The Effects of Graded Abomasal Glucose Infusion on Milk Yield and Composition in Lactating Goats

Four non-pregnant multiparous lactating goats were used in a 4 × 4 latin square experiment in the present study. The four treatments were abomasal infusion of 0, 50, 100, and 150 g d^-1 glucose. The results showed that graded glucose infusion increased milk yield （P 〈 0.01）. The highest milk yield was observed when 50 g d^-1 glucose was infused. An infusion of glucose at 100 or 150 g d^-1 failed to increase milk yield further and milk yield of the 100 g d ^-1 glucose infusion treatment was even significantly lower than that of the 50 g d^-1 treatment （P 〈 0.01）. Though milk fat content was gradually decreased by graded glucose infusions and milk fat yield of the 100 and 150 g d 1 treatments were lower than that of the control （P 〈 0.01）; milk fat yield of the 50 g d i treatment was not depressed and was higher than that of the control （P 〈 0.01）. Graded glucose infusion did not change the contents of milk protein and non-fatty solids. Yields of milk protein （P 〈 0.05）, lactose （P 〈 0.01）, non-fat solids （P 〈 0.01）, and lactose content （P 〈 0.01） of the 50 g d^-1 treatment were higher than those of the control but had no difference among the other three treatments. Contents of those de novo synthesized fatty acids in milk fat remained unchanged or increased and those preformed fatty acids remained unchanged or decreased by graded glucose infusion. Glucose infusion decreased the total yields of C16 ＋ C16：1 and 〉 C16 fatty acids and had no influence on the yield of C4-C14：1 fatty acids （P 〈 0.05）. Results of the present study implied that increased glucose supply had positive effects on the production of milk, milk protein, milk fat, and lactose only when glucose was a limiting factor for milk synthesis. Excessive glucose supply had no further beneficial effects and might depress milk fat synthesis.

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.

Changes in milk fat globule membrane proteins along lactation stage of Laoshan dairy goat

The milk fat globule membrane(MFGM)is a complex structure with numerous functions,and its composition is affected by many factors.There have been few systematic investigations on goat MFGM proteome profiling during lactation.Individual milk samples from 15 healthy dairy goats were obtained at six lactation time points for investigation of the MFGM proteome using both data-independent acquisition(DIA)and data-dependent acquisition(DDA)proteomics techniques combined with multivariate statistical analysis.Using the DIA method,890 variably abundant MFGM proteins were discovered throughout the lactation cycle.From 1 to 240 d,butyrophilin subfamily 1 member A1,lipoprotein lipase,perilipin-2,and adipose triglyceride lipase were upregulated,while APOE,complement C3,clusterin,and IgG were downregulated.Furthermore,from 1 to 90 d,annexin A1,annexin A2,and antithrombin-ll were downregulated,then upregulated by d 240.Albumin had a high degree of connectedness,indicating that it was a key protein,according to protein-protein interaction research.Overall,our findings gave new insights into the biological features of MFGM protein in goat milk throughout lactation,which may aid in the creation of specialized MFGM products and infant formula.

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.

Branched-chain fatty acids from goat milk alleviate ulcerative colitis via the TLR4/NF-κB/NLRP3 pathway

Branched-chain fatty acids(BCFAs)are new bioactive fatty acids with anti-inflammatory properties.However,the role of BCFAs in alleviating ulcerative colitis has not been clarified.Herein,we evaluated the protective effect of BCFAs from goat milk in mice with colitis induced using dextran sodium sulfate(DSS)and explored the corresponding mechanism.These results show that BCFAs extracted from goat milk can significantly alleviate weight loss in mice,and reduce the disease activity index and the activity of myeloperoxidase while increasing the content of antioxidant enzymes in colon tissue and reducing the oxidation stress response.These data also show that BCFAs can down-regulate the gene and protein expression of the toll-like receptor 4(TLR4)/nuclear factorκB p65(NF-κB p65)/NOD-like receptor thermal protein domain associated protein 3(NLRP3)signaling pathway,and at the same time significantly reduce the expression of pro-inflammatory factors tumor necrosis factorα(TNF-α),interleukin 1β(IL-1β),and IL-18 in colon tissue,and significantly increase the expression of the anti-inflammatory factor IL-10.In conclusion,these results demonstrated that BCFAs in goat milk exerted effects on colitis-related inflammatory cytokines and inhibited inflammation by inducing the TLR4/NF-κB/NLRP3 pathway to alleviate DSS-induced ulcerative colitis.This study provides evidence for the potential of BCFAs as bioactive fatty acids in food products and to ameliorate ulcerative colitis development in mice.

Negative effects of long-term feeding of high-grain diets to lactating goats on milk fat production and composition by regulating gene expression and DNA methylation in the mammary gland

Background： It is well known that feeding a high concentrate（HC） diet to lactating ruminants likely induces subacute ruminal acidosis（SARA） and leads to a decrease in milk fat production. However, the effects of feeding a HC diet for long periods on milk fatty acids composition and the mechanism behind the decline of milk fat still remains poorly understood. The aim of this study was to investigate the impact of feeding a HC diet to lactating dairy goats on milk fat yield and fatty acids composition with an emphasis on the mechanisms underlying the milk fat depression. Seventeen mid-lactating dairy goats were randomly allocated to three groups. The control treatment was fed a low-concentrate diet（35% concentrate, n = 5, LC） and there were two high-concentrate treatments（65% concentrate, HC）, one fed a high concentrate diet for a long period（19 wks, n = 7, HL）; one fed a high concentrate diet for a short period of time（4 wk, n = 5, HS）. Milk fat production and fatty acids profiles were measured. In order to investigate the mechanisms underlying the changes in milk fat production and composition,the gene expression involved in lipid metabolism and DNA methylation in the mammary gland were also analyzed.Results： Milk production was increased by feeding the HC diet in the HS and HL groups compared with the LC diet（P 〈 0.01）, while the percentage of milk fat was lower in the HL（P 〈 0.05） but not in the HS group. The total amount of saturated fatty acids（SFA） in the milk was not changed by feeding the HC diet, whereas the levels of unsaturated fatty acids（UFA） and monounsaturated fatty acids（MUFA） were markedly decreased in the HL group compared with the LC group（P 〈 0.05）. Among these fatty acids, the concentrations of C15：0（P 〈 0.01）, C17：0（P 〈 0.01）, C17：1（P 〈 0.01）, C18：1 n-9 c（P 〈 0.05）, C18：3 n-3 r（P 〈 0.01） and C20：0（P 〈 0.01） were markedly lower in the HL group, and the concentrations of C20：0（P 〈 0.05） and C18：3 n-3 r（P 〈 0.01） were lower in the HS group compared with the LC group. However, the concentrations of C18：2 n-6 c（P 〈 0.05） and C20：4 n-6（P 〈 0.05） in the milk fat were higher in the HS group. Real-time PCR results showed that the m RNA expression of the genes involved in milk fat production in the mammary gland was generally decreased in the HL and HS groups compared with the LC group. Among these genes, ACSL1, ACSS1 ＆ 2, ACACA, FAS, SCD, FADS2, and SREBP1 were downregulated in the mammary gland of the HL group（P 〈 0.05）, and the expressions of ACSS2, ACACA, and FADS2 m RNA were markedly decreased in the HS goats compared with the LC group（P 〈 0.05）. In contrast to the gene expression, the level of DNA methylation in the promoter regions of the ACACA and SCD genes was increased in the HL group compared with the LC group（P 〈 0.05）. The levels of ACSL1 protein expression and FAS enzyme activity were also decreased in the mammary gland of the HL compared with the LC group（P 〈 0.05）.Conclusions： Long-term feeding of a HC diet to lactating goats induced milk fat depression and FAs profile shift with lower MUFAs but higher SFAs. A general down-regulation of the gene expression involved in the milk fat production and a higher DNA methylation in the mammary gland may contribute to the decrease in milk fat production in goats fed a HC diet for long time periods.

Study Properties of Fermented Camels’ and Goats’ Milk Beverages Fortified with Date Palm (<i>Phoenix dactylifera L</i>.)

Camels’ milk (CM) and goats’ milk (GM) are rich in nutrients and vitamins necessary for the health of humans and have therapeutic properties as they are rich in antioxidants and have a protective role against free radicals that have harmful effects on human health. Date palm (DP), camels’ milk and goats’ milk have been reported to be used for the prevention and treatment of various diseases in Arab countries. This study was designed to mix date palm with camels’ milk and goats’. Eight formulations of both camels’ milk and goats’ were made from different percentages of date palm. These formulations were added at ratios of 0 (control), 10%, 20% and 30% (w/v) to camels’ milk and goats’ and the effect of this date palm on the composition and texture properties of the fermented obtained products were followed. It has been found that pH, protein, fat decreased and total solid, carbohydrate, ash, viscosity, vitamins, minerals and antioxidants increased with the increase of the added percentage of date palm compared to control. Microbial counts of the fermented camels’ milk (FCM) and goats’ milk (FGM) increased significantly (P < 0.05) with the addition of different formulations and during storage. Also, fermented camels’ milk (FCM) and fermented goats’ milk (FGM) fortified with different ratios date palm (DP) concentration resulted in good properties and higher acceptable sensory values (at a rate of 10% - 20%) in fresh and till the end of storage periods. The addition of the date palm to all treatments improved the composition, viscosity, microbiological quality of fermented camels’ and goats’ milk with nutritional functional values and acceptable sensory attributes.

Preparation and Amplification of Colony of Goat Transgenic Fetal Fibroblast and Mammary Gland Epithelial Cell with Human Lactoferrin Gene

[Objective]The aim was to explore technical system of making single transgenic positive cells become colony cells by amplification culture. [Method] Fetal fibroblasts and mammary gland epithelial cells of single goat fetus of pBLM-C1 which specifically expressed human lactoferrin were cloned. Single cell colony of single transfection cell was prepared with 3 concentrations of 0%,50% and 100% conditioned culture media. Transfection cell and non-transfection cell were carried out amplification culture by con-culture,neo gene was as screened gene,genome DNA of transfection cell was detected by PCR method. Chromosome karyotype analysis of single colony cell was tested. [Result] Compared with non-conditioned culture medium,100% conditioned culture medium could greatly increase survived rate of single colony cells (FF: 53.33% vs. 10.00%;MGE: 33.33% vs. 6.67%). Compared with control,con-culture of transfection cell and non-transfection cell could greatly increase rate of transfection cell single colony after amplification culture (FF: 53.33% vs. 10.00%;MGE: 33.33% vs. 6.67%),confluence time of amplification culture was significantly decreased (20-30 d). The result of PCR showed that the colony cell obtained by above method contained hLF target gene. The result of karyotype analysis showed that most cloned cell chromosomes were normal. [Conclusion] The study provides a reliable method for separating transgenic cell,inserting and diagnosing ideal vector,and can save expense and time for transgenic animal production.

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.

Comparison the Genetic Potential of Some Growth ＆ Milk Trait, s of Hybrid （Crossed） Saanen with Native Goat （Lori Black Goat） versus Native Goats in Qom Province

The performance of some growth and milk traits of selected Qomi native （Lori black） goats and hybrids of saanen with native goats during 2008-2010 was compared. Growth traits include birth weight （BW）, one-month weight （1 MW）, weaning weight （WW） and 6-month weight （6 MW）. Also the milk production traits was monthly milk production on 2, 3, 4, 5th months （quantitative traits） and some milk composition included dry matter （%DM）, fat （%F）, and protein （%P） percentage on during of production （qualitative traits）. There were no significant differences in sex, birth type and genetic group for BW. Also the effect of genetic groups on 1 MW, WW, and 6 MW was significant, while effects of sex and birth type on 1 MW, WW and 6 MW was not significant. Also MW （Mothe＇s weight） had no significant effect on BW, 1 MW, WW and 6 MW. The average of daily milk records was 0.48 kg for nativel and 1.1 kg for crossed goats. The maximum monthly milk records in two groups were in second month （native： 0.64 -4- 0.05, crossed： 1.44 ~： 0.12） and the minimum were in fifth month （native： 0.36 ＋ 0.03, crossed： 0.77 -4- 0.05）. %DM, %F and %P in 5th month were higher than other months in two groups. Effects of genetic groups on milk production and also on average of%F, %DM and %P were significant. This study showed that the crossbreeding has a significant effect on most milk production and growth traits in Iranian native goats.

The Effects of a Hyperinsulinemic-Euglycemic Clamp on Milk Fat Synthesis and the Expression of Fat Synthesis-Related Genes in the Mammary Gland Tissues of Lactating Goats

To determine whether insulin exerts an effect on milk fat yield through the direct regulation of milk fat synthesis in the mammary gland, the hyperinsulinemic-euglycemic clamp procedure was performed in lactating goats in the present study. The effects of the hyperinsulinemic-euglycemic clamp on milk yield, milk composition, milk fatty acid yield and the expression levels of mRNAs of milk fat synthesis-related genes were examined. The results revealed that the hyperinsulinemiceuglycemic clamp had no significant effect on the milk yield, the milk protein yield, the yield and content of lactose or the yield and content of solids-not-fat (SNF) (P > 0.05). In contrast, the milk fat percentage and milk fat yield were decreased by 35.3% and 33.6%, respectively (P < 0.01). Among the 19 fatty acids examined, the yields of 9 fatty acids were significantly reduced (P < 0.05) following the clamp procedure, including C16:0 (hexadecanoic acid), 3 fatty acids derived from blood (>C16) and 5 fatty acids synthesized de novo in the mammary gland ( 0.05), including acetyl-coenzyme A carboxylase (ACC), fatty acid synthase (FAS), fatty acidbinding protein (FABP), lipoprotein lipase (LPL), stearoyl-CoA desaturase (SCD) and glycerol-3-phosphate acyltransferase (GPAT). However, the expression level of the SCD gene was significantly reduced during the post-procedure period (P < 0.05) but returned to a normal level at 48 h after termination of the clamp procedure. It was concluded that the hyperinsulinemic-euglycemic clamp exerted a direct effect on milk fatty acid desaturation.

Pregnancies Resulting from Transgenic Embryos with Human Lactoferrin Gene Produced by Somatic Cell Nuclear Transfer

[Objective] The aim of this study is to understand the effects of donor cell type,embryo stage,number and transfer position on the efficiency of goat transgenic clone.[Method] Using somatic cell nuclear transfer technology,the single goat fetal fibroblasts(GFF)and mammary gland epithelial cells(GMGE)harboring human lactoferrin(hLF)gene were transferred to the enucleated oocyte.Reconstructed karyoplast-cytoplast couplets were fused,activated,and cultured in vitro.Embryos at 2-8 cell stage were transferred into oviduct of synchronized recipients,and blastocysts were transferred into uterine horn.[Result] The pregnancy rate was similar between GFF and GMGE(oviduct transfer:26.47% vs.20.00%),and between oviduct transfer and uterine horn transfer(26.47% vs.25.00%)for GFF group;pregnancy rate in the group with the mean number of embryo transferred per recipient of 21.2 was significantly higher than in those the 5.93 group and 9.64 group(40.00% vs.26.67% and 21.43%).[Conclusion] These results indicate that pregnancy rate of goat transgenic clone couldn't be affected by donor cell type,embryo stage and transfer position but be done by the number of embryo transferred per recipient.In addition,the study also suggests the feasibility of making transgenic goat using GMGE as donor cells.

High rumen degradable starch decreased goat milk fat via trans-10,cis-12 conjugated linoleic acid-mediated downregulation of lipogenesis genes,particularly,INSIG1

Background:Starch is an important substance that supplies energy to ruminants.To provide sufficient energy for high-yielding dairy ruminants,they are typically fed starch-enriched diets.However,starch-enriched diets have been proven to increase the risk of milk fat depression(MFD)in dairy cows.The starch present in ruminant diets could be divided into rumen-degradable starch(RDS)and rumen escaped starch(RES)according to their different degradation sites(rumen or intestine).Goats and cows have different sensitivities to MFD.Data regarding the potential roles of RDS in milk fat synthesis in the mammary tissue of dairy goats and in regulating the occurrence of MFD are limited.Results:Eighteen Guanzhong dairy goats(day in milk=185±12 d)with similar parity,weight,and milk yield were selected and randomly assigned to one of three groups(n=6),which were fed an LRDS diet(Low RDS=20.52%),MRDS diet(Medium RDS=22.15%),or HRDS diet(High RDS=24.88%)for 5 weeks.Compared with that of the LRDS group,the milk fat contents in the MRDS and HRDS groups significantly decreased.The yields of short-,mediumand long-chain fatty acids decreased in the HRDS group.Furthermore,increased RDS significantly decreased ruminal B.fibrisolvens and Pseudobutyrivibrio abundances and increased the trans-10,cis-12 conjugated linoleic acid(CLA)and trans-10 C18:1 contents in the rumen fluid.A multiomics study revealed that the HRDS diet affected mammary lipid metabolism down-regulation of ACSS2,MVD,AGPS,SCD5,FADS2,CERCAM,SC5D,HSD17B7,HSD17B12,ATM,TP53RK,GDF1 and LOC102177400.Remarkably,the significant decrease of INSIG1,whose expression was depressed by trans-10,cis-12 CLA,could reduce the activity of SREBP and,consequently,downregulate the downstream gene expression of SREBF1.Conclusions:HRDS-induced goat MFD resulted from the downregulation of genes involved in lipogenesis,particularly,INSIG1.Specifically,even though the total starch content and the concentrate-to-fiber ratio were the same as those of the high-RDS diet,the low and medium RDS diets did not cause MFD in lactating goats.

Relationship between the Contents of MDA, the Activity of SOD in Serum of the Milk Goat with Fluorosis and the Erythrocytic Membrane Liquidity

To research the relation among the erythrocytic membrane.liquidity and the contents of MDA, the activity of SOD in serum of the milk goat with fluorosis. An animal model with fluorosis was constructed, and the fluorescent probe technique of DPH was used to measue the erythrocytic membrane liquidity. At the same time, the contents of MDA and the activity of SOD in serum were measured. The results showed that the erythrocytic membrane liquidity in the control group and flurosis group were 5.6742 ± 0.4417 and 3.7248 ± 0.4521 （P 〈0.01） respectively, the contents of MDA in serum were 2.0408 ± 0.198 and 4.494± 0.438 （P 〈0.01） respectively, the activities of SOD were 175.638 ± 22.201 and 113.714 ± 34.258 （P 〈0.01） respectively. The correlation analysis indicated that the relation between the activity of SOD and the liquidity of erythrocytic membrane was positive correlation （ r= 0.7321, P 〈0.05）, whereas the relation between the contents of MDA and the liquidity of erythrocytic membrane was negative correlation （r = -0.6438, P 〈0.01）. The erythrocytic membrane liquidity decreased in milk goat with fluorosis, which played a role in the occurrence and development of the fluorosis. There was correlation among the erythrocytic membrane liquidity and the contents of MDA, the activity of SOD.

Evaluation of 20 Macro and Trace Mineral Concentrations in Commercial Goat Milk Yogurt and Its Cow Milk Counterpart

Concentrations of 20 different minerals in commercial goat milk yogurt (CGY) and its cow milk yogurt (CCY) counterpart were evaluated in reference to goat milk yogurt manufactured from Fort Valley State University (FVGY), Fort Valley, GA, USA. Three different lots of CGY and CCY each were purchased from local retail stores at Warner Robins, GA, and 3 batches of FVGY were made using goat milk from the University milking herd. All 3 types of experimental yogurts were stored at 4°C refrigerator for 4 weeks. Twenty major and trace minerals were analyzed by an Inductively Coupled Plasma Optical Emissions Spectrometer (Thermo Jarrel Ash Enviro 36, Worchester, MA), using argon as the carrier gas and the EPA method 6010. Total solids (TS) content (%) of FVGY, CGY and CCY products were 11.03, 13.1 and 11.3, respectively, indicating CGY had higher TS than the CCY and FVGY yogurt. Respective mean mineral concentrations (ppm, wet basis) of FVGY, CGY and CCY were: Ca 1057, 1162, 1160;P 838, 974, 929;K 1327, 1717, 1208;Mg 102, 133, 113;Na 545, 449, 475;Fe 4.28, 3.33, 2.11;Mn 0.24, 0.19, 0.13;Cu 10.5, 9.85, 7.22;Zn 17.5, 11.7, 11.8. Levels of all macro minerals except potassium were higher in commercial goat and cow yogurts than FVGY, which may be due to the higher TS contents. FVGY had higher Fe, Mn, Cu and Zn than both commercial products. The heavy metal (Pb, Cd and Ni) contents (ppm) appeared to be normal range, while Al contents of FVGY, CGY and CCY were 11.9, 8.66 and 7.65, respectively, which were higher than those of Pb, Cd and Ni. Both commercial products contained higher major mineral contents than the university yogurt, which might be attributable to the differences in diet, breed, and stage of lactation of milking animals, as well as the tapioca additive used in the commercial products.

Genomic patterns of homozygosity and inbreeding depression in MurcianoGranadina goats

Background:Inbreeding depression can adversely affect traits related to fitness,reproduction and productive performance.Although current research suggests that inbreeding levels are generally low in most goat breeds,the impact of inbreeding depression on phenotypes of economic interest has only been investigated in a few studies based on genealogical data.Results:We genotyped 1040 goats with the Goat SNP50 BeadChip.This information was used to estimate different molecular inbreeding coefficients and characterise runs of homozygosity and homozygosity patterns.We detected38 genomic regions with increased homozygosity as well as 8 ROH hotspots mapping to chromosomes 1,2,4,6,14,16 and 17.Eight hundred seventeen goats with available records for dairy traits were analysed to evaluate the potential consequences of inbreeding depression on milk phenotypes.Four regions on chromosomes 8 and 25were significantly associated with inbreeding depression for the natural logarithm of the somatic cell count.Notably,these regions contain several genes related with immunity,such as SYK,IL27,CCL19 and CCL21.Moreover,one region on chromosome 2 was significantly associated with inbreeding depression for milk yield.Conclusions:Although genomic inbreeding levels are low in Murciano-Granadina goats,significant evidence of inbreeding depression for the logarithm of the somatic cell count,a phenotype closely associated with udder health and milk yield,have been detected in this population.Minimising inbreeding would be expected to augment economic gain by increasing milk yield and reducing the incidence of mastitis,which is one of the main causes of dairy goat culling.

Over-expression of Toll-like receptor 2 up-regulates heme oxygenase-1 expression and decreases oxidative injury in dairy goats

Background： Mastitis, an infection caused by Gram-positive bacteria, produces udder inflammation and oxidative injury in milk-producing mammals. Toll-like receptor 2（TLR2） is important for host recognition of invading Grampositive microbes. Over-expression of TLR2 in transgenic dairy goats is a useful model for studying various aspects of infection with Gram-positive bacteria, in vivo.Methods： We over-expressed TLR2 in transgenic dairy goats. Pam3CSK4, a component of Gram-positive bacteria,triggered the TLR2 signal pathway by stimulating the monocytes-macrophages from the TLR2-positive transgenic goats, and induced over-expression of activator protein-1（AP-1）, phosphatidylinositol 3-kinase（PI3K） and transcription factor nuclear factor kappa B（NF-κB） and inflammation factors downstream of the signal pathway.Results： Compared with wild-type controls, measurements of various oxidative stress-related molecules showed that TLR2, when over-expressed in transgenic goat monocytes-macrophages, resulted in weak lipid damage, high level expression of anti-oxidative stress proteins, and significantly increased m RNA levels of transcription factor NF-E2-related factor-2（Nrf2） and the downstream gene, heme oxygenase-1（HO-1）. When Pam3CSK4 was used to stimulate ear tissue in vivo the HO-1 protein of the transgenic goats had a relatively high expression level.Conclusions： The results indicate that the oxidative injury in goats over-expressing TLR2 was reduced following Pam3CSK4 stimulation. The underlying mechanism for this reduction was increased expression of the anti-oxidation gene HO-1 by activation of the Nrf2 signal pathway.

Fermented Goat Milk and Cow Milk Produced by Different Starters of Lactic Acid Bacteria： Quality Studies

Lactic acid bacteria （LAB） is widely used as culture starters in dairy fermentation. The aim of this study was to investigate the quality of fermented goat milk and cow milk, as well as the viability of LAB in the same products. Fermentations were performed with pasteurized goat milk or cow milk added with skim milk （18% of solids） using three separately different starters; yoghurt starter （a combination of Streptococcus thermophilus FNCC-0040 and Lactobacillus bulgaricus FNCC-0041）, single starter of Lactobacillus acidophilus FNCC-0029 and Lactobacillus casei FNCC-0051. The parameters observed were pH, acidity, nutritional quality including protein, fat and lactose content and product＇s viscosity. Acidity, pH and viability of LAB were also monitored during storage at refrigerated temperature （4 ℃） for 28 days. Results show that the different LAB starters did not affect the pH, acidity, lactose and protein content. Differences on LAB starters affected fat content and viscosity. The highest score of viscosity （30.00 Pa.s ± 7.02 Pa.s） was observed on products fermented by yoghurt starters, followed by products obtained using starter of L. acidophilus （17.7 ±11.4） and L. casei （8.62 ±0.35）. Protein content, acidity, pH and viscosity were not significantly different between products obtained from goat milk and cow milk. Fat content in fermented goat milk was higher （5.03% ±0.62%） than in fermented cow milk （3.52% ±0.37%）, however, lactose content was higher in fermented cow milk （5.16% ±0.40%） than in fermented goat milk （4.53% ±0.35%）. Total LAB concentration in fermented cow milk during storage was 8.03± 0.52 logt0 cfu/mL, while in fermented goat milk was 7.81 loglo cfu/mL ± 0.67 loglo cfu/mL. There was a 10.83% decrease in LAB viability in fermented cow milk and 11.40% in fermented goat milk after 28 days of storage. In conclusion, quality of fermented milk is affected by the starters applied, raw milk source and storage period.

Fluorescence-based PCR Detection of Goat Milk Powder Mixed with Cow Milk

[Objectives]To amplify and identify the specific gene fragments of cattle and sheep by real-time fluorescence-based PCR,and quickly and accurately identify the adulteration problem of goat milk powder according to the differences of mitochondrial genes among different species.[Methods]The specificity,limit of detection and repeatability test were carried out by isolating somatic cells,extracting template DNA and determining the reaction conditions of real-time fluorescence-based PCR.[Results]The real-time fluorescence-based PCR method could be used to identify the bovine and ovine-derived materials of milk powder with high specificity,high sensitivity and good repeatability,and the limit of detection of milk components in goat milk powder could reach 0.01%.[Conclusions]The real-time fluorescence-based PCR method can be used to quickly and accurately detect the milk components in goat milk powder,and provide some technical support for the adulteration detection of dairy industry.

Composition of Triacylglycerols in Fats of Cow and Goat Milk Produced in Four Zones of Mexico

The study of the triacylglycerols (TAG) by gas chromatography (GC) using capillary columns is an efficient technique for the determination of some characteristics of quality of fats and oils. The objective of the present study was to determine by GC the content of TAG present in fat of cow and goat milk produced in four zones of Mexico. According to criteria established in Mexican Standardization, 25 samples were obtained of 1 L of ultra-pasteurized cow milk (UHT) and 27 and 48 of raw cow and goat milk, respectively. The fat was extracted from all of the milk samples by detergent solution, and was stored at –20℃ until its analysis. The chromatographic conditions made it possible to identify and quantify TAG of 28 to 54 numbers of carbons, which were analyzed under descriptive and inferential statistical techniques. For the cow milk fat, the statistical analyses indicated significant difference (p < 0.05) in the TAG C34, C50 and C52, and for the goat milk fat in the TAG of C36 to C52. No equality of means was found among the TAG of the cow and goat milk fat. This study offers an advance in the characterization of the TAG present in the cow and goat milk fat produced in Mexico.