The aim of this study was to determine the effect of β-1,3/1,6-D-glucan, isolated from Saccharomyces cerevisiae , on indicators of milk and meat performance in sheep as well as on selected non-specific indicators of humoral and cellular defense. The experiment was carried on 26 suckling ewes divided into 2 equal groups, and their offspring (21 in each group). The ewes were administered concentrate with the addition of β-1,3/1,6-D-glucan at a dose of 3 g/kg. Indicators of milk performance and markers of humoral and cellular immunity were analyzed on days 28 and 70 of lactation; and the indicators of meat performance of lambs on day 28 and 70 of their life. The addition of β-1,3/1,6-D-glucan was observed to cause an increase in milk performance by 13.5–14%. Simultaneously, milk was characterized by a lower somatic cell count. Diet supplementation had a positive effect on the chemical composition of milk, which was manifested by increased percentage contents of fat (by 15– 30%) and protein (by 11%). Lambs were characterized by a higher growth rate and better muscle tissue development. The supplementation caused an increase of gamma-globulin concentration (by 6.33–9.5 g/l), lysozyme activity (by 0.1 mg/l), respiratory burst activity (by 0.11–0.14), potential killing activity (by 0.10–0.12), proliferative response of T-cells stimulated by mitogen concanavalineA (by 0.07–0.09 RI) and proliferative response of B-cells stimulated by mitogen lipopolysaccharide (by 0.13–0.16 RI) in sheep’s blood. The activity of β-1,3/1,6-D-glucan as a natural immunostimulator has been studied in many animal species, however, this is the first study conducted on sheep.

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.

Yoghurt is one of the well‐known fermented dairy products that play an important role in the human diet. At present, products made of goat's milk are becoming more popular. This study was conducted to evaluate the effect of physicochemical properties of yoghurt fortified with vitamin C. Six different yoghurts were developed: from goat's and cow's milk without any addition, with L‐ascorbic acid and acerola addition. The results showed that the addition of L‐ascorbic acid significantly decreased pH. Based on the sensory evaluation, the natural cow's yoghurt has scored higher in the overall rating among yoghurts. The addition of L‐ascorbic acid to natural goat's yoghurt positively affected the color, taste, flavor, and consistency. In the case of cow's milk yoghurt, the addition of L‐ascorbic acid and acerola deteriorated the taste of the product.

The aim of the study was to evaluate the effect of vacuum packaging and modified atmosphere packaging (80 % N₂ + 20 % CO₂) on the microbial and physicochemical parameters of lamb meat and the sensory properties of cooked meat. Musculus longissimus thoracis et lumborum samples were examined at 10 d intervals (0, 10, 20 and 30 d) during storage at 4 ^∘C. There was no significant effect of the packaging method and storage time used on cooking loss, natural drip loss, lightness, yellowness, and intensity of taste and aroma. An interaction between storage time, packaging method, and mesophilic aerobic bacteria and coliform counts was observed. Storage time significantly affected the number of aerobic psychrotrophic bacteria, redness, pH (P≤0.001), shear force value (P=0.006), and the desirability of aroma (P<0.026) and taste (P<0.01). During the storage time, an increase in red saturation from 11.92 to 13.33 and pH value from 5.69 to 5.80 was recorded. Moreover, the storage method affected sensory properties. Vacuum-packed meat was characterized by higher scores in juiciness, tenderness and taste desirability in comparison to MAP. The obtained results suggest that both packaging methods allow for maintaining high-quality lamb meat during a long period of storage under refrigeration conditions.

The aim of this study was to evaluate the effects of a long-acting selenium (Se) preparation administered to sheep. The experiment was conducted on 30 dams and 36 lambs divided into three equal groups of 10 dams and 12 lambs each: Control—C, and two experimental groups—E (Se administered to pregnant ewes) and EI (Se administered directly to lambs after the colostral period). The Se preparation (Barium Selenate Injection, BVP Animal Care, 50 mg/mL) was administered by injection at 1 mL/50 kg (1 mg Se/kg) body weight (BW) to group E ewes in the third month of pregnancy (between 70 and 90 days) and to group EI lambs between 4 and 7 days of age. The following parameters were determined: Se concentration in the blood of ewes, milk yield, milk composition, Se concentration in milk; hematological, biochemical, and immunological parameters and Se concentration in the blood of lambs; growth rate and in vivo measurements of lean meat and fat content in lambs. Barium selenate significantly improved the Se status of dams and lambs, regardless of whether it was administered to pregnant ewes or directly to lambs in the first week of their life. The milk of ewes receiving the Se preparation was characterized by higher concentrations of fat and dry matter. The Se preparation induced significant changes in immunological parameters, thus enhancing defense mechanisms in lambs. The Se preparation exerted more stimulatory effects on humoral and cellular immune responses when administered directly to lambs after the colostral period (group EI) than to pregnant ewes (group E). The results of this study indicate that the long-acting Se preparation delivers benefits to sheep by boosting their immunity and, therefore, improving performance.