Dragan Šefer

Effects of selenium supplementation as sodium selenite or selenized yeast and different amounts of vitamin E on selenium and vitamin E status of broilers.

The aim of this experiment was to determine the effects of broiler meal supplementation with different forms of selenium (as Na-selenite or selenized yeast) and different amounts of vitamin E on selenium and vitamin E status in broiler tissues. A total number of 240 broilers (Cobb 500) were divided in four experimental groups supplemented with Se and vitamin E for a period of 42 days: group SS+E20 - 0.3 mg/kg sodium selenite and 20 IU of vitamin E; group SY+E20 - 0.3 mg/kg selenized yeast and 20 IU of vitamin E; group SS+E100 - 0.3 mg/kg sodium selenite and 100 IU of vitamin E; group SY+E100 - 0.3 mg/kg selenized yeast and 100 IU of vitamin E. Blood plasma Se and MDA concetrations and Se dependent GSH-Px were determined on days 1, 21 and 42, wheres content of Se and vitamin E in breast muscle and liver were measured on days 21 and 42 of the experiment. Highest blood plasma glutathione peroxidase (GSH-Px) activities were detected in groups SS+E20 and SS+E100. Supplementation with selenium enriched yeast did not result in a significant increase in plasma GSH-Px activity. Selenium and vitamin E concentrations in breast meat and liver were significantly higher in groups supplemented selenized yeast compared to those receiving Na-selenite. Selenium and vitamin E supplementation did not alter plasma MDA concentrations, but in tissues, selenized yeast provided a consistent, although not significant, reduction in MDA content. The increased dose of vitamin E supplemented in broiler meal was not justifiable on the basis of vitamin E tissue content and antioxidative effect.

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.

Corrigendum to “The effects of dietary Selenium-yeast level on glutathione peroxidase activity, tissue Selenium content, growth performance, and carcass and meat quality of broilers”

Abstract The present study was conducted to assess effects of selenium (Se)‐yeast supplementation on glutathione peroxidase activity, Se levels in tissues, growth performance, carcass, and meat composition in broilers. A total of 275 one‐d‐old Cobb 500 broilers of both sexes were randomly allotted to 1 of 5 treatments during a 42‐d period. The 5 treatments differed only in Se content: group 1 had no additional Se (background only); groups 2, 3, and 4 received 0.3 mg/kg of added Se from the beginning of the trial until d 21, whereas in the second half of the study (from d 22 to 42), these groups received 0.3, 0.6, and 0.9 mg/kg of added Se, respectively; and group 5 received 0.9 mg/kg of Se for the entire experimental period. At the end of the study, the control group showed significantly lower (P < 0.01) glutathione peroxidase activity in blood plasma compared to Se‐supplemented groups. Regarding Se concentration in various tissues, the groups receiving Se yeast showed higher plasma, feces, and meat Se contents than the control group (P < 0.01). Supplementation of Se improved broilers’ body weight, weight gain and feed conversion ratio (P < 0.01). Dressing percentage was lower in the control group and the group with 0.3 mg/kg of added Se compared to other experimental groups (0.6 and 0.9 mg/kg of dietary Se). The proportion of less valuable carcass parts (wings and legs) was higher (P < 0.01) in the group fed the basal diet compared to groups supplemented with 0.9 mg/kg of Se. Initial and ultimate pH values differed among experimental groups (P < 0.05). Supplementation of Se improved the broilers antioxidative resistance, growth performance, carcass quality, and chemical composition of meat.

The nutritive value of Valjevac grassland - zasavica reservation.

Valjevac pasture of Zasavica reservation with its area of 300 ha presents a significant area for grazing cattle. In order to evaluate its potential for livestock production, the botanical and chemical composition of hay in three different time periods was observed (spring, summer and autumn). The determined plants species confirmed the richness of Zasavica grasslands, as well as the presence of dry, moist and forest habitat plants. The analyzed plants mostly belong to the Poaceae, Fabaceae, Asteraceae and Plantaginaceae families. Chemical analysis determined that the protein content decreased (P<0.01) from April (17.22±0.40 %) to October (10.30±0.16 %), and cellulose content increased (P<0.01) (from 19.07±0.38 % in April to 21.65±0.41 % in October). The calculated energy density of hay samples ranged from 0.425 Starch Units (SU) in October, 0.443 SU in April to 0.448 SU in June. The Valjevac pasture with its numerous plant species is of great importance in upkeeping biodiversity and also presents a solid base for livestock production. The determined levels of manganese and copper point out to the need of copper supplementation especially during the late summer and autumn periods. [Projekat Ministarstva nauke Republike Srbije, br. III46002]

Chemical composition of complete fodder mixes for pig diet during 2007-2009.

Intensive pig breeding implies, among other things, the use of complete mixes in their diet in correspondence with the animals’ age and purpose. In the course of a threeyear period (2007-2009) the accredited laboratory of the Department for Nutrition and Botanics of the Faculty for Veterinary Medicine, Univerisity of Belgrade, analysed 65 fodder mix samples from the territory of Serbia intended for the diet of all categories of pigs, namely: 6 samples of complete mixes for the diet of pregnant sows and gilts, 9 samples of complete mixes for the diet of nursing sows and boar, 4 samples of complete mixes for enhanced diet of piglets, 13 samples of complete mixes for piglets in programme I up to 15 kg, 12 samples of complete mixes for piglets in programme II from 15-25 kg, 10 samples of complete mixes for growing pigs in fattening programme I from 25-60 kg, and 11 samples of complete mixes for pigs in fattening programme II from 60-100 kg. The analyses covered the contents of the elementary nutritive matter and the obtained results were compared with the quality conditions prescribed under the Regulations on the quality of animal feed (Official Gazette of the Republic of Serbia No. 41/09). It was established that there were certain deviations with regard to the values presented in the Regulations on the quality of animal feed (Official Gazette of the Republic of Serbia No. 41/09) in the average protein content in complete mixes for piglet diet II, 15-25 kg (17.89±1.19%) and in the mixes for growing pig diet II, 60-100 kg (13.95±0.53%). The established average fat content was lower in the mixes for enhanced piglet diet (5.99± 0.72%) and in mixes for piglet diet I, up to 15 kg (4.95±1.41%). A higher average cellulose content (4.08±0.73%) was established in mixes for enhanced piglet diet. Furthermore, significant differences from the values prescribed under the Regulations were established in certain samples. The established differences in the chemical composition of certain samples of the examined mixes without a doubt indicate the need for constant and multilevel monitoring of raw materials and finished products in order to preserve health and to ensure the best possible utilization of the production potential of animals. [Projekat Ministarstva nauke Republike Srbije, br. III 46002: Molekularno-geneticka i ekofizioloska istraživanja u zastiti autohtonih animalnih genetickih resursa, ocuvanja dobrobiti, zdravlja i reprodukcije gajenih životinja i proizvodnji bezbedne hrane]

Nutritive value of fodder mixes for nutrition of cattle in territory of Republic of Serbia

Over a period of five years (2005-2009), the laboratory of the Department for Nutrition and Botanic analyzed 22 samples of mixes from the territory of Serbia, intended for the diet of two categories of cattle (fattening calves I and dairy cows with over 20 liters of milk). The analysis was performed using standard methods, and the obtained results were compared with the quality conditions prescribed under the Regulations on quality and other requirements for animal feed (SRY Official Gazette numbers 20/00 and 38/01). Intensive breeding of cattle implies the use of concentrated mixes for all categories which are adapted to the age and purpose of maintenance of the animals. The mixes are products of the animal food industry, and they are obtained through an established technological procedure using the required raw materials. The inadequate quality of raw materials causes problems involving the quality of the finished products, so that strict adherence to the established recipes does not necessary result in a satisfactory quality of the mixes. All of the above imposes the need for the constant monitoring of the nutritive value of the mixes, and consequently also of their quality. On the grounds of the analysis of the presence of the elementary nutritive matter, no significant differences were established with regard to the prescribed quantity of nutritive matter, so that the use of the examined mixes in the diets of the respective categories of cattle can be expected to yield satisfactory production results. .