Discipline: Animal Science
Twinning data were analyzed from the production of 123 kids (64 males and 59 females) from 93 kiddings of 41 registered Philippine native does from July 2000 to June 2003 at the University Animal Farm, Institute of Animal Science, College of Agriculture, University of the Philippines Los Banos (ca 14° 11'N, 121° 15' E). Twinning constituted 31.2% of all kiddings. The number of twinning was associated (P<.01) with breed of dam and breed of sire. Percent twinning was highest in Native Black dams (50.0%) and lowest in Native Brown does (15.7%). It was highest in the Anglo Nubian sires (35.3%) and lowest in the Native Brown bucks (23.5%). However, parity (age of dam) and month of kidding did not influence (P>.05) the incidence of twinning. Birth weight of twins (2.61 kg) was greater (P<.05) than single births (1.37 kg). Total weight of kid(s) at birth was (P<.01) affected by breed of sire. The highest total birth weight (2.28 kg) may be attributed to the high incidence of twinning associated with the Anglo Nubian sire. Parity did not affect (P>.05) total birth weight and sex of kid. Although no significant relationships between total birth weight of kids and average monthly temperature and relative humidity were found, highly significant correlation (r=.28, P<.OI) existed between total birth weight of kids and average monthly rainfall.