Effect of rearing system on growth, body composition and development of digestive system in young lambs

Yeast Peptides Improve the Intestinal Barrier Function and Alleviate Weaning Stress by Changing the Intestinal Microflora Structure of Weaned Lambs

Early weaning stress in lambs leads to decreased feed intake, damage to intestinal morphology, changes in the microbial flora structure, and subsequent complications. Yeast peptides are antimicrobial peptides with anti-inflammatory, antioxidant, and bacteriostasis effects. To study the effects of yeast peptides on relieving weaning stress in lambs, 54 lambs were randomly divided into three groups: ewe-reared (ER), yeast-peptide-treated (AP), and early-weaned (EW) lambs. The body weight and dry matter intake did not significantly differ among all groups. After weaning, the daily gain and feed conversion rate decreased significantly (p < 0.01), but AP showed an upward trend. In the EW group, immunoglobulin (Ig) levels changed significantly post-weaning (IgG decreased; IgA and IgM increased); the villi shortened, the crypt depth increased, and the villi height/crypt depth decreased (p < 0.001). The abundance and diversity of microflora among all groups were not significantly different. A column coordinate analysis showed significant differences in the intestinal microbial structure between the AP and EW groups. Lactobacillus, Aeriscardovia, Ruminosaceae_UCG-014, and Catenisphaera may play key roles in alleviating weaning stress in lambs. Our study provides new clues for alleviating weaning stress in lambs by describing the influence of yeast peptides on the intestinal microflora during weaning.

Effects of Rearing System and Fattening Intensity on the Chemical Composition, Physicochemical Properties and Sensory Attributes of Meat from Young Crossbred (Holstein-Friesian × Hereford) Bulls

The study was aimed at determining the effects of the rearing system and intensity of fattening on beef physicochemical properties and sensory quality, fatty acid composition, and mineral compounds and vitamins concentration. The study was conducted using meat from 38 young, crossbred bull calves, which were reared with nurse cows (C) or were fed milk replacer (R). In the study, intensive (Int) or semi-intensive (SInt) fattening system were applied. The bulls were slaughtered at the age of 560 days and samples of the longissimus lumborum (LL) muscle were collected. Meat from C bulls was juicier (p < 0.05) and had a higher concentration of conjugated linoleic acid (CLA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), as well as zinc (Zn), iron (Fe), and α-tocopherol, compared with meat from R bulls. The Int system resulted in the intramuscular fat (IMF) content increase (p < 0.01) and reduced shear force (p < 0.05), compared with the SInt system. Meat from Int bulls had a better eating quality and a higher monounsaturated fatty acid (MUFAs), Zn, and Fe; however, it had a lower proportion of polyunsaturated fatty acids (PUFAs) and α-tocopherol concentration than meat obtained from SInt bulls.

Influence of the Use of Milk Replacers on Carcass Characteristics of Suckling Kids from Eight Spanish Goat Breeds

Simple Summary

Goats are important species due to their contributions to the development of rural areas. Spain has one of the largest goat populations in Europe; however, literature on goat carcasses is very scarce and, therefore, it is crucial to study the specific productive potential of each breed. Previous studies by our team on other Spanish goat breeds have shown some interactions between breed and rearing systems and, consequently, further analysis is necessary. This paper aims to contribute to the general knowledge on the subject.

Abstract

Since goat milk has a higher value than kid meat in Europe, some farmers rear kids with milk replacers, although some studies have stated that kids raised on natural milk yield higher-quality carcasses. Our previous studies showed some interactions between breed and rearing system on carcass and meat quality. This study evaluated the influence of the use of milk replacers on several carcass characteristics of suckling kids from eight Spanish goat breeds (Florida, Cabra del Guadarrama, Majorera, Palmera, Payoya, Retinta, Tinerfeña, and Verata). A total of 246 kids fed milk replacer (MR) or natural milk (NM) were evaluated. Carcass, head, viscera, and kidney fat weights, as well as several carcass measurements (round perimeter, forelimb width, carcass length, forelimb length, and carcass compactness index), were registered. Forelimbs were dissected to study tissue composition. For all studied variables, interactions were found between rearing system and breed. In general, the MR rearing system increased the head and visceral weights, as well as the length measurements and muscle percentages. Conversely, the NM rearing system increased carcass compactness and resulted in higher fat contents, independent of the deposit. The choice of one or another rearing system should be made according to the needs of the target market.

Dose-response effect of dietary vitamin E concentration on meat quality characteristics in light-weight lambs

The research was carried out to evaluate the effect of different dietary α-tocopheryl acetate (DTA) concentrations in light-weight lambs on muscle α-tocopherol accumulation and on quality characteristics of stored meats. Thirty-two Manchego lambs were randomly distributed to four groups and given diets containing four levels of DTA (20, 270, 520 and 1020 mg/kg diet) for 6 weeks. Lambs were slaughtered at live weights ranging from 23·5 to 26·4 kg. A linear (P < 0·001) and quadratic (P < 0·001) effect of dietary supplementation level was observed on muscular α-tocopherol concentration, which fitted the following equation: mg muscle α-tocopherol per kg muscle = 1·78(s.e. 0·18) + 7·08 (s.e.0·89)(1 - e00012DTA)) (P < 0·001, R2 = 0·99). There was a linear effect (P < 0·001) of muscle vitamin E concentration on thiobarbituric acid reactive substance on day 0 of storage, but a linear plus quadratic effect (P < 0·001) on days 3, 6 and 9. Broken line analysis of data at day 9 of storage indicated a target muscle α-tocopherol concentration of 5·4 mg/kg. Evolution of surface redness of lamb chops also showed a linear and quadratic effect of dietary treatment on days 3 and 6 of storage, but only a linear effect on day 9. Broken line analysis of data at 3 and 6 days indicated a target α-tocopherol concentration in the range 5·3 to 5·6 mg/kg muscle for optimum red colour stability. Surface luminosity showed no effect of dietary treatment at days 0, 3 and 6 of storage but a linear (P < 0·01) plus quadratic (P < 0·05) effect on day 9 of storage. Broken line analysis at this point indicated a target muscle α-tocopherol concentration of 3·2 mg/kg. It is concluded that the effectiveness of dietary α-tocopheryl acetate supplementation depends on the meat quality attribute assessed. A significant positive effect for lipid oxidation can be reached even at the lower supplementation level utilized in this experiment (270 mg/kg diet). However, considering the protecting effect at different storage times and particularly the effect on meat surface redness, the optimum level would be in the range 5·3 to 5·6 mg/kg muscle, which correspond to a dietary inclusion of 550 to 625 mg α-tocopheryl acetate/kg diet.

Effect of artificial rearing on lamb welfare and meat quality

Twenty male Comisana lambs were equally divided into two groups. Ten subjects were artificially reared, 10 others were ewe reared and used as control. Unseparated control animals displayed increased cellular immune response to a percutaneous injection of phytohemagglutinin (P<0.001). During the open field test, ewe-reared lambs showed a higher number of flight attempts (P<0.01). Carcass yield were higher for artificially reared animals (P<0.05). Conversely, legs of ewe-reared animals had significantly more fat (P<0.05) and a higher content of saturated fatty acids (P<0.001). Polyunsaturated fatty acid content was higher in artificially reared lamb meat (P<0.01), although the ratio n-6/n-3 was well above the recommended values. The triangle test showed a significant difference in sensory analysis between the two products (P<0.05). Finally, for both rearing systems legs without subcutaneous fat showed a higher percentage of polyunsaturated fatty acids and a corresponding lower content of saturated fatty acids (P<0.001).

Use of carcass weight to classify Manchego sucking lambs and its relation to carcass and meat quality

Eighty-seven Manchego sucking lambs raised exclusively on maternal milk were slaughtered. The carcasses were weighed immediately after dressing and classified according to hot carcass weight (HCW): low HCW (<5.5 kg), medium HCW (5.5 to 6.5 kg) and high HCW (≥ 6.5 kg). The effects of this classification system on carcass and meat quality were studied. Carcass conformation improved as carcass weight increased; carcasses became more compact. Carcass fatness increased (P< 0.001) as carcasses became heavier. With regard to the joints, leg (P< 0.001) and shoulder (P< 0.05) proportions decreased as carcass weight increased, whereas loin-rib (P< 0.001) and flank (P< 0.001) proportions increased. The proportion of fat in the leg clearly increased in the heavier carcasses (P< 0.001), while that of bone decreased (P< 0.001) and that of muscle was not affected. pH at 24 h in them. longissimusdorsi andm. semitendinosusdecreased as carcass weight increased. The only meat colour parameter affected by carcass weight was the yellowness index; lighter-weight carcasses displayed lower index (P< 0.05). Cooking losses were unaffected as carcass weight increased, whereas with regard to tenderness, the shear force value tended to be higher in the low carcass weight group. No differences between carcass weight groups were found in the sensory analysis. Fatty acid composition did not show any significant effect due to carcass weight except in stearic fatty acid (C18:0); C18:0 proportion decreased (P< 0.01) as carcasses became heavier. Carcass weight affected carcass quality (all carcass quality parameters studied were higher in the heavier carcasses), whereas meat quality varied little as a result the small variation between carcass weights in sucking lambs.