Peri‐oestrus Hormone Profiles and Follicle Growth in Lactating Sows with Oestrus Induced by Intermittent Suckling

Abstract

This study describes follicle dynamics, endocrine profiles in multiparous sows with lactational oestrus compared with conventionally weaned sows (C). Lactational oestrus was induced by Intermittent Suckling (IS) with separation of sows and piglets for either 12 consecutive hours per day (IS12, n = 14) or twice per day for 6 h per occasion (IS6, n = 13) from day 14 of lactation onwards. Control sows (n = 23) were weaned at day 21 of lactation. Pre-ovulatory follicles (> or =6 mm) were observed in 100% of IS12, 92% of IS6 and 26% of C sows before day 21 of lactation and in the remaining 74% C sows within 7 days after weaning. All sows with pre-ovulatory follicles showed oestrus, but not all sows showed ovulation. Four IS6 sows and one IS12 sow developed cystic follicles of which two IS6 sows partially ovulated. Follicle growth, ovulation rate and time of ovulation were similar. E(2) levels tended to be higher in IS sows (p = 0.06), the pre-ovulatory LH surge tended to be lower in IS12 (5.1 +/- 1.7 ng/ml) than in C sows (8.4 +/- 5.0 ng/ml; p = 0.08) and P(4) levels were lower in IS12 and IS6 than in C sows (at 75 h after ovulation: 8.8 +/- 2.4 ng/ml vs 7.0 +/- 1.4 ng/ml vs 17.1 +/- 4.4 ng/ml; p < 0.01). In conclusion, sows with lactational oestrus induced by IS are similar to weaned sows in the timing of oestrus, early follicle development and ovulation rates, but the pre-ovulatory LH surge and post-ovulatory P(4) increase are lower.

Group housing of sows in early pregnancy: A review of success and risk factors

“…Current sows have a high ovulation rate of 20-25 on average (e.g. Town et al, 2005;Gerritsen et al, 2008), and, in sows that remain pregnant, also fertilization rates are normally considered to be very high (Soede et al, 1995). As a consequence, litter size of sows is pre-dominantly determined by the level of embryo mortality.…”

032 Use of Triptorelin Acetate for Inducing Ovulation and Facilitating Fixed Time Artificial Insemination of Sows Weaned on Small-Scale and Niche Market Pig Farms

“…Multiparous sows tend to have larger follicles at weaning (~3.3 mm) than primiparous sows (2.5 mm; Langendijk et al, 2000b) and are less susceptible to compromised follicle development at weaning compared to primiparous sows (Gerritsen et al, 2008). Our results indicate that four out of 24 sows that were treated with P.G.…”

Effects of intermittent suckling on the performance and digestive efficiency of Iberian piglets weaned at 35 days of age

“…At 60 d of age the gastrointestinal tract increased considerably its relative weight respect to weaning (62.2 vs. 93.8 g/kg EBW, P b 0.001), probably as a result of the ingestion of solid feed as a single nutrient source for three and a half weeks. Gerritsen et al (2008) studied follicle dynamics and related endocrine profile in sows with lactational oestrus induced by two methods of IS during a prolonged lactation (41-45 days) in comparison with sows under continuous lactation and conventional weaning at day 21 of lactation. They concluded that sows subjected to IS were similar to weaned sows in timing of onset of oestrus, early follicle development and ovulation rate, but the pre-ovulatory LH surge and post-ovulatory progesterone increase was lower.…”