George Stilwell

Melatonin reduces lipid peroxidation and apoptotic‐like changes in stallion spermatozoa

Abstract:  Lipid peroxidation (LPO) has been claimed as a major factor involved in stallion damage during storage or cryopreservation. Because melatonin is a well‐known potent antioxidant, the aim of the present study was to investigate the effect of melatonin during in vitro incubation. Furthermore, we investigated the presence of specific melatonin receptors (MT1 and MT2) using specific polyclonal antibodies and western blotting. Stallion spermatozoa were incubated up to 3 hr at 37°C in the presence of different concentrations of melatonin (0, 50 pm, 100 pm, 200 pm, or 1 μm). At the beginning and at the end of the incubation period, sperm motility (using computer‐assisted sperm analysis), membrane integrity and permeability, fluidity of the sperm membrane, LPO, and mitochondrial membrane potential (Δψm) were flow cytometrically evaluated. Melatonin reduced changes in the spermatozoa related to apoptosis (increased sperm membrane permeability and lowered Δψm) (P < 0.05). Furthermore, LPO was dramatically reduced (P < 0.01) while no effect was observed on sperm motility or kinematics. Interestingly, melatonin helped maintain a more fluid sperm plasmalemma (P < 0.05). Our results clearly show the absence of MT1 and MT2 receptors in the stallion spermatozoa. It is concluded that melatonin is a useful tool to improve the quality of stored stallion sperm, increasing their life span and reducing premature aging, this likely relates to melatonin’s antioxidant properties.

Glycaemia as a sign of the viability of the foetuses in the last days of gestation in dairy goats with pregnancy toxaemia

Pregnancy toxaemia is one of the most common diseases affecting small ruminants in the last month of gestation. Nearly 80% of the foetal growth occurs in the last 6 weeks of gestation. Fat goats and goats carrying twins and triplets are at greater risk. Pregnancy toxaemia is characterized by metabolic acidosis, hypoglycaemia and ketonaemia and a very high mortality rate. In our study five does with pregnancy toxaemia showed a marked hyperglycaemia (12.4 ± 5.4 mmol/L). Although our findings are based on a small population sample (10 goats), we nonetheless postulate that hyperglycaemia could be explained by the death of the foetuses. Caesarian surgery was performed on four of the five does with hyperglycaemia (HG does). In the fifth, kidding was induced. In this group, two does had two dead foetuses, two had three dead foetuses and one does had four foetuses, only one of which was alive. Caesarian surgery was performed on all five does with hypoglycaemia (LG does). Four does of the LG group had three foetuses and one had two foetuses, all alive. The HG doe had lower rectal temperatures, lower sodium and higher urea nitrogen (BUN) in the blood when compared with the LG does. As the condition of affected does may deteriorate quickly, the results of the present study suggest that in the last days of pregnancy goats with pregnancy toxaemia and concurrent hypoglycaemia should be considered for caesarian surgery.

Effect of hot-iron disbudding on behaviour and plasma cortisol of calves sedated with xylazine

We investigated cortisol and behaviour for the first hour after hot-iron disbudding of calves aged 37+/-4 days: disbudded after i/m xylazine (n=10); disbudded after i/m xylazine and regional anaesthesia with lidocaine (n=10); sham-disbudded after xylazine and lidocaine (n=11); sham-disbudded after i/m saline and lidocaine (n=10). Xylazine-treated groups had higher cortisol than saline-treated animals and showed no differences among them at any time. Sham-disbudded calves with xylazine had lower cortisol at 60 min compared with all other times. Xylazine-alone disbudded calves struggled more during the procedure than all other groups. Xylazine-alone disbudded calves showed more ear-flicks at 10, 25 and 40 min and head-shakes at 40 min than all other groups. We conclude that cortisol should not be used as an indicator of pain in disbudded calves while under the sedative effect of xylazine and that some behaviours during and after the procedure are useful in showing that xylazine alone does not control hot-iron disbudding pain.

Effects of hot-iron disbudding, using regional anaesthesia with and without carprofen, on cortisol and behaviour of calves

The objective of this study was to assess cortisol and behaviour changes in calves hot-iron disbudded after different analgesic protocols. We assessed the response of 27 calves at 1, 3, 6 and 24 h after disbudding with regional anaesthesia (DA), regional anaesthesia plus carprofen (DAC), disbudded only (D) or sham-disbudded (ND). At 1h cortisol was higher in D compared with all other groups. At 3h DA showed higher cortisol than ND but did not differ from baseline. At 15 min and 1h pain-related behaviours were more frequent in the D group than in all other groups. Group D (3 h) and DA (3 and 6 h) showed more ear flicks and head rubs compared with DAC and ND. We concluded that head rubbing, head shaking and ear flicking are useful behaviours for evaluating pain after hot-iron disbudding. Disbudding causes severe pain in calves and only the association of regional anaesthesia with carprofen assures good welfare for 24 h.

Effect of a quadrivalent vaccine against respiratory virus on the incidence of respiratory disease in weaned beef calves

Abstract We investigated the effect of vaccination of male beef calves (mean age±S.D.: 158±31days) against bovine herpes virus (BHV-1 or IBR virus), bovine respiratory syncitial virus (BRSV), bovine viral diarrhea (BVD) virus and para-influenza (PI3) virus on the incidence of respiratory disease during the first forty days after weaning and entering a feed-lot in Portugal. In May 2003, Mertolenga, Preta and mixed-breed calves from 10 different beef herds, were systematically assigned (by order of entrance in a chute) to two treatment groups, before moving to a common feed-lot. One hundred and twenty five male calves were vaccinated with a quadrivalent vaccine (Rispoval 4®) and revaccinated after 21–27 days while 148 herdmates were injected with saline (0.9% NaCl) on the same occasions. The incidence and severity of clinical cases of “bovine respiratory disease” (BRD) were evaluated every day during the first 40 days after entering the feed-lot. Morbidity (3% vs. 14%) and mortality (0% vs. 4%) due to BRD were significantly lower in the vaccinated group. Ten days after revaccination, the calves were treated with an antimicrobial – ending the study – after an outbreak of BRD caused a high incidence of disease in the non-vaccinated group. In conclusion, our results showed that Rispoval 4®, a quadrivalent vaccine against respiratory viruses, under field conditions, reduces morbidity and mortality due to BRD in beef calves after weaning.

Development and validation of a visual body condition scoring system for dairy goats with picture-based training

Body condition scoring (BCS) is the most widely used method to assess changes in body fat reserves, which reflects its high potential to be included in on-farm welfare assessment protocols. Currently used scoring systems in dairy goats require animal restraint for body palpation. In this study, the Animal Welfare Indicators project (AWIN) proposes to overcome this constraint by developing a scoring system based only on visual assessment. The AWIN visual body condition scoring system highlights representative animals from 3 categories: very thin, normal, and very fat, and was built from data sets with photographs of animals scored by a commonly used 6-point scoring system that requires palpation in 2 anatomical regions. Development of the AWIN scoring system required 3 steps: (1) identification and validation of a body region of interest; (2) sketching the region from photographs; and (3) creation of training material. The scoring systems reliability was statistically confirmed. An initial study identified features in the rump region from which we could compute a set of body measurements (i.e., measures based on anatomical references of the rump region) that showed a strong correlation with the assigned BCS. To validate the result, we collected a final data set from 171 goats. To account for variability in animal size and camera position, we mapped a subset of features to a standard template and aligned all the rump images before computing the body measurements. Scientific illustrations were created from the aligned images of animals identified as representative of each category to increase clarity and reproducibility. For training material, we created sketches representing the threshold between consecutive categories. Finally, we conducted 2 field reliability studies. In the first test, no training was given to 4 observers, whereas in the second, training using the threshold images was delivered to the same observers. In the first experiment, interobserver results was substantial, showing that the visual scoring system is clear and unambiguous. Moreover, results improved after training, reaching almost perfect agreement for the very fat category. The visual body condition scoring system is not only a practical tool for BCS in dairy goats but also shows potential to be fully automated, which would enhance its use in welfare assessment schemes and farm management.

Results of testing the prototype of the AWIN welfare assessment protocol for dairy goats in 30 intensive farms in Northern Italy

Abstract The AWIN project aimed at developing an on-farm welfare assessment protocol for adult dairy goats. A prototype protocol was tested in 30 intensive dairy goat farms to evaluate its feasibility in farms of different size. Time for applying the prototype was recorded and any other constraint was taken into account. Moreover, data collected during the prototype testing provided information on the prevalence of welfare issues in intensive dairy goat farms in Northern Italy. The prototype included 25 animal-based indicators (14 group- and 11 individual-level indicators). The prototype showed a good on-farm feasibility and it was highly accepted among stakeholders, as its application did not interfere with the daily routine. Approximately 2 h were required for the application of the prototype. When feeding racks were available, using them for locking the animals during the individual assessment resulted advantageous to speed the data collection and to reduce handling stress to the goats and disturbance to the farmers. Farm size and different management systems influenced the prevalence of some indicators, with small farms in general better welfare conditions compared to larger farms. The results of the present study represent an important starting point to set up an epidemiological database that may lead to improve the welfare status of goats.

Cryptococcal meningitis in a goat - a case report

BackgroundCryptococcus spp. are saprophytic and opportunistic fungal pathogens that are known to cause severe disease in immunocompromised animals. In goats there are reports of clinical cryptococcal pneumonia and mastitis but not of meningitis.Case presentationThe following report describes a case of a five year old buck showing severe neurological signs, including paraplegia and strong pain reaction to touch of the hindquarters region. Treatment with antibiotics was unsuccessful and the animal was euthanized for humanitarian reasons. Postmortem examination revealed lumbar meningitis, lung nodules and caseous lymphadenitis lesions. Encapsulated Cryptococcus neoformans were identified from the lungs and meninges, showing that cryptococcal meningitis should be included in the differential diagnosis of goats showing paresis and hyperesthesia. The possibility of concurrent immunosuppression due to Corynebacterium pseudotuberculosis infection is raised.ConclusionsCryptoccocal meningitis should be included in the differential diagnosis list of goat diseases with ataxia and hyperesthesia.

On-farm welfare assessment of dairy goat farms using animal-based indicators: the example of 30 commercial farms in Portugal

ABSTRACT Welfare assessment can play multiple roles in the path to welfare improvement. In the dairy goat area, identification of the main welfare problems across countries and different production systems is needed. By the application of a prototype welfare assessment protocol, based on animal-based indicators, we aimed to provide an insight into the main welfare problems affecting intensively kept dairy goats in Portugal. Thirty farms, organised in three size categories, were assessed. The main areas of concern were claw overgrowth, queuing at feeding and hindquarter dirtiness, with larger farms heading higher concerns. Additionally, this paper aimed to investigate indicators’ consistency over time. Ten of the 30 farms were revisited four months later, during which no major husbandry changes were made. Our results showed an overall consistency. This study can help define intervention thresholds or minimum legal levels for each indicator, by determining their overall prevalence.

Modulation of in vitro rumen biohydrogenation by Cistus ladanifer tannins compared with other tannin sources

BACKGROUND Tannins are polyphenolic compounds able to modify the ruminal biohydrogenation (BH) of unsaturated fatty acids, but their activity may vary among different tannin sources. The effect of rockrose (Cistus ladanifer) on BH has never been compared with other more common tannin sources. Tannin extracts (100 g kg-1 substrate dry matter) from chestnut (CH), quebracho (QB), grape seed (GS) and rockrose (CL) were incubated in vitro for 6 h with ruminal fluid using as substrate a feed containing 60 g kg-1 of sunflower oil. A control treatment with no added tannins was also included. RESULTS Compared with the control, GS and CL, but not CH and QB, increased (P < 0.05) the disappearance of c9,c12-18:2 with a consequent larger production of c9,t11-18:2 and t11-18:1. However, no differences among treatments (P > 0.05) were observed for the disappearance of c9-18:1 and c9,c12,c15-18:3. The production of 18:0 was not different (P > 0.05) among treatments, although its proportion in the total BH products was lower (P < 0.05) for GS than for the other treatments. CONCLUSION Condensed tannins from GS and, to a lesser extent, from CL stimulate the first steps of BH, without a clear inhibition of 18:0 production.