Expression and Characterization of Constitutive Heat Shock Protein 70.1 (HSPA‐1A) Gene in In Vitro Produced and In Vivo‐Derived Buffalo (Bubalus bubalis) Embryos

Cells are blessed with a group of stress protector molecules known as heat shock proteins (HSPs), amongst them HSP70, encoded by HSPA‐1A gene, is most abundant and highly conserved protein. Variety of stresses hampers the developmental competence of embryos under in vivo and in vitro conditions. Present work was designed to study the quantitative expression of HSPA‐1A mRNA in immature oocytes (IMO), matured oocytes (MO), in vitro produced (IVP) and in vivo‐derived (IVD) buffalo embryos to assess the level of stress to which embryos are exposed under in vivo and in vitro culture conditions. Further, HSPA‐1A gene sequence was analysed to determine its homology with other mammalian sequences. The mRNA expression analysis was carried out on 72 oocytes (40 IMO; 32 MO), 76 IVP and 55 IVD buffalo embryos. Expression of HSPA‐1A was found in oocytes and throughout the developmental stages of embryos examined irrespective of the embryo source; however, higher (p < 0.05) expression was observed in 8–16 cell, morula and blastocyst stages of IVP embryos as compared to IVD embryos. Phylogenetic analysis of bubaline HSPA‐1A revealed that it shares 91–98% identity with other mammalian sequences. It can be concluded that higher level of HSPA‐1A mRNA in IVP embryos in comparison with in vivo‐derived embryos is an indicator of cellular stress in IVP system. This study suggests need for further optimization of in vitro culture system in which HSPA‐1A gene could be used as a stress biomarker during pre‐implantation development.     

中西医结合防治鸭传染性浆膜炎

鸭传染性浆膜炎即鸭疫里默氏杆菌病，是严重危害鸭生产的主要传染病之一。根据病鸭的流行病学、临床症状、剖检症状及实验室诊断，确诊为鸭传染性浆膜炎。采取中西医综合防治措施，取得较好疗效。     

Estradiol feedback inhibition of luteinizing hormone concentrations in the anestrous sow

The suppressive effects of exogenous 17 beta-estradiol (E2) on LH concentrations in sows that remained anestrus following weaning and in those that returned to estrus were evaluated. Four anestrous and four cyclic sows were treated subcutaneously with silastic implants containing E2 at 13 d after ovariectomy (d 0). Three anestrous and six cyclic sows received silastic implants without E2. Blood was collected at 6-h intervals from d -1 to d 12 and at 15-min intervals for 8 h on d -1, 2, 7 and 12. Sows were treated with 1 microgram GnRH/kg BW at the completion of each 8-h frequent sampling period. Blood was collected at intervals of 10 to 30 min for 3 h after GnRH treatment. Concentrations of E2 remained less than 5 pg/ml in sham-treated sows and were between 20 and 25 pg/ml in E2-treated females. Pulsatile LH concentrations was similar between anestrous and cyclic sows prior to implant treatment. Sham-treated anestrous sows had greater (P less than .05) pulse frequency and mean LH concentrations than E2-treated anestrous sows on d 2, 7 and 12. Differences in pulsatile LH concentrations between E2-treated and sham-treated cyclic sows were not detected. Pulse frequency was less (P less than .05) in E2-treated anestrous sows than in E2-treated cyclic sows on d 7 and 12. Peak LH concentrations were greater (P less than .05) in E2-treated cyclic sows than in E2-treated anestrous sows at each GnRH challenge. These results suggest that the hypothalamo-hypophyseal axis is more sensitive to the negative feedback effects of E2 in anestrous sows than in cyclic sows. In addition, chronic E2 treatment reduces pituitary responsiveness to GnRH to a greater extent in anestrous than in cyclic sows. Failure to return to estrus in swine may be due, at least in part, to an increased sensitivity of the hypothalamo-hypophyseal axis to the negative feedback effect of estradiol.     

Sow wastage: reasons for and effect on productivity.

The purpose of this study was to examine the reasons for, the rate and the effect of sow culling on productivity. Sow removal or wastage was investigated by means of producer questionnaires and by detailed production data recorded on 30 swine farms for two years. The sow removal rate was high (mean = 44.2%) with a wide herd-to-herd variation (range = 16% to 100%), and correlated negatively with litter size. Reproductive failure was the most common cause of culling cited by producers. It was concluded that sows on many Ontario farms were being culled prior to reaching their reproductive potential.     

Oxytocin precipitation of prostaglandin-induced farrowing in swine: determination of the optimal dose of oxytocin and optimal interval between prostaglandin F2 alpha and oxytocin

The influence of dose of oxytocin and the interval between prostaglandin (PG) F2 alpha and oxytocin administration on the synchrony of farrowing, the prevalence of intrapartum complications, and the number of pigs dying perinatally was investigated. In study 1, sows were given 10 mg of PGF2 alpha IM on day 112, 113, or 114 of gestation or were not treated. Twenty hours after PGF2 alpha administration, sows were given 0, 5, 10, 20, or 30 USP U of oxytocin IM. Sows treated with PGF2 alpha or PGF2 alpha plus oxytocin had a shorter interval to farrowing than sows not treated or treated with oxytocin alone. Treatment with PGF2 alpha plus 30 U of oxytocin induced the most rapid onset and the greatest synchrony of farrowing, with the mean onset occurring 2.1 +/- 0.4 hours after oxytocin vs greater than 8 hours for all other treatments. Sows treated with 5 or 10 U of oxytocin had a delayed onset and a less synchronous farrowing, compared with sows treated with 0 or 20 U. Day of PGF2 alpha treatment influenced (P less than 0.05) the interval from oxytocin to onset of farrowing. As day during gestation decreased, there was a corresponding decrease in the interval between oxytocin administration and farrowing. Number of interventions to remove retained pigs was not influenced (P greater than 0.05) by day of PGF2 alpha administration. All sows treated with PGF2 alpha followed by oxytocin had a higher rate of manual interventions, compared with that in sows given PGF2 alpha but not oxytocin.(ABSTRACT TRUNCATED AT 250 WORDS)     

In situ characterization of hydraulic conductivities of individual soil profile layers during infiltration over long time periods

Several studies have raised serious doubts about the suitability of small cores for measuring water‐movement attributes, due to their potential to provide unrealistic representation of macropore connectivity and abundance. This study explored the potential of lysimeter‐scale experiments to calculate the hydraulic conductivity, K(ψ_m), of undisturbed soil layers in a matric potential (ψ_m) range between 0 and −4 kPa. Four large lysimeters were collected from a Dystric Cambisol. For each lysimeter a tension infiltrometer supplied infiltrating water under suctions of 0, 0.5, 1 and 1.5 kPa. Soil water dynamics were measured in situ using arrays of tensiometers, at depths corresponding with layer boundaries. The results show clearly that infiltration and drainage rates are intimately linked to temporal ψ_m dynamics, which themselves are determined by preferential flow and soil‐layer interactions. A quasi‐steady state was identified as when infiltration matched drainage, and ψ_m measurements showed each layer had a stable hydraulic gradient, which then allowed in situ determination of the K(ψ_m) relationship of individual soil layers. For this soil K(ψ_m) is distinctly different for each soil layer, and these differences are consistent among the four lysimeters. A consistent feature is that all layers have a distinct change in the slope of the K(ψ_m) relationship, in the ψ_m range of −0.5 to −1.5 kPa, highlighting a dual‐porosity character. The whole‐column infiltration behaviour was strongly linked to the K(ψ_m) relationship of the surface layer (0–2 cm depth), and therefore hydraulic characterization of this layer should be a critical component of a soil survey.     

Infection of growing swine with porcine reproductive and respiratory syndrome virus and Mycoplasma hyopneumoniae--effects on growth,serum metabolites,and insulin-like growth factor-I

This study evaluated the influence of concomitant infections with porcine reproductive and respiratory syndrome virus (PRRSV) and Mycoplasma hyopneumoniae on growth performance, serum metabolite concentrations, and serum insulin-like growth factor-I (IGF-I) in growing pigs. Twenty-two barrows (10 weeks of age) were treated with either an intranasal administration of PRRSV and an intratracheal infusion of M. hyopneumoniae (treatment; n = 8) or a sham inoculation with medium (sham; n = 8), or were not treated (control; n = 6). The sham pigs were matched by body weight and pair-wise fed with treatment pigs. Pigs were weighed on the day of inoculation (day 0) and at 4 weeks postinoculation (day 28). Blood samples were collected prior to inoculation and at weekly intervals for 4 weeks. Pigs in the treatment group exhibited clinical signs consistent with PRRSV infection and M. hyopneumoniae pneumonia. Diagnostic procedures confirmed that treatment pigs were inoculated with PRRSV and M. hyopneumoniae and that sham and control pigs remained free of both pathogens. Average daily gain and feed conversion did not differ among the 3 groups. The IGF-I levels differed (P < 0.05) between control and treatment pigs, even after feed intake returned to similar levels among groups. At day 7, IGF-I concentrations were greater in sham pigs compared with treatment pigs, despite similar feed intake. Sham inoculation and decreased feed intake in sham pigs did not alter serum IGF-I concentrations. Evidently, IGF-I status of pigs affected with disease is influenced by nutritional and nonnutritional factors during the disease process.     

Steroid hormone and luteinizing hormone concentrations in the anestrous sow.

This investigation characterized serum concentrations of luteinizing hormone (LH), estradiol-17 beta (E2), progesterone (P4) and cortisol (C) in anestrous sows. Twenty-two sows that had not returned to estrus within 45 days after weaning (anestrous sows), and ten sows that had returned to estrus within seven days following weaning (cyclic sows) were nonsurgically fitted with indwelling jugular vein cannulae. Blood samples were collected at 6 h intervals for seven days and at 15 min intervals for 8 h on the fifth day after cannulation. Serum LH concentrations were determined in all samples, while C, E2 and P4 levels were quantitated in serum collected at 6 h intervals. Serum P4 concentrations in anestrous sows were consistently less than 0.5 ng/mL, and E2 levels ranged from 10 to 19 pg/mL. Concentrations of LH remained less than 1.0 ng/mL in anestrous sows, whereas a preovulatory LH surge was observed in five of ten cyclic sows. There was a circadian rhythm in mean C levels with C peaks occurring at 0600 or 2400 h and nadir levels observed at 1200 and 1800 h. Few differences in C levels were detected between anestrous and cyclic sows. It was evident that anestrous sows did not exhibit cyclic or predictable variations in steroid hormone concentrations. Unfortunately, the results of this study failed to elucidate the endocrine pathogenesis of the anestrous sow.