Effects of dietary curcumin nano-micelles on performance, biological responses, and thermal stress resilience in heat-stressed fattening lambs across varying temperature-humidity index conditions: Implications for climate change.

Heat stress poses a significant challenge to sheep farming in arid and semi-arid regions, impacting growth performance, health, and physiological responses. While sheep have innate mechanisms to manage heat stress, prolonged exposure impairs their performance and health. This study evaluated the influence of varying doses of Curcumin Nano-Micelle (CNM) on heat-stressed fattening lambs in northeastern Iran over three months, examining the relationship between CNM doses and growth performance, feeding behavior, physiological responses, immune function, and antioxidant status. Thirty-two crossbred male lambs were included in a completely randomized design with four treatments and eight replications. The experimental treatments were as follows: 1) CTRL: No dietary inclusion of CNM, (control group); 2) T20: Dietary inclusion of 20 mg of CNM per head per day; 3) T40: Dietary inclusion of 40 mg of CNM per head per day; and 4) T80: Dietary inclusion of 80 mg of CNM per head per day. The results revealed that dietary supplementation with 20 and 40 mg of CNM significantly improved live body weight, weight gain, average daily gain (ADG), and feed conversion ratio (FCR) compared to the control treatment. Regression analysis demonstrated quadratic models between growth performance parameters and the Temperature-Humidity Index (THI), indicating a correlation between CNM doses and the animals' responses to heat stress. Regarding eating behavior, CNM doses of 40 and 80 mg/day significantly reduced eating time while increasing ruminating time. Blood analysis indicated significant reductions in glucose levels across all treatments, with T40 significantly reducing both cholesterol and triglyceride (TG) levels. Additionally, CNM supplementation decreased serum malondialdehyde (MDA) levels and increased superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities, indicating enhanced antioxidant status. Physiological responses were influenced by CNM, notably reducing rectal temperature (RT), skin temperature (ST), respiration rate (RR), while pulse rate (PR) increased across various time intervals, particularly in the T80 group. This study demonstrates that CNM supplementation can enhance performance, physiological responses, and antioxidant status in heat-stressed fattening lambs, highlighting its potential to mitigate heat stress effects in sheep farming.

Evaluating the dose-dependent effects of curcumin nano-micelles on rumen fermentation, nitrogen metabolism, and nutrient digestibility in heat-stressed fattening lambs: Implications for climate change and sustainable animal production.

Global warming threatens livestock production, especially in hot climates. This study evaluated the dose-dependent impacts of dietary curcumin nano-micelles (CNM) on rumen fermentation, nitrogen metabolism, and nutrient digestibility in heat-stressed fattening lambs. Thirty-two crossbred male lambs [ˆIle-de-France × (Dalagh × Romanov)] were utilized within the current study. The initial weight of lambs was documented as averaged by 31.2 ± 1.55 kg, while they were in their 4th to 5th months of age. Animals were fed increasing doses of dietary CNM (0, 20, 40, and 80 mg/day) over 97 days, under severe heat stress conditions with average temperature-humidity index (THI) of 24.5. Quadratic improvements (p < 0.01) occurred in weight gain, average daily gain (ADG), and feed conversion ratio (FCR) by 28.7%, 27.4%, and 23.9%, respectively, in the T40 group compared to the control. Additionally, T40 increased fiber digestion by 2.8% (p < 0.05). Furthermore, T40 quadratically improved parameters of rumen fermentation, including concentrations of NH3-N (p < 0.05), total volatile fatty acids (TVFA; p < 0.01), acetate (p < 0.05), and iso-valerate (p < 0.05), by 13.9%, 12.5%, 15.0%, and 43.5%, respectively, compared to the control. Quadratic increases were also observed in nitrogen balance (p < 0.05) and microbial protein synthesis (p < 0.01) by 19.8% and 37.6%, respectively, in the T40 group. Quadratic models estimated optimal CNM levels between 41.5 and 48.6 mg/day for multiple parameters. These findings indicate CNM at dose level of 40 mg/day could benefit heat-stressed lambs through enhanced rumen function and microbiota. Further research should refine ideal dosing for various species and production phases as higher levels adversely impacted fiber digestibility. Overall, CNM shows promise as a sustainable nutritional intervention for livestock production facing global warming.

Quantitative Associations between Season, Month, and Temperature-Humidity Index with Milk Yield, Composition, Somatic Cell Counts, and Microbial Load: A Comprehensive Study across Ten Dairy Farms over an Annual Cycle.

This current study addresses the knowledge gap regarding the influence of seasons, months, and THI on milk yield, composition, somatic cell counts (SCC), and total bacterial counts (TBC) of dairy farms in northeastern regions of Iran. For this purpose, ten dairy herds were randomly chosen, and daily milk production records were obtained. Milk samples were systematically collected from individual herds upon delivery to the dairy processing facility for subsequent analysis, including fat, protein, solids-not-fat (SNF), pH, SCC, and TBC. The effects of seasons, months, and THI on milk yield, composition, SCC, and TBC were assessed using an analysis of variance. To account for these effects, a mixed-effects model was utilized with a restricted maximum likelihood approach, treating month and THI as fixed factors. Our investigation revealed noteworthy correlations between key milk parameters and seasonal, monthly, and THI variations. Winter showed the highest milk yield, fat, protein, SNF, and pH (p < 0.01), whereas both SCC and TBC reached their lowest values in winter (p < 0.01). The highest values for milk yield, fat, and pH were recorded in January (p < 0.01), while the highest protein and SNF levels were observed in March (p < 0.01). December marked the lowest SCC and TBC values (p < 0.01). Across the THI spectrum, spanning from -3.6 to 37.7, distinct trends were evident. Quadratic regression models accounted for 34.59%, 21.33%, 4.78%, 20.22%, 1.34%, 15.42%, and 13.16% of the variance in milk yield, fat, protein, SNF, pH, SCC, and TBC, respectively. In conclusion, our findings underscore the significant impact of THI on milk production, composition, SCC, and TBC, offering valuable insights for dairy management strategies. In the face of persistent challenges posed by climate change, these results provide crucial guidance for enhancing production efficiency and upholding milk quality standards.

Effects of dietary curcumin nano-micelles on growth performance, blood metabolites, antioxidant status, immune and physiological responses of fattening lambs under heat-stress conditions.

The aim of the current study was to investigate the effects of dietary curcumin nano-micelles (C-NM) on the growth performance, blood metabolites, antioxidant status, and immune and physiological responses of fattening lambs under heat stress conditions. Thirty-two crossbred male lambs [Île-de-France × (Dalagh × Romanov)] with an average weight of 31.2 ± 1.55 kg and age of 4-5 months were assigned to experimental treatments in a completely randomized design including four treatments and eight replications. The treatments were T0, T20, T40, and T80, representing dietary supplementation of C-NM at 0, 20, 40, and 80 mg per head per day, respectively. The study lasted for 37 days including 7 days of adaptation period. Lambs were weighed on days 0 and 30 of the experiment before morning feeding to determine the average daily gain (ADG) and feed conversion ratio (FCR). Blood samples were collected from the jugular vein on day 30 of the experiment and physiological parameters, including rectal temperature (RT), skin temperature (ST), respiration rate (RR), and pulse rate (PR), were measured once a week on a certain day during the study. Lambs in the T40 group showed higher final live weight (FLW) and ADG, while exhibiting lower FCR (P < 0.01). Regression analysis predicted the optimum levels of dietary inclusion of C-NM to be 44.7, 38.3, and 42.0 mg/day for FLW, ADG, and FCR, respectively. Dietary supplementation of C-NM decreased RT, ST, and RR, while increasing PR (P < 0.01). The levels of immunoglobulins G (IgG) and A (IgA) increased linearly with the dietary inclusion of C-NM (P < 0.01), while levels of immunoglobulin M (IgM) remained unaffected (P > 0.05). Dietary inclusion of C-NM had a quadratic reducing effect on the serum concentration of malondialdehyde (MDA) and a cubic increasing effect on the serum activities of glutathione peroxidase (GPx) (P < 0.05). Superoxide dismutase (SOD) was linearly increased in T80, while total antioxidant capacity (TAC) showed a linear increase in T40 and T80 groups (P < 0.01). Based on the results of this study, we recommend the administration of C-NM in the diet of fattening lambs during hot months in tropical and subtropical areas. However, further studies are needed to assess the long-term effects of C-NM during various physiological and production statuses.

Effects of Environmental Temperature and Humidity on Milk Composition, Microbial Load, and Somatic Cells in Milk of Holstein Dairy Cows in the Northeast Regions of Iran.

The present study aims to examine the relationships between temperature and humidity and milk composition, microbial load, and somatic cells in the milk of Holstein dairy cows. For this purpose, the temperature−humidity index, ambient temperature, and relative humidity data were obtained from the nearest weather stations. Production data were obtained from four dairy farms in Golestan province, Iran, collected from 2016 to 2021. The traits investigated were protein, fat, solids-not-fat (SNF), microbial load, and somatic cell count (SCC) in milk. The effects of the environmental temperature, humidity, month, and season on the milk composition, microbial load, and somatic cells were analyzed through analysis of variance. The effects of environmental temperature, humidity, month, and season on the milk composition, microbial load, and somatic cell composition were analyzed using a mixed procedure with a restricted maximum likelihood model. Although our findings revealed that there were significant differences in fat, protein, SNF, and SCC among the different months of the year (p < 0.01), no significant difference was observed in the total microbial count in milk. Environmental temperature presented significant impacts on fat, protein, SNF, SCC, and total microbial count within various temperature ranges (p < 0.01). When the temperature increased from 6.2 °C to 31.3 °C, the milk protein, fat, SNF, and somatic cell count significantly decreased, by approximately 4.09%, 5.75%, 1.31%, and 16.8%, respectively; meanwhile, the microbial count in milk significantly increased, by approximately 13.7%. Humidity showed an influence on fat, protein, non-fat solids, somatic cells, and total microbial count within different temperature ranges (p < 0.01). When the humidity increased from 54% to 82%, the milk protein, fat, SNF, and SCC significantly increased, by approximately 3.61%, 4.84%, 1.06%, and 10.2%, respectively; meanwhile, the microbial count in milk significantly decreased, by approximately 16.3%. The results demonstrate that there is a negative correlation between different months of the year, temperature, and the humidity of the environment, in terms of milk components and SCC. Our findings demonstrate that the optimum performance, in terms of milk composition, occurred in the first quarter of the year. As temperature increases and humidity decreases, milk quality decreases. Therefore, the adverse effects of environmental conditions on agricultural profits are not negligible, and strategies to better deal with the negative environmental effects are needed in order to improve milk quality in dairy cows.