Animal Bioscience最新文献

Objective: Nicotinamide (NAM) is easily degraded in the rumen, but the rumen-protected NAM (RPN) supplementation might enable the use of NAM in ruminants. This study aimed to elucidate the effects of RPN supplementation on growth performance, rumen fermentation, antioxidant status and amino acid (AA) metabolism in growing lambs.

Methods: A total of 128 healthy and similar lambs (21.3±0.28 kg, 70±6.3 days of age) were allotted to 1 of 4 groups. The treatments were 0, 0.5, 1, and 2 g/d RPN supplementation. The RPN products (50% bioavailability) were fed at 0700 h every day for 12 weeks. All lambs were fed the same pelleted total mixed rations to allow ad libitum consumption and had free access to water.

Results: The RPN tended to increase the average daily gain and feed efficiency. The tendencies of RPN×day interaction were found for dry matter intake during the entire study (p = 0.078 and 0.073, respectively). The proportions of acetic acid, isobutyric acid and isovaleric acid were decreased, whereas the proportions of propionic acid and valeric acid were increased (p<0.05). The ratio of acetic acid to propionic acid was decreased (p<0.05). Moreover, the antioxidative status was enhanced and the glucose concentration was increased by RPN (p<0.05). In addition, 17 AAs were detected in plasma, of which 11 AAs were increased by RPN (p<0.05). Plasma metabolomics analysis identified 1,395 compounds belonging to 15 classes, among which 7 peptides were significantly changed after RPN supplementation.

Conclusion: Overall, the results suggested that RPN supplementation favoured the rumen fermentation pattern to propionic acid-type with benefited glucose metabolism, enhanced antioxidant capacity, and changed the AA and small peptide metabolism. This study provides a new perspective for studying the relationship between vitamin and AA metabolism.

Objective: This study was conducted to determine the effects of capsaicin (CAP) on productive performance, blood profile, intestinal morphology, carcass and meat quality of growing-finishing pigs.

Methods: Two experimental diets were offered to 36 crossbred barrows: basal diet (0% CAP) and basal diet with CAP at 0.02%. Each experimental group consisted of 18 pigs, with six replications (three each).

Results: Supplementation of CAP at 0.02% decreased average daily feed intake (p = 0.003) and feed cost/gain (p = 0.056), increased return on investment (p = 0.052) and increased gain:feed ratio (p = 0.037) during the growing period. There was no effect of CAP on the growth rate. The blood urea nitrogen and nitrogen (N) levels in faeces tended to decrease (p = 0.093 and p = 0.087), whereas the basophil level increased with CAP supplementation (p = 0.029). In addition, dietary CAP supplementation decreased crypt depth (p = 0.022) and tended to increase the villus height/crypt depth ratio in the segment of the jejunum (p = 0.084). Backfat (BF) thickness (p = 0.047) was reduced by supplementing CAP. Whereas the protein content increased with CAP supplementation (p = 0.021). Using CAP in the diet of growing pigs increased the pH at 6 h post-mortem (p = 0.046) and tended to increase the springiness value (p = 0.078) of the meat. In terms of meat color, CAP supplementation increased the yellowness (p = 0.029).

Conclusion: Supplemental CAP improves gut morphology and blood profiles, consequently promoting productive performance as well as carcass and meat quality.

Objective: N6-methyladenosine (m6A) is the most prevalent methylation of mRNA and plays crucial roles in various physiological processes, including pigmentation. Yet, the regulatory mechanisms, including long noncoding RNAs (lncRNAs) m6A methylation contributing to pigmentation in sheep skin remains unclear. The purpose of this study was to identify potential lncRNAs and the m6A methylation of lncRNAs associated with pigmentation.

Methods: RNA-seq and MeRIP-seq were performed to study the expression of lncRNAs and the m6A methylation of lncRNAs in black and white sheep skin. Furthermore, quantitative real-time polymerase chain reaction (qRT-PCR) was used to verify the consistency with the RNA-seq and MeRIP-seq data.

Results: We identified 168 differentially expressed lncRNAs between the two sheep skin colors. The differentially expressed lncRNAs enriched in the pathway of ECM-receptor interaction, Rap1 signaling pathway, and Non-homologous end-joining may play essential roles in pigmentation. We identified 577 m6A peaks and 617 m6A peaks in black and white sheep skin, respectively, among which 20 m6A peaks showed significant differences. The enriched motif in sheep skin was "GGACU", which aligned with the consensus motif "RRACH" (R = A or G, H = A, C or U). Differently methylated lncRNAs enriched in PI3K-Akt signaling pathway and Wnt signaling pathway might participate in skin pigmentation. ENSOARG00020015168 was the unique lncRNA with high expression and methylation (Hyper-Up) in black sheep shin. A lncRNA-mRNA network was constructed, with pigmentation-related genes, such as PSEN2, CCND3, COL2A1, and ERCC3.

Conclusion: The m6A modifications of lncRNAs in black and white colored sheep skin were analyzed comprehensively, providing new candidates for the regulation of pigmentation.

Objective: The livestock handler attitude and their handling of animals is crucial for improving animal welfare standards, minimizing stress, improving productivity and meat quality. The present study was undertaken to assess the effect of training livestock handlers on behavioral, physiological, and hormonal responses during preslaughter handling in goats.

Methods: A total of 6 handlers were divided into trained (trained in basic animal handling practices, animal behavior, and animal welfare), contact trained (not trained directly but interacted and saw the working of trained handlers), and untrained groups (no formal training). The handling experiment was conducted on 18 male goats by following a crossover design. The goats were moved from lairage to slaughter point by trained, contact-trained, and untrained handlers. Various behavioral, physiological, and hormonal parameters were recorded at the lairage before handling and at the slaughter point after handling the goats.

Results: The training of livestock handlers had a significant effect on behavioral, physiological, and hormonal responses in goats. The goats handled by untrained and contacttrained handlers were recorded with intense vocalization, significant (p<0.05) increase in heart rate and blood glucose, and catecholamines (adrenaline and nor-adrenaline), thereby indicating stress and poor animal welfare. The trained handlers were observed to use visual interactions (waving of hands or objects, blocking, hand raising, etc), and lower stress responses were recorded in the goats handled by this group.

Conclusion: The present study highlights the importance of training to livestock handlers in improving animal welfare and minimizing stress in goats during pre-slaughter stress.

Objective: Tropical plants are composed of phytonutrients (PTNs) and are utilized for their capacity to manipulate rumen fermentation characteristics and methane production. The aim of this experiment was to determine the impact of microencapsulated phytonutrients-extracted from lemongrass and mangosteen peel (M-LEMANGOS), as well as crude protein levels on nutrient degradability, rumen ecology, microbial population, and methane emission in an in vitro study.

Methods: The treatments were randomly assigned in a 2 × 4 Factorial arrangement in a Completely randomized design. The two factors consisted of crude protein (CP) percentage in the concentrate diet (16% and 18% CP) and the levels of M-LEMANGOS addition (0%, 2%, 4%, and 6% of the total substrate).

Results: The results showed that nutrient degradability both 12 and 24 h were significantly increased with M-LEMANGOS at 4% total substate. In part of volatile fatty acids (VFAs), particularly propionate and total VFA, these were enhanced by %CP and M-LEMANGOS combination. The %CP increased ruminal ammonia-nitrogen concentration (NH3-N), while M-LEMANGOS supplementation reduced such concentration. Methane production and Methanobacteriales population at 12 and 24 h were reduced when supplemented with M-LEMANGOS at 4% total substate. The population of Fibrobacter succinogenes, Ruminococcus flavefaciens, and Megasphaera elsdenii were increased with the interaction between %CP and M-LEMANGOS addition.

Conclusion: M-LEMANGOS indicates promising potential as a plant-based PTN for dietary modulation of rumen fermentation and mitigation of methane production.

Objective: This study aims to investigate the selection history, genome regions, and candidate genes associated with different chicken body sizes, thereby providing insights into the genetic basis of complex economic traits such as chicken body size and growth.

Methods: In this study, a total of 217 individuals from eight breeds were selected. According to body size, they were divided into two groups: large chickens and bantam chickens, with four breeds in each group. Firstly, we investigate population structure by principal component analysis (PCA), phylogenetic tree, and ancestry component analysis. Next, we recognize runs of homozygosity (ROH) islands through calculating ROH. Finally, we carry out selection signatures analysis utilizing population differentiation index and nucleic acid diversity.

Results: The population structure analysis show that large and bantam chickens are clearly separated. Large chickens are clustered together, the bantam chickens are relatively dispersed. The results of ROH island analysis show that 48 and 56 ROH islands were identified in large and bantam chickens respectively. Among the interesting ROH islands, a total of eight candidate genes were identified. In selection signatures analysis, a total of 322 selected genes were annotated in large chickens, such as POU1F1, BMP10, enrichment in 16 GO terms. In bantam chickens, a total of 447 selected genes were annotated, such as IGF1, GRB10, enrichment in 20 GO terms and 2 KEGG pathways. The haplotype analysis results show that GRB10 has differences in chickens of different body sizes.

Conclusion: By population structure, ROH islands, and selection signatures analysis, we have identified multiple genes associated with chicken body size, growth, and development (such as BMP10, IGF1, GRB10, etc). This provides a theoretical reference for the subsequent development of molecular markers for chicken body size and the analysis of the genetic mechanism of chicken body size.

Objective: Animals will experience energy deprivation processes such as moulting, clutching, migration and long-distance transportation under natural survival conditions and in production practices, and the body will trigger a series of adaptive metabolic changes during these processes. Fasting and refeeding after fasting can induce remodeling of nutrients and energy metabolism. This study aims to investigate the mechanisms by which the gut microbiota and liver of poultry respond to energy deprivation under specific conditions.

Methods: Ninety 252-day-old laying hens were randomly divided into 3 groups: (1) fed ad libitum (control group); (2) fasted from day 13 to day 17 (fasting group); (3) fasted from day 1 to day 5, then refed on a specific feeding way (refeeding group). After that, the serum, liver, jejunum tissues, and cecum contents were sampled and sent for metabolome, transcriptome, morphology, and 16S rDNA sequencing analyses, respectively.

Results: Results showed that food deprivation not only observably decreased the body weight, liver index, and the villus height and villus/crypt ratio of jejunum, but also significantly changed the gut microbiota compositions, serum metabolic profiles, and the hepatic gene expression patterns of laying hens, whereas these changes were effectively reversed by the following refeeding operation. At the same time, metabolome combined transcriptome analysis revealed that both serum differential metabolites and hepatic differential expressed genes (DEGs) were consistently enriched in the lipid and amino metabolism pathways, and strong correlations were synchronously found between the differential metabolites and both of the differential gut microbial genera and DEGs, suggesting the crosstalks among gut, liver and their resulting serum metabolic products.

Conclusion: The results suggested that the organism might coordinate to maintain metabolic homeostasis under energy deprivation through a combination of changes in gut microbial composition and hepatic gene expression.

Objective: Piglet diarrhea poses a serious threat to piglet health and the livestock economy, and is one of the most pressing problems in animal husbandry. This study aims to investigate the genetic factors involved in piglet diarrhea and to identify key genes that regulate this condition.

Methods: We screened 600 diarrheal piglets based on unique diarrhea scores for resequencing and conducted a genome-wide association study (GWAS). Through this process, we identified 308 single nucleotide polymorphisms (SNPs) and annotated 151 candidate genes. Extensive functional validation and systematic analysis were performed on key candidate genes KSR1, SKAP1, SLC35F6, and OR12.

Results: The study found that the four key genes were involved in the regulation of piglet diarrhea through various mechanisms. OR12 affects the levels of ZO-1 and claudin-1. Changes in the expression levels of KSR1 could alter the expression of IL1-β, IL6, and TNF-α, as well as cell migration and proliferation. SKAP1 could affect the expression of CD3 and CD4, and influence the migration and proliferation ability of cells. SLC35F6 is involved in cell apoptosis through the Bcl2/BAX/caspase3 pathway and can also affect mitochondrial membrane potential.

Conclusion: The results of this study provide strong support for breeding programs aimed at disease resistance and offer potential solutions to the problem of piglet diarrhea.

Objective: Semen cryopreservation acts a crucial role in enhancing breed improvement and conserving genetic resources. However, it often leads to decreased sperm activity and reduced pregnancy rates. Despite significant advancements in semen freezing techniques for goats, the precise factors and mechanisms causing cryo-injury remain unclear.

Methods: In this study, we examined the motility characteristics of fresh semen versus frozen-thawed semen and investigated changes in the metabolite profiles of seminal plasma using liquid chromatograph-mass spectrometry (LC-MS).

Results: A total of 364 differentially expressed metabolites (DEMs) were identified between fresh and frozen-thawed semen samples. Among these, 185 metabolites were significantly up-regulated, while 179 were down-regulated (p<0.05). The majority of these DEMs belonged to lipids and lipid-like molecules, as well as organic acids and derivatives. The Kyoto Encyclopedia of Genes and Genomes (KEGG) indicated that these DEMs were primarily involved in pathways related to amino acid synthesis and metabolism. Additionally, metabolite set enrichment analysis (MSEA) underscored the critical role of amino acid synthesis and metabolic pathways in semen cryopreservation. Specific metabolites such as alanine, proline, phenylalanine, tryptophan, tyrosine, adenosine, citric acid, flavin adenine dinucleotide (FAD), and choline emerged as potential biomarkers for sperm cryo-injury in goats.

Conclusion: These findings provide valuable insights into enhancing the quality of semen cryopreservation in goats, contributing to improved breeding and genetic resource conservation efforts.

Objective: This study aimed to investigate effects of apparent metabolizable energy (AMEn) levels in diets on productivity, fat deposition, and biochemical parameters of Woorimatdag1 (WMD1) breeder pullets.

Methods: A total of 240 four-week-old WMD1 breeder pullets were divided into four dietary groups with five replicates (12 birds per replicate). These groups had the following dietary energy levels: standard ME (SME), SME-200, SME-100, and SME+100 (diets containing 2,800, 2,600, 2,700, and 2,900 kcal AMEn/kg, respectively). These pullets were provided with diets and water ad libitum until 16 weeks old.

Results: Weight gain was significantly (p < 0.05) higher in SME-100, SME, and SME+100 groups than in the SME-200 group. SME+100 and SME groups exhibited significantly (p < 0.05) improved feed conversion ratio compared to the SME-200 group. Laying ages of 30% egg production occurred significantly (p < 0.05) earlier in SME-100, SME, and SME+100 groups than in the SME-200 group. SME and SME+100 groups had significantly (p < 0.05) higher liver fat (%) than the SME-200 group. Additionally, the SME+100 group had higher (p < 0.05) abdominal fat (%) than other groups. However, blood parameters were not significantly different among dietary groups.

Conclusion: SME-100 (2,700 kcal AMEn/kg) might be suitable for improving productivity and fat deposition of WMD1 breeder pullets.