Trop Anim Health Prod (2006) 38:511–519
DOI 10.1007/s11250-006-4419-zThe objectives of this study were to assess
changes in nutritional status/body condition score, percentage
pregnancy and calving rate in Zebu cows and
to establish the relationship between body condition
score loss and postpartum interval to resumption of
ovarian activity. A total of 198 cows and postpubertal
heifers of the Tanzanian Shorthorn Zebu kept under
a traditional management system were randomly
selected from 200 smallholder herds. Factors investigated
during bi-weekly visits include body condition
score (BCS), heart-girth circumference, milk yield
and reproductive status of the animals, pregnancy/nonpregnancy
and cyclicity/non-cyclicity. Local weather
conditions and dates of occurrence of other reproductive
events such as calving were also recorded. Calvings
occurred all year round but with a strong seasonal distribution
characterized by annual peaks observed between
April and July. The annual calving pattern was closely
related to rainfall, with peak precipitation occurring a
few months before peak calving. The overall percentage
pregnancy varied from 30% to 50% throughout the
N. L. Kanuya ( ) · M. K. Matiko · R. Nkya ·
S. B. P. Bittegeko · M. N. Mgasa
Department of Veterinary Surgery and Theriogenology,
Faculty of Veterinary Medicine, Sokoine University
of Agriculture, Morogoro, Tanzania
e-mail: [email protected]
O. Reksen · E. Ropstad
Department of Production Animal Clinical Sciences,
Norwegian School of Veterinary Science, Oslo, Norway
year. Postpartum cows exhibited minimum mean BCS
and heart-girth circumference 12–14 weeks after calving,
and cows with BCS loss >1 point exhibited the
longest time interval from calving to onset of ovarian
activity