Date of Graduation


Document Type


Degree Type



Davis College of Agriculture, Natural Resources and Design


Animal and Nutritional Sciences

Committee Chair

Eugene Felton.


Successful reproduction in alpacas is highly dependent upon postnatal survival, which in turn is dependent upon a pattern of continuous gain in weight as an indicator of health. Weighing alpacas is the primary method used to assess their general health. Unfortunately, the measurement of cria weight is not always a simple, routine, or easy determination. The purpose of this study was to determine if, as in other species such as cattle and horses, morphometric body measurements can be used to estimate weight. In this study, continuous weight and girth measurements were taken on 34 alpaca cria. Age and girth were shown to be good predictors of weight in male and female Suri alpaca. However, in Huacaya alpaca, girth did not account for much variation not accounted for age in either male or female cria. This could have been due to the small sampling size of Huacaya alpaca. Overall, girth could be used in a predictive equation to estimate weight; individual relationships exist for males and females of the same breed and therefore the equations for the sexes would be different. Early rumen development will affect body weight measures as rumen volume changes and may need to be considered. Rumen development and functionality was examined via ultrasonography and fecal sampling in nine lambs of comparable ages. Rumen area and volume, as determined from ultrasonographic measurements, increased with time with a somewhat more rapid increase in growth occurring between days 40 and 50 of age. In vitro true digestibility of fecal samples decreased, demonstrating that the lambs' own ability to digest fiber increased over the sampling period. Tracking rumen development via ultrasound is a feasible method. The fecal sample data supported the conclusions drawn from the ultrasound images. However, fecal fiber analysis is still a better method to track rumen maturity. With possible improvement to the ultrasound method and more practice, this method could be used to track rumen maturity.