The concept of supplementation of ruminant diets with exogenous enzymes is not new though a considerable research interest on this field has been emerged from 1990s. Availability of wide range of exogenous enzyme products, development of better methods to evaluate enzyme activity, revised knowledge on rumen functions and recent advances of biotechnology which lowers the cost of enzyme production have fuelled the enzyme utilization in ruminant industries. The exogenous enzymes used in ruminant diets can be characterized in to main categories as fibrolytic, amylolytic and proteolytic based on specific substrate on which their enzyme activity can perform. The sources of these exogenous enzymes are mainly four bacterial species, three fungal species and some yeasts. Solid State Fermentation (SSF) and Submerged Fermentation (SmF) are the major methods for enzyme extraction which have combined with several other biotechnological aspects. The enzyme application method can vary in a wide range from applying to forage at harvesting, at ensiling, at feeding and the portion of feed which is mixed with enzyme may also vary from to forage to concentrate to a part of totally mixed rations. Up to date numerous number of researches have been done with ruminants like cattle both dairy and beef, goat, sheep and less with buffalo. The results seems to be inconsistent but positive results on feed intake, nutrient digestibility, growth performance, other production parameters, manure nutrient excretion etc., have been obtained. Therefore more fine-tuned research efforts are highly suggested for the generalization of exogenous enzyme usage in ruminant nutrition.

<p class="abstrak2">Recently the utilization of biological feed additives over chemical feed additives in animal feeds have increased. The objective of the present study was to evaluate the effect of supplementing wild guinea grass (panicum maximum) with two plant species, artocarpus heterophyllus (jack leaves; ah) and tridax procumbens (Tp) containing plant secondary metabolites tannin and saponin, respectively and the enzyme product dyadic cellulase (Ce) and yeast (Ye). For each suplement two levels of treatments were tested. In plant-based suplements 20 (Aht1, Tpt1) and 30% (Aht2 and Tpt2) substituted the base substrate. The enzyme was applied as 10 µl (Cet1) and 20 µl (Cet2) and yeast as 4 mg (Yet1) and 6 mg (Yet2). the experimental design was a randomized complete block design (rcbd) and the period of in vitro rumen fermentation incubation was 72 hrs. All treatments significantly (P &lt; 0.05) enhanced the in vitro gas production (Ivgp) compared with the control. Treatments of ah and ce significantly (P &lt; 0.05) improved the in vitro rumen dry matter degradability (ivrdmd). All treatments significantly (P&lt;0.05) suppressed the ruminal protozoa population as compared to the control. Ammonia nitrogen (Nh3-N) production was not significantly (P&gt;0.05) influenced with supplements. in conclusion, treatments enhanced the rumen fermentation in means of enhanced ivgp, ivrdmd and reduced protozoa numbers.</p>

A field experiment was conducted to evaluate the effect of three concentrate supplements with different metabolizable energy (ME) levels on weight gain, milk yield and composition in milking buffalos. Sixteen Murrah × non-descriptive crossed bred milking cows (720±50kg) were used. Animals in treatment 1 (T1) were fed only with forages while animals in other three treatments were given 90% forages +10 % concentrate. The three treatments were Commercial concentrate feed (T2) (ME (Kcal/kg): 2500 ±0.75), farm made concentrate feed (T3) (ME (Kcal/kg): 2733.25±2.32) and experimental feed (T4) (ME (Kcal/kg): 2933.03±2.15). Experimental design was a Randomized Complete Block Design (RCBD) with four treatments and four replicates. Forage intake was reduced, when feeding concentrate rations with high energy and CP, recording highest reduction with T4 followed by T3 and T2. Significant enhancement (P<0.05) and also highest values of weight gain, milk yield, fat, protein, and solid non-fat were observed with T4. Conclusion can be drawn that, higher milk yield with better composition could be obtained by feeding high energy rations formulated with low cost, locally available ingredients.

Materials and methods Substrate preparationThe substrate (rice straw) was prepared by oven drying (55 °C, 48 h) and grinding to pass through a screen (1 mm). Organic matter and crude protein were analyzed according to the AOAC (8), and fiber fractions were determined following methods described by Van Soest et al. (9). Five hundred milligrams of substrate were used as the sample. Enzymes and dosesThe enzyme products were characterized for the activity of cellulase (CE; E.C.

The objective of this meta-analysis was to explore variability in milk production associated with rumen fermentation parameters and diet characteristics. Data were extracted from 138 journal articles and used to derive 6 models to predict MY. Each model considered a different set of independent variables, including rumen fermentation parameters (R), diet (D) and their combination (R+D), with or without interactions with rumen pH. Rumen fermentation parameters included total volatile fatty acid (VFA) concentration, molar proportions of major and minor VFA, rumen pH and ammonia nitrogen, and diet variables included dry matter intake (DMI) dietary percentages of dry (DM) and organic matter (OM), crude protein, neutral (NDF) and acid detergent fiber (ADF), ether extract, and starch. Linear mixed-effects models weighted by the inverse of the standard error were employed. Models were compared based on concordance correlation coefficients after removing random study effects (CCC). The MY models using D, R, D+R and D*pH performed similarly with CCC values ranging from 0.63 to 0.65. Models including an interaction with rumen pH were superior at explaining variation within the data (CCC: 0.75 to 0.76). The Final model derived using D, consisted of DMI and ADF. Molar proportions of acetate and propionate and DMI were in the final model based on R. The interaction between starch and pH remained in the final D*pH model along with DMI, DM, NDF and pH. From these models, we can conclude that rumen pH is an important moderator explaining variability in the associations among diet, rumen VFA, and milk production.