Nutritional value of feed consumed by buffaloes under stable conditions and grazing from the rangelands of the main habitats of buffalo breeding in different climate zones of Ardabil province

Ensuring the availability of high-quality forage and a balanced diet is essential for cost-effective milk and meat production in buffaloes. In Iran, limited forage supply, poor access to forage, and imbalanced diets are major constraints that negatively impact buffalo production and hinder profitable breeding. To address these challenges, a comprehensive understanding of buffalo breeding areas, methods, production issues, problems, and feeding practices is crucial. This study aimed to determine the nutritional value of feed consumed by breeding buffaloes under stable and rangeland grazing conditions in the primary buffalo breeding habitats across different climatic regions of Ardabil province.

The nutritional value of feed consumed by buffaloes was assessed using gas production techniques in a completely randomized design. Digestibility, metabolizable energy, gas production and degradability parameters, microbial mass production, volatile fatty acids, and grazing diets were evaluated. The study was conducted in three selected locations: Damirof in Bilesavar, Gharabaghlar in Meshginshahr, and Arpatapeh Fandoghlu in Namin counties. Grazing periods and paddocks for buffalo herds were determined based on the Deputy of Livestock Production Improvement's recommendations. Plant samples grazed by buffaloes were collected at three stages of the grazing season in Meshginshahr and Namin (May 15 to June 15, June 15 to July 15, and July 15 to August 15), and one month earlier in Bilesavar (March 15 to July 15). Chemical composition and digestibility tests were conducted on the plant samples. Two types of diets, a "traditional diet" commonly used by buffalo breeders (control diet) and a "standardized diet" formulated based on metabolic energy and protein requirements for buffaloes with an average weight of 550 kg, were selected for feeding buffaloes in stable conditions. Chemical composition and digestion tests were performed on the fodder and concentrate used in the diets.

The results revealed that the balanced diet (standard diet) had significantly higher values of gas production, parameters b and c (slow decomposition and gas production rate), metabolizable energy (ME), net lactation energy (NEL), apparent organic matter digestibility (AOMD), true organic matter digestibility (TOMD), apparent fermentation of organic matter (AFOM), true fermentation of organic matter (TFOM), volatile fatty acids (SCFA), and rumen microbial biomass (MB) production and efficiency compared to the traditional diet (control) (p < 0.05) in all paddocks. Gas production, parameters b and c, ME, NEL, AOMD, TOMD, AFOM, TFOM, SCFA, and rumen microbial biomass and efficiency showed higher mean values during the early grazing season in each paddock compared to the middle and end of the grazing season. Overall, these parameters exhibited a decreasing trend throughout the grazing season (p < 0.05). The TOMD and TFOM values were higher in the early grazing season in the warm semi-arid region of Bilesavar compared to the cold regions of Namin and Meshginshahr (p < 0.05). However, SCFA and MB values were higher in the early grazing season in the cold regions compared to the warm semi-arid region (p < 0.05).

The study demonstrated that balanced diets (standard) had superior nutritional value compared to traditional diets (control) commonly used by buffalo breeders in the selected paddocks. Therefore, these balanced diets can be recommended as alternatives to traditional diets for feeding buffaloes. Additionally, the nutritional value of rangeland habitats varied depending on plant species composition, growth stage, and climatic conditions. For effective stocking intensity and livestock feeding planning in the rangeland, these variations should be considered.