Exploring the effects of palm kernel meal feeding on the meat quality and rumen microorganisms of Qinghai Tibetan sheep

Effect of alfalfa supplementary change dietary non-fibrous carbohydrate (NFC) to neutral detergent fiber (NDF) ratio on rumen fermentation and microbial function in Gansu alpine fine wool sheep (Ovis aries)

Bodyweight loss and rumen microbial dysfunction of grazing sheep was a challenge for the sheep production industry during cold season, which were considered to correlated with under-roughage-feeding. Alfalfa is a good roughage supplementary for ruminants, which can improve grazing sheep bodyweight-loss and rumen microbial dysfunction during grass-withering period. This study evaluated the effects of alfalfa hay supplementary change dietary non-fibrous carbohydrate/neutral detergent fiber (NFC/NDF) ratios on rumen fermentation and microbial function of Gansu alpine fine wool sheep during extreme cold season. 120 ewes (3-4 yrs) with an average body weight of 28.71 ± 1.22 kg were allocated randomly into three treatments, and fed NFC/NDF of 1.92 (H group), 1.11 (M group), and 0.68 (L group), respectively. This study was conducted for 107 d, including 7 d of adaption to the diets. The rumen fermentation parameters and microbial characteristics were measured after the end of feeding trials. The results showed that the concentrations of sheep body weight, nitrogen components (Total-N, Soluble protein-N and Ammonia-N), blood biochemical indices (LDH, BUN and CHO) and ruminal volatile fatty acids (TVFA and propionate) significantly increased with an increase in the proportion of NFC/NDF ratios (p < .05), and the acetate and acetate/propionat ratio presented a contrary decreasing trend (p < .05). A total of 1018 OTUs were obtained with 97% consistency. Ruminococcus, Ruminococcaceae and Prevotella were observed as the predominant phyla in ruminal fluid microbiota. Higher NFC/NDF ratios with Alfalfa supplementary increased the richness and diversity of ruminal fluid microbiota, and decreased ruminal fluid microbiota beta-diversity. Using clusters of orthologous groups (COG), the ruminal fluid microbiota of alfalfa supplementary feeding showed low immune pathway and high carbohydrate metabolism pathway. In summary, the study suggested that there was an increasing tendency in dietary NFC/NDF ratio of 1.92 in body weight, ruminal fermentation, microbial community composition and fermentation characteristics through developing alfalfa supplementary system.

Effects of yeast cultures on meat quality, flavor composition and rumen microbiota in lambs

Since the banning of antibiotics, the use of feed additives to improve meat quality to satisfy people's pursuit of high quality has become a research hotspot. Yeast culture (YC) is rich in proteins, mannan oligosaccharides, peptides, and yeast cell metabolites, etc., and its use as a feed additive has a positive impact on improving meat quality. So the study aimed to provide a theoretical basis for YC improving mutton flavor and quality by detecting and analyzing the effects of YC on muscle physicochemical properties, amino acids, fatty acids, flavor composition, expression of related genes, and rumen microbiota of lambs. A total of 20 crossbred F1 weaned lambs (Australian white sheep♂ × Hu sheep♀; average 23.38 ± 1.17 kg) were randomly assigned to 2 groups, the control group (CON) and the 1.0% YC supplemented group (YC) (n = 10), and were reared in separate pens. The experiment had a pre-feeding period of 10 d and a treatment period of 60 d. After the experiment, 6 lambs in each group were randomly selected for slaughtering. The results showed that dietary YC supplementation increased rumen total VFA and acetate concentrations (p < 0.05), and muscle carcass fat (GR), a∗ value, intramuscular fat (IMF), lysine (Lys), arginine (Arg), nonessential amino acid (NEAA), oleic acid (C18:1n9c), and eicosanoic acid (C20:1) contents were significantly increased (p < 0.05), while cooking loss and γ-linolenic acid (C18: 3n6) were decreased (p < 0.05). Furthermore, we found that dietary YC improved the types of flavor compounds, and the key flavor substances such as hexanal, nonanal, styrene, benzaldehyde, p-xylene, and 1-octen-3-ol contents were changed (p < 0.05). Additionally, the expression of fat metabolism related genes PPARγ, FASN, and FABP4 were increased. Adding 1% YC to lamb diets increased profits by 47.70 CNY per sheep after 60 d of fattening. All of which indicated that YC could improve meat quality, especially flavor, which may be related to the regulation of the relative abundance of rumen microorganisms Bacteroidota, Prevotella_7, Succiniclasticum and Lachnospiraceae_NK3A20_group.

Effects of fermented unconventional protein feed on pig production in China

Unconventional protein feeds, characterized by low nutritional value, high variability, and poor palatability, have limited their application in swine production. Fermentation technology holds the key to addressing these shortcomings. Given the ban on antibiotics in China, the inferior quality of imported pig breeds, and long-term dependence on imported soybean, the prospects for fermented unconventional protein feeds are promising. This paper delves into the common types of fermented unconventional protein feeds, factors influencing the fermentation process, the mechanisms by which they enhance swine health, and the challenges and prospects of fermented feeds, offering theoretical insights for the future development of the feed industry.

Fatty Acids and Volatile Flavor Components of Adipose Tissue from Local Tibetan Sheep in Qinghai with Dietary Supplementation of Palm Kernel Meal (PKM)

Substituting traditional protein feed with palm kernel meal (PKM) in the diet of Tibetan sheep can be a cost-effective feeding strategy. To determine the impact of PKM on flavor development in different adipose tissues of Tibetan sheep, subjects were fed with 15% and 18% of PKM, while the control group received no PKM. The fatty acids and volatile compounds in the samples were then analyzed by GC-MS and HS-GC-IMS. Adding PKM to the diet significantly increased the C12:0, C14:0, C16:0 and C18:1N9 content in adipose tissues compared with the control, and most of these were associated with flavor formation (p < 0.05). The flavor compounds in the adipose tissues predominantly consisted of alcohols, ketones, acids and aldehydes. In particular, including PKM in the diet increased the proportion of ketones but decreased the proportion of alcohols, acids and aldehydes in subcutaneous and tail fat. Specifically, the proportion of acetone, acetoin monomer, 2,3-butanedione, 2-butanone monomer, 2-methyl-2-propanol, 2-methyl-2-propanol and methyl acetate increased significantly in the subcutaneous and tail fat (p < 0.05), while that of ethanol, 1-propanol monomer, butanol monomer, acetic acid monomer and acetic acid monomer decreased. Intermuscular fat exhibited variable results, mainly because the addition of PKM resulted in higher proportions of alcohols, including ethanol, 1-propanol and butanol monomer, especially at 15% PKM. In summary, the addition of PKM improved the flavor of Tibetan sheep fat and increased the amount of favorable volatile flavor compounds. This study can serve as reference for understanding the effects of dietary PKM on the adipose tissue flavor profile of Tibetan sheep.

Insights into the effects of saline forage on the meat quality of Tibetan sheep by metabolome and multivariate analysis

This work aimed to investigate how two different types of forage (saline and alkaline) impact the meat quality and muscle metabolism of Tibetan sheep. An integrative multi-omics analysis of meat quality and different metabolites was performed using untargeted and targeted metabolomics approaches. The research results indicated that GG grass (saline and alkaline forage) possessed superior characteristics in terms of apparent quality and secondary metabolite content compared with HG grass (Non saline alkali forage), regardless of the targeted metabolites or non-targeted ones. Simultaneously, under stress conditions, the carbohydrates-rich salt-alkali grass play a significant role in slowing down the decline in pH, increasing the unsaturated fatty acid content and reducing the thawing loss in Tibetan sheep. This study provides an understanding of the impact of different salt-alkali grass on the quality of Tibetan sheep meat, while providing a scientific basis for the future development of salt-alkali livestock industry.

Integrated metabolome and microbiome analysis reveals the effect of rumen-protected sulfur-containing amino acids on the meat quality of Tibetan sheep meat

Introduction

This study investigated the effects of rumen-protected sulfur-containing amino acids (RPSAA) on the rumen and jejunal microbiota as well as on the metabolites and meat quality of the longissimus lumborum (LL) in Tibetan sheep.

Methods

By combining 16S rDNA sequencing with UHPLC-Q-TOF MS and Pearson correlation analysis, the relationship between gastrointestinal microbiota, muscle metabolites and meat quality was identified.

Results

The results showed that feeding RPSAA can increase the carcass weight, abdominal fat thickness (AP-2 group), and back fat thickness (AP-2 and AP-3 group) of Tibetan sheep. The water holding capacity (WHC), texture, and shear force (SF) of LL in the two groups also increased although the fatty acids content and brightness (L*) value significantly decreased in the AP-2 group. Metabolomics and correlation analysis further showed that RPSAA could significantly influence the metabolites in purine metabolism, thereby affecting L* and SF. In addition, RPSAA was beneficial for the fermentation of the rumen and jejunum. In both groups, the abundance of Prevotella 1, Lachnospiraceae NK3A20 group, Prevotella UCG-003, Lachnospiraceae ND3007 group in the rumen as well as the abundance of Eubacterium nodatum group and Mogibacterium group in the jejunum increased. In contrast, that of Turicibacter pathogens in the jejunum was reduced. The above microorganisms could regulate meat quality by regulating the metabolites (inosine, hypoxanthine, linoleic acid, palmitic acid, etc.) in purine and fatty acids metabolism.

Discussion

Overall, reducing the levels of crude proteins in the diet and feeding RPSAA is likely to improve the carcass quality of Tibetan sheep, with the addition of RPMET (AP-2) yielding the best edible quality, possibly due to its ability to influence the gastrointestinal microbiota to subsequently regulate muscle metabolites.

Production performance and rumen bacterial community structure of Hu sheep fed fermented spent mushroom substrate from Pleurotus eryngii

This study aimed to investigate the effect of fermented spent mushroom substrate from Pleurotus eryngii (SMPE) supplementation on production performance, meat quality and rumen bacterial community structure of Hu sheep. 120 2-month-old Hu sheep with average body weight [(13.50 ± 3.10) kg] were selected and randomly divided into 4 groups with 3 replicates per group and 10 sheep per replicate. The control group (RL1) was fed a total mixed ration (TMR), and group RL2, RL3 and RL4 were fed the basal diets supplemented with 15%, 30% and 45% fermented SMPE, respectively. The pretest period lasted for 10 days and the test period lasted for 150 days. The results showed that: (1) Difference (p < 0.05) was observed in average daily feed intake (ADFI) and feed conversion ratio (FCR) between RL2 and RL4 groups. The eye muscle area (EMA) and grade rule (GR) values in RL2 and RL3 were significantly higher than those in RL1 and RL4 groups (p < 0.05). (2) The contents of threonine, valerine, leucine, lysine, histidine, essential amino acids, flavor amino acids, aspartic acid, serine, glutamic acid and arginine of the longissimus dorsi muscle in RL2 and RL3 groups were significantly higher than RL1 and RL4 (p < 0.05). (3) A total of 1,202,445 valid sequences were obtained from rumen of Hu sheep fed different amounts of fermented feed, and the valid sequences were clustered into 9824 Operational Taxonomic Units (OTUs). (4) α diversity analysis showed that the richness and diversity of rumen bacterial communities in Hu sheep in RL1, RL2, RL3 and RL4 groups were significantly higher than RL0 (raw materials of fermented SMPE) group (p < 0.05). β diversity analysis showed that the bacterial community structure was the most different between RL0 and RL3. (5) At the genus level, compared with RL1, the relative abundance of Christensenellaceae R-7 in RL3 group decreased significantly by 33.59%, the relative abundance of Prevotellaceae UCG001 in RL2, RL3 and RL4 decreased significantly by 50.41%, 62.24% and 49.17%, respectively, and the relative abundance of Ruminococcaceae NK4A214 in RL2 group increased significantly by 35.01% (p < 0.05). In summary, the addition of fermented SMPE to TMR can significantly improve the production performance, meat quality and rumen bacterial community diversity and abundance of Hu sheep.