A large-scale dairy farm in China suffered an annual profit loss of up to 8 million RMB due to neglect of key reproductive indicators.This case highlights that reproductive efficiency has become a decisive factor affecting the economic benefits and sustainable development of dairy farms under intensive farming systems.This study focused on reproductive data from large-scale farms,systematically analyzing the calculation methods,influencing factors,and improvement strategies for key indicators such as 21-day pregnancy rate,breeding rate,conception rate,and 150-day non-pregnancy rate.Using real production data, practical application approaches are illustrated,and comprehensive improvement plans are proposed,including calibration of management software parameters,enhancing timeliness of estrus detection and pregnancy diagnosis,and optimizing synchronization protocols.The results showed that through in-depth interpretation and precise application of reproductive data,farms can fully grasp the reproductive status of the herd,significantly improve expansion efficiency,accelerate genetic progress,and optimize production benefits.Efficient management of reproductive data serves as a critical foundation for achieving refined operations and maximizing economic benefits in large-scale dairy farms.

Heat stress exerts significant negative impacts on the production performance, reproductive function, and immune system of dairy cows, leading to a 15%~20% decrease in milk yield, a 25%~35% reduction in conception rate, and various health disorders. This paper systematically elaborated the mechanisms through which heat stress affects dairy cows, with a focus on the scientific application strategies of reproductive hormones （such as GnRH and progesterone）, glucocorticoids （such as dexamethasone）, and melatonin in alleviating heat stress. Practical cases from dairy farms in both northern and southern regions demonstrate the effectiveness of hormonal regulation in enhancing stress resistance,improving reproductive efficiency, and restoring production performance. The study emphasized that hormone use should adhere to the principles of short-term and low-dose application, combined with comprehensive measures such as physical cooling and nutritional adjustments, to ensure dairy product safety and farming profitability. This paper provides a theoretical basis and practical guidance for dairy farms to mitigate heat stress.

Heat stress is a critical environmental factor affecting the reproductive performance of dairy cows,leading to endocrine disorders,impaired ovarian and uterine functions,abnormal estrus behaviors,and significantly reduced conception rates and reproductive efficiency. This paper systematically elaborated on the physiological impacts of heat stress on the reproductive system of dairy cows,with a focus on regulatory strategies involving reproductive hormones（such as GnRH,progesterone,FSH/LH,and PGF2α）. These strategies include the optimization of hormone administration protocols,dosage adjustments,and their synergistic application with comprehensive management measures such as environmental control,nutritional support,and precision monitoring. Practical evidence demonstrates that scientifically applied hormonal interventions,combined with integrated management,can effectively enhance the reproductive performance of dairy cows under heat stress conditions.

Estrus synchronization technology in dairy cows is a core method for modern dairy farms to enhance reproductive efficiency and economic benefits. By employing hormonal regulation and precise management, this technology concentrates the estrous cycle of dairy cows within the "golden breeding period" of 50~80 days postpartum, effectively reducing days open, improving conception rates, and minimizing the risk of missed breeding. This paper systematically elaborated on the stratified implementation of estrus synchronization technology on dairy farms, including treatment strategies for different groups such as postpartum unbred cows, open cows, heifers, and adult cows. It also analyzed key influencing factors such as animal mixing, headlock utilization, effectiveness of drug administration, and estrus detection. Furthermore, a data supervision system centered on the "TAI proportion" is proposed to promote the transition from experience-based management to data-driven decision-making, providing practical guidance for improving reproductive management on dairy farms.

With socio-economic development, working capital management has become an increasingly important component of financial management theory. In the face of ongoing market changes and intense competition, sound working capital management is essential for the stable operation and long-term development of enterprises.Therefore,companies need to strengthen their working capital management. Due to their specific characteristics,dairy enterprises often require large-scale working capital to support production,making it even more critical for them to enhance their working capital management capabilities.This paper took Manor Ranch as the research object and analyzed the effectiveness of its working capital management based on channel theory,aiming to propose suitable improvement strategies for corporate working capital management.

Bovine staphylococcal mastitis is primarily caused by Staphylococcus aureus and non-aureus staphylococci.S. aureus is the most common pathogenic bacterium responsible for mastitis,capable of inducing acute or chronic infections in the mammary gland through its virulence factors,leading to reduced milk production and elevated somatic cell counts in milk. Although non-aureus staphylococcal strains are generally considered minor pathogens,they can also cause subclinical mastitis in dairy cows and impair milk quality.Staphylococci evade the host's immune defenses through various mechanisms,including biofilm formation,intracellular survival,and the production of immune evasion factors. Additionally,by inducing autophagy and altering cell wall structures,staphylococci enhance their persistence and pathogenicity within the host.The host immune response involves the coordinated action of innate and adaptive immunity, with neutrophils and macrophages playing a critical role in early immune defense,while antibodies and cell-mediated immune responses contribute to infection clearance. This review aimed to analyze the pathogenic and defensive mechanisms of bovine staphylococcal mastitis,providing new insights for disease prevention and treatment.

[Objective] This study aimed to investigate the preventive and therapeutic effects of Chinese herbal medicine extract （CHME） on subclinical mastitis in dairy cows.[Method] Twenty-four dairy cows with subclinical mastitis were randomly divided into four groups.The control group received a standard diet,while the three treatment groups were supplemented with CHME at 20 g/d,40 g/d,and 80 g/d,respectively.Milk yield,milk composition （including lactose percentage,protein percentage,and somatic cell count）, and the levels of key biomarkers were recorded. These biomarkers included myeloperoxidase（MPO）,lactate dehydrogenase（LDH）,glutathione peroxidase （GPX）,superoxide dismutase （SOD）,catalase（CAT）, malondialdehyde （MDA）,interleukin-6 （IL-6）,interleukin-1β （IL-1β）,and tumor necrosis factor-α （TNF-α）.[Result] Cows supplemented with 40 g/d and 80 g/d of CHME exhibited a significant increase in milk yield,lactose percentage,and protein percentage,along with a significant reduction in somatic cell count. Concurrently,the levels of MPO and LDH decreased.Furthermore,the activities of the antioxidant enzymes GPX,SOD,and CAT were enhanced,while MDA content decreased. The expression of the pro-inflammatory cytokines IL-6,IL-1β,and TNF-α was significantly suppressed.[Conclusion] Chinese herbal medicine extract effectively improved milk yield and quality in cows with subclinical mastitis.It regulated the levels of active enzymes in milk,enhanced antioxidant capacity,and inhibited the expression of inflammatory cytokines,demonstrating good preventive and therapeutic effects.

[Objective] In order to find out the etiology and pathogen resistance of diarrhea calves in a large-scale dairy farm in Shandong Province,the pathogenic identification and drug resistance analysis were carried out. [Method] A total of 18 samples of mesenteric,lung,spleen and other tissues of dead calves were collected aseptically and put into sampling bags. Through bacterial isolation and culture and biochemical test,bacterial 16 S rRNA was amplified by PCR and toxin typing was identified. The K-B agar diffusion paper method was used to test the drug resistance of the isolated strains,and 14 drug resistance genes were detected by PCR electrophoresis. [Result] The results showed that 5 strains of C.perfringens type C were detected,and the detection rate was 27.8%. The isolated bacteria showed resistance to a variety of antibiotics,and β-lactams,aminoglycosides,sulfonamides and chloramphenicol resistance genes were detected. [Conclusion] The results showed that C.perfringens type C was the pathogenic bacteria causing diarrhea in calves on dairy farms,and it was resistant to some antibiotics. The results of this study provide a reference for the prevention and control of Clostridium perfringens in dairy farms.

In modern intensive dairy farming,disease prevention and animal welfare management directly impact farm profitability. The rational use of anti-inflammatory drugs can effectively alleviate pain,control inflammatory responses,and significantly improve animal welfare and production performance. This study integrated the latest domestic and international research findings,supported by empirical data from Hebei Leyuan Jiasi Farm,to explore the critical role of anti-inflammatory drugs in calf dehorning. The results demonstrated that administering meloxicam （a highly selective COX-2 inhibitor） post-dehorning significantly reduces pain scores （by over 30%）,increases average daily weight gain by 10%~15%,and shortens wound healing time by 2~3 days. Compared to traditional non-steroidal anti-inflammatory drugs（NSAIDs）,meloxicam exhibits advantages such as fewer gastrointestinal side effects and lower drug residues,making it more suitable for calves. Additionally,this study proposed optimized dehorning techniques and improved feeding management practices,providing a systematic approach for the scientific use of anti-inflammatory drugs on farms. The research confirms that standardized application of anti-inflammatory drugs can simultaneously enhance animal welfare and economic benefits,offering significant implications for advancing high-quality development in China's dairy farming industry.

Mastitis is a common disease affecting dairy cows globally,primarily caused by Staphylococcus aureus,and is typically treated with antimicrobial drugs administered via intramammary and intramuscular injections.However,with the increasing rise of antimicrobial resistance,the treatment faces greater challenges and the available therapeutic options are gradually diminishing.The formation of biofilms formation and the adhesion of pathogens to mammary epithelial cells complicate treatment further.This paper discusseed factors such as the rise in antimicrobial resistance,biofilm formation,and intracellular bacterial survival,analyzing the challenges of conventional antibiotic treatment for mastitis.Additionally,it introduces alternative therapeutic approaches,including phytochemicals,antimicrobial peptides,bacteriophage therapy,and graphene-based nanomaterials,which may address the shortcomings of current antimicrobial treatments and mitigate the threat of antimicrobial resistance to mastitis treatment.This paper aimed to explore emerging alternative approaches in the treatment of mastitis,with the goal of providing robust support for future clinical therapies.

[Objective] Somatic cells are a core component of the dairy cow mammary gland immune system,and their quantity variation serves as a key indicator for assessing cow health status and raw milk quality. [Method] Based on the performance test data from a dairy farm in Tianjin between January 2024 and March 2025,this study systematically analyzed the correlation patterns between somatic cell count（SCC）and factors such as lactation stage,parity,and season. [Result] The somatic cell count showed a significant upward trend with increasing cow parity,with the proportion of cows in their third parity or higher exceeding 500 000/mL reaching 46.2%. The mean SCC during late lactation（121~150 days,296 000/mL）was significantly higher than during early lactation （within 30 days,192,000/mL）.Summer SCC（e.g.,reaching 410 000/mL in August 2024）was 10%~30% higher than in spring and autumn,and high SCC exhibited a significant negative correlation with milk yield（t-test,p=0.0024<0.05）.[Conclusion] This study,in conjunction with international and domestic SCC limit standards,thoroughly examines the causes and hazards of high SCC and proposes a multidimensional comprehensive prevention strategy encompassing disease control,environmental optimization,feeding management,and milking protocols. The findings provided technical support for improving raw milk quality and dairy cow health.

[Objective] To investigate the changes in progesterone and milk composition traits in dual-purpose cattle during estrus, reveal their regulatory mechanisms, and provide a scientific basis for optimizing breeding management.[Method] Sixty-five healthy dual-purpose cattle were selected. Progesterone concentrations during the estrous cycle were measured using enzyme-linked immunosorbent assay （ELISA）,while milk fat rate,milk protein rate, and lactose content were determined with a fully automatic milk composition analyzer.The associations between progesterone and milk components were analyzed via linear mixed models （LMMs）, multiple regression, and analysis of covariance （ANCOVA）, with parity and lactation stage evaluated as regulatory factors.[Result] Progesterone exhibited significant dynamic changes during estrus, peaking at 48 hours pre-estrus and sharply declining on the day of estrus. Milk fat and protein rates fluctuated synchronously, showing strong positive correlations with progesterone （r>0.30,p< 0.05）.Lactose content varied minimally, with no significant association to progesterone （r < 0.1,p> 0.05）. The progesterone-milk fat correlation was 23.60% higher in second-parity cows than in multiparous cows, with the strongest correlation observed during mid-lactation（r=0.42,p< 0.01）.[Conclusion] Progesterone significantly influences milk fat and protein synthesis by regulating mammary gland metabolic activity, with effects modulated by parity and lactation stage. These findings provided a critical time window and scientific basis for targeted nutritional interventions and reproductive management.

[Objective] Develop a technology for the precise detection of nitroimidazole drug residues in goat milk using ultra-performance liquid chromatography-tandem mass spectrometry （UHPLC-MS/MS）,including metronidazole,dimetridazole,ronidazole and tinidazole,etc.[Method] The Goat milk samples were extracted with acetonitrile and citric acid buffer solution,and then purified by MCX cation exchange solid-phase extraction column and PEP-2 polymer solid-phase extraction column.After the nitrogen purge eluent was nearly dry,it was made up to 1 mL with a water-methanol containing 0.1% formic acid, and eluted gradually with 0.1% formic acid aqueous solution and acetonitrile in the flow phase. Chromatographic separation was accomplished on a BEH C18 column（2.1 mm×100 mm,1.7 μm chromatographic column） . The mass spectrometer conducted real-time detection through the positive ion multiple reaction monitoring（MRM）mode and completed quantitative analysis by external standard method combined with the matrix-matched standard curve.[Result] Within the concentration range of 1~80 ng/mL,the four nitroimidazole drugs had a good linearity,with correlation coefficients（r）were all greater than 0.998.The average recovery rate was 83.2%~106.8% at three spiked levels（1.0 μg/kg,2.0 μg/kg and 10.0 μg/kg）,the relative standard deviation（RSD）was 1.8%~20.1%.The detection limit of the method 1 μg/kg.[Conclusion] This method is simple to operate,sensitive and accurate,and is suitable for the detection of nitroimidazole drugs（metronidazole,tinidazole,dimedinidazole,ronidazole） residues in goat milk.

[Objective] As a nutritious daily food,the safety and quality of milk is highly concerned.Quinolone drugs are widely used in the prevention and treatment of diseases in dairy cows due to their broad-spectrum antibacterial properties and low cost.However,irrational use may lead to its residues in milk,which poses potential threats to human health.The existing detection methods have problems such as complicated sample processing steps,limited detection items,and multiple detection interferences,which cannot meet the needs of efficient and accurate detection of multiple quinolone drugs in milk.Therefore,a high performance liquid chromatography-tandem mass spectrometry method was established to simultaneously detect the residues of 17 quinolone drugs,providing strong technical support for ensuring the safety and quality of milk.[Method] Quinolone drugs in the sample were extracted with acetonitrile and phosphate buffer,purified by HLB solid phase extraction column,eluted with 5% ammoniated methanol,separated by C18 chromatographic column with methanol-formic acid aqueous solution as the mobile phase. The mass spectrometry using electrospray positive ion mode（ESI+） and multiple reaction monitoring（MRM）. Detection was carried out using UPLC-MS（Waters UPLC-TQD）,and quantification was performed using the external standard method to enhance repeatability.[Result] All 17 quinolone drugs elminated within 6 minutes with good peak shapes,and the detection limit range of the method was 0.005~0.228 μg/kg,the quantitation limit range was 0.017~0.759 μg/kg,the recovery rate of the sample spiked was 60.0%~118.0%,and the RSD was 1.4%~19.9%. It meets the requirements of 4.1.5 and 4.1.6 in the“GB 5009.295—2023 National Food Safety Standard - General Rules for Validation of Chemical Analysis Methods”.[Conclusion] This method is easy to operate,has good stablility and high accuracy.It is suitable for the detection of 17 quinolone drugs residues in milk.

[Objective] To deeply explore the differences in coagulation performance among animal-derived,plant-derived and microbial-derived chymosin during the production of Halloumi cheese.[Method] By adding different types of chymosin respectively in the production of Halloumi cheese,the proteolytic activity,yield,texture characteristics,volatile flavor substances,conventional physicochemical indicators and free fatty acid content of the obtained products were comprehensively analyzed.[Result] Animal-derived chymosin exhibited the lowest proteolytic activity and the highest yield.Halloumi cheese produced under the action of animal-derived chymosin performed better in the retention of fat and protein.In the analysis of texture characteristics,the hardness,chewiness and adhesiveness of this Halloumi cheese were all at a moderate level.In addition,the total amount of free fatty acids in Halloumi cheeses produced from animal-derived chymosin was the highest,followed by plant-derived chymosin,and the lowest from microbial-derived chymosin .A total of 22 flavor substances were detected in Halloumi cheeses made from three types of chymosin,among which the flavor substances in Halloumi cheese made from microbial-derived chymosin were the most diverse.[Conclusion] Halloumi cheeses processed from different types of chymosin exhibited their own characteristics in terms of flavor substances.This study revealed the unique role of animal-derived chymosin in the production of Halloumi cheese,and microbial-derived chymosin was expected to replace animal-derived chymosin.The experimental results could provide a theoretical basis for the application of different types of chymosin.

[Objective] To study the changes of α-lactalbumin and β-lactoglobulin Contents in long-shelf-life fresh milk at different storage temperatures.[Method] 3 batches of long-shelf-life fresh milk were stored at 4 ℃ and 10 ℃ respectively,and the contents of α-lactalbumin and β-lactoglobulin were detected regularly.3 batches of long-shelf-life fresh milk were stored at 25 ℃ and 4 ℃ respectively for 18 days and then transferred to 25 ℃ for storage,and the sensory changes were observed regularly.[Result] The content of α-lactalbumin in 3 batches of long-shelf-life fresh milk fluctuated at 4 ℃ and 10 ℃,but there was no obvious changing trend.The content of β-lactoglobulin in 3 batches of long-shelf-life fresh milk generally showed an downward trend at 4 ℃ and 10 ℃. 3 batches of long-shelf-life fresh milk were stored at 25 ℃ for 24 hours without any sensory issues,but by 36 hours, they had clumped and were inedible. 3 batches of long-shelf-life fresh milk had normal sensory after being stored at 4 ℃ for 18 days,but they had clumped and were nedible after being stored at 25 ℃ for 36 hours.[Conclusion] After purchasing long-shelf-life fresh milk ,consumers should store it at low temperature. Once the storage temperature exceeds 25 ℃,it is recommended to finish drinking it within 24 hours.

[Objective] This paper reviewed the detection methods of cholesterol content in milk and dairy products.[Method] In accordance with the second method of “GB 5009.128—2016 National Food Safety Standard - Determination of Cholesterol in Foods”,the test operation was carried out based on high performance liquid chromatography to detect the cholesterol content in different milk and dairy samples.[Result] The average cholesterol content was the lowest in pure milk（5.32 mg/100 g）,the highest in ice cream（11.57 mg/100 g）,and the 10.56 mg/100 g and 8.67 mg/100 g in yogurt and cheese respectively. The quantitative detection limit of measured cholesterol content was 2.6 mg/100 g,and the recovery rate were all between 80% and 120%.[Conclusion] The test results had certain reference value for residents（especially those with chronic diseases such as cardiovascular diseases） in their daily choice of dairy products,and could provide some reference for improving the health level of residents. This research method has a promising application prospect in the food industry and could provide a theoretical basis for the improvement and innovation of future detection technologies.

With the rapid development of technologies such as big data and artificial intelligence,along with the widespread use of internet applications,personal information faces increasingly severe security risks during large-scale collection and utilization. The dairy industry,especially in areas such as infant formula,involves a vast amount of consumer personal information （e.g.,identity,health status,consumption habits）and has become a high-risk field for information leakage and misuse. This not only infringes upon consumers’privacy rights but may also lead to criminal activities. As the last line of defense for safeguarding citizens’rights and interests,criminal law plays a crucial role in personal information protection. This paper took the dairy industry as the research object,analyzed the criminal law risks and regulatory gaps in its personal information processing,and proposed improvement paths from technical,legal,and corporate self-regulation perspectives to strengthen the criminal law protection mechanism for personal information in this industry.