Abstract:
This paper is the first attempt to accurately describe the hematological parameters for
any African breed of cattle, by capturing the changes in these parameters over the first
12 months of an animal’s life using a population-based sample of calves reared under
field conditions and natural disease challenge. Using a longitudinal study design, a
stratified clustered random sample of newborn calves was recruited into the IDEAL
study and monitored at 5-weekly intervals until 51 weeks of age. The blood cell analysis performed at each visit included: packed cell volume; red cell count; red cell
distribution width; mean corpuscular volume; mean corpuscular hemoglobin
concentration; hemoglobin concentration; white cell count; absolute lymphocyte,
eosinophil, monocyte, and neutrophil counts; platelet count; mean platelet volume;
and total serum protein. The most significant age-related change in the red cell
parameters was a rise in red cell count and hemoglobin concentration during the
neonatal period. This is in contrast to what is reported for other ruminants, including
European cattle breeds where the neonatal period is marked by a fall in the red cell
parameters. There is a need to establish breed-specific reference ranges for blood
parameters for indigenous cattle breeds. The possible role of the postnatal rise in the
red cell parameters in the adaptability to environmental constraints and innate disease
resistance warrants further research into the dynamics of blood cell parameters of
these breeds.
