Effect of humic acid supplementation on rumen parameters in Arab male lambs

This study was conducted in the animal field of the Department of Animal Production/College of Agriculture/ University of Basrah. The study lasted for 105 days from 1/11/ 2021 until 15/2/ 2022. In the experiment, 12 Arabi lambs purchased from local markets aged 5-4 months. The lambs were placed in similar cages 3 x 3 m for each treatment inside a semi-closed barn. The cages were provided with feeders and fountains for drinking water. The lambs were fed for 14 days on the basic ration. A preliminary period was counted for the purpose of adaptation, and then the lambs were weighed using an electronic scale. This was counted as the initial weight (26.5 kg), then the lambs were divided into three treatments according to their weight, four lambs each treatment. The three treatments were the control treatment, the addition of 6 gm humic acid/kg fodder, and the addition of 12 gm humic acid/kg fodder. pH measured after 3 hours of feeding at the beginning and at the end of the study of the addition treatment 6 gm humic (6.73, 6.79 respectively) exceeded over the control treatment (6.46, 6.10 respectively). Significant superiority in the total bacteria count after feeding at the end of the study for the addition treatments 6 and 12 gm humic (1.00 x 109 and 0.85 x 109 ) CFU/ml, compared to the control treatment (0.65 x 109 ) CFU/ml as well as the addition treatment of 6 gm humic was superior to the addition treatment of 12 gm humic. Significant superiority in the concentration of total volatile fatty acids for the addition treatment of 6gm Humic (86.77) mmol/L compared to the control treatment and the 12gm Humic supplementation treatment (76.41 and 83.33 mmol/L), respectively. There was also a significant superiority in the proportion of propionic acid for the addition treatment of 6 gm humic (28.75%) compared to the control treatment and the addition treatment of 12 gm humic (24.00% and 24.00%), respectively. Significant decrease in methane gas emission in the addition treatment of 6 gm humic (23.19) L/day compared to the control treatment and the addition treatment of 12 gm humic (26.66 and 26.40) L/day, respectively. The supplement with humic acid (6 gm/ Kg) improves rumen ecology and parameters