Tomislav Šperanda

Changes of thyroid hormones concentration in blood of sheep depending on age and reproductive status

Abstract The influence of the reproductive status was tested in the blood serum of 30 sheep (10 pregnant sheep on the 15th day prior to lambing, 10 lactating sheep on the 20th day of the lactation and 10 non-pregnant sheep). The influence of age was determined in the blood serum of 20 sheep and 20 lambs. Analysis of the impact of age in sheep and lamb on the concentration of thyroid hormones showed that 30-day old lambs had significantly higher (P<0.01) concentration of T3 and T4 compared to the other age categories of sheep. At the same time, 100-day old lambs had significantly higher concentration of T4 if compared to the 1 and 3-year old sheep. Referring to the reproductive status, there was significantly lower (P<0.01) concentration of T3 determined in the blood of lactating sheep than of non-pregnant and pregnant sheep. These findings point out unsatisfactory energy supply in the older sheep, sheep during late pregnancy and sheep at the beginning of lactation.

STEROID HORMONES PROFILE DURING AN OVARIAN SYNCHRONIZATION PROCEDURE IN DIFFERENT AGE CATEGORIES OF RED DEER HINDS (Cervus elaphus L.)

The objective of the present study was to compare estradiol/progesterone ratios of different age categories of red deer hinds and use it as a predictor of estrus synchronization success and consequently conception rate. To accomplish this we used 38 red deer hinds to establish serum progesterone and estradiol levels in young (21 animals), mature (10 animals) and old (7 animals) hinds during the estrus synchronization procedure (transvaginal/cervical AI). The following estrus synchronization was used: at the start of the experiment each hind received a controlled intravaginal drug-releasing device (CIDR, Pharmacia&Upjohn, New Zealand) containing 0.3 g of progesterone. The device was removed on day 11, simultaneously with an application of 250 IU of Pregnant Mare Serum Gonadotropin (PMSG, Folligon® Intervet International, Boxmeer, Holland). Transvaginal/cervical AI (artificial insemination) was performed 48 hours after CIDR withdrawal (day 13). Blood samples were obtained from the jugular vein using a Venoject® vacutainer without an anticoagulant for hormonal tests on the same experimental day (0, 11th and 13th day). A statistically (p<0.01) higher progesterone level was found in young hinds on the 11th day after controlled intravaginal drug-releasing device insertion. A significantly higher (p<0.01) estrogen level was observed in the young in regard to mature and old hinds on the expected day of estrus (13th day). Estradiol/progesterone ratios showed a statistically significant difference (p<0.01) on insemination day (13th day) between old and young hinds (98.67 : 46.59) and between old and mature hinds (98.67 : 51.79). Out of a total of 38 hinds only 9 had their offspring, 6 of the young and 3 of the mature hinds.

The effects of differently prepared natural zeolite clinoptilolite on weaned piglets

Zeolites are crystalline hydrated aluminosilicates of alkali and alkaline earth cations, consisting of three-dimensional frameworks of SiO4 and AlO4 tetrahedra linked through the shared oxygen atoms to form an open crystal lattice with approximately uniform pores of molecular dimensions. The dietary use of naturally occurring or synthetic zeolites has been reported to improve feed efficiency, thus leading to a beneficial growth response in pigs. Three groups of weaned piglets (N=60), crossbreed (LWxSL)x Pietrein, the same sex proportions, aged 28 to 70 days were involved in the trial. Tribomechanically activated zeolite clinoptilolite (0.2% was added to the first experimental group, modified clinoptilolite was added to the second experimental group in the same concentration. Piglets in all groups were of similar body weights during both experimental periods. Plasma glucose, urea, total protein, sodium, potassium, chloride concentration were changed with the diet added modified clinoptilolite.

Natural zeolite clinoptilolite as a feed additive of weaned piglets

Introduction Natural zeolites are crystalline alumosilicates of volcanic origin with unique cationexchange and absorption properties and have a variety of uses both in industry and in agriculture. After ingestion, powdered clinoptilolites are inert and do not react chemically with food or body fluids. Their properties not to bind amino acids, vitamins and minerals, as well as no to have a detrimental effect on the composition of the serum (Papaioannou et al., 2002) make it suitable for administration in the diet of domestic animals. There are not many data showing systemic effects of zeolits on haematopoiesis and enymatic activities. Ivkovic et al. (2004) found that blood count parameters were not relevantly affected using a natural zeolite clinoptilolite as the dietary supplement. With regard to serum chemistry, Pond and Yen (1983) found no effect of zeolite on plasma potassium, sodium and magnesium lewels in swine. When applied externally in powder form, zeolite has been found to quicken the healing of burns of a bitch (Bedrica at all, 2003) and wounds after surgical incisions (Mumpton F. A., 1999). A faster growing rate with clinoptilolite addition in lambs without differences in carcass characteristics, but faecal egg counts were reduced (Deligiannis et al, 2005) was also determined. Nevertheless, a positive effect of the addition of organozeolite to the feed of piglets (Stojic et al., 1998), sows and gilts (Kyriakis et al., 2002; Papaioannou et al., 2002), diary cows (Enemark et al, 2003) were established.