The production of colostrum from a feeding perspective

Abstract: Feeding good quality colostrum to newborn calves is essential to ensure their health and survival. Therefore, it is important to ensure production of enough yield and good quality colostrum in dairy farms. Some factors that have been shown to affect the quality of colostrum such as parity and time to first milking after calving. However, information about the effects of different dry period feeding strategies on colostrum production is lacking. For this reason, the purpose of this study was to investigate the effects of two different feeding strategies during the dry period on colostrum production and calf health. This study was a field study, data were collected from 20 Swedish farms that were selected according to their feeding strategy: a) total mixed ration (TMR) or b) separate feeding. Data were collected over a 2-month period and included a questionnaire and a visit to each farm. Colostrum yield was registered from 454 cows and the yield ranged from 0.02 to 25 litres the first milking (average 5.1 litres). The results showed that the feeding strategy had no effect on yield of colostrum produced. The quality of the colostrum measured by a Brix refractometer ranged from 11 to 40 % (average 23.6%). Cows fed a TMR diet tended to produce slightly higher quality (24.1%) colostrum than separate feeding cows (22.9%). So many as 26% of the colostrum samples were below the recommended Brix value of 22%, that could ensure calves adequate intake of immunoglobulins. Sixteen of the 20 farms had a strategy to give newborn calves colostrum with a minimum Brix value. Cow parity affected colostrum yield were older cows produce higher yield of colostrum (6 litres) compared with primiparous cows (3.4 litres). In this study 13% of the cows yielded only 1 litre or less in the first milking, which is worrying. The time from calving to first milking affected the quality of colostrum, quality decreased with increased time interval. A higher proportion of calves born to separate fed cows had higher vitality score than calves from TMR cows. Feeding strategy did not affect calf birth weight or calf body temperature at birth. The comparison between TMR and separate strategies should be interpreted with caution due to limitations in the study design such as relatively few farms, unbalanced numbers, differences between individual farms in feeding management strategies and differences in management practices around calving in general.