No abstract

This study investigated follicular development during and after postweaning altrenogest treatment of primiparous sows in relation to subsequent reproductive performance. Primiparous sows (n = 259) were randomly assigned at weaning (d 0) to 1 of 4 groups: control (no altrenogest, n = 71), RU4 (20 mg of altrenogest from d -1 to 2, n = 62), RU8 (20 mg of altrenogest from d -1 to 6, n = 65), or RU15 (20 mg of altrenogest from d -1 to 13, n = 61). Average follicular size (measured by ultrasound) increased during altrenogest treatment and resulted in larger follicles at the start of the follicular phase for RU4, RU8, and RU15 compared with controls (5.3 ± 0.9, 5.5 ± 1.3, 5.1 ± 1.2, and 3.4 ± 0.6 mm, respectively; P < 0.0001). Farrowing rate was greater in RU15 (95%) than in RU8 (76%; P = 0.04). The RU15 group also had more piglets (2 to 3 more piglets total born and born alive; P < 0.05) than the other treatment groups. Follicular development at weaning clearly affected reproductive performance. At weaning, average follicular size: small (<3.5 mm), medium (3.5 to 4.5 mm), or large (≥ 4.5 mm), was associated with farrowing rates of 86, 78, and 48%, respectively (P < 0.001). Sows with large follicles at weaning had low farrowing rates (71%) in RU4, very low farrowing rates (22%) in RU8, but normal farrowing rates in RU15 (83%). In conclusion, this study showed that 15 d of postweaning altrenogest treatment of primiparous sows may allow follicle turnover in sows that had large follicles at weaning and that this was associated with an improved reproductive performance. It also showed that shorter treatment with altrenogest (4 or 8 d) is beneficial for sows with small follicles at weaning, but is not recommendable for sows with large follicles at weaning.

No abstract

<p>Objectives of this study were to determine the fatty acid composition and to analyze the sensitivity to lipid peroxidation of different boar fresh semen samples from two herds, H1 and H2. Lipid peroxidation was evaluated using chemilu­minescence (cpm/mg of protein) and fatty acid profile by means of gas chromatography. The saturated fatty acid content found in the analyzed spermatozoa was approximately 43% in H1 and 33% in H2, whereas the total unsaturated fatty acid content was 47% in H1 and 59% in H2. When control and ascorbate-Fe++ dependent samples were compared, it was observed a significant increase in light emission. Consequently, significant decrease in the percentage of the polyunsaturated fatty acids was determined, being more affected: C22: 5 n6 and C22: 6 n3 in both herds, whereas C20: 4 n6 and C22: 4 n6 only in H2. The great amounts of polyun­saturated fatty acids found in H2 samples could be related to the loss of acrosomal integrity. Our results indicate that boar semen contains great amounts of polyunsaturated fatty acid in its composition, which were vulnerable to the lipid peroxidation.</p>

No abstract