The influence of selected factors on the yield and quality of colostrum produced by Polish Holstein-Friesian cows

The aim of the study was to analyse the concentration of immunoglobulins in colostrum produced by Polish Holstein-Friesian (PHF) cows in relation to selected factors. An important element of the study is the analysis of colostrum yield and density. The research was conducted between April 2017 through April 2018. The yield and selected traits of colostrum obtained from the first 9 milkings from 20 PHF cows calving during this period were analysed. A total of 180 measurements were made. The average immunoglobulin content in the 180 observations was 37.7 g · L–1, ranging between 7 and 140 g · L–1. The study showed a significant effect of time after calving on the content of immunoglobulins. The highest content of the antibodies was found in colostrum obtained immediately after calving. Its average level at that time was 90.2 g · L–1 and in 20 assessed cows it ranged within the wide limits of 32–140 g · L–1. The quality of colostrum radically deteriorated soon after calvong. The lowest level of immunoglobulins was found in the 96th hour after parturition and it was on average 10 g · L–1. The average yield of colostrum was 10.3 kg. The yield of colostrum increased with time elapsing after calving. The lowest colostrum yield was observed within 2 hours, the highest within 96 hours after calving, respectively, 6.9 and 12.4 kg. The average specific density of colostrum was 1.041 g · cm–3. The study showed that the highest density was characterized by colostrum obtained in the first milking post-partum. Its specific weight was 1.059 g · cm–3. In subsequent milkings, the calcareous density of colostrum systematically decreased to 1.030 g · cm–3 in the 90th hour after calving.