Birth of puppies of predetermined sex after artificial insemination with a low number of sex‐sorted, frozen–thawed spermatozoa in field conditions

Abstract

The aim of this study was to evaluate fertility and sex ratios after artificial insemination in dogs under field conditions. Semen was cryopreserved as unsorted (control) or was separated into X- and Y-chromosome-bearing sperm using a cell sorter. Sixty female dogs were inseminated with frozen-thawed spermatozoa of 100 × 10 unsorted (a dose in practice) and 4 × 10 sorted (X and Y group, respectively). A total of 20 dogs became pregnant and 126 puppies were born from the three groups. The percentage of parturition was similar for the X (5/20; 25.0%) and Y (4/20; 20.0%) group (P > 0.05), but lower than controls (11/20; 55.0%) (P < 0.05). Ultimately 28 out of the 32 puppies produced from X group were female (87.5%) and 19/22 (86.4%) puppies of Y group were male. In contrast, sex ratio (51.4% to 48.6%) in the control was significantly different from the X, Y group (P < 0.05). However, male and female puppies in the control had similar birth weights and weaning weights to those from the X and Y groups. This preliminary information indicated that normal puppies of predicted sex can be produced with low numbers of sorted cryopreserved dog spermatozoa at a farm level, making sperm-sexing technology potentially applicable for elite breeding units.

Assisted reproductive techniques for canines: preservation of genetic material in domestic dogs

“…An accuracy of 90% is ideal because a certain percentage of male offspring is necessary to maintain the breeding colony. Sorted frozen-thawed spermatozoa after surgical artificial insemination reportedly yielded pups with a significantly biased sex ratio [ 88 ]. In general, freezing and thawing procedures and cell sorting adversely affect sperm motility.…”

​Spermatozoa Sorting Techniques for the Sex Pre-selection: A Review

“…To date, the sexed semen is used for cattle (Garner and Seidel, 2008;DeJarnette et al, 2011), rams (De Graaf et al, 2007, horses (Clulow et al, 2008;Buchanan et al, 2020), water buffalo (Lu et al, 2010), elk (Schenk and DeGrofft, 2003), boars (Johnson et al 2000), Western Lowland Gorilla (O'Brien et al, 2005, W hite-Tail deer (Kjelland et al, 2011), cats (Pope et al, 2009); bottlenose dolphins (O'Brien et al, 2009); Pigs (Johnson 1991, Martinez et al, 2001Rath et al, 2003), goats (Bathgate et al, 2013) and dogs (Wei et al, 2017) have resulted in the birth of desired sex.…”