Road Transport of Late-Pregnant Mares Advances the Onset of Foaling

Cortisol is involved in the initiation of parturition and we hypothesized that increased maternal cortisol release advances the onset of foaling. Transport is a stressor for horses and induces an increase in cortisol release. To determine stress effects on the time of foaling, late-pregnant mares were transported by road for 3 hours (n = 12) or remained in their stable as controls (n = 4). Starting on day 325 of gestation, saliva and blood samples were taken for cortisol and progestin analysis, respectively. Fetomaternal electrocardiograms were recorded repeatedly. Mares were checked for impending parturition and changes in precolostrum pH. When pH decreased to 6.5, mares were either transported or left untreated. After birth, saliva was collected repeatedly from mares and their foals and heart rate (HR) was recorded. Foals were checked for maturity and health. Gestation length was 337 ± 2 days in stressed and 336 ± 2 days in control mares. Cortisol concentration increased from 3.3 ± 0.9 to 8.4 ± 0.8 ng/mL in transported mares (P < .001) and remained constant in controls. Maternal HR and heart rate variability (HRV) did not differ between groups and neither fetal HR nor HRV changed in response to transport. In transported mares, time from precolostrum decrease to parturition was shorter (40 ± 10 hours) than the respective time in controls (134 ± 49 hours, P < .01). Neither duration of foaling nor times to first standing and suckling of foals or the postnatum increase in HR and decrease in HRV differed between groups. In conclusion, transport-induced maternal cortisol release may have advanced the onset of foaling.     

分娩应激对围产期奶牛免疫机能的影响

本文分析了围产期奶牛的分娩应激对其免疫机能的影响,并从宏观和微观上进行了详细的阐述,为围产期奶牛的饲养管理提供了理论依据。     

Adiponectin links adipose tissue function and monocyte inflammatory responses during bovine metabolic stress

The periparturient period of dairy cows is characterized by intense lipid mobilization from adipose tissue leading to increased plasma concentrations of nonesterified fatty acids (NEFA). High NEFA are a predisposing factor for inflammatory based diseases. A major component of these diseases is uncontrolled macrophage/monocyte inflammatory responses. Changes in the endocrine activity of adipose tissue during the periparturient period could impact macrophage function by modifying the secretion of adipokines including adiponectin. Currently, the effects of adiponectin on monocyte activation in dairy cattle are unknown. In humans and rodents, this adipokine regulates monocyte phenotype and alterations in its plasma levels are linked with the development of inflammatory diseases. The objectives of this study were to establish associations between plasma adiponectin expression dynamics and different markers of lipid mobilization during the periparturient period of dairy cows and to characterize the effects of adiponectin on the inflammatory response of bovine monocytes. Plasma adiponectin, NEFA, BHB, albumin, and subcutaneous and retroperitoneal fat depots depth were measured during the periparturient period of dairy cows. In vitro, bovine monocytes were cultured with adiponectin to assess changes in pro-inflammatory responses following LPS stimulation. Results from this study demonstrate that alterations in plasma adiponectin levels in periparturient cattle are inversely correlated with the concentrations of plasma NEFA, an important marker of lipid mobilization. Furthermore, adiponectin exposure significantly decreased monocyte expression of TNFα after LPS stimulation thus markedly reducing their inflammatory response. Reduced plasma adiponectin during the periparturient period could predispose dairy cows to the development of uncontrolled monocyte inflammatory responses.     

Periparturient Arterial Rupture in Mares: A Postmortem Study

There are limited reports characterizing the occurrence of rupture of uterine and other arteries associated with pregnancy in mares. Cases were retrieved from the records of horses submitted for necropsy to the University of Kentucky Veterinary Diagnostic Laboratory over a 15-year period (1993-2007). Five hundred thirteen horses were diagnosed with periparturient arterial rupture, representing 1.5% of the total equine necropsy cases. Arterial rupture was diagnosed predominately in older mares, with 78% of the horses being ≥15 years of age. Ruptures occurred most commonly during parturition but also were diagnosed before and after parturition. Additionally, during a consecutive 3-year period within this time interval, an extensive workup of cases was performed. In these 71 cases, the area of the arterial rupture was carefully dissected, and the location, size, and appearance of the arterial tear were determined. The uterine artery was the most commonly affected vessel. Although there was overlap, mares with uterine artery rupture tended to be older than those with rupture of other arteries. There was no predilection for the left or right sides, and the uterine artery rupture occurred most often in the first 20 cm from the origin.     

Uterine Vascular Perfusion and Involution During the Postpartum Period in Mares

In horses, limited data is found regarding the vascular events during uterine involution at the puerperal period. Thus, we aimed to evaluate the morphological aspects (size of uterus and intrauterine fluid content) and the hemodynamics (endometrial and mesometrial vascular perfusion) of the uterus during its postpartum involution process. Ten mares were daily scanned by transrectal color Doppler ultrasonography from the first day postpartum (d1) to the 16th day after first postpartum ovulation (D0 = ovulation). The formerly gravid horn (GH) and formerly nongravid horn (NH) were individually evaluated. A reduction (P < .05) in the uterine diameter was observed during the first 7 days postpartum, and the rate of uterine involution decreased after this period. The involution was completed on d21 and d24 for the NH and GH, respectively. Presence of intrauterine fluid was present in large amounts between d1 and d2 postpartum, followed by a decrease (P < .05) between d4 and d7. No fluid was observed after d16 postpartum or after the third day postovulation (D3). During the early postpartum period, an increase (P < .05) in the endometrial and mesometrial vascularization was detected, respectively, between d1 and d4, and between d1 and d2. The vascular perfusion did not differ after d4 for endometrial tissue, whereas was reduced (P < .05) between d2 and d10 for mesometrium. After the first postpartum ovulation, an increase (P < .05) in vascular perfusion was observed from D0 to D5, followed by a decrease (P < .05) between D5 and D11 and an increase (P < .05) between D11 and D14. The novel vascular perfusion profile here described in the endometrium and mesometrium after ovulation is similar to the uterine vascular profile observed during estrous cycles and early pregnancy, indicating a fast return of the mare's uterus to cycling postpartum conditions.     

Implications of the RhoA/Rho associated kinase pathway and leptin in primary uterine inertia in the dog

The underlying functional and molecular changes in canine primary uterine inertia (PUI) are still not clarified. Leptin (Lep) and obesity negatively affect uterine contractility in women, partly mediated by the RhoA/Rho associated kinase pathway, affecting myometrial calcium sensitization. We hypothesized that increased uterine Lep/Lep receptor (LepR) or decreased RhoA/Rho associated kinase expression contributes to PUI in dogs, independent of obesity. Dogs presented for dystocia were grouped into PUI (n = 11) or obstructive dystocia (OD, still showing strong labor contractions; n = 7). Interplacental full-thickness uterine biopsies were collected during Cesarean section for relative gene expression (RGE) of RhoA, its effector kinases (ROCK1, ROCK2), Lep and LepR by qPCR. Protein and/or mRNA expression and localization was evaluated by immunohistochemistry and in situ hybridization. RGE was compared between groups by one-way ANOVA using body weight as covariate with statistical significance at P < 0.05. Uterine ROCK1 and ROCK2 gene expression was significantly higher in PUI than OD, while RhoA and Lep did not differ. LepR RGE was below the detection limit in five PUI and all OD dogs. Litter size had no influence. Lep, LepR, RhoA, ROCK1, ROCK2 protein and/or mRNA were localized in the myometrium and endometrium. Uterine protein expression appeared similar between groups. LepR mRNA signals appeared stronger in PUI than OD. In conclusion, lasting, strong labor contractions in OD likely resulted in downregulation of uterine ROCK1 and ROCK2, contrasting the higher expression in PUI dogs with insufficient contractions. The Lep-LepR system may affect uterine contractility in non-obese PUI dogs in a paracrine-autocrine manner.     

Serological examination and egg production of progeny of fowl experimentally infected with Egg Drop Syndrome 1976 virus

Summary

Following EDS'76 virus (BC14 virus) infection of breeder chickens by the conjunctival route, vertical transmission occurred in the first week after infection. In the progeny which had been infected with EDS'76 virus by the vertical route, increasing haemagglutination inhibiting (HI) litres to BC14 virus and increasing numbers of birds with HI litres were observed from 3 weeks to 15 weeks of age. Sixty‐one per cent of the hens and 77 per cent of the cocks had ²log HI BC14 virus litres exceeding 4 at an age of 15 weeks.

Some birds which had been serologically negative throughout the rearing period, seroconverted between 25 and 28 weeks of age. This phenomenon occurred in hens as well as in cocks. Simulation of stress twice during the laying period by injection of corticosteroid hormone did not increase the number of birds serologically positive to EDS'76 virus.

EDS'76 was observed in the group of hens that was vertically infected, since egg production was significantly depressed between 28 and 34 weeks of age. Probably this was mainly the result of a production drop in the hens showing seroconversion at 27 or 28 weeks of age.

In the group of fowl vertically infected with EDS'76 virus, serologically positive birds appeared to be protected for the greater part to BC14 virus challenge at 50 weeks of age, while negative birds seemed to be fully susceptible. Chicks hatched from eggs collected in the third and fourth week after infection of the dams had maternal antibodies. Fertility and hatchability of apparently normally shelled eggs seemed not to be affected after BC14 virus infection of the dams. Intensive contact with contaminated faeces is probably an indispensable condition for lateral transmission of the virus.     

青海八眉猪及其杂交组合不同胎次的繁殖性能研究

通过青海八眉猪(本)以及与长白猪,大约克夏猪杂交组合不同胎次的繁殖性能的研究,结果表明:青海八眉猪纯繁时,它的产仔数,产活仔数,初生重、初生窝重,断奶仔数,断奶重,断奶窝重七项繁殖性能指标均以3-6胎较高,长×本组合的7项繁殖性能指标均以3-6胎较高。约×本组合的7项繁殖性能指标均以4-6胎较高。     

Quantitative and qualitative assessment of milk production after pharmaceutical induction of lactation in the mare

The induction of lactation is performed in ruminants by steroidogenic impregnation, followed by drugs intended to increase prolactin secretion. The aim of this study was to induce lactation in barren mares and to evaluate milk production. Five treated and 5 control mares were used in June and September in year 1, and 12 mares were used in year 2. Mares were administered a vaginal pessary (500 mg altrenogest and 50 mg estradiol benzoate) for 1 week. The 2nd week, another sponge with 100 mg estradiol benzoate was administered, together with 50 mg/100 kg body weight (BW) sulpiride in oil (IM q12h). All mares were milked by hand. Drug treatment was stopped after I L was obtained. Milk production and composition and plasma prolactin concentration were measured. In year 2, the same steroid treatment was applied, but mares received sulpiride (n = 6) or domperidone (1.1 mg/kg PO q12h) (n = 6). A milking machine and oxytocin injections 1 minute before the start of milking were used. In year 1, all treated mares started milking within 1-5 days after sulpiride treatment. Mean daily milk production was 0.88 +/- 0.52 L/500 kg BW. Milk immunoglobulin G (IgG) contents increased in all mares (IgG concentration range, 14-92 g/L). Plasma prolactin increased during sulpiride treatment (range. 27.7 +/- 2.9 to 43.7 +/- 6.7 ng/mL [before] to 289.0 +/- 7.8 ng/mL during treatment, P < .001). In year 2, results were similar to those in year 1, with peak IgG concentrations ranging from 4.2 to 106.7 g/L and a larger daily milk production (3.13 +/- 0.75 with sulpiride and 3.45 +/- 0.51 L/500 kg BW with domperidone). In conclusion, lactation can be induced in mares within 2 weeks, and some mares produce good-quality colostrum.