Heterospermično osjemenjivanje u pasa

Abstract

The idea of dual sire insemination in dog breeding is to give equal chances to both males to fertilize the eggs due to the specific oestrus cycle of the bitch. Two sexually mature, privately owned females Petit Basset Griffon Vendeen (bitch A and B) aged 3 to 5 years were subjected to dual-sire inseminations. Prior to insemination, the semen of stud dogs (n=5) was collected and evaluated for volume, concentration, total sperm count, motility, membrane integrity (HOS test), percentage of live spermatozoa and sperm morphology (eosin nigrosin staining). The time of insemination was based on serum progesterone (P4) concentrations, where P4 of >5–10 ng/mL was considered ovulation. Bitch A was inseminated in two oestrus cycles with fresh mixed semen from two males using the endoscopic transcervical insemination technique (TCI). Bitch B was inseminated in one oestrus cycle by laparoscopic intrauterine deposition of frozen thawed semen. Semen evaluation showed minimum deviations in all tested parameters between the chosen males on the days of insemination. Depending on sperm concentration and quality, the volume of ejaculates was adjusted, resulting in an equal number of motile spermatozoa from two males in each insemination, providing them an equal chance for fertilisation. Confirmation of pregnancy was carried out 24 days after insemination by ultrasonography. The whelping outcome was obtained directly from the owner of the bitches. Puppy blood was taken immediately after whelping from the umbilical vein into EDTA tubes. Blood samples were also obtained from the dam and both sires for DNA profiling. Parentage was determined for each dual-sired pup by using Thermo Scientific Canine Genotypes Panel 1.1. All inseminations resulted in pregnancy and whelping. A total of 14 puppies were born in three litters. Mixed parentage was determined in 1 of the 3 resultant litters (bitch A). In conclusion, dual sire insemination is a useful breeding tool providing the opportunity to obtain puppies from multiple genetic backgrounds in a single litter. However, as this method usually produces offspring from single father, optimal insemination protocol should be established for producing a litter of mixed paternity.