Kolkata, India

The West Bengal University of Animal & Fishery science was established on January 2, 1995 by a Legislative Act . Before this, veterinary education in the state was imparted by Bengal Veterinary College, a premier institution of the country which was established in 1893. It was the second oldest veterinary college in the country and the college was expanded, enriched and functioned under the University of Calcutta until 1974. In 1974, the college was merged with Bidhan Chandra Krishi Vishwavidyalaya in Mohanpur, district Nadia, as the Faculty of Veterinary and Animal science. Wikipedia.


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Patra A.K.,West Bengal University of Animal and Fishery Sciences | Saxena J.,Coskata
Journal of the Science of Food and Agriculture | Year: 2011

Tannins (hydrolysable and condensed tannin) are polyphenolic polymers of relatively high molecular weight with the capacity to form complexes mainly with proteins due to the presence of a large number of phenolic hydroxyl groups. They are widely distributed in nutritionally important forage trees, shrubs and legumes, cereals and grains, which are considered as anti-nutritional compounds due to their adverse effects on intake and animal performance. However, tannins have been recognised to modulate rumen fermentation favourably such as reducing protein degradation in the rumen, prevention of bloat, inhibition of methanogenesis and increasing conjugated linoleic acid concentrations in ruminant-derived foods. The inclusion of tannins in diets has been shown to improve body weight and wool growth, milk yields and reproductive performance. However, the beneficial effects on rumen modulation and animal performance have not been consistently observed. This review discusses the effects of tannins on nitrogen metabolism in the rumen and intestine, and microbial populations (bacteria, protozoa, fungi and archaea), metabolism of tannins, microbial tolerance mechanisms to tannins, inhibition of methanogenesis, ruminal biohydrogenation processes and performance of animals. The discrepancies of responses of tannins among different studies are attributed to the different chemical structures (degree of polymerisation, procyanidins to propdelphinidins, stereochemistry and C-C bonding) and concentrations of tannins, and type of diets. An establishment of structure-activity relationship would be required to explain differences among studies and obtain consistent beneficial tannin effects. © 2010 Society of Chemical Industry.


The effects of prebiotics on digestibility, short-chain fatty acid (SCFA) concentrations and bacterial populations in the faeces and immunity in dogs were evaluated by meta-analyses. Overall, data from 15 published studies containing 65 different treatment means of 418 observations from different breeds of dogs were included in the data set. Feeding of prebiotics to dogs did not affect the nutrient intake (P>0.10), nor did prebiotics change (P>0.10) the digestibility of dry matter (DM) and fat. However, crude protein (CP) digestibility tended to decrease quadratically (P=0.06) with increasing dosages of prebiotics, although the degree of prediction was low (R2=0.33). The concentration of total SCFA (P=0.08; R2=0.90) tended to increase linearly, whereas concentration of acetate (R2=0.25), propionate (R2=0.88) and butyrate (R2=0.85) increased quadratically with increasing dosage of prebiotics in the faeces of dogs. The numbers of beneficial bifidobacteria (P<0.01; R2=0.62) increased quadratically, but lactobacilli (P<0.01; R2=0.66) increased linearly with increasing supplementation of prebiotics. The changes in healthy bacterial numbers were affected by the interaction of initial bacterial numbers and dose of prebiotics; bacterial numbers increased relatively more when initial bacterial numbers were low. Dietary composition did not influence the response of prebiotics on lactobacilli and bifidobacterial numbers in this study. The numbers of pathogenic Clostridium perfringens and Escherichia coli were not affected by prebiotics. Prebiotics did not affect the serum immunoglobulin (Ig) concentrations such as IgG, IgA and IgM in dogs. Although prebiotics may tend to have an adverse effect on CP digestibility, prebiotics at doses up to 1.40% food intake (DM basis) might increase the beneficial bacterial populations and SCFA concentrations in the faeces of dogs. Thus, the feeding of prebiotics has a great prospective to improve the intestinal health of dogs. © 2011 The Animal Consortium.


Patra A.K.,West Bengal University of Animal and Fishery Sciences
Asian Journal of Animal and Veterinary Advances | Year: 2012

Various feed additives are in widespread use in diets of ruminants to modulate rumen metabolism which ultimately may enhance nutrient utilization and animal performance. Yeast products such as Saccharomyces cerevisiae and Aspergillus oryzae are often utilized in ruminants to improve nutrient utilization, rumen fermentation characteristics, milk production and daily gain. Yeast additives may exert positive effects on digestibility especially fiber components, probably by stimulating the cellulolytic microbial populations in the rumen. Rumen fermentation characteristics such as increased total volatile fatty acids, stabilization of rumen pH and decreased lactate concentration might be observed due to yeast supplementation. The increase in feed utilization and improvement of rumen fermentation along with increased dry matter may also enhance milk production and animal performance. Although, the favourable responses of yeast inclusion are usually moderate in ruminant nutrition, these responses are not always observed. The discrepancies of responses of yeast inclusion as a feed additive in different experiments might be attributed to dose, type of diets, strains of yeast, physiological stage and feeding systems. Therefore, yeast products should be added in diets by taking consideration of various interaction factors to achieve the consistent beneficial responses of yeasts in ruminant nutrition. © 2012 Academic Journals Inc.


Patra A.K.,West Bengal University of Animal and Fishery Sciences
Journal of Environmental Monitoring | Year: 2012

Greenhouse gas (GHG; methane and nitrous oxide) emissions from enteric fermentation and manure management of Indian livestock were estimated from the last two Indian livestock census datasets (2003 and 2007) using IPCC Tier 2 (2006) guidelines. The total annual GHG emissions from Indian livestock increased in 2007 compared to the year 2003 with an annual growth rate of 1.52% over this period. The contributions of GHG by dairy cattle, non-dairy cattle, buffaloes, goats, sheep and other animals (yak, mithun, horse, donkeys, pigs and poultry) were 30.52, 24.0, 37.7, 4.34, 2.09 and 3.52%, respectively, in 2007. Enteric fermentation was the major source of methane, accounting for 89.2% of the total GHG emissions, followed by manure methane (9.49%). Nitrous oxide emissions accounted for 1.34%. GHG emissions (CO2-eq. per kg of fat and protein corrected milk (FPCM)) by female animals were considerably lower for crossbred cows (1161 g), followed by buffaloes (1332 g) and goats (2699 g), and were the highest for indigenous cattle (3261 g) in 2007. There was a decreasing trend in GHG emissions (-1.82% annual growth rate) in relation to milk production from 2003 to 2007 (1818 g and 1689 g CO2-eq. per kg FPCM in 2003 and 2007, respectively). This study revealed that GHG emissions (total as well as per unit of products) from dairy and other categories of livestock populations could be reduced substantially through proper dairy herd management without compromising animal production. In conclusion, although the total GHG emissions from Indian livestock increased in 2007, there was a decreasing trend in GHG production per kg of milk production or animal products. © 2012 The Royal Society of Chemistry.


Patra A.K.,West Bengal University of Animal and Fishery Sciences
Environmental Monitoring and Assessment | Year: 2012

Enteric methane (CH4) emission in ruminants, which is produced via fermentation of feeds in the rumen and lower digestive tract by methanogenic archaea, represents a loss of 2% to 12% of gross energy of feeds and contributes to global greenhouse effects. Globally, about 80 million tonnes of CH4 is produced annually from enteric fermentation mainly from ruminants. Therefore, CH4 mitigation strategies in ruminants have focused to obtain economic as well as environmental benefits. Some mitigation options such as chemical inhibitors, defaunation, and ionophores inhibit methanogenesis directly or indirectly in the rumen, but they have not confirmed consistent effects for practical use. A variety of nutritional amendments such as increasing the amount of grains, inclusion of some leguminous forages containing condensed tannins and ionophore compounds in diets, supplementation of low-quality roughages with protein and readily fermentable carbohydrates, and addition of fats show promise for CH4 mitigation. These nutritional amendments also increase the efficiency of feed utilization and, therefore, are most likely to be adopted by farmers. Several new potential technologies such as use of plant secondary metabolites, probiotics and propionate enhancers, stimulation of acetogens, immunization, CH4 oxidation by methylotrophs, and genetic selection of low CH4-producing animals have emerged to decrease CH4 production, but these require extensive research before they can be recommended to livestock producers. The use of bacteriocins, bacteriophages, and development of recombinant vaccines targeting archaeal-specific genes and cell surface proteins may be areas worthy of investigation for CH4 mitigation as well. A combination of different CH4 mitigation strategies should be adopted in farm levels to substantially decrease methane emission from ruminants. Evidently, comprehensive research is needed to explore proven and reliable CH4 mitigation technologies that would be practically feasible and economically viable while improving ruminant production. © Springer Science+Business Media B.V. 2011.


The objective of this study was to investigate the effects of fats in diets of cattle on methane emissions, and associated impacts on digestibility, milk yield and composition, and rumen fermentation by using meta-analysis. For this purpose, a dataset was constructed compiling data from 29 experiments (27 publications) containing 105 dietary treatments arising from 1339 observations in cattle. Fat supplementation decreased methane production (expressed as g/day, g/kg dry matter (DM) intake, g/kg digestible DM intake, g/kg milk, % of gross energy intake) linearly (P<0.01) with moderate degree of relationship (R2=0.38 to 0.63). Fatty acids C12:0 and C18:3 had marked inhibitory effect on methanogenesis compared with other fatty acids in diets. Methane emissions were not considerably affected by total concentration of saturated fatty acid, but were depressed (P<0.05) by total concentrations of mono- and poly-unsaturated fatty acids in diets. Among other nutrient composition of diets, only non-fibrous carbohydrate content affected the response of fats on methane suppression. Methane yield was influenced by the interaction of fatty acid composition and neutral detergent fiber content of diets. Fats showed a quadratic response (P=0.03) on DM intake, although the relationship was very low (R2=0.15). The digestibilities of DM (R2=0.30) and neutral detergent fiber (R2=0.51) reduced linearly (P<0.01) with increasing fat concentrations. Conversely, fat digestibility increased quadratically (P=0.04; R2=0.53) with increasing fat contents. Milk yield increased quadratically (P<0.01; R2=0.41) with increasing fat supplementation. Milk production reached plateau levels within a range of 3.9-6.0% fat concentrations, and then decreased with increasing fat concentrations. Total volatile fatty acids and acetate percentage in rumen fluid were not altered (P>0.10) by fats, but percentage of propionate increased linearly (P=0.03) with increasing fat concentrations in diets. Fats tended to decrease percentage of butyrate (P=0.10) and acetate to propionate ratio (P=0.07) linearly, but degrees of relationship were very low. From this analysis, it can be concluded that fats with high concentrations of C12:0, C18:3 and polyunsaturated fatty acid up to 6% of dietary DM should, in general, be considered when developing effective feeding strategies for methane mitigation without compromising the productivity in dairy cattle. © 2013 Elsevier B.V.


Patra A.K.,West Bengal University of Animal and Fishery Sciences
Asian Journal of Animal and Veterinary Advances | Year: 2011

Essential Oils (EO) are volatile aromatic compounds extracted from whole plants and are secondary metabolites usually made up of terpenoids and phenylpropanoids. Plant EO has antimicrobial properties, which can be effective against undesirable rumen microbes. Therefore, recently it has been great interests among nutritionists and rumen microbiologists to exploit EO as natural feed additives to improve rumen fermentation such as volatile fatty acids production, inhibition of methanogenesis, improvement in protein metabolism and efficiency of feed utilization and increasing conjugated linoleic acids in ruminant derived foods. Different types of EO from a wide range of herbs and spices have been identified to have potential for rumen manipulations and enhancing animal productivity as alternatives to chemical feed additives. However, their effectiveness in ruminant production has not been proved to be consistent and conclusive. There are varying reports of EO on rumen fermentation, rumen microbiota and ruminant performance depending upon the dose, chemical structures of EO, feed composition and animal physiology, which have not always been adequately described in the literature. The comprehensive research based on individual components of EO, physiological status of animals, nutrient composition of diets and their effects on rumen microbial ecosystem and metabolism of EO will be required to obtain consistent beneficial effects. © 2011 Academic Journals Inc.


Patra A.K.,West Bengal University of Animal and Fishery Sciences
British Journal of Nutrition | Year: 2010

Data on N utilisation by sheep-fed diets containing foliages were analysed to develop prediction equations for N excretion in faeces (FN) and urine (UN), and to determine endogenous N excretion. Overall, 218 dietary treatments from forty-four publications were compiled in the database. This database was split into three subsets: without foliage in the diets (FL-0); foliage levels (FL) in between 0 and 310g/kg (FL-L); FL in between 310 and 800g/kg diets (FL-H) to study the effects of foliages on metabolic faecal N (MFN) and endogenous urinary N (EUN). Nitrogen intake (NI) as single independent factor was the best predictor of FN (R2 075), UN (R2 081) and total N excretion (R2 086). Addition of dietary N concentration and FL for FN (R2 082), dietary N concentration and foliage NI for UN (R 2 085), and FL and foliage NI for total N excretion (R2 092) as supporting predictors to this relationship slightly increased R 2 values. The monomolecular and exponential models slightly improved the prediction of N excretion with NI as a predictor compared with the linear model. The excretion of MFN was greater for FL-H compared with FL-0, but was similar between FL-0 and FL-L, and FL-L and FL-H. However, EUN decreased in FL-H compared with FL-0 and FL-L, but was similar between FL-0 and FL-L. In conclusion, using NI as the primary predictor produced an accurate prediction of N excretion. Inclusion of foliages in the diets may shift N excretion from urine to faeces and increase the excretion of MFN and EUN. © 2009 The Authors.


The objective of this study was to investigate the effect of dietary fat supplementation on methane production, digestibility and rumen fermentation in sheep by means of a meta-analysis, and subsequently to compare the results with response in cattle. A dataset was constructed compiling data from ten published publications containing 41 dietary treatments and 259 observations on sheep. Fat supplementation decreased methane production (expressed as g/day, g/kg dry matter (DM) intake, g/kg digestible DM intake, % of gross energy intake) linearly (P<0.05; R2=0.49 to 0.78). Inclusion of fat did not (P=0.21) affect DM intake. However, digestibilities of DM (P=0.04; R2=0.24) and neutral detergent fiber (P=0.09; R2=0.16) reduced linearly with increasing fat concentrations. Conversely, fat digestibility increased quadratically (P=0.03; R2=0.65) with increasing fat contents. Total volatile fatty acids and acetate percentage in rumen fluid were not altered (P>0.10) by dietary fat supplementation. Percentage of propionate increased linearly (P=0.06; R2=0.17), while butyrate percentage (P=0.06; R2=0.21), acetate to propionate ratio (P=0.05; R2=0.22) and ammonia concentration (P=0.02; R2=0.39) in rumen fluid decreased linearly with increasing fat concentrations. Supplementation of fat had greater suppressive effects on methane production expressed as digestible DM intake in sheep than cattle, but had similar responses on digestibility and rumen fermentation. In conclusion, low concentration of fat in the diet may decrease methane emission without adversely affecting rumen fermentation; but it may lower fiber digestibility at high concentrations. © 2014 Elsevier B.V.


Patra A.K.,West Bengal University of Animal and Fishery Sciences
Journal of the Science of Food and Agriculture | Year: 2010

A meta-analysis study was conducted to investigate the changes in rumen fermentation characteristics when methane inhibition by phytochemicals is employed. The whole database containing 185 treatment means from 36 published studies was divided into four subsets according to the major phytochemicals used in the studies, i.e. saponins, tannins, essential oils (EO) and organosulfur compounds (OS). RESULTS: Changes in protozoal numbers showed linear relationships with changes in methane production by saponins (R 2 = 0.48), tannins (R 2 = 0.30) and EO (R 2 = 0.20) but not OS. Concentrations of total volatile fatty acids (VFA) and acetate did not show any relationship (P > 0.1) with changes in methane due to saponins. However, propionate production increased linearly with increasing inhibition of methane (R 2 = 0.31), which resulted in a linear (R 2 = 0.26) decrease in acetate/propionate ratio (A/P) with decreasing methane production. Concentrations of total VFA, acetate and propionate did not change with changes in methane production by tannins. However, A/P showed a significant linear relationship (R 2 = 0.27) with decreasing methane formation. Concentrations of total VFA (R 2 = 0.44) and propionate (R 2 = 0.15) changed linearly and positively with changes in methane production by EO. However, acetate production (R 2 = 0.22) and A/P (R 2 = 0.17) increased linearly with increasing inhibition of methane by EO. Changes in concentrations of total VFA (R 2 = 0.60) and acetate (R 2 = 0.35) decreased linearly while those of propionate increased linearly (R 2 = 0.23) with increasing inhibition of methane by OS. Consequently, A/P decreased linearly (R 2 = 0.30) with decreasing methane production by OS. Digestibilities of organic matter (OM) and neutral detergent fibre were not affected by inhibition of methane production by saponins, EO and OS, but digestibility of OM decreased with decreasing methane production by tannins. CONCLUSION: The inhibition of methane production by phytochemicals results in changes in rumen fermentation that differ depending on the types of phytochemicals. © 2010 Society of Chemical Industry.

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