In recent decades, Blanket Dry Cow Therapy (BDCT) has been regarded as a cornerstone strategy for the control of mastitis in dairy cows during the dry period. However, concerns regarding the rising incidence of antibiotic resistance and the associated zoonotic risks have prompted a paradigm shift, leading to intensified research into alternative management approaches. In response, many countries have adopted a more targeted approach, known as Selective Dry Cow Therapy (SDCT), which focuses on the therapeutic use of antibiotics, administered only to cows or quarters that are either infected or at high risk of infection during the dry period. This review provides a comprehensive synthesis of the scientific literature regarding the main methods for selecting animals for SDCT, the impact of this strategy on udder health, milk production, farm economics, and antibiotic consumption, as well as the factors that may influence its effectiveness. Over time, a range of methods have been developed to identify infected animals, including bacteriological culture, somatic cell count (SCC), differential somatic cell count (DSCC), and the California Mastitis Test (CMT), which are often used alone or in combination with clinical mastitis history and/or parity. Among these methods, SCC has proven to be the most economically viable and best suited for practical use, while its combination with DSCC has been shown to significantly enhance diagnostic accuracy. According to the studies reviewed, SDCT is a safe and effective strategy for maintaining udder health and farm profitability, as long as infected cows are accurately identified, and internal teat sealants are used in quarters not treated with antibiotics during the dry period. However, since udder health is influenced by herd characteristics, management practices, and regional pathogens, the findings cannot be universally applied and must be adapted to each herd’s specific conditions.

This study evaluated the biological and economic impact of twin calvings in a commercial dairy herd located in Harghita County, Romania. Data from 2019 to 2022 were analyzed retrospectively using production, reproductive, and veterinary records. The incidence of twin pregnancies averaged 11.0% across the study period. Mixed-sex pairs were most frequent (55.3%), followed by female–female (28.2%) and male–male (16.5%) combinations. Twin calvings were associated with significant reductions in subsequent milk yield (−742 kg per lactation; p < 0.05), decreased fertility (2.3 vs. 1.4 inseminations; 103 vs. 79 days service period; p < 0.05), and higher veterinary costs (EUR 90 per case). The expected loss of replacement value due to freemartinism was EUR 63 per twin calving. After accounting for a small gain in calf value, the total economic loss was estimated at EUR 379 per twin calving. These findings demonstrate that twin pregnancies, although relatively uncommon, substantially reduce productive efficiency and profitability in dairy systems. Early detection and targeted reproductive management are recommended to mitigate their adverse effects and enhance farm sustainability.

Selective dry cow therapy (SDCT) has emerged as a key strategy to reduce antimicrobial use in dairy production while maintaining udder health. This study aimed to evaluate the feasibility and impact of implementing SDCT in Romanian dairy farms by comparing low-risk cows treated with internal teat sealant only (ITS) at dry-off with low-risk cows treated with intramammary antibiotics at dry-off. A prospective field study was conducted on two commercial dairy herds, including 87 cows classified based on somatic cell count (SCC) and differential SCC (DSCC), and compared with a historical cohort of 37 cows. Udder health parameters, milk yield during the first 100 days in milk (DIM), antimicrobial use, and economic outcomes were evaluated. No significant differences were observed between groups in terms of postpartum intramammary infections, somatic cell score, DSCC, or clinical mastitis incidence. Milk yield during early lactation was also not affected by treatment. The ITS-only strategy resulted in a substantial reduction in antimicrobial use (−88.8% per cow) without significant differences in total economic costs. Farm-related differences highlighted the influence of management conditions on outcomes. These findings indicate that, in low-risk cows, SDCT using ITS alone is a safe and effective alternative to antibiotic treatment and support the feasibility of implementing SDCT under Romanian dairy production conditions as a sustainable strategy to promote the targeted and prudent use of antimicrobials while reducing unnecessary antibiotic exposure in dairy herds. However, given the limited number of herds and animals included, further studies are needed to confirm these promising findings under a broader range of production conditions.

Reproductive efficiency is a critical determinant of productivity and profitability in both dairy and beef cattle systems. Progesterone-based estrus synchronization protocols have emerged as essential tools to control the timing of ovulation, enhance artificial insemination efficiency, and optimize herd reproductive performance. These protocols exploit the physiological regulation of the hypothalamic–pituitary–ovarian axis, maintaining elevated progesterone levels to suppress ovulation and coordinating luteolysis and follicular wave emergence through prostaglandins, GnRH analogues, and, in some cases, equine chorionic gonadotropin. In beef cattle, progesterone supplementation facilitates fixed-time artificial insemination, shortens calving intervals, and improves calf crop uniformity, whereas in dairy cows it mitigates poor estrus detection, enhances service rates, and reduces days open. Fertility outcomes are influenced by cow physiological status, metabolic condition, and protocol adherence, with pregnancy per AI typically ranging from moderate to high in beef cattle and lower in lactating dairy cows. Economic evaluation indicates that these protocols are cost-effective in herds with moderate to large size, low estrus detection efficiency, and intensive management, although labor, drug costs, and handling requirements must be considered. Critical analysis suggests that synchronization cannot compensate for underlying nutritional, health, or metabolic deficiencies, and future research should focus on precision application, individualized protocols, and integration with automated reproductive monitoring to improve both biological and economic efficiency. This review summarizes physiological principles, protocol designs, practical applications, fertility outcomes, and economic considerations of progesterone-based estrus synchronization in cows, highlighting current challenges and perspectives for enhanced reproductive management.

Reducing antimicrobial use in dairy cattle is essential for limiting antimicrobial resistance while maintaining udder health. Selective dry cow therapy (SDCT), in which antibiotics are administered only to cows at increased risk of intramammary infection, has become an important antimicrobial stewardship strategy, yet information regarding its acceptance in Romania is lacking. This cross-sectional study evaluated the knowledge, perceptions, and acceptance of antimicrobial resistance and SDCT among Romanian dairy farmers and veterinarians using an online questionnaire completed by 132 respondents. The questionnaire assessed current dry-off practices, awareness of antimicrobial resistance and selective dry cow therapy, previous implementation, perceived barriers and facilitators, and willingness to adopt or recommend selective dry cow therapy. Overall, 70.5% of farmers had previously heard of antimicrobial resistance, whereas only 27.9% were familiar with the formal concept of SDCT. Administration of antibiotics only to selected cows at dry-off was already the most commonly reported practice among farmers (41.0%) and veterinarians (47.9%), indicating that selective antibiotic use was already being applied despite limited familiarity with the formal SDCT concept. After receiving standardized information describing the strategy, most respondents expressed favorable attitudes and willingness to implement or recommend selective dry cow therapy. Lack of knowledge, limited availability of herd-level diagnostic information, and concerns regarding mastitis were identified as the principal barriers to implementation. Multivariable analysis demonstrated that concern regarding antimicrobial resistance was the only independent predictor of SDCT acceptance among farmers. These findings suggest that strengthening antimicrobial stewardship education, veterinary guidance, standardized protocols, and access to diagnostic tools may facilitate wider adoption of selective dry cow therapy in Romania.

Semen preservation represents a fundamental component of reproductive biotechnology in small ruminants, supporting artificial insemination programs, genetic improvement, germplasm conservation, and sustainable livestock production. However, ram and buck spermatozoa are highly susceptible to cryoinjury induced by cold shock, oxidative stress, osmotic imbalance, and membrane destabilization during cooling, freezing, and thawing procedures. Consequently, semen extenders play a critical role in maintaining sperm viability, motility, membrane integrity, mitochondrial activity, and fertilizing capacity during preservation. This narrative review summarizes the biological basis of sperm preservation in sheep and goats and discusses the principal conventional and emerging extender systems used in small ruminant semen cryopreservation. Conventional extender components, including buffering systems, energy substrates, cryoprotective agents, egg yolk, and milk proteins, are reviewed with emphasis on their mechanisms of action and protective effects against cryodamage. Particular attention is given to species-specific limitations associated with buck seminal plasma enzymes and their interactions with egg yolk- and milk-based extenders. In addition, recent advances involving chemically defined extenders, soy lecithin formulations, antioxidants, synthetic membrane stabilizers, and nanotechnology-derived additives are discussed as promising alternatives aimed at improving cryosurvival, reducing oxidative stress, and enhancing extender standardization and biosafety. Practical applications of semen extenders in artificial insemination and semen banking are also discussed together with current methodological limitations, species-specific challenges, and future research priorities. Although numerous emerging strategies have demonstrated promising improvements in laboratory sperm-quality parameters, evidence supporting consistent fertility benefits under field conditions remains limited. Overall, this review critically evaluates current knowledge and highlights the need for species-specific, protocol-oriented, and well-standardized approaches to advance semen preservation in small ruminants.