[Objective] In order to understand the distribution of Staphylococcus aureus（S.aureus） and its drug resistance genes from dairy goat mastitis. [Method] 178 milk samples were collected from some dairy goat farms in Liaocheng city,Shandong Province,and S.aureus was isolated and identified by bacterial culture,plasma coagulase test and PCR biological technology,and the drug resistance of the isolated strains was further analyzed. [Result] 23 strains of S.aureus were identified,and the detection rate was 12.92%.The results of drug sensitivity test showed that the isolated strains were resistant to penicillin,doxycycline,streptomycin,clarithromycin and tetracycline.PCR detection of drug resistance genes showed that 10 kinds of drug resistance genes were detected,including β-lactam drug resistance gene mecA,macrolide drug resistance genes ermA,ermB,ermC,tetracycline drug resistance gene tet,aminoglycoside drug resistance genes AAC（6'）-1A,APH（2''）-1B,ant（4',4''）.β-lactam resistance gene mecA, macrolide resistance genes ermA, ermB, ermC, tetracycline resistance gene tet, aminoglycoside resistance genes aac（6'）-Ⅰa, aph（2''）-Ⅰb, ant（4',4''）, aph（3'）-III, and sulfonamide resistance gene sul1 had average carriage rates of 30.43%, 31.88%, 43.48%, 21.73%, and 8.70%, respectively.All strains carried at least 2 kinds of drug resistance genes and up to 7 kinds of drug resistance genes,with the largest number of strains carrying 4~5 kinds of drug resistance genes. [Conclusion] The results suggested that there was a risk of S.aureus epidemic transmission in Liaocheng city dairy goat farms,Shandong Province,and the strains showed different degrees of drug resistance,and the drug resistance gene carrying rate was high,which should be paid attention to and strengthened monitoring and prevention.

[Objective] The contents of benzoic acid and sorbic acid in liquid milk were determined by optimizing the liquid chromatography method in the first step of “GB 5009.28-2016 National Food Safety Standard - Determination of Benzoic Acid, Sorbic Acid and Sodium Saccharin in Foods”,and the extraction effect of the optimized method was verified. [Method] The applicability of this optimized method was verified by monitoring the recovery rate detection,precision detection and repeatability detection,and the data was accumulated. [Result] The optimized method had a higher extraction effect,the precision meets the requirements,and the recovery rate was closer to the true value. [Conclusion] The optimized method was more adequate for the extraction of benzoic acid and sorbic acid.It could be used as anauxiliary in the daily detection of complex matrix samples.

[Objective] A new type of Arabica-flavored coffee beverage with stable quality was developed using fresh buffalo milk and cold-brew freeze-dried Arabica coffee powder as the primary ingredients,supplemented with erythritol,light cream and food additives as auxiliary ingredients. [Method] The optimal single-factor level was screened out through single-factor experiments. On this basis,orthogonal experiments and sensory evaluation methods were used to optimize the preparation process of Arabica-flavored buffalo milk coffee beverage,obtaining the best preparation process ratio. The optimal preparation process parameters were determined based on the mass of 100 g of the final product. [Result] The addition amount of fresh buffalo milk was 45.00%,cold-brew freeze-dried Arabica coffee powder was 0.55%,light cream was 1.70%,erythritol was 3.50%,food additives（mono- and diglycerides fatty acid esters,sodium stearoyl lactylate,sucrose fatty acid esters,carrageenan,sodium tripolyphosphate and potassium carbonate）was 0.20%,and edible salt was 0.03%.The Arabica-flavored buffalo milk coffee beverage had a rich and layered taste,with a mild acidity, saltiness and bitterness,and a mellow and smooth aftertaste.The texture remained stable during shelf life,providing a reference for the industrial production of Arabica-flavored buffalo milk coffee beverages. [Conclusion] Based on single-factor experiments,orthogonal experiments and sensory evaluation data,this study identified the key factors affecting the quality of Arabica-flavored buffalo milk coffee beverages and the preparation process parameters. The development and research of this product have expanded the variety of buffalo milk coffee beverages,and it has a broad and promising market prospects.

[Objective] To identify the main pathogenic bacteria causing clinical mastitis in dairy cows at a large-scale farm in Xinjiang and determine their antibiotic resistance profiles,providing a scientific basis for targeted prevention and control strategies. [Method] Aseptically collected milk samples from 15 cows with clinical mastitis were subjected to bacterial isolation and purification,morphological observation,physiological and biochemical identification,and 16S rRNA molecular characterization. The antibiotic susceptibility of the isolated strains was assessed using the Kirby-Bauer （K-B） disk diffusion method against 12 commonly used antibiotics. [Result] A total of 21 bacterial strains were isolated,including Escherichia coli （11 strains,52.38%）,Staphylococcus aureus （7 strains,33.33%）,and Streptococcus spp. （3 strains,14.28%）. Antibiotic susceptibility testing revealed that E. coli exhibited complete resistance to amoxicillin and clindamycin but moderate sensitivity to gentamicin and enrofloxacin. S. aureus was resistant to polymyxin but highly sensitive to most other antibiotics. Streptococcus spp. showed high sensitivity to tetracycline and enrofloxacin. Mixed bacterial susceptibility testing indicated that enrofloxacin,ofloxacin,and tetracycline were the most effective treatments. [Conclusion] Clinical mastitis in this farm was primarily caused by mixed infections of E. coli,S. aureus,and Streptococcus spp. The recommended treatment regimen includes enrofloxacin,ofloxacin,and tetracycline,complemented by comprehensive measures such as regular screening for subclinical mastitis,environmental management improvements,and strict disinfection protocols to effectively control the occurrence and spread of mastitis.

[Objective] This study investigated the effects of a compound probiotic preparation on milk production performance, rumen fermentation status, and serum metabolic parameters in dairy cows, aiming to provide a theoretical basis for improving production efficiency and health management. [Method] Sixty dairy cows with similar parity, milk yield, and body condition were randomly divided into four groups: a control group （Group A）,a low-dose group（Group B）,a medium-dose group（Group C）,and a high-dose group（Group D）.Group A received the basal diet, while Groups B,C,and D received the basal diet supplemented with 4 g/d, 8 g/d, and 16 g/d of the compound probiotic preparation, respectively.The trial lasted 42 days, during which milk yield, milk quality, rumen fermentation status, and serum parameters were monitored and analyzed. [Results] Cows in the medium-dose（C）and high-dose （D）groups showed significantly increased milk yield and improved milk quality. Rumen fermentation health was effectively improved. Serum glucose levels were regulated, and both Total Antioxidant Capacity （T-AOC） and Superoxide Dismutase （SOD） activity increased significantly. [Conclusion] The compound probiotic preparation significantly enhanced milk production performance, improved rumen fermentation status, and regulated metabolic health in dairy cows, demonstrating promising application potential.

[Objective] To meet the demand for rapid and accurate quantitative determination of lactoferrin content in a large number of samples during dairy processing a detection and correction model for lactoferrin content in milk was established by combining mid-infrared spectroscopy with chemometric. [Method] Taking 108 milk samples as the research objects,the lactoferrin content was measured by high performance liquid chromatography,and the spectral data of the milk samples were collected. To investigate the effects of preprocessing methods such as normalization first derivative second derivative standard normal variable transformation multiple scattering correction and wavelet transform on the prediction accuracy of partial least squares PLS quantitative model lactoferrin. [Result] The first derivative and the standard normal variable transformation were the optimal preprocessing methods for spectral data. The determination coefficient of the model correction set was 0.941 7, and the root mean square error of the correction was 1.142. The root mean square error of prediction was 1.187 which had good prediction ability. [Conclusion] The results of this study are of great significance for quality control and production efficiency optimization in dairy production proces.

The long-distance delivery and artificial insemination technology for fresh goat semen significantly enhances the breeding value and mating efficiency of elite male goats while effectively preventing the spread of diseases. From 2019 to 2024,Qianyang County promoted this technology across the region,led by the Saanen dairy goat breeding farm,by establishing a professional technical team and setting up 32 artificial insemination stations. Over five years,a total of 123 900 dairy goats were artificially inseminated,resulting in 118 000 successful pregnancies,with an overall conception rate exceeding 95%. This reduced the breeding stock of male goats by 90%,saving 9.86 million yuan in breeding costs. Additionally,196 300 kids were born during this period,generating an added output value of 47.11 million yuan. By innovating key techniques such as instrument sterilization,semen collection and testing,dilution and preservation,low-temperature long-distance delivery,and standardized insemination,the technology not only lowered breeding costs but also accelerated herd improvement,driving dual enhancements in both the quality and quantity of dairy goats in the county.

[Objective] This study investigated changes in milk production performance, milk composition traits, and reproductive hormones during estrus in dairy cows. [Method] Thirty-six healthy Holstein cows were selected. Milk yield, body temperature, milk fat, milk protein, lactose, and somatic cell count were recorded during the proestrus, estrus, and metestrus stages. Concurrently, changes in progesterone, estradiol, and prolactin levels were recorded. [Result] During the estrus phase, milk yield decreased, while milk fat and total solids content increased. Progesterone levels decreased, whereas estradiol and prolactin levels increased. [Conclusion] Significant changes in milk production performance and milk composition traits occurred during estrus, particularly the decreased milk yield and increased milk fat and total solids content. These findings indicated significant physiological fluctuations in cows during estrus. Furthermore, the changes in reproductive hormones were closely associated with these alterations in production performance, providing a basis for further optimization of dairy cow management practices.

This paper reviewed the effects of heat stress on dairy cow reproductive performance and corresponding countermeasures. Heat stress can lead to reduced conception and pregnancy rates,ovulation failure,increased risks of abortion and ovarian cysts,prolonged anestrus periods,decreased milk production,and cumulative damage. Its impact on reproduction includes weakened estrus activity and impaired oocyte and embryo development. To address these issues,measures such as embryo transfer （fresh embryo transfer in summer yields higher conception rates than artificial insemination）,ovulation synchronization techniques （improving conception rates）,reducing embryonic loss （e.g.,administering buserelin after breeding）,preventing and treating metritis （postpartum health protocols）,and managing ovarian disorders （e.g.,using Dinoprostone,buserelin,etc.） can be implemented. Additionally,comprehensive approaches such as heat stress mitigation and nutritional adjustments are essential to enhance dairy cow reproductive efficiency during heat stress.

[Objective] This experiment aimed to study the preventive and therapeutic effects of the new calcium supplement pills on postpartum hypocalcemia in dairy cows. [Method] Thirty-four healthy multiparous dairy cows of more than two litters were selected and randomly divided into two groups,with 17 cows in each group. The cows in the experimental group （EG group） were given the new calcium supplement pills,while the cows in the control group （CG group） were given the commonly used calcium supplement. Tail-root venous blood samples were collected at four time points （0 hours postpartum,2 hours after the first administration of calcium supplement,12 hours after the first administration of calcium supplement,and 2~4 hours after the second administration of calcium supplement） to determine the content of blood mineral elements,blood gas indicators,and blood biochemical indicators. The average milk production and the incidence of metabolic diseases within 30 days postpartum were also recorded. [Result] The results showed that：1）After administration of two calcium supplements,the postpartum blood ionic calcium （iCa） content of all dairy cows at the four time points increased. Moreover,after the two administration of calcium supplements in the EG group,the increase in blood calcium was significantly better than that in the CG group. 12 hours after the first administration,the iCa content in the EG group was significantly higher than that in the CG group （P<0.05）. Two - four hours after the second administration of calcium supplements,the contents of sodium ions （Na⁺） and potassium ions （K⁺） in the blood of all dairy cows were significantly higher than those at 0 hours postpartum （P<0.05）. 2） The blood acid-base balance index of dairy cows in the EG group was significantly higher than that in the CG group 12 hours after the first administration of calcium supplement （P<0.05）. The comparison results of blood gas indicators at different time points showed that 12 hours after the first administration of calcium supplement and 2~4 hours after the second administration of calcium supplement in the EG group of dairy cows,the blood acid-base balance index and bicarbonate （HCO₃^-） in the blood were significantly higher than those at 0 hours after delivery and 2 hours after the first administration of calcium supplement （P<0.05）. The total carbon dioxide （TCO₂） content in the blood of dairy cows in the EG group 12 hours after the first administration of calcium supplement and 2~4 hours after the second administration of calcium supplement was significantly higher than that in the EG group 0 hours after delivery （P<0.05）. 3） After postpartum administration of two calcium supplements to dairy cows,the contents of blood glucose （Glu）,hematocrit （Hct）,and hemoglobin （Hb） in both the EG group and the CG group showed a downward trend. Moreover,in the CG group,2~4 hours after the second administration of calcium supplements,the contents of hematocrit （Hct）,blood glucose（Glu）,and hemoglobin （Hb） were significantly lower than those at 0 hours postpartum （P<0.05）. 4） The average milk production of dairy cows in the EG group was significantly higher than that in the CG group （P<0.05）,and the incidence of postpartum diseases in EG dairy cows was lower than that in the CG group. [Conclusion] To sum up,postpartum administration of the new calcium supplement pills to dairy cows can rapidly increase blood calcium concentration and reduce the incidence of postpartum hypocalcemia. Compared with the postpartum calcium rods commonly used in domestic pastures at present,its effect of increasing blood calcium is more significant. This pill helps maintain electrolyte,acid-base balance and energy metabolism homeostasis,thereby reducing the negative impact of calving stress on the production performance of dairy cows and providing a new option for the management of perinatal hypocalcemia in dairy cows.