The experiments included 50 does and 36 weaned rabbits of the White New Zealand breed. The animals were divided into two groups -experimental and control. The exeprimental group was supplemented with probiotic "ZOOVIT". The addition of "ZOOVIT" probiotic increases the fertility rate , which is 85,71 % in the experimental and 66,66% in the control group. The number of the live born rabbits is also higher in the experimental animals. In the experimental group is recorded a 10.8% lower mortality rate before weaning and a 10.9% higher average daily growth rate than in the control one. In rabbits for fattening, the experimental group has a 11.11% lower mortality rate. The additive used reliably increases live weight in the test group. Further studies are needed to establish the optimal doses of "ZOOVIT" in rabbit does, growing rabbits and rabbits for fattening.

The purpose of this study is to determine the effects of the breed on some of the carcass characteristics and the technological properties of Musculus Longissimus Lumborum in lambs from the Bulgarian Dairy Synthetic Population and its F crosses with Ile de France and Mutton Charollais breeds. The 1 scientific study took place at the Agricultural Institute of Stara Zagora, Bulgaria. Object of the study were lambs from the Bulgarian Dairy Synthetic Population and its crosses with Ile de France and Mutton Charollais breeds. The internal organs weight of the animals from the three groups was measured after their slaughter. In order to determine the meat/bones ratio, the left carcass halves were deboned. The eye muscle area and analyzed samples of Musculus Longissimus Lumborum was determined. The results show a slight variation in the weight of the internal organs of the animals from the three groups. The 2 2 Mutton Charollais crosses come first in terms of eye muscle area (11.34 cm), followed by the Ile de France crosses (11.21 cm), and the lambs from the 2 reference group come last with only 8.64 cm (P ≤ 0.001). With regard to the meat/bones ratio, it was found out that in the Ile de France crosses it is the highest (2.90:1), followed by the Mutton Charollais crosses (2.68:1), and the lambs from the reference group (2.43:1) where it is the lowest (P >0.05). Ile de France crosses exhibited statistically significantly higher meat tenderness (P ≤ 0.001) and water-holding capacity (WHC) (P ≤ 0.01), while Mutton Charollais crosses-considerably higher cooking losses (P ≤ 0.001) than control animals.

Оbject of the study were merino sheep raised in the farm of the Agricultural institute -Stara Zagora. The experiment was conducted with a group of 68 animals of different ages, lambing after treated with hormonal preparation according to adopted scheme during the out-of-breeding seasonin May. In the experimental group were included ewes which lambed earlier without making a selection in respect to their productivity.Animals were kept under the same conditions (stall-pasture) and fed the same rations with the concentrate mixture, rough, succulent feed and grazing in quantity and composition according to their physiological status and season from the fertilization until lambing. Hormonal pattern: setting pads for sheep type Sincro-part (30mg), removing pads after 12 days and giving ewes a PMSG injection at a dose of 500 UI, applying artificial insemination at the 50-55th hour.Body condition score and live weight of the animals were determined in 4 separate periods: 1st period (after mating), 2nd period (during pregnancy), 3rd period (after lambing), 4th period (before next mating service). Improving fertility in merino sheep is significantly influenced by the preparation of ewes for the mating by reaching the respective physiological status which is expressed by score over 2.5 according to the Body condition score method and live weight over 60 kg. Animals scored 2.75-3.50 before mating have a share of 91.18% from all the sheep in the flock and have the biggest number of lambs.

The study was carried out to establish dependence between some exterior measurements, productivity and body condition score (BCS) of ewe lambs from the Thracian merino breed, reared in the Agricultural Institute in Stara Zagora, Bulgaria. Ewe lambs included in the research were born during 2011-2015. The growth rate, as well as the main breeding traits as live weight, staple length, wool yield and pure fiber were studied, and body condition score was estimated at the age of 6, 9 and 18 months. Conclusions: 1) The lambs of the Thracian merino breed had high growth rates at an early age. 2) The increase in body weight and bone mass is more intensive from 6 to 9 months of age, followed by the increase of the body condition score. 3) Productive traits as wool production, staple length, wool yield and pure fiber showed high level in ewe lambs at the age of 18 months, when they have their first breeding season.

Abstract. Investigation for determining the amount of in vitro gas production after feeding different groups of forages was performed at the Agricultural Institute-® Stara Zagora. Forages from different regions were collected and analyzed for in vitro gas production at 24 h and 48 h by Ankom Technology . The following parameters of the tested forages were determinated: Neutral detergent fibre (NDF, %), Acid detergent fibre (ADF, %), Digestibility of dry matter (DDM, %), Dry matter intakе (DMI, %) and Relative Feed Value (RFV, %). RFV was calculated on the base of DDM and DMI in comparison with alfalfa biomass in floweringstage. Collected feeds (46 samples) were divided in 11 groups on the base of their composition and structure -fibre component content. Depending on the amount of gas production forages can be divided in 3 groups: 1) Grain feeds generating the highest amount of gas -average 387.93 ml/g DM; 2) Combined feeds, fresh forages, complete feed mixtures -average 213. Hay, silage, straw, ml/g DM. Intensity of gas production in grain feeds was higher at 24 h, while on the opposite, was higher at 48 h in roughage feeds due to the different speed of degradation of feeds -concentrated had a very intensive and quick degradation, roughages -slow degradation. Supplementation of combined feeds with bioadditives Rumanol, Biolife, Bibor decreased the amount of gas production by 9.87% -29.05%.Keywords: forages, feeds, in vitro gas production, additives AGRICULTURAL SCIENCE AND TECHNOLOGY, VOL. 9, No 2, p , 2017 DOI: 10.15547/ast.2017 Introduction (grains, meals, straw, fresh feeds, silages, hays, haylages, compound feeds, total mixed rations, compound feeds + supplements, total mixed rations+biosupplements) from different Ruminants are among the primary sources of greenhouse regions of the country and analyzed for the content of structural gases -methane (CH ) and carbon dioxide (CO ). Unlike 4 2 fibrous components. Neutral detergent fibre (NDF, %; n=46) and monogastric animals, ruminants degrade vegetable cells very acid detergent fibre (ADF, %; n=104) were determined by means of efficiently. Rumen microflora produce enzymes lysing almost all Ankom F57 filter bags (ANKOM Technology Corporation, Fairport, chemical bonds of cellular wall polysaccharides. Regardless of the NY, USA). The NDF digestibility (NDFD, %) was determined through broad array of hydrolases involved in the digestion, there are a lot of in situ analysis according to Spanghero (2010). All samples were undigested nutrients in faeces along with large amounts of methane incubated in Ankom F57 filter bags (ANKOM Technology produced in the rumen and large intestine. Ruminants play an Corporation, Fairport, NY, USA). Every sample contained feed and important role in climate change (Steinfeld et al., 2006; Martín et al., rumen content from fistulated animals (sheep), fed diet formulated 2009; Hook et al., 2010; Martinez-Sibaja et al., 2011), and are from the studied feeds. The amount of produced gas (ml/g) from the responsible for about 45% of anth...