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The objective was to determine the effect of powdered coconut water extender (ACP-106c) on the proportion of female puppies born. Twenty French Bulldog bitches were subjected to natural mating (NM) and, during the subsequent two estrus periods, were bred by intravaginal artificial insemination (AI), using chilled semen (from the same males) diluted in Tris-egg yolk (AI-Tris) or ACP-106c (AI-ACP-106c). Fresh semen was cooled to 5 °C and maintained at that temperature for 6 h, rewarmed (37 °C for 30 s), and used for AI. Pregnancy and whelping rates following NM were both 100% and were both 90.0% following AI with either extender. Litter size (mean ± SD) was 5.4 ±1.1, 4.7 ± 2.0, and 5.1 ± 2.0 (P > 0.05) for NM, AI-Tris, and AI-ACP-106c, respectively. Furthermore, for these groups, the number of female vs. male puppies born were 2.6 ± 0.6 vs. 2.8 ± 1.0, 2.2 ± 1.0 vs. 2.5 ± 1.1, and 3.4 ± 1.6 vs. 1.8 ± 1.2 (P < 0.05 for AI-ACP-106c only). In conclusion, our hypothesis was supported; AI of semen in ACP-106c extender resulted in a significantly higher proportion of female puppies. Furthermore, this extender yielded acceptable litter size and rates of pregnancy and whelping.

The objective was to assess the effect of adding various concentrations of dimethylformamide on characteristics of canine semen diluted in powdered coconut water (ACP-106C; ACP Biotecnologia, Fortaleza, CE, Brazil) and frozen at −196°C. Fifteen ejaculates were collected by manual stimulation from five adult Boxer dogs. The sperm-rich fraction was diluted in ACP-106C (ACP Biotecnologia) containing 10% egg yolk and divided into four aliquots. The cryoprotectants used for each aliquot were 6% glycerol (control group; CG) or 2%, 4%, or 6% dimethylformamide (DF2, DF4, and DF6, respectively). After thawing, total motility (mean ± SEM) for CG (58.4 ± 24.6) was higher (P < 0.05) than that of the other groups (2% dimethylformamide, 24.4 ± 12.3; 4% dimethylformamide, 26.5 ± 16.1; and 6% dimethylformamide, 21.7 ± 17.9). Furthermore, there was a greater percentage of fast, average, and slow moving sperm (assessed with computer-aided semen analysis; CASA) in CG in comparison with the other three groups. Therefore, based on concentrations tested in this study, dimethylformamide, together with ACP-106C (ACP Biotecnologia) and 10% egg yolk as a diluent, yielded unsatisfactory in vitro results for freezing canine semen.

Semen was collected by digital manipulation from six adult dogs. The second fraction of the ejaculate was used in this study. The semen was assessed by macroscopic and microscopic criteria 1 min after collection, first dilution, cooling, glycerol addition and thawing. Experiments were conducted to compare the effect of three different concentrations of glycerol in coconut water extender. The freezing method employed was that one described for caprine semen with slight changes. Semen was thawed at 37 degrees C for 1 min. Spermatozoal motility after thawing was 49.2+/-26, 44.2+/-18.3 and 35.8+/-26.8% for groups with 4, 6 and 8% glycerol, respectively. The vigor after thawing was 2.6+/-1.1, 2.7+/-1.0 and 2.1+/-1.2 for these groups, respectively. There was no difference among groups in motility and vigor. However, a smaller percentage of total and secondary abnormalities was observed using 6% glycerol in coconut water extender. In conclusion, the three glycerol concentrations (4, 6 or 8%) can be used successfully in cryopreservation of canine semen using a coconut water extender.

The objective of this study was to describe the sexual characteristics of domestic queens kept under natural equatorial photoperiod conditions without mating. Estrous signs were detected in 25 pubertal queens by manual stimulation and by exposure to a tomcat twice daily for 6 months (January to June). The signs observed were tail deflection, spinal flexion, rubbing or rolling, vaginal discharge, vocalization, treading of the hind legs, body or tail tremor and rigidity, blow or scratches, and discomfort on manipulation. The queen was considered in estrous when neck grip, tail deflection and attempted penile intromission by the male were allowed after mounting. From 187 cycles, there were (mean +/- S.E.M.) 7.5 +/- 0.7 cycles detected per queen; the duration of the cycle, estrus and non-acceptance were 18.1 +/- 0.9, 7.9 +/- 0.5, and 10.3 +/- 0.9 d, respectively. Queens always maintained some signs of sexual behaviour; they remained ambivalent for no more than 24 h at a time. It was noted that 85.3% of the observations of body or tail tremor and rigidity were made during estrus; therefore, these signs were considered characteristic of sexual receptivity. There was no evidence of prolonged anestrus or of a circannual pattern to estrus cyclicity.