Feeding differing direct-fed microbials and its influence on growth and haematological parameters of growing lambs

A 4 mo feeding trial was conducted to ascertain the effect of direct-fed microbial (DFM) and their products, namely rumen enhancer three (RE3), Paenibacillus polymyxa (P3), and a fermentation product of RE3—RE3 Plus on the growth and haematological profile of lambs at different stages of growth (suckling, weaner, and grower phases). The lambs weighing 2.5 ± 2 kg were blocked by their weights and allotted to four dietary treatments, namely Control, RE3, RE3 Plus, and P3 in a randomized complete block design. Blood sampling of lambs to investigate the effect of the treatments on the haematological and blood biochemistry variables was done on monthly basis and analysis of variance in a repeated measures design was done using the Statistical Analysis System. Feed intake (FI) by lambs was not significantly (P > 0.05) influenced by DFM supplementation for all the phases of growth. However, feed conversion ratio (FCR) for the grower phase of the lamb was higher for T2. Similar (P > 0.05) hemoglobin (Hb), red blood cell (RBC), pack cell volume (PCV), mean corpuscular volume, mean corpuscular hemoglobin concentration (MCHC), eosinophil, lymphocyte, and basophil composition were recorded for lambs on the different experimental diets. Neutrophil and monocytes levels were, however, different (P < 0.05) for lambs fed the varying dietary treatments with lambs on RE3 Plus diets recording the lowest (P < 0.05) neutrophil levels. Monocytes levels were highest (P < 0.05) in lambs fed diets fortified with RE3. Sampling period influenced (P < 0.05) the Hb, RBC, PCV, MCHC, eosinophil, monocyte, and lymphocyte levels. The trial revealed a significant treatment × sampling period interaction (P < 0.0001) for the blood parameters examined. The inclusion of the different DFM products had no influence on the growth characteristics and blood profile of growing lambs.