The aim of this study was to determine the effect of Saccharomyces cerevisiae on indicators of meat performance traits in sheep as well as on selected non-specific indicators of humoral and cellular defense. The experiment was performed on 32 suckling Kamieniec lambs divided into two equal groups (control and experimental). Over a period of 60 days, experimental group of lambs were fed a diet supplemented with Saccharomyces cerevisiae dried yeast (the yeast supplement did not change the value of the feed ration). The following meat performance indicators were determined: body weight, daily gains, growth rate, the dimensions of musculus longissimus dorsi sections, skin and subcutaneous fat thickness and fat thickness over the loin "eye" area. Selected indicators of non-specific humoral immunity (lysozyme activity, ceruloplasmin activity, total protein and gamma globulin content) were determined in the blood serum of lambs. Compared to control, yeast administered to the experimental group of lambs significantly increased the values of the analyzed meat performance traits i.e. body weight, growth rate, musculus longissimus dorsi dimensions (P ≤ 0.05) and daily gains (P ≤ 0.01), pointing to improved muscle development. Lambs fed the yeast showed a significant (P ≤ 0.01) increase in lysozyme and ceruloplasmin activity and increased serum concentrations of gamma globulins. Significant differences between the experimental and control groups were not observed only with respect to the serum concentrations of total protein. Suuplementing the lambs' feed with yeast had a positive effect on meat performance traits and indicators of humoral immunity. Non-specific immunity, prebiotic, yeast, meat traitsRational lamb feeding is a crucial consideration as it may contribute to improving the meat performance of sheep. The end product of optimal quality lamb meat with superior health benefits is obtained through the application of traditional feeding systems with a high share of green forage (Santos-Silva et al. 2002). However, traditional systems are characterized by low production effectiveness. Therefore, attempts are made to develop new solutions that rely on natural conversion of organic feed into lamb meat while ensuring optimal production profitability. One of the most recommended solutions involves the supplementation of animal diets with natural stimulators such as Saccharomyces cerevisiae yeast which has a wide spectrum of activity (Suphantharika et al. 2003). The supplementation of animal feed with yeast can, therefore, have a varied effect, but it usually enhances productivity. Milewski's findings (2009) support the use of Saccharomyces cerevisiae dried brewer's yeast in lamb nutrition. In a study of suckling lambs, the author noted that the administration of the Inter Yeast prebiotic with CJ concentrate in the amount of 50 g/kg of feed stimulated the growth rate and muscle development in lambs. Yeast supplementation also had a significant effect on haematological indicators, resulting in higher red blood cell ...

Abstract. The effect of supplementing sheep diets with Saccharomyces cerevisiae Inter Yeast ® dried brewer's yeast (Leiber GmbH, Bramsche, Germany) or with a Biolex ® Beta-S (Leiber GmbH, Bramsche, Germany) extract containing over 70 % β-1,3/1,6-D-glucan was investigated. Experiment 1 was carried out with 120 ewes and 190 lambs. The animals were divided into three groups: I -control; II -fed yeast; and III -fed Biolex. The supplements were administered during a 3-week preparation period for tupping and a 70-day lamb-rearing period. The following reproductive parameters were analysed: fertility, prolificacy, lamb rearing and breeding performance, milk yield and lamb growth rate. Experiment 2 was conducted with 120 ewes divided into two groups: I -control and II -fed yeast during a 3-week preparation period. Fertility and prolificacy were analysed. Significant increases in prolificacy were recorded in sheep administered dried brewer's yeast: 28.51 % in experiment 1 and 31.33 % in experiment 2. Breeding performance was also higher by 35 %. Both yeast supplements had a stimulating impact on the milk yield of ewes and the growth rate of their offspring. Milk from the experimental ewes, especially in the group fed Biolex, had a substantially higher content of dry matter, mainly fat. The lambs in this group had the highest body weight at the age of 70 days. Finally, however, the production of livestock per mother was highest in the group fed the supplement with Saccharomyces cerevisiae.

The effect of supplementary dried brewer's yeast, Saccharomyces cerevisiae, during 100 days rearing period on meat quality of lambs was investigated. Twenty four male Kamieniecka breed lambs were divided into two groups: I -control, II -experimental -supplemented with preparate Inter Yeast ® S, containing Saccharomyces cerevisiae. Meat quality was determined on samples of M. longissimus lumborum (LL) and M. quadriceps femoris (QF), based on the following parameters: chemical composition, physicochemical properties, the fatty acid composition and profile of intramuscular fat, and sensory properties. Meat of lambs from group II contained more dry matter (0.78%) and intramuscular fat (0.33%), compared with control lambs (P<0.01). An increase the red colour component a* (P<0.01) and improvement the waterholding capacity (P<0.01) of meat were also found in the experimental group. The concentrations of C 14:1 , C 18:2 and C 22:6 fatty acids (P<0.05) and conjugated linoleic acid C 18:2 cis9trans11 were higher (P<0.01) and the content of C 20:4 was lower (P<0.01) in the intramuscular fat of lambs from group II. The above changes had no influence on the sensory properties of meat. The content of dry matter and protein was higher, and cooking loss was lower (P<0.001) in LL than in QF muscle. The sensory properties were better in QF muscle.

The objective of this study was to determine the effect of yeast preparations on selected properties of meat from suckling lambs. The experiment was conducted on 30 Kamieniec rams divided into three groups: I -control, II and III -experimental. Throughout the 100-day rearing period, the experimental animals were fed diets supplemented with Saccharomyces cerevisiae prebiotics: Inter Yeast S® brewer's yeast in group II, and Biolex®-Beta S in group III. Fat content was determined by Soxhlet extraction. The fatty acid composition of intramuscular fat was determined by esterification followed by gas chromatography analysis. The content of vitamins A and E was determined by liquid chromatography. A significant increase in the content of fat, cholesterol, and vitamin E was noted in the meat of lambs of group II in comparison with control. The fat of animals in group II contained more fatty acids: C14:1, C18:2, C22:6 (P≤0.05), and C18:2 n-6 cis9trans11 (P≤0.01), and less C20:4 (P≤0.01). The fat of animals of group III contained more C18:0 and C22:6 fatty acids (P≤0.05), and less C18:0 (P≤0.05). The fat in this group had also lower concentrations of MUFA (P≤0.05), UFA, and, consequently, a lower UFA/SFA ratio (P≤0.05) in comparison with controls. The yeast-based supplements significantly affected selected health-promoting properties of lamb meat. The applied diet supplements had no significant effect on AI and TI values.

:The aim of this study was to determine the quality of modified atmosphere (MA) packaged meat from Pomeranian rams slaughtered at 50 and 100 days of age. Determined: chemical composition, physicochemical and sensory properties of meat, and the fatty acid profile of intramuscular fat. Meat from 100-d-old lambs was characterized by a significantly higher content of dry matter, total protein and crude fat, a darker color and higher physiological maturity (p0.01). Meat from younger lambs was marked by a better water-holding capacity (p0.05), a lower energy value and higher concentrations of monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA). An increase in the content of dry matter, total protein and ash, and energy value was noted in MAstored meat. Meat pH decreased over MA storage and the sensory properties deteriorated. The studied meat remained safe from microbial contamination during storage.