Abstract :

T

he objectives of this paper are to evaluate the addition of nanocobalt  on growth of cellulolytic bacteria, degradability of dry matter, cellulose and hemicellulose regarding In vitro gas production. The different levels of nanocobalt as addition element on fermentation kinetics were 0, 25,50,75,100 and 125 % from requirements of animal in ration as dry matter base. Cellulolytic bacteria had been isolated :Cellu­lomonas cellulasea, Acetobacter xylinum, Thermonospora fusca, Ruminococcus albus , Bacillus sp., Clostridium cellulovorans and Selenomonas ruminantium. Standard ration (1:1 concentrate :clover hay )  was incu­bated for 48 hours. The  results  indicated that the values of DMD , Hemi.D and  Cellul.D, which nanocobalt addition  were higher when levels were  50 and 75% compared control. Total cellulolytic bacteria counts in rumen content were higher (P<0.05) in cobalt 100% (11.30) and nanocobalt 75,100 and 125% (11.73,12.72 and 12.20), respectively, while lower value was in nanocobalt 25% (9.72) compared control (7.58).  Results revealed that added nanocobalt affect on growth of cellulolytic bacteria and increase degradability of cellulose. The nanocobalt additives had no effect on ruminal pH but more effect on ruminal ammonia and TVF's values, as well as degradability of cell wall constituents and microbial protein production . The extent of gas production was high in control ration , adding cobalt (100 %) and nanocobalt (50%) than other adding levels. Microbial protein  (M P) and efficiency microbial protein ( EM P) recorded higher values in all different(25,50,75,100 and 125%) added of nanocobalt compared to control (0%). Gas  production degradability after 48 hours incubation hemicellulose of  25% nanocobalt  recorded  the highest value (2444.69 ) compared to any adding nanocobalt levels and control, while  degradability for cellulose recorded higher values for 50 % nanocobalt  compared to other levels and control. It concluded that adding nanocobalt improved gas production, growth of cellulolytic bacteria ,ammonia ,total volatile fatty acids, metabolisable energy and cell wall constituents degradability.

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Research :