conscription does not exist
There is and has never been conscription in Botswana.  
However, Botswana does have 'national service' (Tirelo Setshaba) since 1980, but this is a purely civilian service, not linked to the military in any way. The twelve months' service is open to men and women who have passed their O level exams and participation in it was voluntary until 1984. From 1985 onwards, those who want to work in the public sector or want to continue their studies must have performed national service. 
Recruitment into the armed forces is on a voluntary basis. 
The minimum recruitment age is not known.
2 Conscientious objection
There is no known legal provision for military personnel who have conscientious objection to further service in the armed forces.
According to the government in 1983 conscientious objection does not arise as enlistment is voluntary. There were no known cases of conscientious objection. 
The penalties for desertion are not known.
An individual who persuades or helps or tries to persuade or help a member of the armed forces to desert may be punished by six months' imprisonment (art. 44 Penal Code).
6 Annual statistics
The armed forces comprise 7,500 troops - 0.5 percent of the population. 
 Eide, A., C. Mubanga-Chipoya 1985. Conscientious objection to military service, report prepared in pursuance of resolutions 14 (XXXIV) and 1982/30 of the Sub-Commission of Prevention of Discrimination and Protection of Minorities. United Nations, New York.  Abecassis, L., P. Duong, S. Perrier, N. Watt, 1994. Conscription Militaire ou Service National a Option Civique, rapport de l'enquête préliminaire effectuée auprès d'une vingtaine d'Etats membres de l'UNESCO. CCIVS - UNESCO, Paris.  Embassy of Botswana & Mission to the European Communities 1996. Reply to CONCODOC questionnaire, Brussels, 30 July 1996.  Institute for Strategic Studies 1997. Military Balance 1997/98. ISS, London, UK.