Reproductive features and faecal progesterone metabolite profile in female ferrets.

Elevated post-partum progesterone metabolite (P(4) -met) levels have been recently postulated to occur in lactating lynxes. The aims of this study were to monitor reproductive features in female ferrets, changes in the faecal P(4) -met concentrations throughout the breeding season and ovarian activity in post-partum lactating and non-lactating (NL) female ferrets. Our results indicate that coinciding with the results described in the lynx, elevated faecal P4-met concentrations occur in lactating ferrets, furthermore, that the duration of elevated secretion of P(4) seems to be dependent on the duration of lactation (P4-met at delivery, n=47: <500 ng/g; 5-7 days after delivery, during lactation, n=47: ≥ 500-800 ng/g; in females weaned at delivery, n=4: baseline levels). Three days after ovariohysterectomy of lactating females, P(4) -met concentrations decreased to baseline levels. In lactating females, the ovarian stroma is more active than that in NL ones implicating that the ovary is at least in part responsible for the elevated P4-met concentrations. Ovaries of lactating females contained many luteinized cells either as luteinized granulose cells in the wall of late pre-antral/early antral follicles or as corpus luteum (CL)-like structures. Early resumption of the entire ovarian activity (developed follicles and oestrus) occurs in NL post-partum females, while final follicular development is blocked (follicles stalls at antral stage) in the lactating ones (however, occasionally lactational oestrus may occur). We suppose that the elevated faecal P4-met during lactation together with suckling and other hormonal effects may contribute to prevention of early returning to oestrus in nursing female ferrets.

Biochemical and physiological effects of long-term sublethal T-2 toxin feeding in rabbits.

Effects of 4-7-week feeding of naturally contaminated wheat grains containing 0.284 mg T-2 toxin/kg were investigated on the health, certain serum biochemical parameters and reproductive status of sexually mature, virgin female rabbits. Three of the ten contaminated animals died before the end of the experiment (acute, fibrinous-purulent peritonitis and pneumonia). Hepatic damages are suggested by significant serum alanine aminotransferase and slight aspartate aminotransferase, gamma-glutamyl transferase, malate dehydrogenase activity increases, as well as by cholinesterase activity decrease as compared to control animals. The damage of kidney function is indicated by significantly higher creatinine level, as compared to the control. The T-2 toxin feeding also impaired ovarian functions, reflecting by unaltered progesteron concentration, macro- and microscopical pictures after GnRH-stimulation.