This study investigated the reproductive and economic costs of four estrus synchronization protocols in multiparous Holstein dairy cows: Ovsynch with one or two artificial inseminations (AIs), and Double Ovsynch with one or two AIs. A total of 216 clinically healthy cows were randomly assigned to one of the four treatment groups (n = 54 each). Pregnancy diagnosis was performed by transrectal ultrasonography at 33 days post insemination. Economic calculations included the cost of hormonal treatments, insemination, and pregnancy diagnosis, reflecting market prices in large scale Romanian dairy operations. The highest pregnancy rate (64.8%) and lowest cost per confirmed pregnancy (EUR 89.51) were achieved in the group treated with Double Ovsynch followed by a single AI. The standard Ovsynch protocol with one AI yielded the lowest conception rate (42.6%), indicating limited effectiveness under fixed-time AI conditions. These findings suggest that Double Ovsynch with a single insemination is the most effective and economically viable protocol for reproductive management in intensively managed dairy herds.

This study evaluated the microbiological quality, presence of virulence genes, and antimicrobial resistance of Staphylococcus aureus and Escherichia coli in sheep and goat milk and traditional Romanian dairy products (Telemea and Burduf cheeses). Raw milk contained high levels of coagulase-positive staphylococci (CPS; 5.2 log CFU/mL) and E. coli (4.3 log CFU/mL), with several samples exceeding legal limits. Sour cream exhibited moderate CPS (1.2–1.9 log CFU/g) and E. coli (0.4–3.12 log CFU/g) counts, with occasional non-compliance. Cheeses had low CPS (0.52–0.84 log CFU/g) and E. coli (0.37–0.89 log CFU/g) levels, all within permissible limits. Molecular analysis detected the nuc gene in 21 sheep milk samples, of which 85.7% also carried the sea gene and 14.3% carried seb. Additionally, two goat milk samples tested positive for both nuc and sea. Three Telemea cheese samples were also sea-positive. Among raw milk samples, 10 E. coli isolates carried stx1, and two additionally harbored hly, while dairy products were negative for E. coli virulence genes. Antimicrobial susceptibility testing showed high resistance of S. aureus to penicillin (90.5%) and ampicillin (85.7%), with multidrug resistance among sea- and seb-positive isolates. STEC isolates showed resistance to ampicillin (70%), tetracycline (50%), and trimethoprim–sulfamethoxazole (40%), but remained susceptible to amoxicillin–clavulanic acid.

Efficient reproductive management is essential for optimizing productivity and sustainability in sheep and goat production systems. Estrus synchronization (ES) has emerged as a pivotal tool for coordinating mating, enhancing fertility, facilitating artificial insemination (AI), and supporting out-of-season breeding. Hormonal protocols, including progesterone devices, prostaglandins, and gonadotropin or gonadoliberine treatments, provide the highest precision in estrus and ovulation timing, with estrus response rates exceeding 90% and conception rates commonly between 65–85%. These methods are particularly effective in intensive or AI-based systems but are constrained by cost, labor, regulatory restrictions, and welfare considerations. Non-hormonal strategies, such as the ram effect, photoperiod manipulation, nutritional flushing, and management-based interventions, exploit natural physiological, socio sexual, and nutritional cues to partially synchronize estrus. While these approaches exhibit greater variability and lower precision than hormonal methods, they offer advantages in low input, organic, and extensive systems by improving reproductive clustering, ovulation, and lambing compactness. Among these, the ram effect is the most effective and widely applicable. Integrated reproductive management, combining hormonal or non-hormonal strategies with optimized nutrition, health, and flock management, is critical for achieving predictable and sustainable reproductive outcomes. Future research should focus on refining hormone-sparing protocols and enhancing the reliability of natural synchronization methods.

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.

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.

Retained placenta (RP) in bovines is a significant postpartum complication that can lead to severe reproductive issues if not managed promptly