Oestrous cycle synchronization in Zebu cattle and its use in cattle production and management in the tropics

Abstract

SummaryBetween March and August 1968 to 1970, Chlormadinone acetate (CAP), 10 mg/head/ day, was administered to 668 Zebu cows and heifers for oestrous cycle synchronization for 14, 12, or 9 days, the latter schedule supported by an injection of 5 mg estradiol valerate on day 2 to achieve luteolysis. Applied orally over a period of 14 days, CAP provided a reliable method for cycle synchronization. The severe anoestrous rate experienced in all herds reduced the overall percentage of synchronized animals. Fertility from insemination during the first synchronization period (day 2 to 10 after treatment) was slightly, yet insignificantly reduced, but was completely restored during the second synchronization period (day 20–30). Insemination only during this second synchronization period resulted in conception and pregnancy rates similar to those combined from the first and second synchronization period.Of factors tested for influencing synchronization and fertility, presence or absence of penis-deviated teaser bulls (psycho-stimulation) had no effect on the percentage of animals synchronized, or on post-treatment fertility. In well-managed herds, the percentage of animals responding to treatment was predetermined by the number of animals already cycling, reflecting their phase of reproductive life. Levels of management had an important impact on the success of cycle synchronization combined with artificial insemination. Both methods are managerial tools for improvement of already good management. Their failure under insufficient management conditions has diagnostic value.Possibilities and limits shown for oestrous cycle synchronization in Zebu cattle were similar to those reported in European cattle. Within these limits, CAP can be employed successfully as a means for cycle synchronization, providing sufficient synchronization and acceptable fertility and allowing economical use of artificial insemination.

Oestrous cycle synchronization and oestrus induction in indigenous and European cattle in Tanzania

“…Both treatment schedules -the oral application period over 14 days, and the CAP injection followed by 4-or 5-day feeding periods commencing 9 or 11 days thereafterresulted in good synchronization and unimparied fertility. Our data confirmed data from previous studies in Zebu cattle under tropical ranch conditions obtained in the Mexican Gulf Coast area by Jochle et al (1973) and . Contrary to the experiences reported from European cattle in the moderate climate belt and shown as a consistent but insignificant factor in the Mexican Zebu cattle study, no reduction in conception rate from inseminations or natural services during the first synchronization period were observed.…”

“…Effect of CAP on anoestrus. A consistent, but rarely significant effect of overcoming the sometimes severe anoestrous rate in Zebu and Zebu-hybrid cattle was reported by Jochle et al (1973) and . In our work, reduction of anoestrus became highly significant in the majority of our studies.…”

“…Management and its influence on synchronization and conception rates. As previously shown (Jochle et al 1973), management factors have substantial influences on the outcome of treatment success in regard to synchronization and fertility as well. Management varied between the locations of our trials.…”

“…during cycle synchronization studies with Zebu and Zebu hybrid cattle under tropical ranch conditions The cattle population of developing countries in in the Mexican Gulf Coast (Jochle et al 1973), the the tropics and subtropics can play an important same compound (chlormadinone acetate = CAP) role in alleviating the world's shortage in animal and the same protocol was used in our studies protein supply. Cattle production in these countries in Tanzania.…”

“…Treatment schedules. Based on previous studies in European cattle (Schmidt, Smidt & Jochle, 19706;Schmidt et al 1970a) and Zebu cattle (Jochle et al 1973), chlormadinone acetate (CAP) was administered as 10 mg per day oral doses in capsules which were given manually, or was injected (i.m.) as an oily solution (lOmg/ml).…”