Brachiaria decumbens is a highly productive tropical grass used for ruminant production. However, it can cause hepatogenous photosensitization, general ill-thrift, and deaths in ruminants due to the presence of steroidal saponins. This study determined the acute and chronic clinico-pathological responses of sheep to graded levels of B. decumbens diet. A total of 30 male crossbred Dorper sheep (six-month-old) used in the study were randomly divided into three treatment groups of 10 sheep each. Treatment 1 (T1), which served as the control group, was fed with Pennisetum purpureum and concentrates, whereas Treatments 2 (T2) and 3 (T3) were fed low (10%) and high (60%) levels of B. decumbens, respectively. The study period was divided into acute (7 days) and chronic (90 days) phases. The rectal temperature, respiratory rate, heart rate, and mucous membrane color were monitored throughout the experiment. At the end of each stage, five animals were selected from each treatment group and euthanized by slaughter to collect organs for gross pathology, organ morphometric and histopathological evaluations. The treated animals did not show significant changes (p>0.05) in rectal temperature, pulse, and respiration rates throughout the study period. However, the mucous membranes were noticeably becoming pale starting from day 60 to 90 in T3 and during the chronic phase (day 90) in T2. There was no lesion or morphometric change in any organ at postmortem examination. At histopathology, both T2 and T3 exhibited mild to moderate necrosis, hemorrhage, congestion, hydropic degeneration and edema (p<0.05) in the liver and brain. In summary, this study has established that both low and high levels of B. decumbens diets cause chronic brain and liver damages in the sheep model. This study can be used for future research on the effects of B. decumbens on grazing animals.

The main goal of feed analysis is to predict the productive response of animals, in this case ruminant production, when fed diets of a given nutrient composition. A systematic approach to the overall aspects of animal production is vital for a stable and profitable output. Ranking forages can benefit the local producers to value each type of forages they feed the animals. From this point of view, a database must be developed containing sufficient samples of feeds and forages with relevant data determined under relatively uniform conditions, although animal variation due to preference, physiological state or genetic potential for production may, on the other hand, contribute to errors in measurements of forage quality. Relative feed value (RFV) is the forage quality index used widely in the United States as an important tool in the marketing of forages. In Malaysia, however, this index has not been established for assessing the status of local grass quality and how it relates to the performance of the local ruminant industry. The objective of this paper is to estimate RFV of the local B. decumbens grass towards the future establishment of its index under tropical climate. RFV between 74-84 obtained from this study was calculated using CP and ME values from a 5-year proximate analysis data from the Department of Veterinary Services (DVS) of local B. decumbens, sampled from the southern region of Peninsular Malaysia. If this forage is produced on a large scale, this assessment can help the producers and farmers differentiate between lots that are more or less valuable, thus making it a useful marketing and decision-making tool.