This review is aimed at highlighting the role of selenium (Se) in enhancing the antioxidant status in the blood, immune response, reproductive performance, rumen fermentation, as well as feed efficiency, and weight gain in small Ruminants. Selenium is supplied in small ruminant’, s diet in organic form, inorganic form, or selenium nanoparticles (nano-Se). Each form of Se is metabolized differently and exhibits different levels of bioavailability with nano-Se having the highest bioavailability followed by organic Se. A suffi-cient supply of Se in small ruminant’, s diet is important to maintain the proper functioning of the antioxidant defense system which reduces the detrimental effects of free radicals in cells thereby preventing the inci-dence of metabolic diseases. The ability of Se to improve the antioxidant capacity of the cells also helps to strengthen the immune response of animals and ameliorate the detrimental effects of heat stress. Selenium has also been proven to modify rumen fermentation and microbiota which translated to improved feed effi-ciency and enhanced weight gain. However, the activities and bioavailability of Se are limited by several factors including the rumen microbiota, the form of Se, and competition with other minerals. Further studies need to investigate the effects of Se on rumen microbiology and heat stress in small Ruminants.

Forty two small Ruminants, 26 (61.90%) sheep and 16 (38.10%) goats were treated for rumen acidosis. 19 (45.24%), 12 (28.57%), 6 (14.29%) and 5 (11.90%) animals had eaten apple, cooked rice (wazwan left over) turnip and chapatti respectively and manifested clinical form of ruminal acidosis with, 2.86%; (n=18) as mild (Rumen fluid pH=6.32 ±0.09316), 38.09%; (n=16) moderate (Rumen fluid pH=5.71 ±0.074) and 19.05%; (n=8) (Rumen fluid pH=4.54 ±0.159) as severe ruminal acidosis and accordingly they were classified as group I, II and III, respectively. In group I rumen motility was reduced (1.67±0.162) and subsequently it was almost absent in group III (0.13±0.125). Rectal temperature recorded to be 102.58±0.166, 101.26±0.188 and 100.83±1.061 in group I, II and III respectively. There was a significant increase heart and respiratory tares before treatment in all the groups. A significant increase in blood glucose and Hb, PCV and TEC was also observed in mild, moderate and severe acidotic animals. Therapeutic measures consisted of neutralization of acidity by oral and / or parenteral use of isotonic (1.3%) and hypertonic (5%) sodium bicarbonate with adequate fluid therapy. Oral and parenteral use of isotonic (1.3%) sodium bicarbonate was given to moderate rumen acidosis. Administration of oral sodium bicarbonate, bolus Rumentas was given to groups I and II and a course of antihistaminic drug was also given to all the groups of animals. Moreover, animals of group II and III were also offered intravenous injection of high dose vitamin B1 along with fluids. Gastric lavage and cud transplantation following rumenotomy was done in animals of group III. All animals except two (one each from group II and III) were recovered uneventfully.