Seasonal changes in nutritional status and reproductive performance of Zebu cows kept under a traditional agro-pastoral system in Tanzania.
Trop Anim Health Prod
; 38(6): 511-9, 2006.
Article
en En
| MEDLINE
| ID: mdl-17243480
ABSTRACT
The 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 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.
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Base de datos:
MEDLINE
Asunto principal:
Reproducción
/
Bovinos
/
Estado Nutricional
/
Fenómenos Fisiológicos Nutricionales de los Animales
Límite:
Animals
/
Pregnancy
País/Región como asunto:
Africa
Idioma:
En
Revista:
Trop Anim Health Prod
Año:
2006
Tipo del documento:
Article
País de afiliación:
Tanzania