The effects of bone meal supplementation in breeding beef cattle at different times of the year as reflected in body mass and body tissue levels of phosphorus, calcium and magnesium

Abstract

The study was carried out to determine the effects of bone meal supplementation on breeding beef cattle. Twenty-four animals (Bonsmara cows) were randomly assigned to control and three treatment groups, each with 6 animals. The treatment groups were given a lick containing 45, 5% bone meal, 45, 5% salt and 9% molasses while the control group was offered only common salt. Blood, bone and faecal samples were collected during the first week of every two months. The animals were weighed on each sampling date. All groups of cows depended entirely on natural pasture, were managed alike, and grazed together. The project was conducted at the University farm, North West University (Mafikeng Campus) for a period of one year (June 2003 to June 2004). Bone meal (P) supplemented cows generally gained more weight over the entire trial period. This effect of phosphorus was also reflected in higher serum, bone and faecal phosphorus content on a mg/g basis though the difference were not significant (P> 0.05). During the trial it was found that mineral content in blood, faeces and bone was directly related to the mineral content in the pasture since the minerals peaked in summer months when grass was abundant and declined as the pasture became scarce during winter months. Blood P concentration was very low and inconsistent.