Long interval prostaglandin-based treatment regimens do not affect ovulatory or prolificacy rates of multiparous ewes after cervical fixed timed AI.

To evaluate effects of a longer, than conventional, interval between time of prostaglandin F2α (PG)-based administrations in a PG-based treatment regimen for fixed timed AI (FTAI) on ovulation rate (OR), non-estrous return rate on Day 21 subsequent to the time of AI (NRR21), as well as conception, prolificacy and fecundity rates, ewes were assigned to two groups. Ewes of treatment group (PG15) were estrous-synchronized using two PG doses 15 days apart and FTAI was conducted at 56 h after the second PG administration (Day 0). Ewes of the Control group (SE) had imposed a pre-estrous synchrony treatment regimen with two PG doses 7 days apart and AI was conducted after detection of spontaneous estrus from 17 to 19 days after the second PG administration (Day 0). Ovulation rate on Day 8, NRR21, conception, prolificacy and fecundity rates on Day 60 were evaluated. There were no differences (P > 0.05) between ewes of the PG15 and SE groups in OR (1.47 ± 0.50 and 1.54 ± 0.50, respectively) or prolificacy (1.42 ± 0.80 and 1.33 ± 0.62, respectively), however, there were lesser values (P< 0.05) in the PG15 than SE group for NRR21 (65.2% and 91.3%, respectively), conception (59.8% and 91.3%, respectively) and fecundity (84.8% and 120%, respectively). The longer interval with the PG-based treatment regimen does not affect OR and prolificacy, but there is a lesser NRR21, conception and fecundity rate in comparison to ewes of the Control group.

Short-term dietary protein supplementation improves reproductive performance of estrous-synchronized ewes when there are long intervals of prostaglandin or progesterone-based treatments for timed AI.

To evaluate the reproductive effects of a short-term dietary protein supplementation (Days -10 to -3) before timed AI (TAI = Day 0), 471 Merino ewes grazing native pastures were estrous-synchronized when there were either long intervals between prostaglandin administrations (two prostaglandin injections 15 or 16 d apart; PG15 and PG16, respectively) or with a progesterone-eCG (P4-eCG) protocol, resulting in a 3 × 2 experimental design. Ovulation rate on Day 8 (OR), non-estrous-return to Day 21 (NRR21), and fertility, prolificacy and fecundity on Day 70 were evaluated. The interaction between estrous synchronization protocol and supplementation was not significant for any of these variables (P > 0.05). Supplementation increased OR, prolificacy and fecundity (+0.14, +0.15 and +0.14, respectively, P < 0.01), but did not affect NRR21 or fertility of ewes (+6.2% and +6.7% respectively, P > 0.05). Ewes treated using the PG15 and PG16 protocols had a lesser OR (-0.27), prolificacy (-0.22) and fecundity (-0.20) than ewes treated using P4-eCG protocol (P < 0.01 for each), and similar NRR21 and fertility (-5.4% and -7.9% respectively, P > 0.05 for both variables), without significant differences between the PG15 and PG16 groups. In conclusion, a short-term dietary protein supplementation before TAI improved OR, prolificacy and fecundity of ewes which were estrous-synchronized by imposing long interval PG (15 or 16 d apart) or P4-eCG-based protocols. There was a greater OR, prolificacy and fecundity when there was use of the P4-eCG compared to long interval PG-based protocols. Estrous-non-return rate after AI and fertility as a result TAI were not affected by either the supplementation or the estrous synchronization protocols used.

The Pattern of Secreted Molecules During the Co-Inoculation of Alfalfa Plants With Sinorhizobium meliloti and Delftia sp. strain JD2: An Interaction That Improves Plant Yield.

Delftia sp. strain JD2 is a plant-growth-promoting bacterium that enhances legume nodulation and growth, acting as nodule-assisting bacterium during the co-inoculation of plants with rhizobial strains. In this work, we evaluate how the co-inoculation of alfalfa with Sinorhizobium meliloti U143 and JD2 increases plant yield under greenhouse conditions and we analyze the pattern of secreted bioactive compounds which may be involved in the microbe-plant communication. The chemical composition of extracellular cultures (EC) produced in hydroponic conditions (collected 4, 7, and 14 days after bacterial treatment) were characterized using different chromatographic and elucidation techniques. In addition, we assessed the effect that plant irrigation with cell-free EC, produced during co-inoculation experiments, would have on plant yield. Results showed increased alfalfa shoot and root matter, suggesting that U143-JD2 co-inoculation might be a beneficial agricultural practice. The pattern of secreted secondary metabolites among treatments showed important differences. Qualitative and quantitative changes in phenolic compounds (including flavonoids), organic acids, and volatile compounds were detected during the early microbe-plant interaction, suggesting that the production of some molecules positively affects the microbe-plant association. Finally, the irrigation of co-inoculated plants with cell-free EC under greenhouse conditions increased plant yield over agronomic expectations. This effect might be attributed to the bioactive secondary metabolites incorporated during the irrigation.