Tomasz M. Gruszecki

Risk factors associated with small ruminant lentivirus infection in eastern Poland sheep flocks.

An analysis of the risk factors for ovine lentivirus infection was performed in sheep flocks located throughout the central-eastern region of Poland. Here, we report the infection details for 98 flocks with a total of 6470 ewes, 15 sheep breeds. The identification of infected animals and a review of the epidemiological status of each flock were based on an evaluation of serological tests performed on collected blood serum samples. Blood for examination was obtained from 2925 ewes of the 98 flocks under observation. Specific antibodies for Maedi Visna Virus (MVV) were detected via ELISA. Data illustrating the conditions at each sheep farm were obtained through questionnaires completed by farmers, as well as observations, measurements, and breeding records that were available. These observations were used to assess risk factors contributing to small ruminant lentivirus (SRLV) infection in sheep flocks. It was found that both sheep flock size and the type of management system had a significant effect on the increased risk of lentiviral infection. In addition, we demonstrate that there is a significant (p<0.0001) relationship between the occurrence of mastitis (OR 2.01, CI: 1.55-2.61) and diarrhea (OR 4.22, CI: 3.30-5.39) with SRLV infection in the observed sheep. Additionally, the infection rate of the animals translated directly to an impaired physical condition. Notably, the risk of infection could potentially be reduced if sheep producers are further acquainted with SRLV detection and invoke a control program based on diagnostic tests. Moreover, marketing approval should be granted for solely SRLV-seronegative animals.

21. Effect of Vacuum Ageing on Instrumental and Sensory Textural Properties of Meat from Uhruska Lambs

Abstract The objective of the present research was to assess the instrumental and sensory textural attributes of lamb meat depending on the cold storage ageing under vacuum. The research material included two skeletal muscles, i.e. semimembranosus (SM) and rectus femoris (RF) from carcasses of Uhruska lambs. The age of animals ranged from 120 to 135 days. The ageing and muscle influenced significantly shear force and shear energy. However, significantly lower shear force and higher score of tenderness were observed on 7 vs. 2 days of ageing only for SM. The evaluated factors (ageing and muscle) affected slightly and not significantly the parameters of texture profile analysis. The muscle samples after the 7-day ageing showed higher hardness and chewiness. Significant correlation of sensory tenderness with instrumental shear and energy force and springiness was confirmed. The obtained results indicated that vacuum-packed lamb meat during cold storage for 7 days following slaughter develops the sensory attributes, especially tenderness.

EFFECT OF PRNP GENE POLYMORPHISM ON REPRODUCTIVE PERFORMANCE OF MOTHER SHEEP AND THEIR OFFSPRING GROWTH

Abstract The polymorphism of prion protein (PrP) amino acids in codons 136 (A/V), 154 (R/H); and 171 (Q/R/H) was established. Reproductive performance of mother sheep was evaluated analysing the fertility coefficient and litter size, i.e. the number of born and reared lambs. The studies included mothers of synthetic lines BCP - 111 sheep and SCP - 104 sheep born in 2001-2007. In the examined ovine PRNP gene, the following four alleles were identified: ARR, AHQ, ARQ, and VRQ, with the absence of the ARH allele. The highest frequency was determined for the ARR (49.8%) and ARQ (45.8%) alleles. In the studied sheep population, the occurrence of seven different genotypes was reported. It was found that 71.6% of the animals had the genotypes ARR/ARR, ARR/ARQ, and ARR/AHQ, which are regarded as the most resistant to scrapie, while 7.9% of the population had ARR/VRQ-bearing genotypes (low resistance) or ARQ/VRQ ones (high susceptibility to scrapie). The analysis of the obtained results indicates that the PRNP genotype does not affect reproduction efficiency of mothers, or their offspring growth. It was concluded that flock elimination of ewes of genotypes with high and very high susceptibility to scrapie will not reduce the reproduction parameters of ewes or growth of their lambs.

Foraging Behavior Patterns of Sheep and Horses Under a Mixed Species Grazing System

ABSTRACT The research objective was to assess the behavior patterns of the Polish Konik horse breed and the Uhruska variety of the Polish Lowland Sheep breed under a mixed-grazing system, and their relationship with climatic factors. The observation included 4 adult horses, 27 ewes with lambs and 10 primiparous ewes. The behavior of the animals and the weather conditions were recorded at 60-min intervals. Horses and sheep displayed similarities in both species-specific behavioral patterns and timing of grazing activity, and the duration of foraging sessions was mostly influenced by time of day, lower temperature and relative humidity. In addition, the two species showed more interest in the watering place in the afternoon, and drinking frequency was mainly dependent on air temperature. The animals that pastured together gradually began to mix, but at first, they remained within their species group. Both animal species can be used for environmental protection and landscape conservation making rational use of pastures within protected areas.

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 mothers 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 studys 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.

The impact of intensive sheep grazing in the spring on the vegetation of xerothermic grasslands in Stawska Góra nature reserve

The aim of study was to assess the impact of intensive sheep grazing in the spring on the vegetation of xerothermic grasslands in Stawska Gora nature reserve, particularly the Carlina onopordifolia seedling development and preferences concerning the ingestion of specific plant species, including shrubs and tree-understory. In May 2015, 40 specimens of the Świniarka Sheep and Polish Lowland Sheep were grazed in an area of 1.85 ha. Phytosociological releves were taken using the Braun-Blanquet method. Changes in the plant cover were assessed in July 2015 under grazing and non-grazing conditions. The flowery grassland plants were assigned to the Cirsio-Brachypodion pinnati alliance and thicket communities - to the Rhamno-Prunetea class. There was confirmed that community under study is distinguished by a large share of Carlina onopordifolia . The number of Carlina onopordifolia seedlings in the grazed areas was significantly greater than in the non-grazed areas. The sheep ingested all herbaceous plants appearing in the grasslands in May, except for the poisonous Adonis vernalis and most of shrubs. Preliminary research results indicate that grazing in the spring led to a decreased cover-abundance of Brachypodium pinnatum and some shrubs, and also - to smaller share of dead organic matter in the plant cover. It can create favourable conditions for the generative reproduction of xerothermic plants such as Carlina onopordifolia .

The utility of nanowater for ram semen cryopreservation

Nanowater (NW; water declusterized in the low-temperature plasma reactor) has specific physicochemical properties that could increase semen viability after freezing and hence fertility after artificial insemination (AI) procedures. The main goal of this study was to evaluate ram semen quality after freezing in the media containing NW. Ejaculates from 10 rams were divided into two equal parts, diluted in a commercially available semen extender (Triladyl®; MiniTüb GmbH, Tiefenbach, Germany) prepared with deionized water (DW) or NW, and then frozen in liquid nitrogen. Semen samples were examined for sperm motility and morphology using the sperm class analyzer system and light microscopy. Cryo-scanning electron microscopy (cryo-SEM) was employed to determine the size of extracellular water crystals in frozen semen samples. Survival time at room temperature, aspartate aminotransferase (AspAT) and alkaline phosphatase (ALP) concentrations post-thawing as well as conception/lambing rates after laparoscopic intrauterine AI of 120 ewes were also determined. There were no significant differences between DW and NW groups in sperm progressive motility (26.4 ± 12.2 and 30.8 ± 12.4%) or survival time (266.6 ± 61.3 and 270.9 ± 76.7 min) after thawing and no differences in the percentages of spermatozoa with various morphological defects before or after freezing. There were, however, differences (P < 0.05) in AspAT (DW: 187.1 ± 160.4 vs. NW: 152.7 ± 118.3 U/l) and ALP concentrations (DW: 2198.3 ± 1810.5 vs. NW: 1612.1 ± 1144.8 U/l) in semen samples post-thawing. Extracellular water crystals were larger (P < 0.05) in ejaculates frozen in NW-containing media. Ultrasonographic examinations on day 40 post-AI revealed higher (P < 0.05) conception rates in ewes inseminated with NW (78.3%) compared with DW semen (58.3%), and the percentages of ewes that carried lambs to term were 73.3% and 45.0% in NW and DW groups, respectively (P < 0.01). In summary, the use of a semen extender prepared with NW was associated with a substantial improvement in the fertilizing ability of frozen-thawed ram semen and lamb productivity of inseminated ewes.

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

Abstract 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.