Shyam S. Paul

Effect of phenolic monomers on biomass and hydrolytic enzyme activities of an anaerobic fungus isolated from wild nil gai (Baselophus tragocamelus)

Aims: To test the anaerobic fungus, Piromyces sp. FNG5, for its tolerance to phenolic monomers released in the rumen by degradation of lignocellulosic poor‐quality feeds.

Deriving nutrient requirements of growing Indian sheep under tropical condition using performance and intake data emanated from feeding trials conducted in different research institutes

Data from 24 feeding trials conducted on lactating cattle from different institutes across India were subjected to regression analysis to derive requirements of ME, TDN, CP and DCP for maintenance, milk production and body weight gain. Maintenance requirements for ME, TDN, CP and DCP were 598 KJ, 39.5 g, 6.27 g and 2.90 g/kg W 0.75 , respectively and the corresponding requirements for production of 1 kg 4% FCM were 5,023 KJ, 332 g, 82 g and 58 g. The corresponding requirements for one g gain in BW were 27 KJ, 1.78 g, 0.44 g and 0.19 g. Regression equations had high R 2 values (0.67 to 0.90) and the equations (F value) as well as coefficients were highly significant (p<0.001). Regressed values were used to develop feeding standards. Derived values matched well with the actual intake versus performance of animals under diverse feeding conditions. The new standards so derived predicted requirements and intake of nutrients for different production levels better than existing feeding standards; as these are based on a more thorough analysis of a larger database, the new feeding standards will be appropriate for wide use in India. (Asian-Aust. J. Anim. Sci. 2004. Vol 17, No. 6 : 769-776)

Fibrolytic potential of anaerobic fungi (Piromyces sp.) isolated from wild cattle and blue bulls in pure culture and effect of their addition on in vitro fermentation of wheat straw and methane emission by rumen fluid of buffaloes.

BACKGROUND Ten isolates of anaerobic fungi of Piromyces genus from wild cattle and blue bulls (five isolates from each host species) were evaluated for their fibrolytic ability in pure culture, their suitability for use as a microbial additive in buffaloes and their effect on methane emission. RESULTS In pure culture, only two out of five isolates from wild cattle degraded wheat straw efficiently, whereas all five isolates from wild blue bulls did. Isolate CF1 (from cattle) showed the highest apparent digestibility (53.4%), true digestibility (70.8%) and neutral detergent fibre digestibility (75.0%) of wheat straw after 5 days of incubation. When added to buffalo rumen fluid, all five isolates from cattle increased (P < 0.05) in vitro apparent digestibility of wheat straw compared with the control (received autoclaved culture), but all five isolates from blue bulls failed to influence in vitro digestibility of wheat straw. Isolate CF1 showed the highest stimulating effect on straw digestion by buffalo rumen fluid microbes and increased apparent digestibility (51.9 vs 29.4%, P < 0.05), true digestibility (57.9 vs 36.5%, P < 0.05) and neutral detergent fibre digestibility (51.5 vs 26.9%, P < 0.05) of wheat straw compared with the control after 24 h of fermentation. There were also significant increases in fungal count and enzyme activities of carboxymethylcellulase and xylanase in the CF1-added group compared with the control group. Gas and methane production g(-1) truly digested dry matter of straw were comparable among all groups including the control. CONCLUSION Wild cattle and blue bulls harbour some anaerobic fungal strains with strong capability to hydrolyse fibre. The fungal isolate CF1 has high potential for use as a microbial feed additive in buffaloes to improve digestibility of fibrous feeds without increasing methane emission per unit of digested feed.

Feeding standards for lactating riverine buffaloes in tropical conditions

Data from 33 feeding trials, conducted on lactating riverine buffaloes from different institutes across India, were subjected to multiple regression analysis to derive nutritional requirements for dry matter (DM), total digestible nutrients (TDN), crude protein (CP) and digestible crude protein (DCP) for maintenance, milk production and body weight gain. Maintenance requirements for DM, TDN, CP and DCP were 59.9, 35.3, 5.43 and 3.14 g/kgW(0.75), respectively; corresponding requirements for producing 1 kg 6% FCM were 688, 406, 90.3 and 55.2 g and for 1 g gain in body weight were 3.37, 1.97, 0.327 and 0.23 g. Regression equations had high R2 values (061. 0.66, 0.84 and 0.68 for prediction of DM, TDN, CP and DCP, respectively) and the equations (F-value) as well as coefficients were highly significant (P <0.001). Regressed values were used to derive feeding standards. Derived values matched well with the actual intake versus performance of animals under diverse feeding conditions. New standards predicted requirements and intake of nutrients for different production levels better than existing feeding standards. Because they are based on a more thorough analysis of data, the new feeding standards will be appropriate for use widely in India.

Fermentative characteristics and fibrolytic activities of anaerobic gut fungi isolated from wild and domestic ruminants

Fermentative characteristics and fibrolytic enzyme activities of anaerobic gut fungi from wild (17 isolates) and domestic ruminants (15 isolates) were examined. In a medium containing 0.5% wheat straw and 0.02% cellobiose as energy source, activities of carboxymethyl cellulase (CMCase), avicelase, xylanase, acetyl esterase and protease produced by the fungal isolates were investigated. Average activity of CMCase (17.4 vs. 8.25 mIU ml−1), acetyl esterase (134 vs. 57 mIU ml−1) and protease (4400 vs. 1683 mIU ml−1) were significantly higher in isolates from wild ruminants than those from domestic ruminants. Xylanase and avicelase activities were comparable. When compared irrespective of source, fungal isolates having monocentric growth pattern produced more fibrolytic enzymes than isolates having polycentric growth pattern. CMCase, xylanase, avicelase activities were highest in Neocallimastix isolates. Acetyl esterase activity was highest in Piromyces and Neocallimastix isolates. Protease activity was highest in Piromyces isolates followed closely by Neocallimastix isolates. Between isolates from wild and domestic ruminants few differences were observed in pattern of carbohydrate utilisation and end products of fermentation. Inter-strain differences in the end product formation were apparent. All of the isolates produced acetate, lactate and formate; only a few isolates produced succinate. For isolation of superior fibrolytic isolates of anaerobic fungi, greater emphasis should be given to the screening of enzyme activities of isolates of genera Neocallimastix and Piromyces.