EN
The aim of the study was to assess the endogenic production of vitamin C contained in the sow’s colostrum and milk and its influence on piglet rearing parameters. The study was conducted on 60 Zlotnicka White sows and 642 piglets from their litters (366 male and 276 female piglets). The sows were in their 3rd, 4th, 6th or 7th lactation. There were 15 sows in each lactation group. The study covered a period of one lactation. The feed of the sows was not supplemented with vitamin C. During the experiment the piglets received only their mothers’ milk. The piglets were weighed on the 1st, 7th and 21st day of life (kg). Their mortality between the 1st and 7th day of life and between the 8th and 21st day of life (%) was recorded. The daily growth (g) was measured on each day when the piglets were weighed. Samples of colostrum and milk were collected manually from all active mammary glands on the 1st, 7th and 21st day of lactation. On each day of the experiment, two samples of about 7 ml were collected from each sow. A total of 360 samples were analysed (60 sows × 3 days × 2 samples). In order to verify the influence of vitamin C on piglet rearing, two concentration levels of vitamin C were distinguished according to its content in colostrum and milk (Tab. 1). The research showed that the content of vitamin C varied during lactation. The highest mean concentration of vitamin C, i.e. 1.14 mg/100 ml, was noted on the 1st day. On the 21st day it decreased to 0.65 mg/100 ml. During 21 days of lactation the content of vitamin C decreased by 43%. Sows in their fourth lactation produced colostrum with the highest content of vitamin C, i.e. 1.29 mg/100 ml. Animals that lactated for the sixth time had the highest content of vitamin C in their milk, i.e. 0.75 and 0.70 mg/100 ml, on the 7th and 21st day, respectively. The daily growth of piglets was greater if the content of vitamin C in colostrum and milk collected during rearing was high (level II). On average, the differences amounted to about 68 g. The higher the content of vitamin C in the secretion from the sows’ mammary glands was, the lower the piglet mortality was. Statistically significant (p ≤ 0.01) relationships were found between daily growth and the content of vitamin C. The higher concentration of vitamin C produced better results in rearing in the form of a faster growth and lower mortality of piglets.