Milk of Italian Saddle and Haflinger nursing mares: physico – chemical characteristics, nitrogen composition and mineral elements at the end of lactation

Aim of this work was to investigate nursing mares milk characteristics at the end of lactation (D) and to make a comparison with milk taken during early lactation (3 to 30 d post partum) (E). The survey was carried out on 17 Italian Saddle mares (IS) (193 days in milk; 147 pregnancy days) and on 12 Haflinger mares (H) (174 days in milk; 146 pregnancy days). N fractions were determined by means of Kjeldahl; fat and lactose by means of mid infrared lectures; mineral elements were determined by Atomic Absorption Spectrophotometry; P by colorimetry. Data referring to 58 individual milk samples were analyzed by ANCOVA. Significant variations, similar in both breeds, were observed (E vs D) for density at 15°C (1.036 vs 1.034), pH (6.94 vs 7.24), titratable acidity (3.56 vs 1.70 °SH), fat (1.17 vs 0.76% g/100g of milk), crude protein (2.31 vs 1.68% g/100g), casein number (52.37 vs 46.59) and ash (0.50 vs 0.30% g/100g); similarly (mg/100g) for non casein N (172.31 vs 142.05), non protein N (34.43 vs 29.09), P (61.30 vs 32.48), Ca (112.88 vs 54.42), Mg (8.40 vs 4.38) and K (60.77 vs 41.31). Freezing point, lactose and Na showed no significant variations. At the end of lactation, milk resulted poorer in all main organic components, except lactose, and in all mineral components, except Na. Only freezing point and phosphorus variations differed in IS from H. Breed significantly affected fat, casein N and ash mean contents.