Probiotic feed additives have attracted considerable research interest in recent years because the effectiveness of probiotics can differ across microbial strains and the supplemented macroorganisms. The present study was conducted on 16 lambs divided into two groups (C - control and E - experimental). The examined lambs were aged 11 days at the beginning of the experiment and 40 days at the end of the experiment. The diet of group E lambs was supplemented with a multi-strain probiotic formulation (Lactobacillus plantarum AMT14, Lactobacillus plantarum AMT4, Lactobacillus rhamnosus AMT15, and Bifidobacterium animalis AMT30), whereas group C lambs did not receive the probiotic additive. At the beginning of the experiment (day 0) and on experimental days 15 and 30, blood was sampled from the jugular vein to determine and compare: phagocytic activity (PHAGOTEST) and oxidative metabolism (PHAGOBURST) of peripheral blood granulocytes and monocytes by flow cytometry. An analysis of the phagocytic activity of granulocytes and monocytes revealed significantly higher levels of phagocytic activity (expressed as the percentage of phagocytic cells and mean fluorescence intensity) in lambs administered the multi-strain probiotic formulation than in the control group. The probiotic feed additive also exerted a positive effect on the oxidative metabolism of both granulocytes and monocytes (expressed as the percentage of oxidative metabolism and mean fluorescence intensity) after stimulation with Escherichia coli bacteria and with PMA (4-phorbol-12-β-myristate-13-acetate).

Many factors affect the quality of red meat. The aim of the study, carried out on 44 Polish Merino lambs, was analysis of physicochemical traits (pH, meat color, expressed juice, content of moisture, protein, fat, total collagen and fatty acid ) and content of carnosine, taurine, L-carnitine on fresh and meat aged for 7 and 14 d in the longissimus lumborum (LL) and gluteus medius (GM) muscles., Higher (p<0.05) redness value (a*), lower yellowness (b*) were recorded in meat after of aging in gluteus medius muscle. A lower value (p<0.05) of expressed juice was found in both LL and GM after 7 days of aging. The increase (p<0.05) in protein and fat content in both muscle and collagen content in LL was observed in aged meat. There was no difference in fatty acid groups and C18:2 c9, t11 content between GM and LL muscle and fresh and aging meat. A higher TBARS content (p<0.05) was recorded in meat after aging in both GM and LL. The meat aging process increased (p<0.05) the content of carnitine and taurine, while the content of carnosine decreased. In summary the processes that turn muscles into meat in different types of muscles affect the physicochemical characteristics and the content of bioactive ingredients.

Fifty-eight Karacabey Merino lambs were used to evaluate the effects of feeding system (triticale pasture, oat pasture, or stall fed), birth type (single or multiple), gender (male or female) and birth year (2016 or 2017) on various carcass and meat quality characteristics. Stall lambs had higher conformation (CS) and fatness scores (FS), meat L* and h* values than both pasture groups, possibly as a result of higher fat content, while oat pasture lambs had the most tender meat. Single lambs had higher CS, FS and Longissimus thoracis muscle section area, while females had higher subcutaneous and non-carcass fat depositions, over their counterparts. Both single born lambs and 2016 born lambs had a higher meat a* and C* values than their counterparts. In conclusion, a pasture-based feeding system is thought to be more suitable for Karacabey Merino than stall feeding system, for those who prefer leaner meat and/or meat products. However, it should not be ignored that stall fed lambs showed a better fattening performance in terms of conformation and fatness, in the same period.

Forty-five male Dorper crossbred lambs (40.17 ± 0.35 kg BW) were used in order to investigate the effects of the duration of calcium propionate (CaPr) supplementation in lambs finished with zilpaterol hydrochloride (ZH) on the productive performance, carcass characteristics, and meat quality. Lambs were individually housed and fed a finishing-diet for 42 d before being slaughtered. Lambs received the following treatments: 1) No additives (CTL), 2) ZH supplementation for 28 d (with 3 d ZH withdrawal before slaughter) at a dosage of at 7.2 mg/kg diet (ZH), for treatments 3, 4, and 5, lambs received ZH and 10g CaPr/lamb/d throughout the entire phase (42 d), or during the last 28 or 14 d before slaughter. Compared to CTL, ZH lambs exhibited a similar average daily gain (ADG) but had lower dry matter intake (DMI), leading to increased feed efficiency. Supplementing with ZH alone did not affect carcass traits, visceral mass, whole cuts, or meat quality. Lambs that received both CaPr and ZH exhibited quadratic increases (p < 0.05) in final BW (FBW), ADG, and dressing percentage (D%). These increases were optimal at an estimated inclusion durations of 26 d for FBW, 30 for ADG, and 39 d for D%. The ADG:DMI ratio and the longissimus muscle area (LMA) both exhibited quadratic increases (p < 0.05). The optimal duration of CaPr supplementation for ADG:DMI ratio was found to be 28 d, while for LMA, it was 14 d. As the period of CaPr supplementation increased, there was a linear increase (p <0.05) in hot carcass weight, leg circumference, and whole cuts of breast IMPS209 and shoulder IMPS207. Cook loss percent increased quadratically (p < 0.05), being higher when CaPr was included for an estimated duration of 26 d. As the duration of CaPr supplementation increased, the purge loss percentage (PLR) also increased linearly (p < 0.05). In conclusion, including CaPr in the diet for a duration of 28 d in lambs improved the response to ZH supplementation on the productive performance, carcass weight and some whole cuts. However, it can also have a negative effect on PRL%.

In this article, we first assessment of peste des petits ruminants (PPR) antibodies in vaccinated pregnant ewes of Kazakh breed fine-fleeced immunized with the PPR vaccine and the duration of maternal immunity in their lambs. Ewes in the last trimester of pregnancy of gestation were immunized with a vaccine from the Nigeria 75/1 strain of the PPR virus (PPRV) produced by the Research Institute of Biological Safety Problems (RIBSP), Kazakhstan. Serum samples from lambs born from vaccinated and unvaccinated ewes were collected a week after birth and at intervals of 7 days for 18 weeks after birth. Serum samples collected from lambs were tested for PPR antibodies using competitive ELISA and Virus neutralization test (VNT). Maternal antibodies (MAs) in lambs born from vaccinated ewes were detected up to 18 weeks with a tendency to decrease starting at week 14 and by the end of the experiment receded below the protective level (<1:8). In the blood serum of a 14-week-old lamb with MAs (1:8), post vaccination with a field dose (103 TCID50) of the vaccine against PPR, the titers of protective antibodies to the PPRV increased to 1:16 on 14 day post vaccination and lamb protected from infection upon field PPRV. A lamb of the same age with MAs in the 1:8 titer was 100% protected from infection with the field PPRV. Therefore, it is recommended that lambs of the Kazakh fine-wool breed be immunized from the age of 14 weeks or older to avoid a period of susceptibility.

The purpose of this study was to see how feeding cotton gin trash (CGT) as an alternative meal affected the growth performance, carcass features, and meat quality of Mecheri ram lambs. A growth performance trial was conducted with thirty-two weaned Mecheri ram lambs from four months to nine months (180 days) of marketing age and assigned into four groups (T1, T2, T3 and T4) of eight animals in each group. The lambs were fed with CGT at 0 (T1), 25 (T2), 50 (T3) and 75 (T4) per cent inclusion levels in the roughage portion at 60:40 roughage: concentrate ratio. All the group of animals were fed on dry matter requirement basis at four per cent of their body weight. The lambs fed with 75 (T4) and 50 (T3) per cent inclusion level of CGT showed signifi-cantly (P<0.01) higher total body weight gain (kg) than T1 (14.54) and T2 (15.05) groups. The av-erage daily gain (g) of lambs in T3 (99.24) and T4 (105.51) were significantly (P<0.01) higher than T1 (80.77) and T2 (83.61) groups. Over the course of the 180-day trial period, there was no statisti-cally significant difference in the average DMI (g) between the groups (P>0.05), however the lambs in T4 demonstrated higher feed efficiency (7.4) than the T1 (9.3) group. The slaughter studies revealed that the lambs in T4 followed by T3 group registered significantly (P<0.01) higher hot carcass weight, dressing percentage and Meat: Bone ratio than T2 and T1 group ani-mals. The weights of the liver, spleen, head, stomach, and intestines empty were considerably (P<0.05) larger in the T3 and T4 groups than in the other groups, although there was no signifi-cant (P>0.05) difference in the weights of edible and inedible offals. Meanwhile, there were no significant variations (P>0.05) in pH, water holding capacity, shear force value, sensory charac-teristics, or proximate composition of meat across treatment groups. In accordance to the find-ings, CGT can be added up to 75% of the roughage component in sheep feed as an effective un-conventional supplementation, as it improves body weight, feed efficiency, and carcass characteristics in Mecheri ram lambs.

The mutton quality of Chinese Tan lambs (Ovis aries) has declined as feeding patterns have shifted from pasturing to pen rationing. Mutton quality is affected by fatty acids, and rumen microorganisms play a role in the synthesis of short-chain fatty acids, long-chain fatty acids, and conjugated linoleic acids. We used 16S rDNA sequencing to analyze the effects of two feeding patterns on the rumen bacteria of Tan lambs. In a randomized block design with 24 newborn Tan lambs, 12 lambs were fed by ewes in pasture and 12 were fed by pen-fed ewes. At 2 months, the biceps femoris and the longissimus dorsi were analyzed by gas chromatography for intramuscular fat content and fatty acid composition, and DNA in the rumen contents was extracted and used to analyze the structure of the bacterial community. Different feeding patterns had no significant effect on the intramuscular fat content of the biceps femoris and longissimus dorsi of the lambs, but there was a significant effect on fatty acid composition. Rumen bacteria were significantly more diverse in the pasture group than in the pen-ration group (P < 0.01). Twenty-one phyla were identified in the pasture group, and 14 phyla were identified in the pen-ration group. The dominant phyla in the pasture group were Bacteroidetes and Fibrobacteres; the dominant phyla in the pen-ration group were Proteobacteria and Bacteroidetes. The relative abundance of Proteobacteria was significantly higher in the pen-ration group than in the pasture group (P < 0.01). Diversity at the genus level was also higher in the pasture group, with 176 genera in the pasture group and 113 genera in the pen-ration group. The dominant genera in the pasture group were Prevotella_1, Rikenellaceae_RC9_gut_group, and Bacteroidales_BS11_gut_group_Na; the dominant genera in the pen-ration group were Prevotella_1, Prevotella_7, Succinivibrionaceae_UCG-001, and Succinivibrionaceae_NA.