B-mode ultrasound and grey-scale analysis of the epididymis in boars, and the relationship to semen parameters.

This study investigated the epididymis of mature boars (n=10) by means of B-mode ultrasound and grey-scale analysis (GSA) for echogenicity (EG) determination using an ultrasound unit HS 1500V, a linear transducer (frequencies 7.5-9.0 MHz), and standardized unit settings. All boars had their epididymal caput, corpus and cauda scanned six times before and after semen collection, respectively, at weekly intervals. Semen was subjected to spermatological examination including volume, total and forward motility, sperm abnormalities, as well as total sperm count and concentration. The caput and corpus both had a homogeneous fine echotexture. The cauda was homogeneous too but had a marbled echotexture. Echogenicity before and after semen collection was caput > corpus > cauda, respectively (p<0.001). Echogenicity was higher before than after semen collection for all parts of the epididymis, respectively (p<0.001). Echogenicity of the caput correlated slightly positively with the total sperm count pre-collection (r=0.301; p=0.020) and with ejaculate volume pre- and post-collection (r=0.302 vs 0.306; p=0.017 vs 0.019), and slightly negatively with sperm concentration post-collection (r= -0.275; p=0.034). No relationship was found for EG of the corpus and cauda for any of the ejaculate parameters. In conclusion, B-mode ultrasound and GSA proved feasible for imaging the epididymis in boars. Single relationships between EG and ejaculate parameters were found and deserve further investigation.

Effects of feeding level during lactation on FSH and LH secretion patterns, and follicular development in primiparous sows.

In the primiparous lactating sow undernutrition affects LH, but the effect on FSH is less clear. This study was conducted to investigate the effect of ad libitum (AL; n = 5) and restricted (RE; 70% of the AL feed; n = 5) feeding on the secretion patterns of FSH and LH, and on follicular development in primiparous lactating sows. Body side fat thickness (BSFT) was measured prior to farrowing and at weaning on day 21 postpartum (pp). Sows had an intravenous catheter fitted on day 6 or 7 pp. Blood samples were taken on days 12, 15 and 18 pp, every 15 min starting at 0700 h for 11 h, and plasma analysed for FSH and LH by radioimmunoassay (RIA). Daily transcutaneous ultrasonography of the ovaries was performed between days 10 and 20 pp to monitor follicular growth. Reduction in BSFT was higher in RE than in AL sows (p < 0.05). Mean and basal LH were significantly higher in AL than in RE sows on days 12 and 15 pp. (p < 0.05), and LH pulse frequency tended to be higher (p < 0.1). Mean FSH was higher in AL than in RE sows on days 15 and 18 (p < 0.05), and had a tendency to be higher on day 12 (p = 0.1). Follicle size increased in AL sows between days 10 and 20 of lactation (p < 0.05; r = 0.71), but remained unaffected in RE sows. In conclusion, the study demonstrates that feed restriction of primiparous sows during lactation affects not only LH, but also FSH, as well as lactational follicular growth. An association between those events is suggested.

Postinsemination treatment of primiparous and multiparous cows with cloprostenol failed to affect ovulation and pregnancy rate in dairy cattle.

Previous studies have demonstrated the facilitating effect of a single cloprostenol treatment postinsemination on ovulation and pregnancy rate in dairy cattle and Italian buffalos. This study was conducted to test the effects of 500 microg cloprostenol given intramuscularly immediately postinsemination to 55 primiparous and 60 multiparous Holstein cows (Bos taurus; TR) of a typical dairy operation in East Germany and to compare them with 57 primiparous and 48 multiparous saline-treated cows (CON). Animals of the TR and CON groups did not differ or only differed marginally for age at treatment, interval calving-treatment, lactation number, milk production on the day of treatment, body condition score, and their peri- and postparturient case histories. All animals were clinically and reproductively healthy on the day of treatment. They were inseminated once 12h after the onset of estrus, scanned 24h after insemination to confirm ovulation, and tested for pregnancy by transrectal palpation between Days 42 and 48 postinsemination. Treatment did not affect the number of cows ovulating. The overall combined pregnancy rate (PR) was 47.3%. Pregnancy rate did not differ statistically between TR and CON (46.1% vs. 48.6%; P>0.05). In conclusion, this study failed to demonstrate beneficial effects of a postinsemination treatment of primiparous and multiparous cows with cloprostenol on ovulation and PR in a typical dairy cattle operation in East Germany.