Poisoning by Brachiaria spp. in suckling lambs supplemented and unsupplemented in a creep-feeding system

This study assessed the frequency of poisoning by Brachiaria spp. grasses in 34 suckling lambs in a creep-feeding treatment supplemented with a proteinaceous concentrate and 34 lambs in an unsupplemented control group. Samples of Brachiaria were collected every 28 days for determining the protodioscin content of the grass. Lambs with consistent clinical signs of poisoning by Brachiaria spp. were separated from the flock, along with their dams, and fed on hay from alfalfa (Medicago sativa) and Tifton 85 (Cynodon dactylon) as alternative fibrous feeds. The concentrations of protodioscin were 0.3-0.9 and 0.4-1.4% in the creep-feeding and control treatments, respectively. Creep-fed and control lambs showed clinical signs at 41-48 and 34-74 days of age, respectively. Clinical signs included swelling of the face and ears, alopecia and erythema that evolved to crusting and would slough, leaving exposed areas of erosion, later becoming retracted scars in both ears. The effect of the nutritional treatment differed significantly between treatments (p < 0.1) but not between genetic makeup or year (p > 0.1). We concluded that Brachiaria spp. was toxic to the suckling lambs. Low concentrations of protodioscin were toxic to the lambs, especially if they were genetically susceptible to the poisoning. The intake of the proteinaceous concentrate in the creep-feeding system decreased the effects of intoxication by Brachiaria spp. in the suckling lambs.