Ajay Kumar Dang

Background: Somatic cell count (SCC) in goat milk is influenced by both udder health and physiological factors, which limits its interpretation as a sole screening measure. Aims: This study compared milk pH, electrical conductivity (EC), and three region-specific udder surface temperatures across a graded SCC scale in clinically healthy early-lactation Alpine × Beetal crossbred does and identified the lowest SCC class at which each indicator differed from the reference. Study Design: Cross-sectional, six SCC strata. Place and Duration of Study: Livestock Research Centre and Division of Animal Physiology, ICAR-National Dairy Research Institute, Karnal, Haryana, India. Methodology: Forty-eight clinically healthy, multiparous, early-lactation Alpine × Beetal crossbred does were sampled on three consecutive days. Daily values were averaged per doe, and does were allocated according to their three-day mean SCC (12 × 10⁵ cells/mL; n = 8 per group). Milk pH and EC were measured using a Lactoscan MCC Combo; teat apex (TAT), teat skin surface (TSST) and udder skin surface (USST) temperatures were measured by infrared thermography. Data were analysed by one-way ANOVA with Tukey’s HSD and Pearson correlation, with the doe as the experimental unit. Results: Milk pH rose 9.84% (6.30 to 6.92), first differing from the reference at 8–10 × 10⁵ cells/mL (P < .05). EC rose 24.72% (5.46 to 6.81 mS/cm) but, varying widely between animals, separated only at 10–12 × 10⁵. TSST rose 2.65 °C, separating at 8–10 × 10⁵; TAT rose 1.53 °C, separating at 10–12 × 10⁵; USST rose by 2.38 °C, but no group differed significantly from the reference. SCC correlated with EC (r = 0.906), pH (r = 0.898), TSST (r = 0.894), TAT (r = 0.741) and USST (r = 0.400). Conclusion: Milk pH and TSST responded earliest, at 8–10 × 10⁵ cells/mL, followed by TAT and EC at 10–12 × 10⁵; USST did not respond detectably. Milk pH offers the best combination of sensitivity, cost and speed. The closer tracking of SCC by TSST than by USST is contrary to earlier reports and requires replication with ambient conditions recorded.

Thermal stress threatens dairy productivity in tropical climates, even for heat-adapted indigenous Sahiwal cows (Bos indicus). Temperature extremes combined with humidity impair thermoregulation, immune function, and welfare amid climate change. This study evaluated physiological and immune endocrine responses in nulliparous Sahiwal heifers (n = 6) aged 12-18 months across THI levels of 50, 59, 67, and 76. Repeated measurements on the same animals generated 12 observations per THI level. Physiological parameters (rectal temperature, respiration, and pulse rates) and plasma biomarkers (cortisol, IL-6, IL-10, and TNF-α, via ELISA) were measured at each THI level. Escalating THI from 50 (cold-humid) to 76 (hot-dry; dry-bulb 29.52 °C, wet-bulb 23.27 °C) elicited graded responses. Rectal temperature increased modestly (P < 0.05) to 39.47 °C at THI-76 (+ 2.3% vs. thermoneutral THI-67). Respiration rate showed the greatest sensitivity, surging + 18.7% at THI-76 and declining - 18.3% at THI-50. Pulse rate rose + 13.6% under hot-dry stress. Cortisol followed a biphasic pattern, dropping at THI-67 before rebounding 1.8-fold at THI-76 (+ 84.3% vs. THI-67), with even greater elevation (+ 127.6%) at cold-humid THI-50. Cytokines displayed stress-specific shifts: IL-6 fluctuated, anti-inflammatory IL-10 surged + 39.6% at THI-76, and TNF-α declined then mildly rose. Respiration rate and cortisol emerged as prime stress indicators. Both cold and heat disrupt Th1/Th2 balance, underscoring the need for season-specific microclimate management in tropical dairy systems.

Background: Heat stress represents a major challenge to livestock health and welfare under intensive housing systems in tropical and subtropical regions. Especially during the hottest periods of the day, when high temperatures and humidity intensify the physiological burden on dairy cows. This pilot study investigates the influence of varying high-speed airflow within the dairy barn on both the barn microclimate and the animals’ circadian heat load. Methods: This pilot study investigated the short-term effects of varying high airspeed airflow on the barn microclimate and animal physiology to optimize maximum effectiveness. Airflow-based treatments were applied along the barn axis at targeted airflow speeds of ASc (control), AS1 (1.8 m/s), AS2 (3.6 m/s) and AS3 (4.8 m/s). At each airspeed treatment level, observations were recorded to evaluate diurnal physiological responses, specifically rectal temperature and respiration rate. The study involved six heifers (12-18 months) and both environmental and physiological measurements were taken three times daily during the hot-dry (HD) and hot-humid (HH) seasons. Result: THI ranged from 74-85 under hot-dry conditions and increased to 76-89 under hot-humid conditions, with relative humidity rising from 48-95%. Within each season, THI showed a slight decline with increasing air speed (ASc-AS3), indicating localized improvement in the shed microclimate. CO2 concurrently decreased from 720-760 to 310-340 ppm (p less than 0.001). Rectal temperature peaked at 39.59°C and 39.98°C and respiration rate at 33.50 and 37.33 breaths/min, respectively, both significantly reduced at higher air speeds (p less than 0.001). Peripheral surface temperatures (forehead, head, eye, flank) were higher under humid heat but declined markedly with increasing airflow (3.6-4.8 m/s), with eye temperature decreasing from 39.79 to 39.20°C and 40.18 to 38.78°C. The skin temperature gradient increased from 2.76 to 3.34°C and from 2.36 to 3.25°C, reflecting enhanced heat dissipation. Overall, increasing air speed improved microclimate quality and effectively mitigated thermal and physiological stress.

Livestock management practices like the provision of shade, air movement using fans, and wallowing are important methods to alleviate heat stress (HS) and maintain the productivity of buffaloes during extreme summer seasons. This study evaluated the effectiveness of heat mitigation strategies in lactating Murrah buffaloes under extreme summer conditions, with temperature-humidity index (THI) values ranging from 82.29 to 84.62, indicating periods of critical HS. A total of 84 buffaloes were taken and divided into 7 groups, with each group subjected to different strategies: Group I (tree and shed); Group II (mist and fan system); Group III (shower system); Group IV (mud pool); Group V (water pool); and Group VI (water pond) while Group VII (open area) served as the control. Infrared thermography (IRT) was used to measure muzzle, eye, and forehead temperatures. Milk somatic cell counts (SCC) and cortisol levels were measured in milk samples. Statistical analysis was conducted using ANOVA and Pearson correlation, with P < 0.05 considered significant. Buffaloes under Group III showed the most significant (P < 0.05) reductions in body surface temperatures, milk SCC, and milk cortisol levels, followed by Groups VI and II. Positive correlations were found between muzzle (r = 0.672, P < 0.01) and eye (r = 0.747, P < 0.01) temperatures with milk cortisol. Regression analysis confirmed moderate associations between milk cortisol and both muzzle (R² = 0.452, β = 1.12, P < 0.001) and eye (R² = 0.558, β = 1.26, P < 0.001) temperatures. Results indicated Group III as the most effective method for reducing HS in buffaloes, followed by Group VI and II. These strategies help to sustain buffalo productivity during extreme summer conditions.

Buffalo milk is renowned for its nutritional and functional properties. Milk somatic cells protect the mammary gland, contribute to the functionality of the udder, and also aid in the health and development of newborn calves, particularly during the critical early lactation period. However, proteomic changes in buffalo milk somatic cells during the transition from colostrum to mature milk remain poorly understood. This study was formulated to characterize the proteomic dynamics of buffalo milk somatic cells using Liquid chromatography-tandem mass spectrometry (LC-MS/MS) during colostrum-to-mature milk transition and to reveal shifts in metabolic and immune functions. A total of 4,429 high-confidence proteins were identified in the colostrum and milk of buffaloes. Up-regulated proteins [P_adj2(Fold change, FC) ≥ 1.5] across different days of sampling were involved in metabolism of sugars, lipids, and amino acids, pentose-phosphate pathway, insulin-signaling, biosynthesis of amino acids and cofactors, and ubiquitin-proteasome system. Down-regulated proteins [P_adj2(FC) ≤ 0.5] were associated with lipid transport, aldosterone synthesis and secretion, mineral balance, complement-coagulation system, antigen processing and presentation, and mRNA processing. A notable shift in hub proteins was detected, and selected ones were validated by real-time qPCR. These findings highlight significant changes in the proteome profile, biological functions, and specific pathways in milk somatic cells during early lactation in buffaloes. In conclusion, milk somatic cells contribute not only to mammary immunity but also to the nutritional support of the growing calf.