EARLY-PREGNANCY DIAGNOSIS IN ALPACA (LAMA-PACOS) AND LLAMA (LAMA-GLAMA) BY ULTRASOUND

An ultrasonography study of early pregnancy diagnosis was carried out in 19 alpacas and 12 llamas, after controlled matings. The aim was to determine the earliest gestational age at which pregnancy diagnosis by transrectal ultrasonography could be achieved, and to generate an emp irical formula for gestational sac diameter (GSD) growth as a function of gestational age (GA), allowing an estimate of GA during the first month of pregnancy. We found that pregnancy diagnosis may be carried o ut as early as 9 days after mating in alpacas and 7 days in llamas. Th is diagnosis was found to be accurate at 23 days in alpacas and 34 day s in llamas. The empirical relations that best describe the relationsh ip between GSD and GA were GA = log GSD + 1.2339/0.0585 r = 0.85, P < 0.001 in alpacas, and GA = log GSD + 1.2649/0.0546 r = 0.77, P < 0.001 in llamas, where GA is measured in days and GSD in centimeters. Our r esults also indicate that ultrasonography is a reliable technique for early pregnancy diagnosis. Furthermore, the empirical formulae reliabl y make it possible to estimate GA from GSD during the first month of p regnancy and their use might improve the efficiency of camelid breeder s. (C) 1997 Elsevier Science B.V.