The purposes of this study were to describe the clinical signs observed in PRRS positive herds during a porcine reproductive and respiratory syndrome (PRRS) outbreak in Ontario and to determine associations between these clinical signs and herd demographics and PRRS control strategies. All PRRS polymerase chain reaction-(PCR)-positive submissions to a diagnostic laboratory between September 1, 2004 and August 31, 2007 were identified (n = 1864). After meeting eligibility requirements and agreeing to voluntary study participation, producers from 455 of these submissions were surveyed for information on clinical signs observed in their herds, herd demographics, and PRRS control strategies used in their herds at the time that the PCR-positive samples were taken. Larger herd size was associated with an increased risk of reporting abortion, weakborn piglets, off-feed sows, and sow mortality in sow herds, and with an increased risk of reporting mortality in finishing herds. When disease control strategies were examined, use of a commercial PRRS vaccine in sows and gilts was associated with a decreased risk of reporting weakborn pigs and high pre-weaning mortality, while the use of serum inoculation in breeding animals was associated with an increased risk of reporting off-feed sows and sow mortality. Providing biofeedback of stillborn/mummified piglets, placenta or feces to gilts was associated with an increased risk of reporting respiratory disease and mortality in finishing pigs while all-in/all-out flow in farrowing rooms was associated with an increased risk of reporting sow mortality and weakborn piglets.

Eight female piglets from each of three farrowed crossbred (75% Hampshire x 25% Local) gilts grouped as A, B and C were weaned at 28, 42 and 56 days respectively. Piglets of each weaned groups were divided into two sub-groups _ 'a' and 'b' consisting of 4 piglets in each. Piglets of sub-groups _ 'a' were supplemented with strategic mineral mixture while the piglets of sub-group 'b' were offered commercial mineral mixture. There was significant (P0.01) rise of serum oestradiol-17â at the pubertal oestrus compared to the levels before puberty in gilts. Oestradiol concentration did not differ significantly among piglets weaned at different days of age and between piglets supplemented with strategic and commercial mineral mixture. Serum progesterone was lowest during oestrus and highest on day 10 of the oestrus cycle in all the groups. Progesterone concentration in the piglets weaned at different days of age did not differ significantly. However, the level was found significantly (P 0.05) high in piglets supplemented with strategic mixture over the piglets supplemented with commercial mineral mixture.

In the conditions of the Republic of Belarus there was studied the influence of methods and means of spot heating and localization of warmth on growth, viability and physiological status of piglets. In course of realization of the experiment there was issued a task of scientific substantiation of application of brooders of different construction and proposition of the most optimal method of microclimate formation in resting area of piglets for the increasing of their growth and viability, and improvement of physiological state. Research results showed that the highest indexes of growth and viability, and intensity of metabolic processes in piglets were obtained after the combined application in course of the first three weeks of suckling period of filament lamps and heated floors and brooders in the form of tops with shields, and at a later stage – only brooders of this construction in comparison with animals which were in course of a suckling period under the infrared radiation lamps or at the space-heating floor.

In the conditions of the Republic of Belarus there was studied the morphology and growth dynamics of vomeronasal cartilage of swine at postnatal period. The vomeronasal cartilage covers the vomeronasal body outside. Lateral and medial bases of vomeronasal cartilage formed an antrum in which there was an organon vomeronasal. The most intensive growth of a cartilage of pigs occurred in the first two months of animal life. Arrangement of cartilage was dissymmetric - at the right it was sited more caudad than at the left; this fact caused the differences in its dimensions at the transverse sections.

In the conditions of the Republic of Belarus there was studied the influence of a number of pigs in a group on swine productivity and blood indexes of pigs. In course of the study there were analyzed blood indexes of piglets before and at the end of the experiment. Research results showed that it was efficient to organize husbandry in small groups (10 heads per carriage). The adaptative period of animals in the conditions of husbandry in large groups (20 heads) was longer (the adaptation took place by the seventh day). In these conditions the average daily live weight gain of piglets was lower than in the conditions of small group husbandry on 5,1%. Research results showed that animal husbandry in the conditions of different number of heads per group did not render negative influence on morphological and biochemical blood composition.

On the basis of realized in the conditions of the Republic of Belarus research it was established, that Cryptosporidial infection was found at adult and young pigs. The data on influence studying cryptosporidiosis invasion on pathomorphological changes in internal organs of piglets in the conditions of an associative course with infectious. Associative diseases give clearer clinical findings and proceed much harder, with heavier morphological changes. The majority of diseases in the conditions of an associative course proceeds harder in comparison with a mono-infection or invasion. In the conditions of mono-invasion the basic changes are localized in small intestines, causing acute and subacute catarrhal enteritis and a serous inflammation of regional mesenteric lymphonodus. These histological processes are presented as non-uniform locus of infection of a mucous membrane of intestines with atrophy of villus, hypertrophy of crypth and mononuclear polymorphic-nuclear infiltration of basal membranes. In the conditions of association of Cryptosporidial infection with infectious diseases it was noted that the pathomorphological changes progress and are showed not only by catarrhal, but also by hemorrhagic and local necrotic enteritis. Epithelium of mucous membrane is exposed to desquamation, intestines walls become thinner because of meteorism. Thick intestines are also involved into inflammatory process. Associations of Cryptosporidial infection with infectious diseases lead to development of severe pathomorphological changes in intestines. Alteration has prevailing character that is expressed in progressive development of atrophic, dystrophic processes and decline of cells and tissues that conducts to increase of permeability of vessels and proliferation of cells of reticuloendothelial system. | На основании проведенных исследований установлено, что криптоспоридиозная инвазия выявляется у поросят. Представлены данные по изучению влияния инвазии криптоспоридиоза на патоморфологические изменения во внутренних органах поросят при ассоциативном течении с инфекционными болезнями. Ассоциативные заболевания дают более яркую клиническую картину и протекают гораздо тяжелее, с более выраженными морфологическими изменениями в организме. Большинство болезней при ассоциативном течении протекает более тяжело в сравнении с моноинфекцией или инвазией. При моноинвазии основные изменения локализуются в тонком кишечнике, вызывая острый и подострый катаральный энтериты и серозное воспаление регионарных брыжеечных лимфоузлов. Гистологические данные процессы представлены, как неоднородные участки инфицирования слизистой оболочки кишечника с атрофией ворсинок, гипертрофией крипт и мононуклеарной полиморфнооядерной инфильтрацией базальной мембраны. При ассоциации криптоспоридиоза с инфекционными заболеваниями патоморфологические изменения прогрессируют и проявляются не только катаральным, но геморрагическим и очаговым некротическим энтеритами. Эпителий слизистой оболочки подвергается десквамации, стенки кишечника истончаются вследствие метеоризма. В воспалительный процесс также вовлекается толстый кишечник. Ассоциации криптоспоридиоза с инфекционными заболеваниями приводят к развитию в кишечнике тяжелых патоморфологических изменений. Альтерация имеет преобладающих характер, что выражается в прогрессивном развитии атрофических, дистрофических процессов и некроза клеток и тканей, что ведет к повышению проницаемости сосудов и пролиферации клеток ретикулоэндотелиальной системы.

The spectrum of acaricides changes continuously and improves. At the same time, big attention is given to research of new, more effective preparations meeting modern requirements. Research on studying the efficiency of Akaribil preparation against swine sarcoptosis (Sarcoptidae) was realized in the conditions of swine breeding farm in the Republic of Belarus. The preparation possesses high insect-acaricidal activity. In the conditions of the preparation storage and repeated opening of a ware in the course of tests there were stated no changes in drug smell or color. The scheme of the preparation application is applied in industrial production technology. It possesses anti-inflammatory properties, antiseptic stimulating healing of skin damages, does not irritate integuments, renders weak irritating effect on mucous membranes of eyes. In recommended doses Akaribil does not cause any adverse effects and complicating disease. There were stated no contraindications to preparation application. High therapeutic efficiency against arachnoentomosis was proved. Application the preparation made it possible not only to reduce disease incidence and animal death, but also to facilitate the severity of scabietic diseases. As a result of realized research it was established that efficiency of Akaribil against swine sarcoptosis was 100%.

In the conditions of the Republic of Belarus as a result of task-specific selection and breeding work there was developed and approbated Berezinsky breed type of Belarusian meaty breed. Sows of the studied breed type were notable for high indices of reproductive signs: the average multiple pregnancy in three breeding swine herd was 11,1 pigs per farrowing; milkability - 55 kg, litter size at weaning stage at 35-day age - 87,1 kg. The predominancy over the forecast exponent indices made 4,7-5,7%. In course of the study there were analyzed the forecasted indexes of the basic breeding signs of Berezinsky breed type of Belarusian meaty breed for 2005-2010; productivity indices of the experimental sows; coefficient of variations of sow productivity.

In the conditions of the Republic of Belarus there was determined the influence of lactulose of the clinical state of weanling piglets, as well as analysis of its preventive and therapeutic efficacy. For the experimental group of piglets in course of 5 days before weaning the lactulose for administrated daily in combination with feed in course of 5 days in dose of 0,002 gram per kilogram of live weight. In 3-5 days after weaning the diarrhea was stated in 4,1% of experimental piglets. The clinically evident efficiency of application of the synthetic disaccharide was showed in lowering of disbacteriosis level in weaning piglets on 33,7%. Besides, there was analyzed the therapeutic efficacy of lactulose for weaning piglets diseased with gastroenteritis. They were administrated lactulose in dose of 0,03 grams per kilogram of live weight once a day after feeding in course of 7 days. Haematologic and biochemical blood indexes of experimental and control groups of piglets were analyzed. Research results showed that application of lactulose promoted the creation of optimal conditions for beneficial microflora, stimulated its reproduction, suppressed the development of opportunistic pathogens.

In the conditions of the Republic of Belarus there was realized an ecological monitoring of sources of water supply in the conditions of a swine breeding complex and adjoining settlements. There was studied the influence of a large swine breeding complex on water quality of closed type water sources. There was marked a microbial contamination of water depending on remoteness of animal breeding object and season of a year. There were determined the seasonal changes of physical properties, chemical and bacteriological composition of water used for swine breeding. There were noted changes in water quality in the process of its flow from the point of water inlet up to the place of its consumption. Results of influence of improved water on piglets were presented. There was studied the possibility of improvement of water quality by means of its treatment with solution of potassium hypermanganate (0,01%) which made it possible to increase average daily live weight gain of piglets. In course of the study there was realized the analysis of protein spectrum of blood serum of piglets; dynamics of body weight and average daily weight gain of experimental piglets.