Physiological and behavioural effects of intradermal injection of sodium lauryl sulfate as an alternative to mulesing in lambs

Objective To assess the effects on physiology and behaviour of intradermal injection of sodium lauryl sulfate (SLS) as an alternative to mulesing. Procedures Three groups of Merino lambs were studied: Control (n = 10), SLS (n = 11) and Mulesed (n = 11). The SLS group received SLS (7% w/v) and benzyl alcohol (20 mg/mL) in phosphate buffer, and the Mulesed group received 6 mL topical local anaesthetic as a wound dressing. Haematology, cortisol, beta-endorphin and haptoglobin concentrations, rectal temperatures, body weight and behaviours were monitored for up to 42 days post treatments. Results SLS treatment induced mild swelling followed by thin scab formation. Fever (>40°C) was observed at 12 and 24 h, cortisol concentration was elevated on days 1 and 2, haptoglobin concentration was highly elevated on days 2–7, white blood cell count was elevated on days 2 and 4 post treatment, but average daily gain was not affected. Fever at 12 h was significantly higher in the SLS than in the Mulesed group, whereas maximum temperature, temperature area under the curve (AUC), occurrence of fever, cortisol profile, cortisol AUC, white blood cell counts and haptoglobin concentrations until day 7 were comparable. The behaviours of normal standing, total standing and total lying were modified for 2 days by SLS treatment, but changes were less marked and of shorter duration than in the Mulesed group. On day 1, the SLS group spent <5% of time in total abnormal behaviours compared with 18% in the Mulesed group. The SLS group tended to spend more time in abnormal behaviours on day 1 than the Controls. Conclusions The behaviour of the SLS group was similar to that of the unmulesed Controls and their physiological responses were intermediate between the Mulesed lambs receiving post-surgical analgesia and the Controls.     

SHH在美利奴羊与小尾寒羊背部皮肤表达差异的研究

为了研究音猬因子(sonic hedgehog, SHH)在不同品种绵羊背部皮肤中的表达差异,以探索SHH与羊毛弯曲形成的关系,选取美利奴羊和小尾寒羊作为研究对象,利用HE染色法观察2种绵羊背部皮肤的组织结构,采用免疫组织化学技术、实时荧光定量PCR和Western blot方法探究2种绵羊背部皮肤中SHH蛋白和基因水平的相对表达量差异。结果显示:HE染色显示美利奴羊与小尾寒羊背部皮肤毛囊的组织结构存在毛囊数量及弯曲程度等差异;免疫组织化学试验显示,SHH蛋白在美利奴羊和小尾寒羊背部皮肤中均有表达,在美利奴羊背部皮肤中的毛乳头、毛基质、内外根鞘、皮脂腺和表皮细胞中显著表达,在小尾寒羊背部皮肤中的毛基质、内外根鞘和皮脂腺中显著表达;光密度分析显示,美利奴羊背部皮肤组织中SHH蛋白的表达量显著高于小尾寒羊(P<0.001);实时荧光定量PCR显示,美利奴羊SHH mRNA相对表达水平显著高于小尾寒羊(P<0.01);Western blot显示,美利奴羊SHH蛋白相对表达水平显著高于小尾寒羊(P<0.01)。提示:羊毛弯曲的形成与其组织结构有关,并受SHH的调控。     

SHH在美利奴羊与小尾寒羊背部皮肤表达差异的研究

为了研究音猬因子(sonic hedgehog, SHH)在不同品种绵羊背部皮肤中的表达差异,以探索SHH与羊毛弯曲形成的关系,选取美利奴羊和小尾寒羊作为研究对象,利用HE染色法观察2种绵羊背部皮肤的组织结构,采用免疫组织化学技术、实时荧光定量PCR和Western blot方法探究2种绵羊背部皮肤中SHH蛋白和基因水平的相对表达量差异。结果显示:HE染色显示美利奴羊与小尾寒羊背部皮肤毛囊的组织结构存在毛囊数量及弯曲程度等差异;免疫组织化学试验显示,SHH蛋白在美利奴羊和小尾寒羊背部皮肤中均有表达,在美利奴羊背部皮肤中的毛乳头、毛基质、内外根鞘、皮脂腺和表皮细胞中显著表达,在小尾寒羊背部皮肤中的毛基质、内外根鞘和皮脂腺中显著表达;光密度分析显示,美利奴羊背部皮肤组织中SHH蛋白的表达量显著高于小尾寒羊(P<0.001);实时荧光定量PCR显示,美利奴羊SHH mRNA相对表达水平显著高于小尾寒羊(P<0.01);Western blot显示,美利奴羊SHH蛋白相对表达水平显著高于小尾寒羊(P<0.01)。提示:羊毛弯曲的形成与其组织结构有关,并受SHH的调控。     

Effectiveness of a non-surgical alternative to the Mules operation in sheep

Objective To measure changes to the perineal bare area, local tissue reaction and healing responses of young sheep, following intradermal administration of cetrimide and polyvinylpyrrolidone (PVP), with and without ethanol, to the breech and tail. Method A needle‐less injector was used to deposit formulations containing 40 g/L cetrimide and 30 g/L PVP (group 2) or 20 g/L cetrimide, 30 g/L PVP and 15 g/L ethanol (group 3), within the dermis of the tail and the region surrounding the perineal bare breech area of groups (N = 8) of Merino weaner sheep. The dimensions of the perineal bare area (length, width and diagonal distances left and right) and tail width were recorded before and at intervals after treatment for 60 days. Observations of swelling and bruising and scab formation at the treatment sites were recorded for up to 35 days after treatment. Rectal temperatures were monitored for up to 35 days after treatment and bodyweight for up to 60 days after treatment. An untreated control group (group 1) was included. Results Comparison of day ‐3 and day 35 measurement data showed that both treated groups had significantly (P < 0.05) wider breech bare areas compared to the untreated controls and that group 2 sheep had significantly (P < 0.05) longer breech bare areas compared to group 3 sheep or to the untreated controls, which were not significantly different. At this time scabs were still firmly in place on many treated sheep. At day 35 there was no increase in tail bare area caused by either treatment. By day 60 there was no significant difference between the treated and control groups in either the breech or tail regions indicating that the changes present at day 35, were not permanent. Mean weight gain in the groups throughout the 60‐day interval was unaffected by treatment. Intradermal treatment was associated with a significant elevation in body temperature. This effect lasted for 3 days and was associated with signs of discomfort and depressed appearance in at least some of the treated sheep. Bruising was mild to severe in all treated sheep within two days of treatment but was not evident in any sheep by day 21. Mild to moderate swelling was also associated with treatment but was not uniform across sheep in the groups. The tail of one sheep was severely swollen for several days. Swelling remained obvious in most treated sheep until day 14 but was not present at day 21. Conclusion Under the conditions of this study intradermal injection of cetrimide had no permanent effect on bare area measurements on the breech or the amount of wool‐bearing skin on the tail. It also caused signs of discomfort and pain that raise welfare concerns.     

Effect of plastic occlusive clips used as an alternative to mulesing on breech conformation, body weight and survival of Merino lambs

Objective To determine the effect of applying plastic clips to the breech and tail of lambs on the perineal and tail bare areas, breech wrinkle, dag (faecal) accumulation, urine stain, body weight and survival of lambs, compared with unclipped, unmulesed lambs and mulesed lambs. Method The study was conducted on five commercial wool‐growing farms in southern Australia. On each study site lambs (2–12‐weeks‐old) were divided into three groups: (1) unclipped, unmulesed control (tail dock only); (2) treated with clips; and (3) treated with the mules operation. Evaluations of effects, including visual scoring, bare area measurements and body weight, were performed before treatment and on or approximately days 30, 60, 90 and 180 after treatment. On each occasion, lambs were recorded as either present or absent to allow estimates of survival. Results The clip treatment increased the size of the perineal and tail bare areas compared with the unclipped, unmulesed control lambs (P < 0.05), although the increases were less than in mulesed lambs (P < 0.05). The clips reduced breech wrinkle, dag and urine stain to levels partway between those recorded in the unclipped, unmulesed controls and the mulesed lambs (P < 0.05). Clipped lambs weighed more than mulesed lambs after treatment (days 30–90 P < 0.001; day 180 P < 0.01) and had higher cumulative percentage survival to 90 days after treatment (P = 0.03). Conclusions The clips successfully modified the breech region of lambs, although the changes were less than with mulesing. The clips did not reduce the body weight of lambs, compared with the unclipped, unmulesed control lambs, and improved 90‐day cumulative percentage survival compared with mulesed lambs.     

Strategic use of crutching and dicyclanil to protect unmulesed sheep against breech strike

Objective   To test strategies for the application of dicyclanil and mid-season crutching to maximise protection of unmulesed sheep against breech strike.
Procedure   Three hundred and eighty unmulesed Merino weaners were randomly allocated to four groups either left untreated or treated by different strategies with 50 g/L dicyclanil. Treatments included breech treatment alone and breech plus body treatment, with two application times, immediately after shearing and 6 weeks after crutching or shearing. To assess protection, larval implants with newly hatched Lucilia cuprina larvae were applied to 10 different sheep from each group at 3, 4, 5 and 6 months after crutching and shearing and assessed for the development of strike at 48 hours. The concentration of dicyclanil was measured in wool samples clipped from the breeches of the test sheep.
Results   All dicyclanil treatments gave significant reduction in strike in comparison to controls up until 4 months after crutching but protection in the sheep treated immediately after shearing had waned at 5 months. Treating at 6 weeks after crutching provided significant reduction ( P < 0.05) in strike for 6 months. Results for strike incidence immediately after shearing and concentration of dicyclanil in the breech wool also suggested improvements in protection by delaying treatment for 6 weeks.
Conclusion   In most environments it should be possible to protect unmulesed sheep against breech strike with a carefully planned integrated control program incorporating strategically timed crutching, shearing and dicyclanil application. Delaying treatment with dicyclanil to at least 6 weeks after shearing or crutching increased the protection provided in comparison to treatment immediately after shearing.     

Pharmacokinetics and bioavailability of tildipirosin following intravenous and subcutaneous administration in sheep

Tildipirosin is a semi‐synthetic macrolide antibiotic commonly used in cattle and swine to treat bacterial pneumonia. The objective of this study was to investigate the pharmacokinetic profile of tildipirosin after a single intravenous (i.v.) and subcutaneous (s.c.) administration in healthy lambs. Eighteen lambs were randomly divided into three groups (n = 6 each). Lambs received a single s.c. dose of tildipirosin at 4 and 6 mg/kg b.w. in group 1 and 2, respectively. Lambs in group 3 received a single i.v. dose of tildipirosin at 4 mg/kg b.w. Blood samples were collected at 0, 0.5, 0.75, 1.5, 2, 3, 4, 6, 8, 10, 24, 36, 48 hr, and every 24 hr to day 21, and thereafter at day 28 posttildipirosin administration. The plasma concentrations of tildipirosin were determined using high‐performance liquid chromatography with tandem mass spectrometry detection (LC?MS?MS). All lambs appeared to tolerate both the intravenous and subcutaneous injection of tildipirosin. Following i.v. administration, the elimination half‐life (T_1/2), mean residence time (MRT), volume of distribution (Vd/F), and total body clearance (Cl/F) were 119.6 ± 9.0 hr, 281.9 ± 25.7 hr, 521.1 ± 107.2 L, and 2.9 ± 0.5 L/hr, respectively. No significant differences in C_max (657.0 ± 142.8 and 754.6 ± 227.1 ng/ml), T_max (1.21 ± 0.38 and 1.35 ± 0.44 hr), T_1/2 (144 ± 17.5, 156.5 ± 33.4 hr), and MRT (262.0 ± 30.2 and 250.6 ± 54.5 hr) were found in tildipirosin after s.c. dosing at 4 and 6 mg/kg b.w., respectively. The absolute bioavailability (F) of tildipirosin was 71.5% and 75.3% after s.c. administration of 4 and 6 mg/kg b.w., respectively. In conclusion, tildipirosin was rapidly absorbed and slowly eliminated after a single s.c. administration in healthy lambs. Tildipirosin could be used for the treatment and prevention of respiratory bacterial infections in sheep. However, further in vitro and in vivo studies to determine the efficacy and safety are warranted. To our knowledge, this is the first study to determine the tildipirosin pharmacokinetic parameters in sheep plasma.     

Effects of meloxicam or tolfenamic acid administration on the pain and stress responses of Merino lambs to mulesing

OBJECTIVE: To determine the effectiveness of two long-acting non-steroidal anti-inflammatory drugs (NSAIDs) at reducing the pain and stress responses to mulesing in lambs. PROCEDURES: Merino lambs (n = 60) were allocated at 5 weeks of age to six treatment groups: (1) sham mules; (2) mules; (3) tolfenamic acid-sham mules; (4) tolfenamic acid administered 45 min before mulesing; (5) tolfenamic acid at the time of mulesing; (6) meloxicam at the time of mulesing. Plasma cortisol was measured at -0.75, -0.25, 0, 0.5, 1, 3, 6, 12, 24, 48 and 72 h relative to mulesing. Beta-endorphin concentrations in plasma were determined at 0, 0.5, 1, 6, 12, 24, and 48 h. Haematology was performed on blood samples taken at -0.75, 0, 24, 48 and 72 h. Plasma haptoglobin was measured at 0, 12, 24, 48 and 72 h. Rate of wound healing was determined 72 h post mulesing, and animal behaviour, including posture, was measured for 6 h after mulesing. RESULTS: The mulesed lambs exhibited large increases in plasma concentrations of cortisol, beta-endorphin and haptoglobin. All mulesed animals lost weight significantly in the week after mulesing, regardless of analgesic administration, but the difference in weight between mulesed and unmulesed lambs was less at the final measurement, 2 weeks after mulesing. Mulesed lambs spent significantly less time lying ventrally than control lambs. All lambs that were mulesed, including those administered NSAIDs, spent more time standing with a hunched posture and less time walking normally than control lambs. CONCLUSIONS: The NSAID treatments applied 45 min before or at the time of mulesing at the dose levels used in this study were not effective in reducing the acute response of lambs to mulesing.     

Ontogenesis of the rumen: A comparative analysis of the Merino sheep and Iberian red deer

The aim of this study is to describe differences in the ontogenesis of the rumen in the sheep (domestic ruminant) and deer (wild ruminant). A total of 50 embryos and fetuses of Merino sheep and 50 of Iberian deer were used, from the first stages of prenatal life until birth. For the study, the animals were divided into five experimental groups according to the most relevant histological characteristics. The appearance of the rumen from the primitive gastric tube was earlier in the sheep (22% gestation, 33 days) than in the deer (25% gestation, 66 days). In both cases it displayed a primitive epithelium of a stratified, cylindrical, non‐ciliary type. At around 28% gestation in the sheep (42 days) and 26% (67 days) in the deer, the rumen was configured of three clearly‐differentiated layers: internal or mucosal, middle or muscular and external or serosal. In both species the stratification of the epithelial layer was accompanied by modifications in its structure with the appearance of the ruminal pillars and papillae. The pillars appeared before the papillae and the appearance of both structures was always earlier in the deer (pillars: 70 days, 27% gestation; papillae: 97 days, 36% gestation) than in the sheep (pillars: 42 days, 28% gestation; papillae: 57 days, 38% gestation). The outlines of the ruminal papillae appeared as evaginations of the basal zone toward the ruminal lumen, dragging in their formation the basal membrane, the lamina propria and the submucosa. The tegumentary mucosa of the rumen was without secretion capability in the first embryonic phases. From 67 days (26% gestation) the neutral mucopolysaccharides appeared in the deer and at 46 days (30% gestation) in the sheep. In both cases they continued to decrease until birth, this diminution being more pronounced in the deer. Finally, the presence of neuroendocrine and glial cells was detected in the deer at earlier stages than in the sheep.     

Pharmacokinetics of ceftiofur sodium in cats following a single intravenous and subcutaneous injection

Ceftiofur, a third‐generation cephalosporin antibiotic, is being extensively used by pet doctors in China. In the current study, the detection method was developed for ceftiofur and its metabolites, desfuroylceftiofur (DCE) and desfuroylceftiofur conjugates (DCEC), in feline plasma. Then, the pharmacokinetics studies were performed following one single intravenous and subcutaneous injection of ceftiofur sodium in cats both at 5 mg/kg body weight (BW) (calculated as pure ceftiofur). Ceftiofur, DCE, and DCEC were extracted from plasma samples, then derivatized and further quantified by high‐performance liquid chromatography. The concentrations versus time data were subjected to noncompartmental analysis to obtain the pharmacokinetics parameters. The terminal half‐life (t_1/2λz) was calculated as 11.29 ± 1.09 and 10.69 ± 1.31 hr following intravenous and subcutaneous injections, respectively. After intravenous treatment, the total body clearance (Cl) and volume of distribution at steady‐state (V_SS) were determined as 14.14 ± 1.09 ml hr^‐1 kg^‐1 and 241.71 ± 22.40 ml/kg, respectively. After subcutaneous injection, the peak concentration (C_max; 14.99 ± 2.29 μg/ml) was observed at 4.17 ± 0.41 hr, and the absorption half‐life (t_1/2ka) and absolute bioavailability (F) were calculated as 2.83 ± 0.46 hr and 82.95%±9.59%, respectively. The pharmacokinetic profiles of ceftiofur sodium and its related metabolites demonstrated their relatively slow, however, good absorption after subcutaneous administration, poor distribution, and slow elimination in cats. Based on the time of drug concentration above the minimum inhibitory concentration (MIC) (T>MIC) calculated in the current study, an intravenous or subcutaneous dose at 5 mg/kg BW of ceftiofur sodium once daily is predicted to be effective for treating feline bacteria with a MIC value of ≤4.0 μg/ml.     

Pharmacokinetics of ceftiofur sodium in Peekapoo dogs following a single intravenous and subcutaneous injection

The present study aimed to determine the pharmacokinetic profiles of ceftiofur (as measured by ceftiofur and its active metabolites concentrations) in a small-size dog breed, Peekapoo, following a single intravenous or subcutaneous injection of ceftiofur sodium. The study population comprised of five clinically healthy Peekapoo dogs with an average body weight (BW) of 3.4 kg. Each dog received either intravenous or subcutaneous injection, both at 5 mg/kg BW (calculated as pure ceftiofur). Plasma samples were collected at different time points after the administration. Ceftiofur and its active metabolites were extracted from plasma samples, derivatized, and further quantified by high-performance liquid chromatography. The concentrations versus time data were subjected to noncompartmental analysis to obtain the pharmacokinetic parameters. The terminal half-life (t_1/2λz) was calculated as 7.40 ± 0.79 and 7.91 ± 1.53 hr following intravenous and subcutaneous injections, respectively. After intravenous treatment, the total body clearance (Cl) and volume of distribution at steady-state (V_SS) were determined as 39.91 ± 4.04 ml hr⁻¹ kg⁻¹ and 345.71 ± 28.66 ml/kg, respectively. After subcutaneous injection, the peak concentration (C_max; 10.50 ± 0.22 μg/ml) was observed at 3.2 ± 1.1 hr, and the absorption half-life (t_1/2ka) and absolute bioavailability (F) were calculated as 0.74 ± 0.23 hr and 91.70%±7.34%, respectively. The pharmacokinetic profiles of ceftiofur and its related metabolites demonstrated their quick and excellent absorption after subcutaneous administration, in addition to poor distribution and slow elimination in Peekapoo dogs. Based on the time of concentration above minimum inhibitory concentration (T > MIC) values calculated here, an intravenous or subcutaneous dose at 5 mg/kg of ceftiofur sodium once every 12 hr is predicted to be effective for treating canine bacteria with a MIC value of ≤4.0 μg/ml.     

A morphometric analysis of the changes with age in the skin surface wax and the sebaceous gland area of Merino sheep

SUMMARY Skin samples were collected from the midside of Merino ewes at 6 weeks, one year, and 3 years of age. The thickness of the surface wax and the number and area of sebaceous glands per unit length of skin were measured with an image analyser. Three-year-old sheep had a significantly (P < .05) thicker skin surface wax layer, (14.4μ± 1.45), than they did as lambs, (7.85μ± 0.88). Both the number (2.91 ± 0.15 per mm) and area (24.27 μ²/μ± 1.54) of sebaceous glands per unit length of skin of 3-year-old sheep were significantly less than in lambs, which measured 4.10 ± 0.15 per mm and 39.30 ± 4.14 μ²/μ respectively and one-year-old sheep, which measured 3.99 ± 0.21 per mm and 35.43 μ²/μ 3.65 respectively.     

氯化钠对托克逊黑绵羊生长性能、氮平衡及尿中氨和一氧化二氮排泄的影响

文章旨在评价饲粮中添加氯化钠对绵羊生长性能和氮平衡的影响,以及随后绵羊尿液处理牧场对氨和一氧化二氮排放的影响。将30只托克逊黑绵羊平均体重(15±1.3)kg随机分为3组,对照组采用基础日粮(氯化钠2 g/kg),处理1和处理2组日粮氯化钠水平分别为4和6 g/kg。随后从对照组和处理2组收集的尿液样本用于土地进行田间试验,共设5个处理组,T1~T5分别为土壤未经任何处理、蒸馏水组、高盐组尿液用蒸馏水10倍稀释、对照组尿液和高盐组尿液。结果表明:补充氯化钠对绵羊生长性能和氮平衡无不良影响(P>0.05)。高盐日粮组总尿量、平均尿量显著高于对照组(P<0.05),但尿pH、尿氮浓度显著降低(P<0.05)。与T4组相比,T5组使土壤一氧化二氮排放峰值延迟,氨气平均排放速率降低48%(P<0.05),一氧化二氮平均排放速率降低26%(P<0.05)。综上所述,放牧绵羊全混合日粮添加高水平氯化钠(6 g/kg)提高了尿液量和降低尿液中总氮浓度,从而降低尿液处理牧场土壤氨气和一氧化二氮的排放。     

Evaluation of a sheep laparoscopic uterine trauma model and repeat laparoscopy for evaluation of adhesion formation and prevention with sodium carboxymethylcellulose

OBJECTIVE: To evaluate topical application of 1% sodium carboxymethyl cellulose (SCMC) for prevention of postoperative adhesions in a laparoscopic model of uterine trauma in sheep. STUDY DESIGN: Experimental study. ANIMALS: Fourteen non-pregnant ewes. METHODS: Ewes were randomly assigned to 1 of 2 groups: control (saline solution) or 1% SCMC treatment. By left flank laparoscopy, traumatic forceps were used to create serosal trauma (1.5 x 5 cm) and hemorrhage on the left uterine horn. Either 30 mL saline solution or 30 mL 1% SCMC was applied topically to the traumatized uterine horn. Adhesion formation was evaluated by repeat laparoscopy at days 14 and 21. Sheep were euthanatized on day 28 for necropsy evaluation of adhesions. RESULTS: Five control sheep had adhesions of the uterine horn by day 14, but only 4 had adhesions at day 21, and 2 at day 28. Adhesions did not occur in SCMC-treated sheep. No adhesions occurred elsewhere in the abdomen. CONCLUSIONS: Laparoscopically created uterine trauma is an effective method for induction of uterine adhesions, and laparoscopy is an excellent method for serial evaluation of adhesion formation. SCMC (1%) was effective at preventing adhesion formation in sheep and no inflammatory response was noted. CLINICAL RELEVANCE: SCMC (1%) should be considered for prevention of adhesions in abdominal surgery in sheep.     

Pharmacokinetics of sodium baicalin following intravenous and intramuscular administration to piglets

The purpose of this study was to determine the pharmacokinetics of baicalin after intravenous and intramuscular administration of sodium baicalin at 50 mg/kg to piglets. Plasma baicalin levels were determined by high‐performance liquid chromatography. The plasma concentration–time data of baicalin for both administration routes were best described by two‐compartmental open model. The area under the plasma concentration–time curve and the elimination half‐lives were 77.47 ± 6.14 µg/ml × h and 1.73 ± 0.16 hr for intravenous and 64.85 ± 5.67 µg/ml × h and 2.42 ± 0.15 hr for intramuscular administration, respectively. The apparent volume of distribution and body clearance were 1.63 ± 0.23 L/kg and 2.74 ± 0.30 L h^?1 kg^?1 for intravenous and 0.51 ± 0.10 L/kg and 0.78 ± 0.08 L h^?1 kg^?1 for intramuscular routes, respectively. An intramuscular injection of sodium baicalin in piglets resulted in rapid and complete absorption, with a mean maximal plasma concentration of 77.28 ± 7.40 µg/ml at 0.17 hr and a high absolute bioavailability of 83.73 ± 5.53%.