Validity of comparisons between expected breeding values obtained from best linear unbiased prediction procedures in genetic evaluations is dependent on genetic connectedness among herds. Different cattle breeding programmes have their own particular features that distinguish their database structure and can affect connectedness. Thus, the evolution of these programmes can also alter the connec...

The aim of this work was to evaluate the efficiency of the intrauterine insemination (IUI) in swine, considering the conception rate, farrowing rate, litter size (alive born pigs). For the IUI, the females had been insemination at 24 and 48 hours after the estrus detection, and the inseminating doses of 500 million, 1 billion, 1.5 billion and 2 billion spermatozoa in 20 mL extender had been use...

Over 18% of cows returning to service within 49 days of first insemination were remated within the first 17 days. A distinct peak representing 31.4% of all short return intervals occurred from 8 to 10 days after first insemination. Because nonreturn rates to second insemination following these service intervals were equal to nonreturn rates for first inseminations, it is probable that some cows...

In several animals, male genitalia create insemination wounds in areas outside the genital orifice of females. I report that such traumatic insemination (TI) occurs in the Drosophila bipectinata complex (Diptera: Drosophilidae) and illustrate a previously unknown evolutionary pathway for this behaviour. Flash fixation of mating pairs revealed the dual function of the paired claw-like basal proc...

Embryo transfer (ET) in cattle has been used for the realisation of breeding programmes world-wide for more than 20 years. The efficiency of breeding technology, i.e. the breeding progress and costs, depends to a large extent on the results of superovulatory treatment and artificial insemination (A.I.). The results of this step are characterised by a high degree of variation. Numerous attempts ...

A total of sixty-six young males were used to evaluate the effect of low (L), medium (M) and high (H) concentrations of dietary digestible energy received during the rearing seasons (autumn and spring) on the performance and main semen characteristics of males for artificial insemination selected by a high growth rate. Males reared during the spring season presented a significantly higher weigh...

There is much interest in the United States and other countries by dog breeders, pet owners, veterinarians and research workers who realize the great potential for the use of frozen semen. This potential is comparable to that already achieved in the cattle breeding industry. Since the first successful pregnancy utilizing frozen dog semen (Seager, 1969), work on aspects of the freezing of dog se...

Lactating rabbits (n=1335) were artificially inseminated to study the effect of the addition of caffeine on rabbit semen stored for up to 96 h. Concentration of 0-5 mM/l were tested. Whereas a concentration of 0.2 mM/l increased spermatozoa motility, higher concentration values adversely affected reproductive parameters. Spermatozoa stored at 18 degrees C for 72-96 h did not have the capacity t...