Risk factors associated with small-ruminant lentiviruses in sheepfold buildings

INTRODUCTION

Small-ruminant lentivirus (SRLV) infection is widespread across Europe. It causes substantial economic losses in sheep breeding. The main route of SRLV infection is through the mother's milk, especially colostrum However, infection can also occur via contact between infected and healthy animals. It should be noted that the mechanisms of contact infection are still relatively poorly understood. The virus can also spread through a flock via an aerogenic mechanism.

OBJECTIVE

Due to the increased risk of SRLV infection in sheep bred in an alcove system, this study sought to define the effect of various selected factors associated with alcove breeding on the frequency of SRLV infection in sheep.

MATERIAL AND METHODS

Risk factors associated with small-ruminant lentivirus (SRLV) infection were analyzed among flocks of sheep in central-eastern Poland. Ninety-eight sheep flocks were selected for detailed investigation and included 6,470 ewes and 15 breeds and lines. Serologic testing of blood samples was used to identify infected animals and evaluate the epidemiologic status of particular flocks. Specific antibodies for Maedi Visna Virus (MVV) were detected via ELISA. Questionnaires were used to gather information concerning risk factors.

RESULTS

The study's results indicate that factors associated with environmental conditions under which sheep are kept play a significant role in determining the risk of SRLV infection.

CONCLUSIONS

Special attention should be focused on airborne contamination associated with the technologies used in sheep breeding. Breeding technologies that limit airborne contamination in farm buildings should be employed. In developing programmes to eliminate SLRV in sheep flocks, improvement of zoohygenic conditions should also be considered.

Blood metabolic profile of goat kids fed a diet supplemented with alfalfa protein-xanthophyll (PX) concentrate during rearing with their dams

The research objective was to assess the effect of dietary supplementation with alfalfa protein-xanthophyll (PX) concentrate on haematological and biochemical parameters of the blood of goat kids. The study was conducted on 82 goat kids of the Saanen breed, reared with their dams. From 30 days of age the experimental group of kids (41 goats) received a feed mixture supplemented with 3% protein-xanthophyll PX concentrate, while the control was fed a standard, unsupplemented diet. Prior to the start of the experiment (29 days of age) and after its completion (121 days), blood was collected from the kids to determine haematological and biochemical indices. The results and their analysis indicate that inclusion of 3% alfalfa protein-xanthophyll (PX) concentrate in the kids’ diet positively affected the haematological and biochemical parameters of the blood. A higher level of erythrocytes, haemoglobin and haematocrit was noted, together with a decrease in the lymphocyte and monocyte count. The blood of goat kids receiving the PX concentrate-supplemented diet had significantly reduced content of total cholesterol and triglycerides, as well as low-density lipoproteins (LDL). The blood of the experimental kids showed a significantly higher level of total protein and urea. The alfalfa concentrate significantly diminished the activity of alanine and aspartate aminotransferases. Protein-xanthophyll (PX) concentrate of alfalfa can be used as a phytobiotic providing an excellent source of protein, vitamins and minerals essential for the proper function of the animal organism.

IN VIVO PERFORMANCE OF THE EXPERIMENTAL CHITOSAN BASED BONE SUBSTITUTE--ADVANCED THERAPY MEDICINAL PRODUCT. A STUDY IN SHEEP

When evaluating a novel bone substitute material, advanced in vivo testing is an important step in development and safety affirmation. Sheep seems to be a valuable model for human bone turnover and remodeling activity. The experimental material composed with the stem cells is an advanced therapy medicinal product (acc. to EC Regulation 1394/2007). Our research focuses on histological differences in bone formation (guided bone regeneration--GBR) in sheep maxillas after implantation of the new chitosan/tricalcium phosphate/alginate (CH/TCP/Alg) biomaterial in comparison to the commercially available xenogenic bone graft and a/m enhanced with the stem cells isolated from the adipose tissue. Twelve adult female sheep of BCP synthetic line, weighing 60-70 kg were used for the study. The 11 mm diameter defects in maxilla bone were prepared with a trephine bur under general anesthesia and then filled with the bone substitute materials: CH/TCP/Alg, BioOss Collagen, Geistlich AG (BO), CH/TCP/Alg composed with the stem cells (CH/S) or left just with the blood clot (BC). Inbreeding cycle of the animals terminated at 4 months after surgery. Dissected specimens of the maxilla were evaluated histologically and preliminary under microtomography. Histological evaluation showed early new bone formation observed around the experimental biomaterial and commercially available BO. There were no features of purulent inflammation and necrosis, or granulomatous inflammation. Microscopic examination after 4 months following the surgery revealed trabecular bone formation around chitosan based bone graft and xenogenic material with no significant inflammatory response. Different results--no bone recreation were observed for the negative control (BC). In conclusion, the tested materials (CH/TCP/Alg and BO) showed a high degree of biocompatibility and some osteoconductivity in comparison with the control group. Although the handiness, granules size and setting time of CHffCP/Alg may be refined for future clinical tests. The relevant beneficial influence of using the adipose derived stem cells in GBR was not confirmed in this model.

Redox status in the blood of ewes in the perinatal period and during lactation

The aim of the study was to determine the effect of the perinatal period on redox status indicators in the blood of ewes before and after lambing and during lactation. The study was performed on 12 ewes of the synthetic SCP line. Blood for testing of redox parameters was collected seven times: before pregnancy, 1.5 months and 24 h before lambing, 2 and 24 h after lambing, and in the fourth and eighth weeks of lactation. The following blood indices were determined by spectrophotometry: lipid peroxides, malondialdehyde, superoxide dismutase, catalase, plasma total antioxidant capacity, uric acid, urea, bilirubin, and creatinine. The tests showed that during the perinatal period reactions are generated which lead to oxidative stress. Oxidative stress in pregnant ewes was found to increase during the period before lambing and may persist even up to weeks 4-8 of lactation.