Sow body condition at weaning and reproduction performance in organic piglet production

The objective was to investigate the variation in backfat at weaning and its relations to reproduction results in organic sow herds in Denmark. The study included eight herds and 573 sows. The average backfat at weaning mean�13 mm; SD�4.2 mm) ranging from 10.5 to 17.3 mm among herds shows that it is possible to avoid poor body condition at weaning even with a lactation length of seven weeks or more. No main effect of backfat at weaning on reproduction performance was found, but the probability of a successful reproduction after weaning tended to decrease with decreasing backfat for first parity sows, whereas the opposite was the case for multiparous sows

Stress and its influence on reproduction in pigs: a review

The manifestations of stress, defined as a biological response to an event that the individual perceives as a threat to its homeostasis, are commonly linked to enhanced activity of the hypothalamo-pituitary-adrenal (HPA) axis and the activation of the sympathetic adreno-medullary (SA) system. Activation of the HPA system results in the secretion of peptides from the hypothalamus, principally corticotropin releasing hormone (CRH), which stimulates the release of adrenocorticotropic hormone (ACTH) and beta-endorphin. ACTH induces the secretion of corticosteroids from the adrenal cortex, which can be seen in pigs exposed to acute physical and/or psychological stressors. The present paper is a review of studies on the influence of stressors on reproduction in pigs. The effects of stress on reproduction depend on the critical timing of stress, the genetic predisposition to stress, and the type of stress. The effect of stress on reproduction is also influenced by the duration of the responses induced by various stressors. Prolonged or chronic stress usually results in inhibition of reproduction, while the effects of transient or acute stress in certain cases is stimulatory (e.g. anoestrus), but in most cases is of impairment for reproduction. Most sensitive of the reproductive process are ovulation, expression of sexual behaviour and implantation of the embryo, since they are directly controlled by the neuroendocrine system

Ovulation induction in sow.

This study reviewed the protocols for ovulation induction in sows by human chorionic gonadotropin (hCG) and gonadotropin releasing hormone (GnRH). In pigs, it was documented that ovulation usually occurred about 70% of the way through oestrus. However, the duration of oestrus in sows highly varies, producing difficulty in performing artificial insemination (AI) in sows at optimal time. In practice, sows are usually inseminated for 2 to 4 times at 12 to 24 hours interval during oestrus, with an attempt to deposit sperm at the optimal time of ovulation. Many protocols have been developed to control time of ovulation, allowing fixed time insemination in gilts and sows. Hormones used for ovulation induction included hCG, GnRH and porcine luteinizing hormone (pLH). The purpose of treatment for weaned sows with hCG, GnRH or pLH performed after gonadotrophic treatment at weaning is to stimulate follicular growth. Such treatments at weaning period are associated with an increase in embryo mortality due to poorer oocyte quality. GnRH and hCG mechanisms of action on ovulation induction are different: GnRH induces ovulation by providing a pre-ovulatory peak of LH, while hCG acts directly on LH receptors on ovarian follicle cells

Development of a modified selective medium to enhance the recovery rate of Brachyspira hyodysenteriae and other porcine intestinal spirochaetes from faeces

Aims: The aim of this study was to develop a modified selective medium to improve the recovery rate of Brachyspira hyodysenteriae and other clinically significant intestinal spirochaetes from porcine faeces. Methods and Results: The susceptibility of five Brachyspira spp. type strains and five Thai field isolates of B. hyodysenteriae to the antimicrobials halquinol and flavomycin was determined by in vitro susceptibility tests in the agar dilution method, and optimal incorporation rates were confirmed by broth dilution. All the spirochaetes were susceptible to halquinol at ≤1μgml -1, while 16μgml -1 of flavomycin (F) allowed their growth, and therefore, only the latter was selected for further use. F and different combinations of colistin (C), spectinomycin (S) and rifampacin (R) were incorporated into pre-enrichment broths and/or agar plates, and growth of the spirochaetes from seeded faeces was determined. Two solid media were selected for further testing using faeces from 90 finishing pigs on 10 farms. A previously recommended method of pre-enrichment did not increase the recovery rate. The use of blood agar modified medium (BAM) containing F (16μgml -1), S (400μgml -1), R (30μgml -1) and colistin (C, 100Uml -1) (assigning as BAM-CSRF) reduced the growth of contaminating intestinal microbiota and resulted in a significantly higher rate of spirochaete recovery than the previous recommended medium. Conclusion: BAM-CSRF is a useful new selective medium for the isolation of B. hyodysenteriae and other intestinal spirochaetes from pig faeces. Significance and Impact of the Study: The new selective medium for isolating B. hyodysenteriae and other Brachyspira spp. from pig faeces will improve their recovery and subsequent disease diagnosis