Acta Univ. Sapientiae, Alimentaria, 2, 1 (2009) 133–148 Composition of mare’s colostrum and milk II. Protein content, amino acid composition and contents of macro- and micro-elements J.Csap´o 1,2 email: csapo.janos@ke.hu Sz. Salamon 2 email: salamonszidonia@sapientia.siculorum.ro K.L´oki 1 email: loki.katalin@ke.hu Zs.Csap´o-Kiss 1 email: csapo.janosne@ke.hu 1 University of Kaposv´ar, Faculty of Animal Science, Guba S. u. 40, 7400 Kaposv´ar, Hungary 2 Sapientia–Hungarian University of Transylvania, Cs´ ıkszereda Campus, RO-530104, Libertatii 1., Miercurea-Ciuc Abstract. Changes in the protein content, protein fractions and amino acid composition of mare’s colostrum and milk, and biological value of milk protein during the first 45 days of lactation were studied. Milk samples (averaging 300–800 cm 3 ) from 29 lactating mares were collected daily at the beginning of the lactation and weekly from the 5 th to 45 th days post-partum. Colostrum samples were obtained by hand milking without oxytocin administration, while the foals nursed and milk samples Key words and phrases: Mare’s colostrum and milk, protein content, protein fractions, amino acid composition, biological value, ash content, macro- and micro-elements 133