Abstract

Goat production in Hawaii has grown steadily in the past decade and this growth necessitated a more controlled diet to sustain production. Local goat pastures on the Big Island, Hawaii, are dominated by Napier grass (Pennisetum purpureumSchumach.), yellow foxtail (Seteria glauca L.), and guava trees (Psidium guajavaL.). These plants contain compounds such as calcium and oxalates that could have detrimental effects on growth and development of goats when consumed in large quantities. This experiment was designed to evaluate the effect of grazing Napier grass and yellow foxtail with and without added guava tree parts using two groups of 14 female goats (Capra hircus L.) crossbred between Boer, Spanish, and Kiko breeds by analysis of some urine characteristics such as color, turbidity, specific gravity, pH, presence of bacteria, fungi, casts, as well as concentrations of nitrite, blood, urobilinogen, protein, glucose, ketones, bilirubin, red blood cells, and white blood cells. Urinalyses were performed on four sampling periods over three months. All variables were subjected to Repeated Measures in General Linear Models and correlation analysis using SAS. Urinalysis results were similar for both the groups. Urine protein levels of the (-) guava group, however, were higher, but not statistically different than those of the (+) guava group; significant interactions existed with some of the variables with time. The increased concentrations of calcium or oxalates in guava tree bark, Napier grass, and yellow foxtail may cause calculogenic minerals to accumulate, over longer periods of grazing, causing uroliths with a calcium and (or) oxalate base in male goats. This could result in penile obstruction in male goats.

Key words: Capra hircus, goat, guava, Napier grass, Pennisetum purpureum,Psidium guajava, Seteria glauca, urinalysis, yellow foxtail