The incidence of urolithiasis in Iranian Raeni kids fed different levels of metabolisable energy and metabolisable protein

Urolithiasis is a well recognized disorder affecting male sheep and goats. The pathophysiology of urolithiasis is multifactorial with environmental, hormonal and nutritional factors implicated (Blood et al.1989). The formation of phosphatic calculi is stimulated by high concentrate, low roughage, low Ca:P ratio, pelleted diets and alkaline urine (Emerick et al. 1963). An experiment was designed to assess the occurrence of urolithiasis in Raeni kids offered various levels of metabolisable energy (ME) and metabolisable protein (MP) was assessed. Seventy five male kids (liveweight, 20 kg) were used in a two factorial experiment with a complete randomized design. Five levels of ME (8.20, 8.92, 9.65, 10.37 and 11.10 MJ/kg DM) and MP (67.1, 76.5, 82.9, 90.9 and 99.1 g/kg DM) were assessed with 3 replications of kids. Diets were pelleted and consisted of barley, lucerne hay, wheat straw, wheat bran and cottonseed meal. The Ca:P ratio of diets was 2:1. After 3 months of ad libitum feeding, 12 cases of urolithiasis were observed. Seventy five percent of the cases of uroliths were in goats fed the rations containing the highest levels of ME (10.37 and 11.10 MJ/kg DM). In these animals, mean urinary pH was 8.36. Offering ammonium chloride (0.25 g/kg liveweight) significantly (P 0.05). It can be concluded that maintaining a dietary Ca:P ratio of 3.5:1 may be effective in minimising the formation of phosphorous uroliths in Raeni kids being fed diets consisting of more than 60% high energy pelleted concentrate.