This study aimed to evaluate the effects of thermal stress on milk yield and milk composition using the time series approach to forecast the trend of daily milk yield and milk components in Holstein cows in a hot-arid environment. Also, this study evaluated the effect of season on the microbiology of raw bulk Holstein cow milk. The obtained data comprised the average daily milk yield, composition, and bacterial counts from a single high-input dairy herd in northern Mexico, registered for seven consecutive years (2014-2020). The autoregressive integrated moving average (ARIMA) procedure showed a distinct pattern for the daily milk yield. A two-year forecasting showed 8.4 kg difference in daily milk yield between winter and summer months. The predicted future values based on past values showed that milk solids were highest in January (12.09 %; CI= 11.86-12.31 %) and the lowest in August (12.02; CI= 11.75-12.29). The mean predicted fat content was highest in January (3.60 %; CI= 3.48-3.71 %) and lowest in July (3.44%; CI= 3.29-3.59 %). Following the repeated observations, forecasting values for milk protein percentage were 3.22 % (CI=3.15-3.28 %) in January and 3.07 (CI=2.98-3.1) in April. The ARIMA method forecasted milk lactose as highest in January (4.87 %; CI=4.79-4.95) and lowest in June (4.77 %; 4.68-4.86 %). Standard plate count was higher (p<0.01) in autumn and winter than spring and summer. During winter, the average thermoduric count (TDC) in raw bulk milk was higher (12.5±2.01) compared with TDC in the spring (9.7±1.5; p<0.01). The somatic cell count did not differ between seasons. The coliform bacteria count was highest in autumn (77.8±28.3 cfu/mL; p<0.01) and lowest in spring (53.7 1.3 cfu/mL). It was concluded that hotter months diminished daily milk yield and its components. The ARIMA model can be used to accurately forecast daily milk yield and composition, which would allow to develop long-term strategies for managing milk production.

Background: Hormonal treatments can influence hematological profiles through direct and indirect mechanisms in sheep’s. The aim was to evaluate the effect of administering equine or human chorionic gonadotropin (eCG, hCG, respectively) at 7 or 14 days post-mating on blood count values in early pregnancy of nulliparous ewes. Methods: A total of 63 ewes were used, which were randomly assigned to five experimental groups (EG): EG-eCG7 (300 IU of eCG, 7 days post-mating (DPM)), EG-hCG7 (300 IU of hCG 7 DPM), EG-eCG14 (300 IU of eCG 14 DPM), EG-hCG14 (300 IU of hCG 14 DPM) and; EG-Control (without hormonal treatment). Hematologic variables were determined on days 7, 14 and 28 DPM and included white blood cell count (WBCC), red blood cell count (RBCC), hematocrits (Ht), hemoglobin concentration (HbC), mean corpuscular hemoglobin (MCHb), mean corpuscular hemoglobin concentration (MCHbC) and medium corpuscular volume (MCV). An ANOVA and Pearson correlation were performed on the response variables. Result: The results showed differences in WBCC on day 7 between the EGs and between days for the EG-Control. The RBCC variable only showed differences between the days of the EG-eCG14. The Ht variable reported differences between the days of the EG-eCG14. Regarding HbC, differences were determined between the EGs for days 14 and 28, as well as between the days of the EG-hCG7. Additionally, positive and negative correlations were evidenced between the variables considered. Based on the above, it is concluded that in the first month of gestation, the variables WBCC, RBCC, Ht, HbC and MCV increase in pregnant ewes. The aforementioned contributes to determining ewes’ reproductive performance and improving their productive and reproductive parameters.

Optimizing semen collection is critical for maximizing genetic advancement and reproductive efficiency in livestock. While exogenous hormones can enhance ejaculate quantity and quality, short windows of biological activity often limit their efficacy. This study was conducted in northern-arid Mexico (25° N, 103 W) to evaluate the comparative effects of oxytocin (OXYT) and carbetocin (CARB) administration on semen quality in French-Alpine bucks. Males (n = 12) were allocated into three groups and received intravenous treatments 10 min prior to artificial vagina collection: (1) OXYT (10 UI oxytocin buck⁻¹), (2) CARB (0.2 mg 100 kg⁻¹ LW⁻¹), and (3) CONT (1 mL saline buck⁻¹). The same bucks received all three treatments separately. CARB outperformed both groups (p ≤ 0.05), improving all evaluated parameters (p ≤ 0.05): ejaculated volume (i.e., increased by 103%), sperm concentration, mass and progressive motility, total sperm count, viability, normal morphology, plasma membrane functionality, acrosome integrity, and chromatin dispersion. Crucially, CARB doubled (p ≤ 0.05) the available projected or theoretical number of doses for intravaginal artificial insemination (POTNDIAI), followed by the OXYT and CONT groups, with 11.14 POTNDIAI each. Therefore, CARB emerges as a highly effective, accessible pharmacological strategy for semen collection protocols, substantially enhancing sperm yield and structural quality in breeding bucks. Ultimately, by bridging advanced reproductive physiology with practical smallholder farming, this methodological optimization provides a viable strategy to enhance reproductive efficiency and long-term sustainability in small ruminant production systems within arid environments.