in the NSAID group (1.1%) than in the NONE group (2.7%). This observation is worth validating in larger studies, particularly considering that lamb mortality is a significant cost to production and welfare concern.

Efficacy of meloxicam in a pain model in sheep.

OBJECTIVE: To evaluate the efficacy of the non-steroidal anti-inflammatory drug, meloxicam, in alleviating pain and inflammation and on production-related variables in a model of sterile acute inflammation in sheep. METHODS: Groups of 12 mature Merino ewes received 0, 0.5, 1.0 or 1.5 mg/kg meloxicam subcutaneously 90 min before injection of 0.1 mL turpentine subcutaneously on the anterior aspect of the proximal phalanx of a forelimb. Pain- and inflammation-related variables were assessed at -18, 3, 6, 9, 12, 24, 48 and 72 h relative to meloxicam administration. Daily feed intake and body weight change 7 days later were also assessed. Pain-related variables measured were weight borne on each forelimb, lameness score, time each forelimb was raised in a 20-s interval and tolerance to a noxious mechanical stimulus. Inflammation-related variables measured were skin temperature, limb circumference, body temperature, plasma haptoglobin concentration and peripheral blood leucocyte parameters. RESULTS: Meloxicam was effective in improving all pain-related variables. A dose-dependent response was seen between 0 and 1.0 mg/kg, with no additional benefit provided by 1.5 mg/kg. At a dose rate of 1.0 mg/kg, meloxicam improved weight borne on the turpentine-treated limb by 14%, reduced the time the treated limb was held in a non-weight-bearing posture by 46%, reduced the lameness score by 58% and improved tolerance to pressure by 52%. No significant effects of meloxicam on inflammatory variables or appetite were observed. CONCLUSIONS: Using a validated pain model, the data suggested that 1.0 mg/kg meloxicam provided significant analgesic benefits to sheep.

Infrared thermal imaging as a method to evaluate heat loss in newborn lambs.

Thermal imaging technology has been identified as a potential method for non-invasive study of thermogenesis in the neonatal lamb. In comparison to measurement of the core body temperature, infrared thermography may observe thermal loss and thermogenesis linked to subcutaneous brown fat depots. This study aimed to identify a suitable method to measure heat loss in the neonatal lamb under a cold challenge. During late pregnancy (day 125), ewes were subjected to either shearing (n=15) or mock handling (sham-shorn for 2min mimicking the shearing movements) (n=15). Previous studies have shown an increase in brown adipose tissue deposition in lambs born to ewes shorn during pregnancy and we hypothesized that the shearing treatment would impact thermoregulatory capacities in newborn lambs. Lambs born to control ewes (n=14; CONTROL) and shorn ewes (n=13; SHORN) were subjected to a cold challenge of 1h duration at 4h after birth. During the cold challenge, thermography images were taken every 10min, from above, at a fixed distance from the dorsal midline. On each image, four fixed-size areas were identified (shoulder, mid loin, hips and rump) and the average and maximum temperatures of each recorded. In all lambs, body surface temperature decreased over time. Overall the SHORN lambs appeared to maintain body surface temperature better than CONTROL lambs, while CONTROL lambs appeared to have higher core temperature. At 30min post cold challenge SHORN lambs tended to have higher body surface temperatures than lambs (P=0.0474). Both average and maximum temperatures were highest at the hips. Average temperature was lowest at the shoulder (P<0.05), while maximum temperatures were lowest at both shoulder and rump (P<0.005). These results indicate that lambs born to shorn ewes maintained their radiated body surface temperature better than CONTROL lambs. In conjunction with core temperature changes under cold challenge, this insight will allow us to understand whether increased body surface temperature contributes to increased overall heat loss or whether increased body surface temperature is indeed a mechanism contributing to maintenance of core body temperature under cold challenge conditions. This study has confirmed the utility of infrared thermography images to capture and identify different levels of thermoregulatory capacity in newborn lambs.

Effect of local infusion of NSAID analgesics administered alone or in combination on the pain associated with band castration in calves.

OBJECTIVE: To evaluate the analgesic efficacy of flunixin alone or in combination with diclofenac administered locally to the scrotum at the time of band castration of calves. METHODS: Angus bull calves (n = 40; ≈7-9 weeks old) were allocated to four treatment groups (n = 10 per group) to examine the effects of two non-steroidal anti-inflammatory analgesics (NSAIDs) administered locally at the time of band castration: sham control; castration + flunixin; castration + flunixin + diclofenac; castration + saline. The NSAIDs and saline were administered subcutaneously into the scrotum under the band. Blood was sampled at -0.5, 0.5, 1.5, 3, 12, 24, 48 and 72 h relative to castration. Haematology parameters and plasma cortisol levels were determined in samples at all time points and plasma haptoglobin levels determined in samples collected at -0.5, 24, 48 and 72 h. Pain avoidance and postural behaviours were measured for 2 and 12 h, respectively, after castration. RESULTS: Band-castrated calves exhibited significantly higher peak cortisol and higher integrated cortisol responses during the first 6 h post-castration relative to sham controls. Individual active pain avoidance behaviours observed for 1 h post-castration were not significantly different between treatment groups; however; the sum of the total behaviours was significantly increased by castration (P = 0.023). Postural changes included increased abnormal ventral lying for all castrated groups and decreased normal standing and increased combined abnormal postures for the flunixin- and saline-treated groups. Growth rates of calves were not affected by treatments during weeks 1 and 2 post-castration; however, growth rates of castrated calves were significantly lower than those of sham-treated calves in week 3 post-castration (1.41 vs 0.84, 0.75 and 0.56±0.19 kg/day for sham, flunixin-, flunixin + diclofenac- and saline-treated groups, respectively). CONCLUSIONS: The administration of flunixin or flunixin + diclofenac intrascrotally at several sites at the time of banding did not improve the welfare of young Angus bull calves undergoing this method of castration when assessed by both physiological and behavioural parameters. In this study, band castration at 7-9 weeks of age had less effect compared with results for older calves reported previously. Further research is required to develop effective analgesic treatments that can be administered at the time of castration to large numbers of animals.

Trial of human laser epilation technology for permanent wool removal in Merino sheep.

OBJECTIVE: To assess whether human laser epilation technology can permanently prevent wool growth in sheep. DESIGN: An observational study. METHODS: Two commercial human epilation lasers (Sharplan alexandrite 755 nm laser, and Lumenis LightSheer 800 nm diode laser) were tested at energies between 10 and 100 J/cm2 and pulse widths from 2 to 400 ms. Wool was clipped from flank, breech, pizzle and around the eyes of superfine Merino sheep with Oster clippers. After initial laser removal of residual wool to reveal bare skin, individual skin sites were treated with up to 15 cycles of laser irradiation. Behavioural responses during treatment, skin temperature immediately after treatment and skin and wool responses for 3 months after treatment were monitored. RESULTS: A clear transudate was evident on the skin surface within minutes. A dry superficial scab developed by 24 h and remained adherent for at least 6 weeks. When scabs were shed, there was evidence of scarring at sites receiving multiple treatment cycles and normal wool growth in unscarred skin. There was no evidence of laser energy level or pulse width affecting the response of skin and wool to treatment and no evidence of permanent inhibition of wool growth by laser treatment. Laser treatment was well tolerated by the sheep. CONCLUSIONS: Treatment of woolled skin with laser parameters that induce epilation by selective photothermolysis in humans failed to induce permanent inhibition of wool growth in sheep. Absence of melanin in wool may have contributed to the result.

Efficacy of a buccal meloxicam formulation for pain relief in Merino lambs undergoing knife castration and tail docking in a randomised field trial.

OBJECTIVE: To assess the efficacy of oral transmucosal meloxicam for pain relief in lambs at marking. DESIGN: A blinded, placebo-controlled, randomised, block design field study of 60 Merino lambs aged 7-10 weeks allocated to placebo and meloxicam treatments and studied in two cohorts of 30. Placebo-treated lambs received 1 mL/10 kg of drug vehicle and meloxicam-treated lambs received 1 mg/kg meloxicam at 10 mg/mL. Treatments were administered into the buccal cavity immediately before knife castration and hot-iron tail docking. Lambs were then released into a grassed paddock (0.34 ha). Time to mother-up was recorded and behaviours were observed every 15 min for 8 h and again for 45 min at 24 h. The sequence in which lambs exited the paddock with their mothers was then recorded. Weight change and wound scores were recorded 4 and 7 days after marking. RESULTS: Meloxicam did not affect mothering-up. In the 8 h following marking, meloxicam led to a 7-fold reduction (P < 0.001) in combined abnormal behaviours (hunched standing, standing with a stretched posture, walking stiffly). The meloxicam group spent significantly less time in standing postures and tended to spend more time grazing, suckling and in normal lying postures. At 24 h, the meloxicam group spent more time lying and less time standing. There was no effect of treatments on the sequence in which lambs moved into a fresh paddock or on weight change. CONCLUSIONS: The buccal meloxicam formulation provided substantial analgesia to lambs on the day of marking. Slight benefits were evident the following morning.

Quality Assessment of Longissimus and Semitendinosus Muscles from Beef Cattle Subjected to Non-penetrative and Penetrative Percussive Stunning Methods.

This study provides a comparative analysis of the effects of pre-slaughter penetrative and non-penetrative stunning and post-slaughter stunning on meat quality attributes in longissimus lumborum (LL) and semitendinosus (ST) muscles in heifers. Ten animals were assigned to each of four treatment groups: i) animals were subjected to conventional Halal slaughter (a clean incision through the structures at the front of the upper neck - the trachea, oesophagus, carotid arteries and jugular veins) and post-cut penetrating mechanical stun within 10 to 20 s of the neck cut (Unstunned; US); ii) high power non-penetrating mechanical stunning followed by the neck cut (HPNP); iii) low power non-penetrating mechanical stunning followed by the neck cut (LPNP); and iv) penetrative stunning using a captive bolt pistol followed by the neck cut (P). For each carcass, muscle samples were removed within 45 min of slaughter, portioned and analysed for pH, cooking loss, water holding capacity (WHC), tenderness (WBS), lipid oxidation (TBARS) and color, over a two week storage period. Stunning did not affect pH and cooking loss. Significant differences in water holding capacity, tenderness, lipid oxidation and color were present at different storage time points. HPNP stunning resulted in lower WHC and color values, particularly lightness (L*), higher TBARS values and peak force values compared with those stunned using LPNP, P and US. These adverse effects on quality were mostly encountered in the ST muscle. In conclusion, the meat quality achieved using P, LPNP and US treatments was comparable, and no treatment stood out as considerably better than another.