Molecular link between dietary fibre, gut microbiota and health.

Natural polysaccharides cellulose, hemicelluloses, inulin etc., galactooligosaccharides (GOS), and fructooligosaccharides (FOS) play a significant role in the improvement of gut microbiota balance and human health. These polysaccharides prevent pathogen adhesion that stimulates the immune system and gut barrier function by servicing as fermentable substrates for the gut microbiota. The gut microbiota plays a key role in the fermentation of non-digestible carbohydrates (NDCs) fibres. Moreover, the gut microbiota is responsible for the production of short-chain fatty acids (SCFAs) like acetate, propionate and butyrate. Acetate is the most abundant and it is used by many gut commensals to produce propionate and butyrate in a growth-promoting cross-feeding process. The dietary fibres affect the gut microbiome and play vital roles in signaling pathways. The SCFAs, acetate, butyrate, and propionate have been reported to affect on metabolic activities at the molecular level. Acetate affects the metabolic pathway through the G protein-coupled receptor (GPCR) and free fatty acid receptor 2 (FFAR2/GPR43) while butyrate and propionate transactivate the peroxisome proliferator-activated receptorsγ (PPARγ/NR1C3) and regulate the PPARγ target gene Angptl4 in colonic cells of the gut. The FFAR2 signaling pathway regulates the insulin-stimulated lipid accumulation in adipocytes and inflammation, however peptide tyrosine-tyrosine (PPY) and glucagon-like peptide 1 regulates appetite. The NDCs via gut microbiota dependent pathway regulate glucose homeostasis, gut integrity and hormone by GPCR, NF-kB, and AMPK-dependent processes.

Nutrient utilisation, growth performance and blood metabolites in Murrah buffalo calves (Bubalus bubalis) divergently selected for residual feed intake.

The aim of this study was to evaluate differences in efficiency of feed utilisation between buffalo calves with low and high residual feed intake (RFI) by comparing feed intake, nutrient digestibility, growth traits and blood metabolites. Eighteen male Murrah buffalo calves (aged 4-6 months; 70 ± 1.0 kg body weight) were fed ad libitum with a total mixed ration for 120 d. Based on linear regression models involving dry matter intake (DMI), average daily gain (ADG) and mid-test metabolic body size, calves were assigned into low and high RFI groups. The RFI varied from -0.33 to +0.28 kg DM/d with an average RFI of -0.14 and 0.14 kg DM/d in low and high RFI calves, respectively. Calves had a mean DMI of 1.9 and 2.4 kg/d and an ADG of 0.5 and 0.6 kg/d in low and high RFI groups, respectively. Low RFI calves ate 19.0% less DM each day and required significantly less metabolisable energy for maintenance compared with high RFI calves (12.5 vs. 16.7 MJ/d). Nutrient digestibility and nitrogen balance did not differ among low and high RFI calves. In more efficient animals (low RFI calves) higher (p < 0.05) plasma level of growth hormone, insulin-like growth factor-1 (IGF-1), triiodothyronine (T3) and lower concentration of thyroxin hormone were detected. No significant differences in levels of insulin, hydroxyproline, plasma and urine creatinine, total protein and albumin between high and low RFI groups were found. Blood metabolites showed significant (p < 0.05) differences at initial and final stages of study in both groups. At final stage of study, RFI showed negative correlations with growth hormone, IGF-1, T3, urine creatinine and albumin. Low RFI buffalo calves are more efficient in feed utilisation and the differences in blood metabolites are probably due to differences in feed intake and body metabolism.

Variability in residual feed intake and nutrient utilization in Murrah buffalo heifers.

A feeding trial with 18 Murrah buffalo heifers (238 ± 63 kg; 1.7 ± 0.4 years old) was conducted for 57 days, and feed intake and body weight were recorded followed by 7 days of urine and feces collection. Heifers were grouped into low (RFI-I) and high (RFI-II) feed efficiency groups by regressing DMI (g head-1 day-1) on BWG (g head-1 day-1) and mid-test MBW (kg). RFI-II heifers had slightly higher DMI (g head-1 day-1 and expressed per unit of BW, %BW, MBW, mid-test BW, and mid-test MBW) and all associated nutrient intakes, BWG, feed efficiency traits (FCR, CPCR), digestibility of nutrients, and retentions of crude protein and fat over RFI-I heifers. The corresponding intake values (kg head-1 day-1) for RFI-I versus RFI-II were the following: DMI (6.73 ± 0.56 vs 6.51 ± 0.50), CPI (0.99 ± 0.008 vs 0.97 ± 0.07), DOMI (5.06 ± 0.47 vs 5.11 ± 0.42), and TDNI (4.95 ± 0.47 vs 5.00 ± 0.42). BWG (669 ± 52 vs 776 ± 47 g head-1 day-1), feed efficiency traits (FCR: 10.32 ± 1.16 vs 8.77 ± 1.04 and CPCR: 1.52 ± 0.17 vs 1.30 ± 0.16), N balance (38 ± 9 vs 45 ± 8 g N head-1 day-1), and protein and fat retentions (239 ± 57 vs 282 ± 51 g CP head-1 day-1 and 430 ± 6 vs 494 ± 59 g fat head-1 day-1) of RFI-I were less than RFI-II heifers, respectively. Based on the predicted RFI values, RFI-II buffalo heifers could be selected for feed efficiency.

Nutrient utilisation and methane emissions in Sahiwal calves differing in residual feed intake.

The presented study aimed at investigating the residual feed intake (RFI) of Sahiwal calves, nutrient utilisation as affected by RFI and its relationship with methane (CH4) emissions and some blood metabolites. Eighteen male Sahiwal calves (10-18 months of age; mean body weight 133 kg) were fed ad libitum with a total mixed ration. After calculating RFI for individual calves (-0.40 to +0.34 kg DM/d), they were divided into three groups with low, medium and high RFI, respectively. Dry matter intake (DMI) was higher (p < 0.05) in Group High RFI, whereas digestibility of all nutrients except crude protein and ether extract was significantly higher in Group Low RFI. Nitrogen balance was also significantly higher in Group Low RFI (20.2 g/d) than in Group High RFI (17.0 g/d). Average daily gain and feed conversion ratio were similar among the groups. With exception of glucose, concentrations of all measured blood metabolites were higher in Group High RFI (p < 0.05). Compared with Group High RFI, the CH4 emission of Group Low RFI was significantly lower (on the basis g/d and g/kg DMI by 11% and 19%, respectively). Furthermore, the CH4 emission [g/d] was significantly correlated with RFI (r = 0.77). Because higher feed efficiency and less CH4 production were observed in Group Low RFI, it was concluded that RFI can be used as a measure of feed efficiency, which has a potential to select Sahiwal calves for lowered CH4 emissions.

Methane emissions from river buffaloes fed on green fodders in relation to the nutrient [corrected] intake and digestibility.

Fifteen male Murrah buffalo calves (15-18 months, 227.98 ± 4.44 kg body weight) were distributed randomly in to three equal groups and fed solely on either berseem (G1), oats (G2), or chicory fodder (G3). A digestibility trial followed by methane measurement using SF6 tracer technique was conducted. No significant difference was observed in nutrient intake; however, crude protein (CP) intake was lower in G2 (0.35 kg) than G1 (0.7) and in G3 (0.71) and non-fibrous carbohydrates (NFC), and neutral detergent insoluble CP (NDICP) intake was significantly (p < 0.05) higher in G3 (1.54 and 0.31 kg) followed by G2 (1.27 and 0.2 kg) and G1 (1.06 and 0.18 kg). The digestible dry matter, organic matter, neutral detergent fiber, and ether extract intake was similar in all the groups, whereas the digestible CP and NFC intake was lower in G2 compared to G1 and G3. Chicory- and berseem-fed groups emitted 12.2 and 5.2 % less methane than oats-fed group. However, no significant difference was observed in the absolute methane loss and methane loss as percentage of energy intake (p > 0.05) among the groups. There was positive correlation between nutrient intake and total methane production. However, an inverse relationship was observed between total digestible carbohydrate intake and methane production (g/kg dry matter intake). The following regression equations were developed to estimate methane production: methane (g/kg BW) = 128.8553 + (167.7456 × dNDFI) + (216.32 × dCPI) - (40.3313 × dNFCI) and methane (g/d) = -1.7494 + (41.42 × NDFI) + (39.8686 × CPI) + (0.5197 × NFCI).

Effects of nickel supplementation on nutrient utilization, mineral balance, haematology and antioxidant status of crossbred dairy calves.

BACKGROUND: Nickel has been identified as an important newer trace mineral playing essential role in animals however, its precise mechanism of action in the body is yet to be determined. Interaction of Ni with other essential minerals is suggested in reports limited to lab animals and needs to be explored further in large animals. AIM: This study was conducted to study the influence of Ni supplementation at different levels, on minerals and health status of crossbred dairy calves. METHOD: Twenty-four Karan Fries crossbred (Tharparkar × Holstein Friesian) male dairy calves were selected based on body weight (137.09 ± 5.68) and age (10.78 ± 0.61) and were divided into 4 treatment groups (n = 6) given basal diet supplemented with 0 (Ni0), 5 (Ni5), 7.5 (Ni7.5) and 10 (Ni10) ppm Ni/kg of DM. Nickel was supplemented in the form of nickel sulphate hexahydrate (NiSO4.6 H2O) solution. To ensure the intake of the required amount of nickel by each animal, the calculated quantity of solution was mixed with 250 g concentrate mixture and offered individually to the calves. The calves were fed total mixed ration (TMR) consisting of green fodder, wheat straw and concentrate mixture in the ratio of 40:20:40 and the nutritional requirements were met according to NRC (2001) guidelines. Growth performance was recorded at fortnightly interval whereas, plasma minerals, haematology, antioxidant and immunity parameters were studied at monthly interval during the 150-day experimental period. Nutrient utilization and mineral balances were estimated with the help of a metabolism trial conducted at the end of feeding trial. RESULTS: Supplementation of Ni exhibited no influence on dry matter intake (DMI), body weight, average daily gain (ADG) and nutrient digestibility of dairy calves. However, the absorption and balance of minerals such as Ni, Fe, Cu, Zn and their respective plasma concentration increased (P < 0.05) with Ni supplementation and highest values were observed in calves fed 10 mg Ni/kg DM. The red blood cell (RBC) count, haemoglobin (Hb) concentration, haematocrit (HCT) and activity of superoxide dismutase (SOD) and catalase antioxidant enzymes showed highest increase (P < 0.05) in calves supplemented with Ni at level of 10 mg/kg DM as compared to other treatment groups. However, white blood cell (WBC) count, glutathione peroxidase (GPx), total antioxidant status (TAS), total immunoglobulins and IgG plasma concentration remained unaltered with addition of different levels of Ni in the diet of calves. CONCLUSIONS: The supplementation of Ni at level of 10 mg/kg DM shows a positive effect on status of trace minerals such as Fe, Cu, Zn and improves the physiological conditions and health status of crossbred dairy calves indicated by improved haematology and antioxidant parameters.

Effect of Boron Supplementation on Nutrient Utilization and Productive Performance of Peripartum Murrah Buffaloes.

Boron (B) has been established as a beneficial micronutrient for some farm animals. However, its impact on coping negative energy balance during transition and subsequent production performance needs critical perusal. Therefore, the present study was undertaken to determine the effect of B supplementation on productive performance, apparent nitrogen (N), and mineral utilization in peripartum Murrah buffaloes. Thirty advanced pregnant buffaloes (60 days prior to expected date of calving) were allocated into three groups, i.e. control, B-200, and B-400, and supplemented with pharmacological concentration of B at 0, 200, and 400 ppm, respectively, from 45 days prior to expected date of calving till 120 days post calving. Two metabolism trials were conducted (with animals having similar expected date of calving), one during prepartum (30 days prior to the expected date of calving) and another during postpartum (90 days post calving) phase to evaluate nutrient utilization and balance of N as well as minerals. Results revealed that B supplementation decreased (P < 0.05) overall plasma nonesterified fatty acids (NEFA), whereas plasma level of ß-hydroxybutyric acid, insulin, triglyceride, and glucose did not differ (P > 0.05) among the groups. Dry matter intake, nutrient digestibility, and N balance remained unaffected with B supplementation. Higher (P < 0.05) apparent absorption coefficient for magnesium (Mg) and zinc (Zn) was observed in pregnant animals, while during lactation, absorption coefficient of calcium, Mg, and Zn was increased (P < 0.05) in B-supplemented groups. Hence, it can be concluded that alteration in NEFA concentration and variation in apparent absorption coefficient of minerals with B supplementation suggest its role in energy and mineral metabolism. However, further investigations are required to determine the underlying mechanism of action for the present findings.

Boron supplementation in peripartum Murrah buffaloes: The effect on calcium homeostasis, bone metabolism, endocrine and antioxidant status.

BACKGROUND: Calcium homeostasis and immuno-endocrine system undergoes drastic changes in peripartum dairy animals and failure to adapt these physiological changes causes major impact on animal health as well as productivity. Boron (B), a newer trace element, influences calcium (Ca), phosphorus (P) and magnesium (Mg) metabolism as well as immune system by manipulating several hormones or enzyme systems. Present study was conducted to determine the effect of dietary B supplementation on Ca homeostasis, bone metabolism, endocrine and antioxidant status in peripartum Murrah buffaloes. METHODS: Thirty advanced pregnant Murrah buffaloes (8th month pregnant) were allocated into three groups based on their most probable producing ability (MPPA) and parity (n = 10 in each group) viz. B0, B200 and B400 and supplemented with 0, 200 and 400 ppm of B in the form of boric acid. Blood samples were collected at periodic intervals (-45, -30, -21, -15, -7, 0, 7, 15, 30, 60, 90 and 120 day relative to expected date of calving) and analysed for minerals concentration, hormonal profile, bone health biomarkers and antioxidant enzymes. RESULTS AND CONCLUSION: Boron supplementation at 200 and 400 ppm increased (p < 0.05) plasma Ca, Mg and osteocalcin (OCN) concentration during postpartum stage. Higher (p < 0.05) levels of plasma 25-hydroxy vitamin D3 were observed in both B supplemented groups as compared to B unsupplemented group irrespective of physiological stages. Plasma parathyroid hormone (PTH) and cortisol levels were lower (p < 0.05) in both B supplemented groups than B unsupplemented group, especially during postpartum stage. Whereas, plasma ferric reducing total antioxidant power (FRAP) activity was found to be higher (p < 0.05) in B supplemented groups as compared to B unsupplemented group. Furthermore, antioxidant enzymes (erythrocytic superoxide dismutase; SOD, catalase, glutathione peroxidase; GPx), plasma level of total immunoglobulins (TIg), bone specific alkaline phosphatase (BALP) and tartrate resistant acid phosphatase (TRAP) remained unaffected by dietary B supplementation. Overall, it can be concluded that supplementation of B at 200 ppm in the diet of peripartum Murrah buffaloes helped to induce metabolic adaptations for improving Ca homeostasis, bone metabolism and antioxidant status without much additional benefits at higher level used in the present study.

Exposure to a high selenium environment in Punjab, India: Effects on blood chemistry.

Many studies have shown that overexposure to environmental selenium may exert a wide pattern of adverse effects on human health, but much uncertainty still surrounds some of them as well as the exact amounts of exposure involved. In particular, very few studies have addressed the possible changes in blood chemistry following high selenium exposure. In a Northeastern part of Punjab, India, very high soil selenium content has been documented, with a value exceeding 2 mg/kg (up to 5) as compared with the <0.5 mg/kg selenium content characterizing the surrounding referent areas. In seven villages located in that seleniferous areas, we carried out a survey by recruiting volunteers and sampling blood, hair and nail specimens. We administered a questionnaire to the participants and analyzed the specimens for the selenium, along with a series of biochemical and haematological parameters in blood. We included 680 adult volunteers (267 men and 413 women), who showed median selenium levels of 171.30 µg/L in serum, 1.25 µg/g in hair, and 5.7 µg/g in nails. Overall, increasing selenium exposure tended to correlate with higher levels of total cholesterol, albumin, free triiodothyronine, deionidase activity, and with red cell and platelet counts. After stratifying the subjects according to category of selenium exposure, we observed a dose-response relation between serum selenium and risk of high total cholesterol, and between hair selenium and risk of high total and low-density lipoprotein cholesterol, high pancreatic lipase, altered thyroid-stimulating hormone and free triiodothyronine levels. Nail selenium exposure category positively correlated with risk of high alanine-aminotransferase, altered albumin levels, high pancreatic lipase and low levels of thyroid-stimulating hormone. Chronic selenium overexposure appears to adversely affect lipid profiles and pancreatic, liver, and thyroid function, with selenium biomarkers having different abilities to predict such effects.

Inorganic Vanadium Supplementation in Crossbred Calves: Effects on Antioxidant Status, Immune Response and Haemato-Biochemical Attributes.

The aim of the study was to assess the effect of inorganic vanadium (V) supplementation on antioxidant enzymes, immune status, and haemato-biochemical attributes of growing crossbred calves. Twenty-four male Karan Fries calves (Tharparkar × Holstein Friesian) (initial body mass 72.83 ± 2.5 kg; age 3-9 month) were randomly allocated to four groups: the control (received basal diet devoid of supplemental V), the 3 ppm (received basal diet with 3 mg/kg V), the 6 ppm (received basal diet with 6 mg/kg V) and the 9 ppm group (received basal diet with 9 mg/kg V). All the calves were fed for 150 days as per ICAR (2013) feeding standards to meet their nutrient requirements for 500 g growth rate/day. Peripheral blood samples were collected at the start of experiment and subsequently at 30, 60, 90, 120 and 150 days post-V supplementation for determination of antioxidant enzyme activity, immunological parameters and haemato-biochemical attributes. Results indicated that dietary supplementation of V did not affect daily gain, feed intake and haematological parameters. Crossbred calves fed with 9 mg V/kg diet showed reduced (P < 0.05) plasma total cholesterol concentration; however, plasma total protein and glucose concentration remained unaltered. Glutathione peroxidase (GPx) activity as well as immunoglobulin G (IgG) concentration was significantly (P < 0.05) higher in group supplemented with 9 mg V/kg DM; however, superoxide dismutase (SOD), catalase activity and total plasma immunoglobulin (Ig) concentration were similar in all experimental group. Dietary V supplementation showed a negative relation with plasma thiobarbituric acid reactive substances (TBARS) concentration, whereas non-esterified fatty acid (NEFA) concentration remained unaltered among all groups. Plasma V level increased (P < 0.05) with increasing dietary V levels without affecting levels of Ca, Mg, Fe, Cu and Zn. In conclusion, a dietary addition of 9 mg V/kg DM reduced cholesterol content and improved antioxidant and immune response in growing crossbred calves.

Fractionation of carbohydrate and protein content of some forage feeds of ruminants for nutritive evaluation.

AIM: To evaluate some forage feeds of ruminants in terms of their carbohydrate (CHO) and protein fractions using Cornell Net Carbohydrate and Protein System (CNCPS). MATERIALS AND METHODS: Eleven ruminant feeds (six green fodders - maize, oat, sorghum, bajra, cowpea, berseem and five range herbages - para grass, guinea grass, hedge lucerne, setaria grass and hybrid napier) were selected for this study. Each feed was chemically analyzed for proximate principles (dry matter, crude protein [CP], ether extract, organic matter and ash), fiber fractions (neutral detergent fiber, acid detergent fiber, acid detergent lignin, cellulose and hemicellulose), primary CHO fractions (CHO, non-structural CHO, structural CHO and starch) and primary protein fractions (neutral detergent insoluble CP, acid detergent insoluble CP, non-protein nitrogen and soluble protein). The results were fitted to the equations of CNCPS to arrive at various CHO (CA - fast degrading, CB1 - intermediate degrading, CB2 - slow degrading and CC - non-degrading or unavailable) and protein (PA - instantaneously degrading, PB1 - fast degrading, PB2 - intermediate degrading, PB3 - slow degrading and PC - non-degrading or unavailable) fractions of test feeds. RESULTS: Among green fodders, cowpea and berseem had higher CA content while except hedge lucerne all range herbages had lower CA values. CB1 content of all feeds was low but similar. All feeds except cowpea, berseem, and hedge lucerne contained higher CB2 values. Oat among green fodders and hybrid napier among range herbages had lower CC fraction. Feeds such as bajra, cowpea, berseem and the setaria grass contained lower PA fraction. All green fodders had higher PB1 content except maize and cowpea while all range herbages had lower PB1 values except hedge lucerne. Para grass and hybrid napier contained exceptionally low PB2 fraction among all feeds. Low PC contents were reported in oat and berseem fodders. CONCLUSION: Based on our findings, it was concluded that feeds with similar CP and CHO content varied significantly with respect to their CHO and protein fractions. Due to lower CC fraction, oat and hybrid napier were superior feeds in terms of CHO supply to ruminants. Similarly, among all feeds oat and berseem had a lower PC fraction, thus were considered good sources of protein for ruminants.

Evaluation of various feedstuffs of ruminants in terms of chemical composition and metabolisable energy content.

AIM: The aim was to determine the chemical composition and metabolisable energy (ME) content of feedstuffs used in ruminant animals using in vitro method. MATERIALS AND METHODS: A total of 18 feedstuffs used for ruminant feeding including cultivated non-leguminous fodders like maize, sorghum, pearl millet, and oat; leguminous fodders like cowpea and berseem; agro-industrial by-products such as wheat bran, deoiled rice bran, rice polish, wheat straw, and concentrates such as mustard oil cake, groundnut cake, soybean meal, cotton seed cake, grains like maize, oat, wheat, and barley were taken for this study. Chemical compositions and cell wall constituents of test feeds were determined in triplicate. The crude protein (CP) content was calculated as nitrogen (N) × 6.25. True dry matter digestibility (TDMD), true organic matter digestibility (TOMD), ME, and partitioning factor (PF) values were determined by in vitro gas production technique (IVGPT). RESULTS: The CP content of non-leguminous fodders varied from 7.29% (sorghum) to 9.51% (maize), but leguminous fodders had less variation in CP. Oilseed cakes/meals had high CP and ether extract (EE) content than other feedstuffs except rice polish, which had 12.80% EE. Wheat straw contained highest fiber fractions than the other ingredients. ME content was highest in grains (wheat-12.02 MJ/kg) and lowest in wheat straw (4.65 MJ/kg) and other roughages. TDMD of grains and oilseed cakes/meals were higher than the fodders and agro-industrial by-products. The same trend was observed for TOMD. CONCLUSIONS: It was concluded that the energy feeds showed a great variation in chemical composition and ME content. The results of this study demonstrated that the kinetics of gas production of energy feed sources differed among themselves. Evaluation of various feedstuffs is helpful in balanced ration formulation for field animals and under farm conditions for better utilization of these commonly available feed resources.