Lachance, M. P., Laforest, J. P., Devillers, N., Laperrie`re, A. and Farmer, C. 2010. Impact of an extended photoperiod in farrowing houses on the performance and behaviour of sows and their litters. Can. J. Anim. Sci. 90: 311Á319. The effects of an extended photoperiod around parturition and throughout lactation on performances of primiparous sows and their piglets were studied. Sows were assigned to two light regimens: (1) standard (CTL, n 028), 8 h of daily light from day 112 of gestation until day 23 of lactation; and (2) extended (TRT, n 026), 23 h of daily light from day 112 of gestation to day 4 of lactation and 16 h thereafter. Colostrum intake was estimated based on a 24-h piglet weight gain starting at the end of farrowing. Piglets were weighed on days 4, 7, 14, 21 (weaning on day 23), 35 and 56. On days 4 and 21 of lactation, milk and blood samples were obtained. Behaviour was recorded on days 3 and 20. Piglet feed intakes were noted post-weaning until day 56. The TRT sows had lower concentrations of melatonin than the CTL sows on day 4 (PB0.05), but prolactin concentrations, milk composition and colostrum intake by piglets were unaffected by treatment (P0.1). Litter growth during lactation was unaffected (P0.1), but TRT piglets consumed less feed between 23 and 34 d of age (P B0.05) and weighed less on day 35 (PB0.05). The TRT piglets were more active than CTL piglets on day 3 of lactation only (PB0.05). Increasing the period of daily light in the farrowing house did not improve the performance of primiparous sows and their piglets.

IntroductionPeripheral arterial disease (PAD) is a major risk factor for lower-extremity amputation in diabetic patients. Unfortunately, previous clinical studies investigating therapeutic angiogenesis using the vascular endothelial growth factor (VEGF) have shown disappointing results in diabetic patients, which evokes the necessity for novel therapeutic agents. The apelinergic system (APJ receptor/apelin) is highly upregulated under hypoxic condition and acts as an activator of angiogenesis. Apelin treatment improves revascularization in nondiabetic models of ischemia, however, its role on angiogenesis in diabetic conditions remains poorly investigated. This study explored the impact of Pyr-apelin-13 in endothelial cell function and diabetic mouse model of hindlimb ischemia.MethodsNondiabetic and diabetic mice underwent femoral artery ligation to induce limb ischemia. Diabetic mice were implanted subcutaneously with osmotic pumps delivering Pyr-apelin-13 for 28 days. Blood flow reperfusion was measured for 4 weeks post-surgery and exercise willingness was assessed with voluntary wheels. In vitro, bovine aortic endothelial cells (BAECs) were exposed to normal (NG) or high glucose (HG) levels and hypoxia. Cell migration, proliferation and tube formation assays were performed following either VEGF or Pyr-apelin-13 stimulation.Results and DiscussionFollowing limb ischemia, blood flow reperfusion, functional recovery of the limb and vascular density were improved in diabetic mice receiving Pyr-apelin-13 compared to untreated diabetic mice. In cultured BAECs, exposure to HG concentrations and hypoxia reduced VEGF proangiogenic actions, whereas apelin proangiogenic effects remained unaltered. Pyr-apelin-13 induced its proangiogenic actions through Akt/AMPK/eNOS and RhoA/ROCK signaling pathways under both NG or HG concentrations and hypoxia exposure. Our results identified the apelinergic system as a potential therapeutic target for angiogenic therapy in diabetic patients with PAD.

The effects of a long photoperiod treatment around parturition and throughout lactation on immune status of piglets were studied. Sows were assigned to 2 light regimens: i) standard short photoperiod (SP, n = 17), 8 h of daily light from d 112 of gestation until d 23 of lactation; and ii) long photoperiod (LP, n = 17), 23 h of daily light from d 112 of gestation to d 4 of lactation and 16 h thereafter. In front of the crates, under the side heat lamps and behind the sow, light intensities were 59 ± 5, 109 ± 6, and 44 ± 6 lx, respectively. On d 15 of lactation and at weaning (d 23), 2 piglets of similar BW per litter were selected and immunized intramuscularly with ovalbumin (OVA). Blood samples (5 mL serum and 10 mL whole blood) were taken at d 15 and d 23 of lactation, and at d 30, 37, and 44 of age after weaning to evaluate the antibody response to OVA and measure phagocytosis, lymphocyte proliferative response, and different circulating blood lymphocyte populations of piglets. Results showed that phagocytosis was increased in piglets submitted to LP (P < 0.05). A treatment × time interaction (P < 0.001) indicated that SP piglets developed a better IgG response to OVA than LP piglets. The percentage of B lymphocytes was also increased (P = 0.02) in SP piglets compared with piglets exposed to LP during lactation; the lymphocyte response to OVA tended to be enhanced (P = 0.07) over time in SP piglets. Different subpopulations of CD8+ lymphocytes were markedly increased in SP piglets at 23 d of age compared with piglets exposed to LP (treatment × time: P < 0.05). These results suggest that exposure of piglets to LP during lactation seems to reduce the capacity of piglets to develop a strong immune response to novel antigens. This may have important consequences on the ability of piglets to resist an infection after weaning.

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