Lactation Weight Loss in Primiparous Sows: Consequences for Embryo Survival and Progesterone and Relations with Metabolic Profiles

Our objective was to study reproductive consequences of lactation bodyweight loss occurring in primiparous sows with mild feed restriction and to relate these lactation weight losses and its consequences to metabolic profiles during lactation and subsequent early gestation. After weaning, 47 first‐litter sows were retrospectively assigned to a high– (HWL, >13.8%, n = 24) or low (LWL, ≤13.8%, n = 23)–weight loss group. Thirty‐six animals received an indwelling jugular vein catheter to determine lactational and gestational profiles of insulin‐like growth factor‐1 (IGF‐1), non‐esterified fatty acids (NEFA) and urea and gestational profiles of progesterone. At day 35 after insemination, sows were euthanized and their reproductive tract collected. Pregnancy rate was 75% (18/24) for HWL and 96% (22/23) for LWL sows. High–weight loss sows had a lower number of implantation sites (17.2 ± 0.8 vs 19.5 ± 0.7, respectively, p = 0.03) and a lower embryonic survival (65.6 ± 3.4 vs 77.4 ± 2.9%, p = 0.02), resulting in fewer vital embryos (14.9 ± 0.9 vs 16.8 ± 0.7, p = 0.07) than LWL sows. Progesterone peak values were reached later in HWL than in LWL sows (day 13.4 ± 0.5 vs 12.0 ± 0.5, respectively, p = 0.05). Gestational concentrations of IGF‐1, NEFA and urea were almost identical for HWL and LWL sows, whilst numerical differences were seen during lactation. The current study shows negative consequences of lactational weight loss in mildly feed‐restricted primiparous sows for embryonic survival and shows that these consequences seem only mildly related with metabolic alterations during lactation and not with metabolic alterations during subsequent gestation.     

Standing low-field magnetic resonance imaging in horses with chronic foot pain

Objective Conventional imaging modalities can diagnose the source of foot pain in most cases, but have limitations in some horses, which can be overcome by using magnetic resonance imaging (MRI). However, there are no reports of the MRI appearance and prevalence of foot lesions of a large series of horses with chronic foot lameness. Methods In the present study, 79 horses with unilateral or bilateral forelimb lameness because of chronic foot pain underwent standing low‐field MRI to make a definitive diagnosis. Results Of the 79 horses, 74 (94%) had alterations in >1 structure in the lame or lamest foot. Navicular bone lesions occurred most frequently (78%) followed by navicular bursitis (57%), deep digital flexor tendonopathies (54%) and collateral desmopathy of the distal interphalangeal joint (39%). Effusion of the distal interphalangeal joint was also a frequent finding (53%). Conclusion Low‐field MRI in a standing patient can detect many lesions of the equine foot associated with chronic lameness without the need for general anaesthesia.     

Effect of TGF‐β1 Superfamily Members on Survival of Buffalo (Bubalus bubalis) Embryonic Stem‐like Cells

This study examined the effects of supplementation of ES‐like cell culture medium with bone morphogenetic protein (BMP)‐4 (0, 10, 20 or 100 ng/ml) or Noggin (250, 500 or 750 ng/ml) or TGF‐β1 (0, 0.1, 1 or 10 ng/ml) or SB431542 (0, 10, 25 or 50 μm ), an inhibitor of TGF‐β1 signalling, on survival, colony area and expression level of pluripotency genes in buffalo ES‐like cells at passage 40–80, under different culture conditions. BMP‐4 supplementation significantly reduced (p < 0.05) colony survival rate, percentage increase in colony area and relative mRNA abundance of OCT4, whereas that of NANOG and SOX‐2 was increased significantly (p < 0.05). Noggin supplementation did not affect the colony survival rate and percentage increase in colony area in the presence of FGF‐2 and LIF. In the presence of FGF‐2 alone, it significantly reduced (p < 0.05) the relative mRNA abundance of OCT4 and SOX‐2 and increased (p < 0.05) that of NANOG. Supplementation with TGF‐β1 at 1.0 ng/ml but not at other concentrations increased colony survival rate but had no effect on percentage increase in colony area at any concentration. Supplementation with SB‐431542 decreased (p < 0.05) colony survival rate at 50 μm but not at other concentrations. The percentage increase in colony area was lower (p < 0.05) with 10 μm SB‐431542 than that in the controls, whereas at higher concentrations of 25 or 50 μm , SB‐431542 decreased (p < 0.05) the colony size instead of increasing it. In conclusion, these results suggest that BMP‐4 induces differentiation in buffalo ES‐like cells, whereas TGF‐β/activin/nodal pathway may not be playing a crucial role in maintaining pluripotency in these cells.     

Administration of Thyroxine Affects the Morphometric Parameters and VEGF Expression in the Uterus and Placenta and the Uterine Vascularization but does Not Affect Reproductive Parameters in Gilts During Early Gestation

The aim of this study was to evaluate the effects of thyroxine administration on morphometric parameters, expression of vascular endothelial growth factor (VEGF) and vascularization in the uterus and placenta and reproductive parameters in gilts at 70 days of gestation. At 150 days of age, i.e., before first heat, 20 gilts were randomly divided into two experimental groups: treated (n = 10) and control (n = 10). The treated group received a daily dose of 400 μg of l ‐thyroxine (T₄) in their diet until slaughter and the control group received only typical meals. Before artificial insemination, blood was collected to determine plasma total T₄. The gilts were inseminated in the second oestrus and slaughtered at 70 days of gestation. The foetal thyroid follicular epithelium height, number, size and weight of foetuses; foetal myogenesis, corpora lutea number, embryonic mortality rate, uterine weight, placental weight and placental fluid volume were measured. Histomorphometric and immunohistochemical analysis of uterus and placenta were determined. The averages of all variables were compared by the Student’s t‐test. The gilts treated with thyroxine showed significant increase of plasma total T₄. At 70 days of gestation, the heights of the trophoblastic epithelium, endometrial epithelium and endometrial gland epithelium were significantly higher in the group treated with T₄. The expression of cytoplasmatic and nuclear VEGF in trophoblastic cells and the number of blood vessels per field in endometrial stroma were significantly higher in the gilts treated with T₄. No other significant differences between groups were obtained with respect to other parameters (p > 0.05). We conclude that oral administration of T₄ up to 70 days of pregnancy in gilts affects the morphometric parameters, the expression of placental VEGF and the uterine vascularization but does not affect reproductive parameters in gilts during early gestation.