Occurrence of polyovular follicles in mouse lines selected for high fecundity.

The aim of this study was to evaluate the prevalence of follicles with more than one oocyte (polyovular follicles, POFs) in mouse lines selected for high fecundity. The ovaries of 18 mice, 6 each from 3 different lines, were examined to evaluate the number of POFs and the follicular histology. Polyovular follicles were observed in the two high fecundity breeds, FL1 and FL2, as well as in the unselected control line, DUKsi.

Effect of dietary fatty acids on expression of lipogenic enzymes and fatty acid profile in tissues of bulls.

This study investigated the effects of dietary linolenic acid (C18:3n-3) v. linoleic acid (C18:2n-6) on fatty acid composition and protein expression of key lipogenic enzymes, acetyl-CoA carboxylase (ACC), stearoyl-CoA desaturase (SCD) and delta 6 desaturase (Δ6d) in longissimus muscle and subcutaneous adipose tissue of bulls. Supplementation of the diet with C18:3n-3 was accompanied by an increased level of n-3 fatty acids in muscle which resulted in decrease of n-6/n-3 ratio.

Studies on fixed-time ovulation induction in the pig.

A technology that allows for manipulating of oestrus and ovulation, and would then also allow for fixed-time insemination, can be of great benefit for swine farms that operate using sow batch management due, at least in part, to savings in labour and the production of large batches of evenly developed pigs. Thanks to the current knowledge on endocrine regulation of follicle development and ovulation, and the availability of numerous reproductively active substances such a technology is now available. It covers procedures for synchronising oestrus based on the use of altrenogest in gilts and of batch-wise weaning in sows, for stimulating follicle development using eCG and for inducing of ovulation using hCG or LH as well as GnRH analogues.

Fertilization and early embryonic development in the porcine fallopian tube.

Fertilization and early embryo development relies on a complex interplay between the Fallopian tube and the gametes before and after fertilization. Thereby the oviduct, as a dynamic reproductive organ, enables reception, transport and maturation of male and female gametes, their fusion, and supports early embryo development. This paper reviews current knowledge regarding physiological processes behind the transport of boar spermatozoa, their storage in and release from the functional sperm reservoir (SR), and of the interactions that newly ovulated oocytes play within the tube during their transport to the site of fertilization.

Holding bovine oocytes in the absence of maturation inhibitors: kinetics of in vitro maturation and effect on blastocyst development after in vitro fertilization.

Holding immature oocytes before maturation simplifies the transport of oocytes and aids in scheduling later manipulations. We examined the effect of holding bovine oocytes in the absence of meiotic inhibitors on their subsequent meiotic and developmental competence. Oocytes were matured immediately after recovery (control) or were held in a mixture of 40% TCM 199 with Earle's salts, 40% TCM 199 with Hanks' salts, and 20% FBS, at room temperature for 16 to 18 h (EH-held) and then matured.

The effect of feeding a diet naturally contaminated with deoxynivalenol (DON) and zearalenone (ZON) on the spleen and liver of sow and fetus from day 35 to 70 of gestation.

Pregnant sows were fed a control diet (CON, 0.15 mg deoxynivalenol (DON) and 0.0035 mg zearalenone (ZON) per kg diet) or diet containing 15% of Fusarium toxin contaminated triticale (MYCO, 4.

In vivo and in vitro effects of the organochlorine pesticides DDT, TCPM, methoxychlor, and lindane on the female reproductive tract of mammals: a review.

The present paper summarizes the toxicological data on the effects of the organochlorine pesticides DDT, its metabolites, TCPM, methoxychlor and lindane on folliculogenesis, ovulation, fertilization, and implantation of female reproductive organs in human, laboratory, and farm animals. These compounds possess the ability to disrupt endogenous hormone synthesis, storage or metabolism. Cells of the ovary, oviduct, and uterus are susceptible to the disruptive effects of organochlorine compounds (OCCs).

Changes in the spleen and liver of pregnant sows and full-term piglets after feeding diets naturally contaminated with deoxynivalenol and zearalenone.

Wheat contaminated naturally with the Fusarium toxins deoxynivalenol (DON) and zearalenone (ZON) was fed to pregnant Landrace sows for 35days. On day 110, caesarean section was carried out, the offspring were killed immediately after birth, and their livers and spleens examined. At necropsy there were no macroscopic lesions observed in any organ of either sows or piglets.

Study of enteral versus parenteral application of the gonadotropin releasing hormone agonist Gonadorelin[6-D-Phe] (D-Phe6-LHRH) on LH secretion in Goettinger miniature pigs.

With respect to the assessment of residue situation and as a part of preclinical trials to determine the biological activities of potential gonadotropin releasing hormone (GnRH) residues in porcine organisms the GnRH agonist Gonadorelin[6-D-Phe] (D-Phe(6)-LHRH) was administered either enterally or intramuscularly (i.m.) to female Goettinger miniature pigs in order to evaluate the GnRH-induced luteinizing hormone (LH) surge.

The embryonic pregnancy signal oestradiol influences gene expression at the level of translational initiation in porcine endometrial cells.

In the pig, conceptus-derived oestrogens (days 11 and 12 of pregnancy) seem to be a critical component of the signalling mechanism for maternal recognition of pregnancy. Embryonic oestrogens can mediate effects on endometrial function by interactions with epithelial and stromal oestrogen receptors (ER). Recent data demonstrate that cell membrane ER interacts with the phosphatidylinositol 3-kinase/Akt pathway in several types of cells.

Luteinizing hormone release after administration of the gonadotropin-releasing hormone agonist Fertilan (goserelin) for synchronization of ovulation in pigs.

The generic GnRH agonist, Fertilan (goserelin), was tested for the ability to induce an LH surge and ovulation in estrus-synchronized gilts. Three experiments were performed to 1) examine the effect of various doses of Fertilan on secretion of LH in barrows, to select doses to investigate in gilts (Exp. 1); 2) determine doses of Fertilan that would induce a preovulatory-like rise of LH in gilts (Exp.

Effects of a preovulatory administered depot gonadotrophin-releasing hormone agonist on reproductive hormone levels and pregnancy outcome in gilts.

The present study aimed to explore the influence of a preovulatory administered depot gonadotrophin-releasing hormone (GnRH) agonist (GnRHa; Decapeptyl Depot) on the endocrine parameters and pregnancy outcome of gilts (n = 6). A GnRHa-supported preovulatory luteinising hormone (LH) surge was detected in all treated gilts. LH pulses were abolished completely by depot GnRHa on Day 7 and partly on Day 21 of pregnancy.

Experimental evidence for the influence of cumulus-oocyte-complexes on sperm release from the porcine oviductal sperm reservoir.

In the pig, a temporal relationship is suggested between sperm release from the sperm reservoir (SR) and ovulation, but the mechanism(s) is still under discussion. In two experiments, the influence of transferred ova on the release of SR-spermatozoa at ovulation and the effect of supplementation with non-sulfated glycosaminoglycan hyaluronan (HA) on embryo development and the number of accessory spermatozoa, respectively, were examined. PMSG/hCG primed ovectomized gilts that had previously received endoscopic low-dose insemination into the cranial uterine horn were used as an experimental model.

Effects of diets with cereal grains contaminated by graded levels of two Fusarium toxins on selected immunological and histological measurements in the spleen of gilts.

Feeding experiments with diets containing Fusarium toxin-contaminated wheat were conducted to clarify the pathogenesis of immunological effects of Fusarium toxins to porcine spleen cells. Contaminated diets were fed to 36 Landrace prepubertal gilts for 35 d. Concentrations (as-fed basis) of the indicator toxins deoxynivalenol (DON) and zearalenone (ZON), respectively, were 210 and 4 (control--group I), 3,070 and 88 (group II), 6,100 and 235 (group III), and 9,570 and 358 microg/kg (group IV).

Activation of Akt (protein kinase B) stimulates metaphase I to metaphase II transition in bovine oocytes.

In somatic cells, the serine/threonine kinase Akt (or protein kinase B) was shown to contribute to processes linked to cellular growth, cell survival and cell cycle regulation. In contrast to these findings, the function of Akt during the meiosis of mammalian oocytes remains to be investigated. We analysed the phosphorylation pattern and the activity of Akt during meiotic maturation (transition from prophase I to metaphase II) of bovine oocytes.

Relative ileal amino acid flows and microbial counts in intestinal effluents of Goettingen Minipigs and Saddleback pigs are not different.

We explored the suitability of Goettingen Minipigs as models to measure ileal AA digestibility and evaluate dietary proteins for conventional pigs. Further, a potential for secondary ileal microbial colonization 5 mo after establishing end-to-end ileorectal anastomosis was investigated. Goettingen Minipigs (BW 18 kg) and Saddleback pigs (BW 27 kg) fitted with end-to-end ileorectal anastomosis were fed six diets based on barley and oilseed meals and three diets based on wheat and milk powder differing in total and ileal digestible lysine.

Clarifications on breakpoints in HSAX and BTAX by comparative mapping of F9, HPRT, and XIST in cattle.

The coagulation factor IX gene (F9), the hypoxanthine phosphoribosyl transferase 1 gene (HPRT1), and the X-inactive specific transcript gene (XIST) were physically assigned in cattle to analyze chromosomal breakpoints on BTAX recently identified by radiation hybrid (RH) mapping experiments. Whereas the FISH assignment of XIST indicates a similar location on the q-arm of the human and cattle X chromosomes, the locus of HPRT1 supported the assumption of a chromosome rearrangement between the distal half of the q-arm of HSAX and the p-arm of BTAX identified by RH mapping. F9 previously located on the q-arm of BTAX was assigned to the p-arm of BTAX using RH mapping and FISH.