Determination of the quality of roughage used in disease-freedairy farms in Aydın Çine district and it's effects on milk yieldand quality

Objective: This study was conducted to examine the effects of roughage sources used in disease-free dairy farms in Aydın Çine District on milk yield and quality. Material and Methods: In the study, milk samples were collected from dairy cows in diseasefree farms, along with alfalfa hay, corn silage, and TMR samples intended for these animals' consumption. The milk samples were analyzed for protein and fat content, while the feed samples were examined for dry matter, crude protein, crude ash, crude fiber, acid detergent fiber, neutral detergent fiber, and acid detergent lignin. Descriptive statistics, including Chisquare, Student's t-test, and Mann-Whitney U test, were used in the analysis of the feed and milk samples. Results: In the study, the relative feed value was calculated to determine roughage quality, and the samples were classified as high or medium quality based on quality standards. The farm sizes visited ranged from 59 to 167 head of cattle. It was found that there was no significant difference between roughage quality and factors such as the education level of farm owners, farm capacity, average milk yield, the type of mixer used for TMR, and the maturity period or usage amount of corn silage (P>0.05). In the physical evaluation of corn silage on the farms, the Flieg score, pH, and temperature values were determined to have no impact on roughage quality. However, a significant difference (P<0.05) was found in the average of samples at the 19 mm particle size using the Penn State Particle Separator for corn silage. In TMR samples, no significant difference related to quality was detected in any particle size (P>0.05). The xv nutrient contents of corn silage, alfalfa hay, and factory feed were found to be similar between the two quality groups. However, in TMR nutrient content, significant differences were observed in NDF, ADF, and ADL values between farms using high and medium-quality roughage. The fiber values were higher in the "medium quality" group, with P-values of 0.026, 0.050, and 0.007, respectively. Milk samples analyzed from disease-free farms in the Çine region showed that milk fat percentage varied depending on roughage quality (P<0.05). The milk fat percentage in the "high quality" roughage group (4.27±0.07) was found to be higher than that in the "medium quality" roughage group (3.54±0.09). Conclusion: The study determined that the quality of roughage in disease-free farms in the Çine region had a significant impact on milk fat percentage (P<0.05). Keywords: Dairy farm, Disease-free farm, Milk yield and composition, Roughage quality.