Association between individual cumulative milk yield and various reproductive disorders in 56,772 Finnish Ayrshire cows belonging to 5,912 herds in 80 communities was studied. All cows delivered calves between September 1985 and September 1986. Five logistic regression models were fitted, 1 for each outcome disorder of interest: early metritis, late metritis, silent heat, ovarian cyst, and other infertility. Cumulative individual 37-day milk yield was used in the early metritis model, and cumulative individual 60-day milk yield was used in the other models, on the basis of median days in milk when these disorders developed. Cumulative 305-day herd milk yield, parity, calving season, presence or absence of other disorders, and community were also included in the models. Point estimates from the models represented odds ratios for the likelihood of having the outcome disorder.Lactational incidence risks for the 5 reproductive disorders studied were: early metritis (2.4%), late metritis (1.1%), silent heat (5.4%), ovarian cyst (6.6%), and other infertility (2.1%). The risk of early metritis decreased with increasing 37-day milk yield. The risk of silent heat, ovarian cyst, and other infertility increased with increasing 60-day milk yield; 60-day milk yield had no effect on late metritis. The 305-day herd milk yield increased the risk of early metritis, ovarian cyst, and other infertility; it had no effect on late metritis or silent heat. Parity had an effect on all disorders, except late metritis. Cows that delivered calves during the colder, darker seasons of the year had a higher risk of reproductive disorders than did those that delivered calves at other times of the year. A number of other disorders, reproductive and otherwise, were significant predictors of development of the outcome disorders.

To compare the effects of milk stasis and milk flow on Brucella abortus infection of the mammary gland under the same systemic conditions, primiparous goats (n = 5) were inoculated IV with B abortus on the day of parturition, and suckling by their neonates was restricted to one mammary gland. Goats were euthanatized and necropsied at 3 weeks after inoculation, and milk, mammary glands, and supramammary lymph nodes were evaluated by bacteriologic, histologic, and immunoenzymatic staining techniques. Nonnursed mammary glands had high titers of brucellae in milk, moderate interstitial mastitis, and brucellar antigen in macrophages located primarily in alveolar and ductal lumina. Brucellae often filled the macrophage cytoplasm. In contrast, nursed mammary glands had fewer brucellae in milk, minimal inflammatory changes, and no detectable brucellar antigen in histologic sections. Hyperplastic changes were only seen in supramammary lymph nodes draining nonnursed mammary glands; these contained more brucellae than lymph nodes draining nursed mammary glands. These studies show that milk stasis may be the sole cause of increased susceptibility of nonnursed mammary glands to B abortus infection.

We investigated the effect of reproductive herd health program (RHHP) on the reproductive performance in high yielding dairy herds. Data collected from 205 lactations at Boeun County, Chungbuk from April 2001 to Dec. 2003 included postpartum reproductive and metabolic diseases, body condition score (BCS), reproductive performance and milking records. First we compared the reproductive performance of cows without RHHP (pre-RHHP group) and cows with RHHP (RHHP group).

One of the first potential biotechnology products for animals production is BST. Effect of BST on lactating buffaloes was studied 8 buffaloes (Bubalus bubalis) were injected with sustained release formation Boosting-250, after 60 plus minus 5 days of calving. The overall increase in milk production was observed 18 percent and in milk fat 6.1 percent. BST is a protein hormone. Quality of management is the major factor affecting the magnitude of milk response to BST.

In the conditions of the Republic of Belarus there was studied the efficiency of application of national mineral additives (mineral feed additive produced on the basis of dolomitic meal) in rations of milking cows. In course of the study there were analyzed physical and chemical blood indexes; hematological indexes of cows; biochemical blood indexes; mineral composition of blood; natural resistance of cows. As a result of the realized study it was established, that an optimum dose of a dolomitic meal for milking cows during the winter period was 0,3% per dry matter of a diet. There was proved the possibility of increasing of a daily average milk yield of cows on 11,7%, fat and protein content in milk - on 0,04 - 0,06%, as well as lowering of quantity of somatic cells on 13,6%. Application of a national mineral additive rendered the positive influence on blood indices to what that was proved by increasing of erythrocytes (on 10,9%), thrombocytes (on 5,4%), haemoglobin (on 6,5%), crude protein (on 10,6%), and also macro- and trace elements. Introduction of a dolomitic meal into cow diets made it possible to increase the indices of natural resistance of cows on 0,5 - 4,0%.

In the conditions of the Republic of Belarus there was analyzed the interrelation between the main indexes of cattle milk performance of dairy cattle of Large Red Belarusian breed and Belarusian Black-and-White breed with different genotypes of kappa casein gene. In course of the study there was determined the frequency of occurrence of genotypes and alleles by kappa-casein gene in population of cows of mentioned above breeds. Values of correlation coefficients between some indexes of milk performance of the studied breeds were analyzed. Correlation factors between the basic indexes of milk performance of cows with different genotypes of kappa casein. Research results showed that milk protein content and butter-fat yielding capacity were in negative association with the main breeding trait of dairy cattle – amount of milk yield. Butter-fat yielding capacity and milk protein content correlated positively. Thus, selection breeding in accordance with one of this traits will promote increasing of the other. Besides, it is necessary to realize DNA-diagnostics of cattle according to kappa casein gene and to select animals having in their genomes allele CSN3**B connected with higher milk protein content.

In the conditions of the Republic of Belarus there was studied a therapeutic effectiveness and influence on milk productivity of 22% Timbendazole after spontaneous infestation of cows with fascioliasis (Fasciola hepatica). As a result of studies the Timbendazole 22% proved to be highly efficient against Fasciola hepatica in cattle – from 92,9% up to 100% (in comparison with Albendatimum-100 granulated material the efficiency of which was 88-90%). As a result of cows treatment by anthelmintics – Timbendazole 22% and Albendatimum-100 against Fasciola hepatica there was stated the substantial increasing of milk productivity of animals (on 23,4 and 11,0%, respectively) in comparison with animals which were not administratec with mentioned above preparations.