Factors affecting the heifer´s age at pregnancy

Abstract: Several factors affect the heifer´s growth and development, the newborn calf´s feeding of co-lostrum during its first hours of life is one important factor. The colostrum contains higher amount of immunoglobulins and insulin growth factors compared to matured milk. A high intake of immunoglobulins from colostrum results in a high blood concentration of immuno-globulins until the age of eight months. This leads to a lower incidence of diseases that can affect the growth and development negatively. Diarrhea is the most common disease in calves younger than 30 days. An infected heifer calf is three times more likely to calve at an age old-er than 30 months compared with a healthy calf. At the age of 3-7 months almost half of all heifers get pneumonia which can result in a delay of the first calving with three months. Every month after the age of 24 months when the heifer has not had her first calf is unneces-sary rearing cost which can affect the producer´s economy negatively. This review showed that access to roughage and concentrate, the intake and quality of colostrum, feeding intensity, diarrhea, pneumonia, housing system and the possibility of estrus detection affect the heifers age of first calving. All factors can be regulated by the producer. If first calving occurs at the age of 24 months and the heifer has attained the right weight this will result in an improved economy.