Enhancing milk quality and modulating rectal microbiota of dairy goats in starch‑rich diet:the role of bile acid supplementation

Background Diets rich in starch have been shown to increase a risk of reducing milk fat content in dairy goats.While bile acids(BAs)have been used as a lipid emulsifier in monogastric and aquatic animals,their effect on ruminants is not well understood.This study aimed to investigate the impact of BAs supplementation on various aspects of dairy goat physiology,including milk composition,rumen fermentation,gut microbiota,and BA metabolism.Results We randomly divided eighteen healthy primiparity lactating dairy goats(days in milk=100±6 d)into two groups and supplemented them with 0 or 4 g/d of BAs undergoing 5 weeks of feeding on a starch-rich diet.The results showed that BAs supplementation positively influenced milk yield and improved the quality of fatty acids in goat milk.BAs supplementation led to a reduction in saturated fatty acids(C16:0)and an increase in monounsaturated fatty acids(cis-9 C18:1),resulting in a healthier milk fatty acid profile.We observed a significant increase in plasma total bile acid concentration while the proportion of rumen short-chain fatty acids was not affected.Furthermore,BAs supplementation induced significant changes in the composition of the gut microbiota,favoring the enrichment of specific bacterial groups and altering the balance of microbial populations.Correlation analysis revealed associations between specific bacterial groups(Bacillus and Christensenellaceae R-7 group)and BA types,suggesting a role for the gut microbiota in BA metabolism.Functional prediction analysis revealed notable changes in pathways associated with lipid metabolism,suggesting that BAs supplementation has the potential to modulate lipid-related processes.Conclusion These findings highlight the potential benefits of BAs supplementation in enhancing milk production,improving milk quality,and influencing metabolic pathways in dairy goats.Further research is warranted to elucidate the underlying mechanisms and explore the broader implications of these findings.

Whole-genome methylation analysis reveals epigenetic variation between wild-type and nontransgenic cloned,ASMT transgenic cloned dairy goats generated by the somatic cell nuclear transfer

Background:SCNT(somatic cell nuclear transfer)is of great significance to biological research and also to the livestock breeding.However,the survival rate of the SCNT cloned animals is relatively low compared to other transgenic methods.This indicates the potential epigenetic variations between them.DNA methylation is a key marker of mammalian epigenetics and its alterations will lead to phenotypic differences.In this study,ASMT(acetylserotonin-Omethyltransferase)ovarian overexpression transgenic goat was produced by using SCNT.To investigate whether there are epigenetic differences between cloned and WT(wild type)goats,WGBS(whole-genome bisulfite sequencing)was used to measure the whole-genome methylation of these animals.Results:It is observed that the different m Cp G sites are mainly present in the intergenic and intronic regions between cloned and WT animals,and their CG-type methylation sites are strongly correlated.DMR(differentially methylated region)lengths are located around 1000 bp,mainly distributed in the exonic,intergenic and intronic functional domains.A total of 56 and 36 DMGs(differentially methylated genes)were identified by GO and KEGG databases,respectively.Functional annotation showed that DMGs were enriched in biological-process,cellularcomponent,molecular-function and other signaling pathways.A total of 10 identical genes related to growth and development were identified in GO and KEGG databases.Conclusion:The differences in methylation genes among the tested animals have been identified.A total of 10 DMGs associated with growth and development were identified between cloned and WT animals.The results indicate that the differential patterns of DNA methylation between the cloned and WT goats are probably caused by the SCNT.These novel observations will help us to further identify the unveiled mechanisms of somatic cell cloning technology,particularly in goats.

circRNA landscape of non-pregnant endometrium during the estrus cycle in dairy goats

Endometrial development is a complicated process involving numerous regulatory factors.Circular RNAs(circRNAs)have been known as a member of the naturally occurring non-coding RNA family,and are reportedly crucial for a variety of physiological processes.This study investigated the circRNA landscape of non-pregnant endometrium of dairy goats during estrus.Non-pregnant endometrial samples of goats at estrus day 5(Ed5)and estrus day 15(Ed15)were used to methodically analyze the circRNA landscape using strand-specific Ribo-Zero RNA-Seq.A total of 2331 differentially expressed(P<0.05)circRNAs(DEciRs)between Ed5 and Ed15 were discovered in the goat endometrium.It was found that Nipped-B-like(NIPBL)and calcium responsive transcription factor(CARF)may participate in the development of the endometrium by decreasing(P<0.05)the levels of their circRNA-transcript forms.Furthermore,Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)analyses of DEciR host genes(hgDEciRs)revealed that tight junctions and GTPases may be involved in endometrial development during the estrus cycle.A total of 2331 DEciRs were discovered in the endometrium at Ed5 and Ed15.Based on GO and KEGG enrichment analyses,it could be inferred that tight junctions and GTPases are likely to play an important role in the development of goat endometrium during the estrus cycle.This circRNA study greatly enhances our knowledge of global trends in the development of non-pregnant endometrium during the estrus cycle in goats;these results help us to better understand the molecular regulation of endometrial development in dairy goats.

Genome-wide association studies of lactation yields of milk, fat, protein and somatic cell score in New Zealand dairy goats

Background: Identifying associations between genetic markers and traits of economic importance will provide practical benefits for the dairy goat industry, enabling genomic prediction of the breeding value of individuals, and facilitating discovery of the underlying genes and mutations. Genome-wide association studies were implemented to detect genetic regions that are significantly associated with effects on lactation yields of milk(MY), fat(FY),protein(PY) and somatic cell score(SCS) in New Zealand dairy goats.Methods: A total of 4,840 goats were genotyped with the Caprine 50 K SNP chip(Illumina Inc., San Diego, CA).After quality filtering, 3,732 animals and 41,989 SNPs were analysed assuming an additive linear model. Four GWAS models were performed, a single-SNP additive linear model and three multi-SNP Bayes C models. For the single-SNP GWAS, SNPs were fitted individually as fixed covariates, while the Bayes C models fit all SNPs simultaneously as random effects. A cluster of significant SNPs were used to define a haplotype block whose alleles were fitted as covariates in a Bayesian model. The corresponding diplotypes of the haplotype block were then fit as class variables in another Bayesian model.Results: Across all four traits, a total of 43 genome-wide significant SNPs were detected from the SNP GWAS. At a genome-wide significance level, the single-SNP analysis identified a cluster of variants on chromosome 19 associated with MY, FY, PY, and another cluster on chromosome 29 associated with SCS. Significant SNPs mapped in introns of candidate genes(45%), in intergenic regions(36%), were 0–5 kb upstream or downstream of the closest gene(14%) or were synonymous substitutions(5%). The most significant genomic window was located on chromosome 19 explaining up to 9.6% of the phenotypic variation for MY, 8.1% for FY, 9.1% for PY and 1% for SCS.Conclusions: The quantitative trait loci for yield traits on chromosome 19 confirms reported findings in other dairy goat populations. There is benefit to be gained from using these results for genomic selection to improve milk production in New Zealand dairy goats.

Exploring the Novel Genetic Variant of PITX1 Gene and Its Effect on Milk Performance in Dairy Goats

Paired-like homeodomain transcription factor 1 （PITX1） plays an important role in pituitary development by indirectly regulating the expression of the GH and PRL genes, and therefore PITX1 gene is regarded as a potential candidate gene for building the relationship between the gene polymorphism and milk traits. The aim of this study was to explore the novel genetic variant in PITX1 gene and its effect on milk performance in dairy goats. Herein, a novel genetic variation （NW_00314033： g.201GA or IVS1＋41GA） located at nt41 position of the first intron of the goat PITX1 gene was reported at the P1 locus, which can be genotyped by the Msp I PCR-RFLP. In the Msp I PCR-RFLP analyis, the GG variant was a major genotype, and the A variant was a minor allele in Guanzhong dairy goats which was at Hardy-Weinberg disequilibrium （chi-square χ2=140, P0.01）. The establishment of associations between different genotypes and milk performance was performed in the analyzed population. A total of three significant associations of the polymorphism with average milk fat content （%） （P=0.045）, morning milk fat content （%） （P=0.049）, and afternoon milk fat content （%） （P=0.050）, were found, respectively. A significant relationship between the polymorphism and average total solid content （P=0.029） was also detected. This novel single nucleotide polymorphism （SNP） extended the spectrum of genetic variation of the goat PITX1 gene, and its significant association with milk performance would benefit from the application of DNA markers related to improving milk performance through marker-assisted selection （MAS） in dairy goats.

TLR7/8 signalling affects X-sperm motility via the GSK3α/β-hexokinase pathway for the efficient production of sexed dairy goat embryos

Background:Goat milk is very similar to human milk in terms of its abundant nutrients and ease of digestion.To derive greater economic benefit,farmers require more female offspring(does);however,the buck-to-doe offspring sex ratio is approximately 50%.At present,artificial insemination after the separation of X/Y sperm using flow cytometry is the primary means of controlling the sex of livestock offspring.However,flow cytometry has not been successfully utilised for the separation of X/Y sperm aimed at sexing control in dairy goats.Results:In this study,a novel,simple goat sperm sexing technology that activates the toll-like receptor 7/8(TLR7/8),thereby inhibiting X-sperm motility,was investigated.Our results showed that the TLR7/8 coding goat Xchromosome was expressed in approximately 50%of round spermatids in the testis and sperm,as measured from cross-sections of the epididymis and ejaculate,respectively.Importantly,TLR7/8 was located at the tail of the Xsperm.Upon TLR7/8 activation,phosphorylated forms of glycogen synthase kinaseα/β(GSK3α/β)and nuclear factor kappa-B(NF-κB)were detected in the X-sperm,causing reduced mitochondrial activity,ATP levels,and sperm motility.High-motility Y-sperm segregated to the upper layer and the low-motility X-sperm,to the lower layer.Following in vitro fertilisation using the TLR7/8-activated sperm from the lower layer,80.52±6.75%of the embryos were XX females.The TLR7/8-activated sperm were subsequently used for in vivo embryo production via the superovulatory response;nine embryos were collected from the uterus of two does that conceived.Eight of these were XX embryos,and one was an XY embryo.Conclusions:Our study reveals a novel TLR7/8 signalling mechanism that affects X-sperm motility via the GSK3α/β-hexokinase pathway;this technique could be used to facilitate the efficient production of sexed dairy goat embryos.

Comparing successful gene knock-in efficiencies of CRISPR/Cas9 with ZFNs and TALENs gene editing systems in bovine and dairy goat fetal fibroblasts

This study aimed to compare the efficiencies of clustered regulatory interspaced short palindromic repeat（CRISPR）/Cas9-mediated gene knock-ins with zinc finger nucleases（ZFNs） and transcription activator-like effector nucleases（TALENs） in bovine and dairy goat fetal fibroblasts. To test the knock-in efficiency, a set of ZFNs and CRISPR/Cas9 plasmids were designed to edit the bovine myostatin（MSTN） gene at exon 2, while a set of TALENs and CRISPR/Cas9 plasmids were designed for editing the dairy goat β-casein gene at exon 2. Donor plasmids utilizing the ZFNs, TALENs, and CRISPR/Cas9 cutting sites were constructed in theGFP-PGK-Neo R plasmid background, including a 5′ and 3′ homologous arm flanking the genes humanized Fat-1（h Fat-1） or enhanced green fluorescent protein（eGFP）. Subsequently, the ZFNs, TALENs, or CRISPR/Cas9 and thehFat-1 or eGFP plasmids were co-transfected by electroporation into bovine and dairy goat fetal fibroblasts. After G418（Geneticin） selection, single cells were obtained by mouth pipetting, flow cytometry or a cell shove. The gene knock-in events were screened by PCR across the homologous arms. The results showed that in bovine fetal fibrobalsts, the efficiencies of ZFNs-mediated eGFP andhFat-1 gene knock-ins were 13.68 and 0%, respectively. The efficiencies of CRISPR/Cas9-mediated eGFP andhFat-1 gene knock-ins were 77.02 and 79.01%, respectively. The eGFP gene knock-in efficiency using CRISPR/Cas9 was about 5.6 times higher than when using the ZFNs gene editing system. Additionally, thehFat-1 gene knock-in was only obtained when using the CRISPR/Cas9 system. The difference of knockin efficiencies between the ZFNs and CRISPR/Cas9 systems were extremely significant（P〈0.01）. In the dairy goat fetal fibroblasts, the efficiencies of TALENs-mediated eGFP andhFat-1 gene knock-ins were 32.35 and 26.47%, respectively. Theefficiencies of eGFP and hFat-1 gene knock-ins using CRISPR/Cas9 were 70.37 and 74.29%, respectively. The knock-in efficiencies difference between the TALENs and CRISPR/Cas9 systems were extremely significant（P〈0.01）. This study demonstrated that CRISPR/Cas9 was more efficient at gene knock-ins in domesticated animal cells than ZFNs and TALENs. The CRISPR/Cas9 technology offers a new era of precise gene editing in domesticated animal cell lines.

Long-term and combined effects of N-[2-(nitrooxy)ethyl]-3-pyridinecarboxamide and fumaric acid on methane production,rumen fermentation, and lactation performance in dairy goats

Background:In recent years,nitrooxy compounds have been identified as promising inhibitors of methanogenesis in ruminants.However,when animals receive a nitrooxy compound,a high portion of the spared hydrogen is eructated as gas,which partly offsets the energy savings of CH4mitigation.The objective of the present study was to evaluate the long-term and combined effects of supplementation with N-[2-(nitrooxy)ethyl]-3-pyridinecarboxamide(NPD),a methanogenesis inhibitor,and fumaric acid(FUM),a hydrogen sink,on enteric CH4production,rumen fermentation,bacterial populations,apparent nutrient digestibility,and lactation performance of dairy goats.Results:Twenty-four primiparous dairy goats were used in a randomized complete block design with a 2×2factorial arrangement of treatments:supplementation without or with FUM(32 g/d)or NPD(0.5 g/d).All samples were collected every 3 weeks during a 12-week feeding experiment.Both FUM and NPD supplementation persistently inhibited CH4yield(L/kg DMI,by 18.8%and 18.1%,respectively)without negative influence on DMI or apparent nutrient digestibility.When supplemented in combination,no additive CH4suppression was observed.FUM showed greater responses in increasing the molar proportion of propionate when supplemented with NPD than supplemented alone(by 10.2%vs.4.4%).The rumen microbiota structure in the animals receiving FUM was different from that of the other animals,particularly changed the structure of phylum Firmicutes.Daily milk production and serum total antioxidant capacity were improved by NPD,but the contents of milk fat and protein were decreased,probably due to the bioactivity of absorbed NPD on body metabolism.Conclusions:Supplementing NPD and FUM in combination is a promising way to persistently inhibit CH4emissions with a higher rumen propionate proportion.However,the side effects of this nitrooxy compound on animals and its residues in animal products need further evaluation before it can be used as an animal feed additive.

The Effects of Insulin and Prolactin on an Epithelial Cell Line from Mammary Gland of Dairy Goat

Mammary epithelial cells with lactational function can be a valuable cellular model for research of the development and regulation of the mammary gland.This paper describes some aspects of function of an epithelial cell line from the mammary gland of the dairy goat.SDS-PAGE,triglyceride and lactose content of cultured cells were used to assess synthetic function of cells and the effects of exposure to insulin and prolactin.Results show that goat mammary epithelial cells can synthesize fat,proteins and lactose when they were cultured in DMEM-F12 medium with added EGF,IGF-1,ITS and FBS.There were no obvious changes after 48h treatment with additional insulin.Prolactin added to the basal medium significantly increased synthesis of proteins and lactose.A mammary gland epithelial cell line from goats which has lactational function has been established.This outcome provides a valuable and convenient model system.

Effects of Different Dietary Cation-Anion Difference on Fiber Degradation in Rumen of Laoshan Dairy Goats

The experiment was conducted to determine effects of different dietary cation-anion difference（DCAD） in diets on ruminal fluid pH and fiber degradation in rumen of Laoshan dairy goats. A 4×4 latin square design was adopted. DCAD in different groups was 0, 50, 100, 200 mEq·kg^-1 of DM, respectively. The results of ruminal pH indicated that different DCAD could significantly influence the ruminal pH （P〈0.05） and ruminal fluid pH increased as DCAD increased from 0 to 200 mEq·kg^-1 of DM at different sampling time-points. There was no effect of DCAD on carboxymethyl cellulase in ruminal fluid at 4 h and 8 h postfeeding （P〉0.05）. Degradation ofNDF, ADF, CF peaked at a DCAD of 100 mEq·kg^-1 of DM. It could be concluded that DCAD of 100 mEq·kg^-1 of DM was advantage to non-pregnancy, non-lactication Laoshan dairy goat.

Potential Genes for Regulation of Milk Protein Synthesis in Dairy Goat Mammary Gland

The lactating mammary gland is a prodigious protein-producing factory, but the milk protein synthesis mechanisms are not well understood. The major objective of this paper was to elucidate which genes and pathways were involved in the regulation of milk protein synthesis in the dairy goat mammary gland. Total 36 primiparous Guanzhong dairy goats were allotted in 12 groups according to their mammary development stages： days 90 and 150 of virgin, days 30, 90, and 150 of pregnancy, days 1, 10, 35, and 60 of lactation and days 3, 7, and 21 of involution （three animals per group）. Mammary tissue RNA was isolated for quantitative real- time RT-PCR of four casein genes alpha-s 1 casein （CSN 1S 1 ）, alpha-s2 casein （CSN 1 S2）, beta-casein （CSN2） and casein kappa （CSN3）, four whey protein genes lactoglobulin （LGB）, laetalbumin （LALBA）, laetofarrin （LTF）, and Whey acidic protein （WAP） and the genes which were potentially to regulate dairy goat milk protein synthesis at the level of transcription or translation [prolactin receptor （PRLR）, AKT1, signal transducers and activators of transcription 5 （STAT5）, E74-Like Factor 5 （ELF5）, eukaryotic translation initiation factor 4E binding protein 1 （EIF4E-BP1）, S6kinase （S6K） and caveolin 1]. The results showed that all genes were up-regulated in lactation period. The expressions of PRLR, AKT1, STAT5, ELF5, and S6K were similar to mRNA expressions of milk proteins. Our results indicated that milk protein synthesis in dairy goat mammary gland was possibly regulated by these genes.

Deuterium oxide dilution can be used to determine the net energy content of feeds for dairy cattle and goats

This article explores a technique for measuring the energy (NEL) value of feeds without respiration calorimetry or slaughter. The objectives were to compare results obtained from goats with those from cows, and to describe factors which limited the precision of these NEL estimates. One lactating Alpine doe and one lactateing Holstein cow were assigned to each of six different sequences of three 56-d feeding treatments consisting of low, medium, and high doses of the basal diet, rice bran, or hominy feed. This resulted in 30 observations of the basal diet and 12 of each byproduct feed for each species and utilized a total of 18 cows and 18 does. The NEL values of the basal diet, rice bran, and hominy feed were calculated as the sum of milk energy, change in body energy, and estimated fasting heat production per kilogram of feed dry matter. Milk energy was determined by bomb calorimetry and body energy from live body weight and deuterium oxide space. The NEL (MJ/kg) determined in this manner were basal diet, 5.73 and 5.98;rice bran, 7.11 and 7.07;and hominy feed, 6.99 and 8.20 for cows and goats, respectively.

Characteristics of Lactation Curves of the Kenya Alpine Dairy Goats in Smallholder Farms

Lactation curves are a graphical representation of the milk production profile of a doe from parturition to drying up. Their shape provides information about the productivity of the doe and offers a means of explaining features of the milk production patterns of each animal. A total of 2732 daily morning milk records from 610 does of the Kenyan Alpine dairy goats’ genetic groups (50% Alpine, 75% Alpine, 87.5% Alpine and > 87.5% Alpine) and local goats (0% Alpine) kept in small-holder farms were used to evaluate factors affecting milk yield and to examine the characteristics of their lactation curve. A nonlinear mixed model was used to fit the lactation curves to all does simultaneously. The Wood’s (1967) equation was fitted within each genetic group and parity to generate genetic group and parity lactation curves. The mean lactation period was 218 ± 46 days and the model accounted for 88% of the total variation. Significant differences (P 87.5% Alpine genetic groups respectively. Genetic group did not significantly affect rate of increase to peak yield (P > 0.05) and rate of decline from peak (P > 0.05) or persistency (P > 0.05). Parity significantly affected rate of increase to peak, rate of decrease from peak and persistency (P < 0.01). The month of kidding significantly affected the rate of increase to peak (P < 0.05) and persistency, but not rate of decrease from peak. The synchronization of breeding with season has a practical implication for the maximization of lactation yield when considered in combination with other biological and economic constraints. The superior production of the pedigree animals supports the development of composite breed types in Kenya to take advantage of the fitness of indigenous breeds, the productivity of imported dairy breeds, heterosis, and the potential for selection within the composite to improve productivity in later generations.

Transfer of PUFA fatty acid protected and carnitin precursor on the ration of chemical composition of milk dairy goat

The experiment was conducted to investigate the effect of transfer of PUFA protected and carnitin precursor on the ration of chemical composition of milk dairy goat. In total, 10 female dairy goats of 2 - 4 years old Peranakan Etawah (PE) with body weight of 25 - 45 kg were used in this experiment. The feed material included a basal diet (control) based on yellow corn, rice bran, soya bean meal, coconut meal, tuna fish oil and lemuru fish oil. The method of the research was experimental in vivo using Randomized Completely Block Design (RCBD). There were 5 treatments in each experiment and 2 replications. The treatment consisted of P0 = control ration, P1 = P0 + 200 ppm L-carnitine on the ration, P2 = P1 + soya bean oil, P3 = P1 + protected tuna fish oil 5 ml or equal with 4% in the ration, and P4 = P1 + protected lemuru fish oil 5 ml or equal with 4% in the ration. The measured variable is chemical composition of milk dairy goat. The results of variance analysis showed that the effect of transfer of PUFA fatty acid in the rations contained 200 ppm L-carnitine significantly

Performance and Genotypes of Dairy Goats in Kenya: Lessons Learnt and the Need to Move beyond Donor Introductions

A study was conducted in three cluster regions in Kenya where the Alpine,Toggenburg and Saanen dairy goat breeds,respectively,were kept.The objective was to determine the breeds’relative performance for use as a basis of their recommendation to farmers.Formal questionnaires were used to obtain information on farm sizes,dairy goat sources,reasons for keeping the dairy goats,goat milk production,amount of feed offered to the goats and the constraints faced.Further information on the actual milk production and live weights of the milking does was collected directly from the farms using hired recorders.Results indicated that the dairy goats were fed between 6 kg/goat/day and 17 kg/goat/day of forage.They had a low production average of 1.4 L milk/goat/day with no clear cut breed differences.Toggenburg milking does were significantly(p<0.05)heavier than the other breeds(48.3 vs.38.0 and 39.0 kg for the Alpine and Saanen dairy goats,respectively).The milk production and goat live weights were below their reported potential.Feed shortage in the dry season was a major constraint.It was concluded that farmers could keep any of the three breeds.It was recommended that data on the comparative performance from the three breeds be generated to guide on farmer choices.Governments receiving donor support on agricultural endeavours should put in place the technical and policy mechanisms to support the ventures after the donor exits,and also ensure recommendations by different donors on a technical issue are consistent and complementary.

The Effect of Age on Milk Yield and Milk Composition in Saanen Dairy Goats

The goals of this study were to determine the weekly milk production of Saanen goats at UniSZA Pasir Akar Farm,and to evaluate milk production and composition in three age groups.From January 2021 to May 2021,a study was conducted at the UniSZA Pasir Akar Farm in Besut,Terengganu.Ninety goat milk samples were collected and stored in sterile falcon tubes.Milk samples were stored in an insulated box at 5℃ before being transported to the laboratory and stored at-20℃ until further analysis.Milk samples were analyzed in four replicates for each sample group using the Milkotester.The one-way analysis of variance(ANOVA)method was used to analyze raw data among age groups,with p<0.05 indicating a significant difference.The highest milk yield was produced by four-year-old goats(943.9 g/d),followed by three-year-old goats(850.5 g/d)and two-year-old goats(571.1 g/d),respectively.Solid non-fat(SNF),protein,and lactose content showed the highest in percentage in the 3-year old group,at 7.80%,2.80%,and 4.27%,respectively.However,the fat content revealed an unusual pattern,with 2.87%,2.77%,and 3.33%representing 2,3 and 4 years old.This occurred due to other factors such as feed,breed,and age.In conclusion,this study found a significant difference in milk yield and composition across three age groups.However,this is only a preliminary result based on a small number of animals and a short study period.Future studies will perhaps,use larger sample sizes and parameters to validate the current result.

Ingredients from integral valorization of Isabel grape to formulate goat yogurt with stimulatory effects on probiotics and beneficial impacts on human colonic microbiota in vitro

Isabel grape(IG)products have high contents of phenolic compounds and fiber recognized for their positive impacts on microorganisms associated with health benefits to host.This study evaluated the effects of goat yogurts formulated with ingredients from IG integral valorization on the growth and metabolism of different probiotic strains,as well as on the population of selected bacterial groups and metabolic activity of human colonic microbiota in vitro.Goat yogurts with IG ingredients(IGI)stimulated the growth of tested Lactobacillus and Bifidobacterium probiotic strains during a 48-h cultivation,as well as decreased the pH values and enhanced the organic acid production.Goat yogurts with IGI increased the population of Lactobacillus spp.and Bifidobacterium spp.during a 24-h in vitro colonic fermentation.A stable Firmicutes:Bacteroidetes ratio close to 1 was found in media with goat yogurt formulations during the colonic fermentation,being similar to the effect caused by fructooligosaccharides.Goat yogurt formulations with IGI caused increased production of short-chain fatty acids and sugar consumption during colonic fermentation.Goat yogurts with IGI should be a valuable strategy for development of novel added-value foods with beneficial effects on gut microbiota and human health.

奶山羊种业的昨天、今天和明天

该文通过溯源四大洲(欧、非、美、大洋洲)优秀奶山羊培育过程,综述了国内外奶山羊种业发展的历史脉络。通过对育种体系和育种技术比较分析,论述了国内外奶山羊种业的发展现状;剖析了制约我国奶山羊种业发展的育种体系不完善、新技术应用不足、性能测定基础薄弱和优良地方品种资源重视不足等问题,提出通过构建现代奶山羊育种体系、加强育种技术研究、强化生产性能测定、加大种质资源创新利用,促进我国奶山羊种业发展的建议,旨在为我国奶山羊种业创新提供参考。

不同发育阶段关中奶山羊睾丸间质细胞的生物学特性

【目的】研究幼龄期、初情期和成年期关中奶山羊睾丸间质细胞(Leydig cells,LCs)的形态、分布特点、超微结构特征及睾酮合成水平,解析不同发育阶段LCs的形态特征与睾酮合成水平之间的相关性。【方法】使用光镜和改良后的透射电镜技术观察不同月龄奶山羊LCs的形态、分布规律及超微结构特征;采用免疫组织化学染色方法检测睾酮合成关键酶3β-羟基类固醇脱氢酶的表达和分布;采用酶联免疫吸附试验检测血清中促黄体生成素(luteinizing hormone,LH)和睾酮含量的变化;采用荧光定量PCR和免疫印迹技术分析LCs成熟和睾酮合成关键基因/蛋白表达的规律。【结果】与幼龄期相比,初情期和成年期的LCs逐渐变大、呈不规则多边形,且逐渐向间质中央移动。初情期和成年期的LCs胞质内含有大量脂滴,且脂滴与线粒体、光面内质网等细胞器密切接触。随着性成熟,血清中的LH和睾酮含量显著或极显著增加,睾丸组织中与睾酮合成相关的基因表达水平显著或极显著上调。【结论】关中奶山羊LCs的睾酮合成能力与其发育成熟过程密切相关,初情期和成年期的LCs胞质内存在大量脂滴且与线粒体直接接触,这为形态学方法研究脂滴参与睾酮的合成提供了科学依据。

青贮黑麦草对奶山羊生产性能、乳成分和血清相关指标的影响

试验旨在探究青贮黑麦草代替饲粮中10%青贮紫花苜蓿对奶山羊生产性能、乳成分和血清相关指标的影响。挑选体重、产奶量、胎次一致的健康奶山羊40只,随机分为2组,每组4个重复,每个重复5只羊。对照组奶山羊饲喂基础饲粮,试验组采用10%青贮黑麦草代替基础饲粮中等量的青贮紫花苜蓿。预试期1周,正式试验期8周(妊娠期和泌乳期均为4周)。结果显示,与对照组相比,试验组初生羔羊体重和断奶羔羊存活率均显著升高(P<0.05),乳脂率显著升高(P<0.05),乳体细胞数显著下降(P<0.05);试验组奶山羊血清免疫球蛋白A(IgA)、免疫球蛋白G(IgG)和球蛋白(GLB)含量均显著升高(P<0.05),甘油三酯(TG)和总胆固醇(TC)含量显著下降(P<0.05)。研究表明,以青贮黑麦草代替10%青贮紫花苜蓿可以提高羔羊存活率和幼羊生长性能,增加奶山羊采食量和产奶量,改善奶山羊的免疫功能,但对奶山羊血清抗氧化和肝功能等相关指标无显著影响。