[Results of impregnating cows and heifers on consolidated farms and the methods for synchronizing their estrus]. / Prouchvane na rezultatite po zaplozhdane na kravite i iunitsite v uedrenite fermi i metodi za sinkhronizirane na estrusa im.

Studied were the conception rate, milk productivity, calving period, and age at first conception with 3265 cows of 12 herds and 3 breed groups--Bulgarian Red Cattle (BRC), Holstein-Friesian Cattle (HFC), and HFC X BRC. The effect was followed up of the enzyme preparations Cytochrome 'C' and Beta-glucuronidase on the conception rate of cows. Tested was the action of prostaglandin F2 alpha and its analogues Equimate, Luteolysine, and Panazelen on the synchronization of the estrus and the conception. It was found that there was a considerable delay in the calving of the heifers (29 months). The calving period of the cows was prolonged and ranged in days from 369.17 +/- 3.17 up to 381.26 +/- 8.61 for BRC, 378.09 +/- 3.56 to 393.21 +/- 14.85--for HFC, and 339.75 +/- 6.56 to 390.42 +/- 3.51--for HFC X BRC. The use of Beta-glucuronidase and Cytochrome 'C' in the artificial insemination of the cows with deep-frozen semen raised the conception rate at first insemination by about 8-10 per cent.

[Effect of ultra low temperatures on the acrosomal proteins of bull and ram spermatozoa]. / Vliianie na ultraniskite temperaturi vurkhu akrozomalnite beltutsi v spermatozoidi na bik i koch.

Tested was the effect in vitro of ultra low temperatures on the activity of the acrosomal enzymes--acrosine and acid phosphatase--in the spermatozoa of bulls and rams. The use of spectrophotometric and electrophoretic methods demonstrated the presence of certain differences in the electrophoretic profile of the studied enzymes so far as spermatozoa of bulls and rams were concerned. Besides, acrosine and acid phosphatase in the acrosomal extracts from ram spermatozoa showed higher lability in treatment with ultra low temperatures as compared to bull spermatozoa. This led to higher losses with regard to some biologic properties of ram spermatozoa following the use of a technology of deep-freezing of semen.

[Biological and biochemical studies of the sperm and blood serum of rams with degraded sperm production]. / Biologichni i biokhimichni izsledvaniia na sperma i kruven serum pri kochove s vloshena spermoproduktsiia.

Experiments were carried out with 27 rams with impaired semen production, belonging to SIBT (11), Hampshire (5), Il-de-France (11) quality indices being tested in 80 ejaculates and in as many samples of blood serum. The semen was investigated in terms of ejaculate volume and motility and concentration of spermatozoa. The pathologic forms observed were classified as primary, secondary, and tertiary. Besides, the content was investigated of citric acid, fructose, and protein polymorphism of semen plasma and blood serum. It was found that ram semen of low spermatozoa motility the percent of abnormal forms was essentially high, and deteriorated semen production was associated with higher citric acid content. The level of the individual protein fractions in the semen plasma and the blood serum in test rams varied within a wide range, and was not related to the quality of their semen production.

[Serum proteins of rainbow trout in viral hemorrhagic septicemia]. / Prouchvane na serumnite proteini u dugovata pusturva pri virusnata khemoragichna septitsemiia.

Investigations on both healthy and sick of viral hemorrhagic septicemia artificially reared trouts aged one and three years were carried out. The total protein amount and the protein fractions were determined. It was established that in case of viral hemorrhagic septicemia the quantity of total protein in the blood serum is considerably reduced both in one year- and in three-year-old trouts. The study on protein fractions proved that the content of serum albumen sharply drops in sick trouts. The sick trouts have considerably higher alpha-globulin values than the healthy ones. beta-globulins are also increased in the fish suffering from septicemia. It was established that the beta 1:beta 2-globulin ratio in healthy one year- and three-year-old trouts is respectively 1.7:1 and 1.5:1. Higher values were established also for the gamma-globulin component in the blood serum of sick fish. In all investigations only one gamma-globulin fraction was assessed. The albumen-globulin coefficient in sick one year- and three-year-old trouts is 0.17 and 0.25, while in healthy fish of the same age it is 0.91 and 1.3 respectively.

[Chloride levels in the estral secretion and the fertility of cows]. / V'rkhu s'd'rzhanieto na khloridite v estralniia sekret i zaplodiaemostta na kravite

Studied was the chloride content of the estral secretion of cows at their insemination. It was found that chlorides vary from 351 to 1130 mg% on an average. In 90 per cent of the cows the chloride content varied within the 701-1200 mg% range. There is certain correlation between the chloride content and the conception rate of cows. The latter had highest values in cases where chlorides ranged from 701 to 800 mg%.