Fine Mapping QTLs Affecting Milk Production Traits on BTA6 in Chinese Holstein with SNP Markers

Our previous studies demonstrated that the region around markers BMS470 and BMS1242 on BTA6 showed a linkage to 305-d milk yield and composition traits in the Chinese Holstein population. We herein focused on such narrow region to fine map milk production QTLs with 15 SNPs across 25 Mb with each SNP in 1 Mb within most regions in a Chinese Holstein population with daughter design. 1 449 Holstein cows and 11 sires were genotyped for such SNPs by using TaqMan probe and RFLP assays. Multipoint linkage analysis across family revealed a QTL affecting milk yield between PPARGC1A C4075T and SLC34A2 T1713C. Meanwhile, within family analysis found three milk yield QTLs （two in CR T60984131G-CEP135 C501T and one in PDLIM5 A106C-OPN T3907, a fat yield QTLin UGDH T1670C-CR T60984131G region, and two protein yield QTLs in TBC1D1 G501C-UGDH T1670C and PPARGC1A C4075T-SLC34A2 T1713C, respectively. Associations between aforementioned significant SNP markers and milk production traits were further implemented. We found significant associations of PPARGC1A C4075T, SLC34A2 T1713C with milk yield （P0.05, P0.01, P0.01）, UGDH T1670C, and CR T60984131G with fat yield （P0.01, P0.01）, and PPARGC1A C4075T, SLC34A2 T1713C, UGDH T1670C and OPN T3907 with protein yield （P0.01, P0.01, P0.01, P0.01）. Our findings implied that QTLs affecting milk production traits on BTA6 were pleictropism or multigenic effect and PPARGC1A and OPN may be the causal mutations behind milk production QTLs on BTA6 in the Chinese Holstein population.

Effect of dietary phosphorus content on milk production and phosphorus excretion in dairy cows

Background：Phosphorus（P） supplementation is costly and can result in excess P excretion.This study investigated the effects of reducing dietary P on milk production and P excretion in dairy cows over a full lactation.Method：Forty-five multiparous Holstein dairy cows were divided into 15 blocks according to expected calving date and previous milk yield,and assigned randomly to one of the three dietary treatments：0.37,0.47,and 0.57%P（DM basis）;these P levels represent the NRC recommendations,Chinese recommendations,and the amount of dietary P commonly fed by Chinese dairy farmers,respectively.Average daily feed intake was calculated from monthly data on feed offered and refused.Milk yields of individual cows were recorded weekly,and milk samples were taken for analysis of protein,fat,solids-not-fat,lactose,and somatic cell count.Blood samples were collected on days-6,-3,0,3,6 relative to calving,and then monthly throughout lactation,and analyzed for P and Ca concentrations.Spot samples of feces and urine were collected for 3 consecutive d during weeks 12,24,and 36,and P concentrations were analyzed.Reproduction and health data were recorded.Results：Dietary P did not affect dry matter intake or milk yield（P〉 0.10）.Milk fat content was slightly higher in cows fed 0.37%P than in cows fed 0.47%P（P = 0.05）.Serum concentrations of P and Ca did not reflect dietary P content（P〉 0.10）.Fecal and urinary P both declined linearly（P〈 0.05） as dietary P decreased from 0.57 to0.37%.Fecal P content was 25%less when dietary P was 0.37%compared to 0.57%.Health events and reproductive performance were not associated with dietary P content（P〉 0.05）.Conclusions：Lowering dietary P from 0.57 to 0.37%did not negatively affect milk production,but did significantly reduce P excretion into environment.

A Capra hircus chromosome 19 locus linked to milk production influences mammary conformation

Background:Economically important milk production traits including milk volume,milk fat and protein yield vary considerably across dairy goats in New Zealand.A significant portion of the variation is attributable to genetic variation.Discovery of genetic markers linked to milk production traits can be utilised to drive selection of highperformance animals.A previously reported genome wide association study across dairy goats in New Zealand identified a quantitative trait locus(QTL)located on chromosome 19.The most significantly associated single nucleotide polymorphism(SNP)marker for this locus is located at position 26,610,610(SNP marker rs268292132).This locus is associated with multiple milk production traits including fat,protein and volume.The predicted effect of selection for the beneficial haplotype would result in an average production increase of 2.2 kg fat,1.9 kg protein and 73.6 kg milk yield.An outstanding question was whether selection for the beneficial allele would co-select for any negative pleiotropic effects.An adverse relationship between milk production and udder health traits has been reported at this locus.Therefore,a genome wide association study was undertaken looking for loci associated with udder traits.Results:The QTL and production associated marker rs268292132 was identified in this study to also be associated with several goat udder traits including udder depth(UD),fore udder attachment(FUA)and rear udder attachment(RUA).Our study replicates the negative relationship between production and udder traits with the high production allele at position 19:26,610,610(SNP marker rs268292132)associated with an adverse change in UD,FUA and RUA.Conclusions:Our study has confirmed the negative relationship between udder traits and production traits in the NZ goat population.We have found that the frequency of the high production allele is relatively high in the NZ goat population,indicating that its effect on udder conformation is not significantly detrimental on animal health.It will however be important to monitor udder conformation as the chromosome 19 locus is progressively implemented for marker assisted selection.It will also be of interest to determine if the gene underlying the production QTL has a direct effect on mammary gland morphology or whether the changes observed are a consequence of the increased milk volume.

Production Systems, Genetic Diversity and Genes Associated with Prolificacy and Milk Production in Indigenous Goats of Sub-Saharan Africa: A Review

Goats are one of the oldest domesticated animal species widely distributed in the world playing an important role in the food production system in Sub-Saharan African Region (SSAR). Due to their multiple uses (milk production, meat, fiber and hides) and adaptation aptitudes to ecological conditions, goats produce and contribute positively to farmers’ socio-economy status in various production systems. This review aimed at giving a summary overview on the goat’s production systems characteristics, the genetic diversity and the candidate genes affecting reproductive and milk production performances in goat breeds in SSAR. It has been observed that traditional livestock production system with communal grazing system is the most used in goat keeping in SSAR. The geographical locations play an important role in the relationships between goat’s distributions in the region. At the same time, goats might have been differentiated and isolated one to others due to the wide geographic range, the diversify climate and the topography in the region. Among the six worldwide known haplogroups of goat (A, B, C, D, G and F), haplogroup A is the most representative in SSAR. However, haplogroup G and B can be found in some goat populations in some countries in east (Kenya and Ethiopia) and south parts of Africa. This review reveals that little is known on the candidate genes associated with prolificacy and milk production traits in indigenous goat breeds in the region. That observation suggests the importance of assessing candidate genes associated with economic traits in the populations of goat in SSAR.

Influence of Mango Feed-Based Diets on the Production and Economic Profitability of Montbeliarde Cows’ Milk at the End of Lactation in Burkina Faso

The study evaluated the effects of a diet incorporating a mango-based feed on the technical-economic performance of milk production of Montbeliard cows at the end of lactation in a dairy farm in Bobo-Dioulasso, Burkina Faso. To do so, 14 cows were subjected to 3 diets, including an experimental diet incorporating mango (ED) in comparison to a balanced control diet (BCD) and to the feeding practice of the farmer (FCD) during 60 days. Results show that the average amount of milk milked per day from ED (10.93 ± 0.17 L) was significantly higher (p < 0.05) than BCD (8.80 ± 0.19 L) and RTA (5.39 ± 0.14 L). The conversion index of FPD (4.24 ± 0.14) was significantly higher (p < 0.05) than that of BCD (1.75 ± 0.19) and ED (1.26 ± 0.16). Average feed costs per liter of milk (FC/L) were significantly different (p (125.95 ± 4.56 FCFA), BCD (83.67 ± 6.36 FCFA) and ED (60.06 ± 5.49 FCFA). The average gross profit margins (GPM) were significantly higher and decreasing (p ,953 ± 5031 FCFA), BCD (167,157 ± 5831 FCFA) and FCD (74,188 ± 4185 FCFA). Mango feed can be used in the diet of dairy cows. Its use contributes to the reduction of production costs and the generation of substantial profits. The valorization of mango residues is an alternative for a greater availability of feed at lower cost for the animals. It could contribute to a better management of processing residues that pollute the environment and to the reduction of fruit flies that affect orchard yields through reinfestation. The increased use of mango in dairy cattle feed should be encouraged.

Effect of Fruit-flavored Agent and Green Pigment on Production Performance of Simmental Cows

[Objective] The paper was to increase utilization rate of roughage to solve current shortage of forage and improve production performance of Simmental cow.[Method] Fruit-flavored agent and green pigment were added in roughage of Simmental cow respectively,and their effects on feed intake,milk production and milk quality of Simmental cow were studied.[Result] After adding fruit-flavored agent and green pigment,the feed intakes of Simmental cow were increased by 30.69% and 12.27%,while the milk productions were increased by 1.74 and 2.25 kg,respectively,and the differences were all significant（P 〈 0.05）.[Conclusion]Adding 0.3% and 0.1% fruit-flavored agent and green pigment in roughage of Simmental cow could significantly improve feed intake and milk production,which can also delay the decline of milk production during late lactation stage and improve milk quality.

Milk Production in Tibet

This paper describes milk production and livestock production in Tibet. Some information of market demand has also been presented. There has been very little information published in Tibetan journals on production and nutrition of cattle. This review provides a brief introduction to feeding systems and feeding resources. Many studies on milk production have been done in isolation, and do not go beyond the basic and practical level. Compared with dairy cattle research in other parts of China, large gaps in knowledge still exist in cattle production science, particularly related to nutrition, and systems approaches for the development of a dairy industry.

Impact of dietary fat levels and fatty acid composition on milk fat synthesis in sows at peak lactation

Background Dietary fat is important for energy provision and immune function of lactating sows and their progeny.However,knowledge on the impact of fat on mammary transcription of lipogenic genes,de novo fat synthesis,and milk fatty acid(FA)output is sparse in sows.This study aimed to evaluate impacts of dietary fat levels and FA composition on these traits in sows.Forty second-parity sows(Danish Landrace×Yorkshire)were assigned to 1 of 5 dietary treatments from d 108 of gestation until weaning(d 28 of lactation):low-fat control diet(3%added animal fat);or 1 of 4 high-fat diets with 8%added fat:coconut oil(CO),fish oil(FO),sunflower oil(SO),or 4%octanoic acid plus 4%FO(OFO).Three approaches were taken to estimate de novo milk fat synthesis from glucose and body fat.Results Daily intake of FA was lowest in low-fat sows within fat levels(P<0.01)and in OFO and FO sows within highfat diets(P<0.01).Daily milk outputs of fat,FA,energy,and FA-derived carbon reflected to a large extent the intake of those.On average,estimates for de novo fat synthesis were 82 or 194 g/d from glucose according to method 1 or 2 and 255 g de novo+mobilized FA/d according to method 3.The low-fat diet increased mammary FAS expression(P<0.05)and de novo fat synthesis(method 1;P=0.13)within fat levels.The OFO diet increased de novo fat synthesis(method 1;P<0.05)and numerically upregulated mammary FAS expression compared to the other high-fat diets.Across diets,a daily intake of 440 g digestible FA minimized milk fat originating from glucose and mobilized body fat.Conclusions Sows fed diets with low-fat or octanoic acid,through upregulating FAS expression,increased mammary de novo fat synthesis whereas the milk FA output remained low in sows fed the low-fat diet or high-fat OFO or FO diets,indicating that dietary FA intake,dietary fat level,and body fat mobilization in concert determine de novo fat synthesis,amount and profiles of FA in milk.

Simultaneous Determination of Melamine, Ammelide, Ammeline, and Cyanuric Acid in Milk and Milk Products by Gas Chromatography-tandem Mass Spectrometry

Objective To develop an analytical method for simultaneously qualitative and quantitative determination of melamine and triazine-related by-products including ammelide, ammeline, and cyanuric acid in milk and milk products by gas chromatography- tandem mass spectrometry （GC-MS/MS）. Methods Melamine and triazine-related by-products namely ammelide, ammeline and cyanuric acid in the samples were extracted in a solvent mixture of diethylamine, water, and acetonitrile （10：40：50, V/V/V）. After centrifugation, an aliquot of the supernatant was evaporated to dryness under a gentle stream of nitrogen gas, and then melamine and triazine-related by-products were derivatized using BSTFA with 1% TMCS. The derivatives of melamine and its analogues were determined by gas chromatography/tandem mass spectrometry using multiple reactional monitoring （MRM） with 2, 6-Diamino-4-chloropyrimidine （DACP） being used as an internal standard. Results The linear detectable ranges were from 0.004 mg/kg to 1.6 mg/kg for melamine, ammelide, ammeline, and cyanuric acid with a correlation coefficient no less than 0.999. The recovery rates of the tour compounds in spiked blank milk powder at concentrations 0.5, 1, 2 mg/kg were between 61.4%-117.2%, and the relative standard deviation was no more than 11.5% （n=6）. The detection limits of melamine, ammelide, ammeline and cyanuric acid in milk powder were 0.002 mg/kg with a ratio of signal to noise of 3. Conclusion This GC-MS/MS method for simultaneous determination of melamine, ammelide, ammeline, and cyanuric acid in milk and milk products is sensitive and specific.

Novel metabolic and physiological functions of branched chain amino acids: a review

It is widely known that branched chain amino acids（BCAA） are not only elementary components for building muscle tissue but also participate in increasing protein synthesis in animals and humans. BCAA（isoleucine, leucine and valine） regulate many key signaling pathways, the most classic of which is the activation of the m TOR signaling pathway. This signaling pathway connects many diverse physiological and metabolic roles. Recent years have witnessed many striking developments in determining the novel functions of BCAA including：（1） Insufficient or excessive levels of BCAA in the diet enhances lipolysis.（2） BCAA, especially isoleucine, play a major role in enhancing glucose consumption and utilization by up-regulating intestinal and muscular glucose transporters.（3）Supplementation of leucine in the diet enhances meat quality in finishing pigs.（4） BCAA are beneficial for mammary health, milk quality and embryo growth.（5） BCAA enhance intestinal development, intestinal amino acid transportation and mucin production.（6） BCAA participate in up-regulating innate and adaptive immune responses.In addition, abnormally elevated BCAA levels in the blood（decreased BCAA catabolism） are a good biomarker for the early detection of obesity, diabetes and other metabolic diseases. This review will provide some insights into these novel metabolic and physiological functions of BCAA.

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.

Role of miRNA in Mammary Gland Development and Lactation

miRNA can regulate development and milk yield of the mammary gland through epigenetic mechanism, miRNA can directly and indirectly modulate the activity of the epigenetic machinery, target genes through post-inhibition of translation initiation, mediate miRNA decay, target genes and inhibit the positive regulation, regulate tone modification, and regulate DNA methylation of target genes. Here we reviewed the role of miRNAs in mammary gland development and lactation. Researching miRNA in mammary gland development and lactation process, and understanding the response of the epigenetic mechanisms to external stimuli will be an important necessity to devise new technologies for maximizing their activity and milk production in the dairy cow.

Performance and plasma concentration of metabolites in transition dairy cows supplemented with vitamin E and fat

The objective of this study was to evaluate the effects of vitamin E（VE; 1 500 or 3 000 international units（IU） d^（-1）） and fat（2% of dry matter calcium salt of soybean oil） supplementation during the transition period on feed intake, milk yield and composition and blood metabolites of dairy cows. 48 multiparous Holstein cows were randomly assigned into one of four treatments in a 2×2 factorial arrangement of vitamin E and supplemental dietary fat during the transition period. Treatments were： 1） 1 500 IU d^（-1） vitamin E without fat supplementation（1 500VE-F）; 2） 1 500 IU d^（-1） vitamin E with fat supplement（1 500VE＋F）; 3） 3 000 IU d^（-1） vitamin E without fat supplementation（3 000VE-F）; and 4） 3 000 IU d^（-1） vitamin E with fat supplement（3 000VE＋F）. Dietary treatments were initiated at approximately 28 d before expected calving dates and continued through 28 d postpartum. Dry matter intake（DMI） was unaffected（P〉0.05） by prepartum treatment. Regardless of vitamin E supplementation, DMI was greater（P〈0.01） in fat-supplemented cows compared with un-supplemented cows（19.60 vs. 18.45 kg d^（-1）; SEM=0.42） during the postpartum period. Energy balance and body weight were not affected（P〉0.05） by treatments. Postpartum diets had no significant effect on milk yield or milk composition. Plasma concentrations of non-esterified fatty acids, glucose, and insulin were not affected（P〉0.05） by treatments. Regardless of vitamin E supplementation, plasma β-hydroxybutyrate concentration was greater（P〈0.05） in fat-supplemented cows compared with un-supplemented cows during the postpartum period. These results showed no indication of positive effects on lactation performance associated with vitamin E and dietary fat supplement in transition cows.

Mammary stem cells:expansion and animal productivity

Identification and characterization of mammary stem cells and progenitor cells from dairy animals is important in the understanding of mammogenesis, tissue turnover, lactation persistency and regenerative therapy. It has been realized by many investigators that altered lactation, long dry periods （non-milking period between two consecutive lactation cycles）, abrupt cessation of lactation （common in water buffaloes） and disease conditions like mastitis, greatly reduce milk yield thus render huge financial losses within the dairy sector. Cellular manipulation of specialized cell types within the mammary gland, called mammary stem cells （MaSCs）/progenitor cells, might provide potential solutions to these problems and may improve milk production. In addition, MaSCs/progenitor cells could be used in regenerative therapy against tissue damage caused by mastitis. This review discusses methods of MaSC/progenitor cell manipulation and their mechanisms in bovine and caprine animals. Author believes that intervention of MaSCs/progenitor cells could lessen the huge financial losses to the dairy industry globally.

Fabrication and evaluation of a portable and reproducible quartz crystal microbalance immunochip for label-free detection ofβ-lactoglobulin allergen in milk products

In this study,a label-free,portable and reproducible immunochip based on quartz crystal microbalance(QCM)was developed for the qualitative detection ofβ-lactoglobulin(β-LG),an allergen,in milk products.Experimental parameters in the fabrication and regeneration procedure such as pH of the coupling microenvironment,amount of anti-β-LG antibody and regeneration reagent were optimized in detail.Under optimal conditions,the proposed QCM immunochip exhibited good recognition of β-LG,with a calibration curve of ΔF=12.877 C_(β-LG)^(0.4809)(R^(2)=0.9982)and limit of detection of 0.04μg/mL.Additionally,this portable QCM immunochip had good stability,high specificity,and no obvious cross-reaction to three other milk proteins(α-casein,α-lactalbumin,and lactoferrin).It could compete a qualitative measurement within5 min,and could be reused at least ten times.In the β-LG analysis of actual milk samples,the developed QCM immunochip yielded reliable and accurate results,which correlated strongly with those from the standard HPLC method(R^(2)=0.9969).Thus,the portable,stable,and reproducible QCM immunochip developed in this study allowed the rapid,cost-effectively and sensitively measure theβ-LG in milk products.

Effect of Different Roughages on Milk Protein and Milk Fat Synthesis in Dairy Cows

The main purpose of this study was to determine the effect of a corn straw or mixed diet on milk production, milk composition and the expression of genes associated with lactation in mid-lactation Chinese Holstein cows. In this study, 10 healthy Chinese Holstein cows were randomly assigned to two groups and fed with different diets respectively, corn straw （CS） or mixed forage （MF） diet. CS group was fed roughage consisting of 53.8% corn straw only and the forge to concentrate （F ： C） ratio [dry matter （DM）] was about 40： 60. MF group was fed roughage consisting of 3.7% Chinese wildrye and 23.4% alfalfa hay, the forge to concentrate （F ： C） ratio （DM） was 70： 30. All the cows were fed 8 weeks and body weight, dry matter intake, body condition score, fat, protein, lactose, milk yield, total solid and somatic cell count （SCC） were recorded. Quantitative real-time PCR （qRT-PCR） was used to analyze cow mammary gland samples representing two different diets. The results suggested that different diet types had significant effects on milk yield, lactose, milk fat, milk protein, dry matter intake and somatic cell count in dairy cows, and cows fed MF diet improved milk production and lactation performance clearly （P〈0.05）. In addition, mRNA expression of genes ACC, roTOR, STATS, CSN2, PPAR）,, FABP3 and PTEN in MF group was extremely significantly higher than that in CS group （P〈0.05）. mRNA expression ofAKT1, FAS, SCD and SREBPlc in MF group was significantly higher than that in CS group （P〈0.01）. In summary, the milk yield and composition in mixed forage group were significantly improved than those in corn straw group.

Appraisement on Contributive Ratio of Scientific and Technical Progresses in Milk Productive Enterprises by Model C^2GS^2

Scientific and technical progress has been the driving forces of enterprises development.Milk productive enterprises are developing faster and growing better.It is very important to measure the contributive ratio of scientific and technical progress in milk productive enterprises.And the appraisement could help to develop milk productive enterprises.The model C^2GS^2 was established to appraise the contributive ratio of scientific and technical progress in milk productive enterprises in the research.And the appraisement on the contributive ratio of scientific and technical progress in milk productive enterprises was made by the model.In the results of appraisement,science and technology play a main role in milk productive enterprises.It is shown that our milk productive enterprises are developed by scientific and technical progress while not by input of productive factors.

Dry Season Feeding Technologies: Assessing the Nutritional and Economic Benefits of Feeding Hay and Silage to Dairy Cattle in South-Western Uganda

South-western Uganda annually experiences prolonged drought that results in dramatic drop in milk production of dairy cattle. This study was conducted to assess the nutritional value and economic benefits of feeding silage and hay to dairy cattle in the sub-region. The cross-sectional study covered seven districts with 105 farmers interviewed during the wet and 45 others in the dry season. Up to 88 soil samples were collected and analyzed for soil texture, soil pH, organic matter and total Nitrogen, Phosphorus, Potassium, Calcium, Sodium and Magnesium. Likewise, 148 forage (105 fresh, 25 silage and 18 hay) tissues from 21 pasture species were collected and analyzed for nutritional values. Using a questionnaire, data on production costs and milk revenues were collected for cost-benefit analysis. Results showed that silage of Napier grass treated with molasses (10.2 MJ/kg) and hay of naturally established pastures (10.6 MJ/kg) had the highest metabolisable energy (ME) values, while the lowest (8.30 MJ/kg) was for star grass. Hay of star grass presented the highest level of crude protein (21.4%) with maize (corn) showing the lowest (9.38%). Digestibility of hay of naturally established mixed pastures was the highest (64.4%), followed by that of silage of Napier grass treated with molasses (62.0%), while star grass hay had the lowest (52.6%). With exception of silage made from maize, all the other six forms of silage had a good crude protein (CP) content. Regardless of the good CP content (≥9.9%), all silage untreated with additives was poor in quality since its ME was less than 9.9 MJ ME/kg and ration digestibility less than 67%. Nonetheless, feeding of silage and hay increased milk yield and farm productivity with a benefit-cost ratio of 5.5 and 2.7 for silage and hay respectively.

Nutrition Regulation of Dairy Cows based on Extruded Cottonseed Meal

[Objective]The paper was to study the effects of extruded cottonseed meal on the nutrition of dairy cows.[Method]Holstein cows were selected for feeding and milk production test.[Result]Extruded cottonseed meal could substitute soybean meal,and there was no significant difference in milk yield and butter-fat percentage.Extruded cottonseed meal could increase milk yield when substituting corn germ meal.In addition,the health of diary cow had not been affected.[Conclusion]Extruded cottonseed meal could guarantee protein nutrition,increase milk yield,reduce feed cost and improve economic benefit of dairy cows when substituting soybean meal and corn germ meal.

<i>Aflatoxin</i>M1 (<i>Aspergillus parasiticus, flavus</i>) Occurrences in Milk and Milk Products and Its Possible Health Effects

Aflatoxin M1 (AFM1) occurrence in milk and milk products has been a major concern among food scientists over the past three decades owing to its possible health risk in humans. The well-documented AFM1 associated adverse health outcomes include hepatocarcinogens, mutagens genotoxins, mutagenicity, and teratogen. The paper reviews the occurrence of AFM1 in milk, milk products, and human milk in developing and developed countries, with its safety standards of regulation. The health associated risks with AFM1 are the important methods used in detecting and reducing AFM1 in milk and other milk products are presented.