Urinary Excretion Of Purine Derivatives Research Articles

Effects of folic acid on growth performance, ruminal fermentation, nutrient digestibility and urinary excretion of purine derivatives in post-weaned dairy calves

ABSTRACTThis study evaluated the effects of folic acid (FA) supplementation on growth performance, ruminal fermentation, nutrient digestibility and urinary purine derivatives (PD) excretion in dairy calves. Forty-eight Chinese Holstein male dairy calves at 60 ± 3.2 d of age and 89 ± 5.9 kg body weight (mean ± standard error) were assigned to one of four groups in a randomised block design. Calves in control group were fed basal diet, calves in low FA, medium FA and high FA groups with 3.6, 7.2 and 10.8 mg FA per kg basal diet, respectively. The dietary corn silage to concentrate ratio was 50:50 (dry matter [DM] basis). DM intake and average daily gain (ADG) quadratically increased, and feed conversion ratio quadratically decreased with increasing FA supplementation. Ruminal pH linearly decreased, whereas total volatile fatty acids quadratically increased. The unchanged acetate-to-propionate ratio was due to the similar change in acetate and propionate concentration. Ammonia N content quadratically decreased. Digestibility of DM, organic matter, crude protein, ether extract, neutral detergent fibre and acid detergent fibre linearly increased. Activities of carboxymethyl cellulase, cellobiase, xylanase and pectinase linearly increased, but α-amylase and protease quadratically increased. Abundance of Ruminococcus albus, Ruminococcus flavefaciens and Fibrobacter succinogenes linearly increased, but Butyrivibrio fibrisolvens and Prevotella ruminicola quadratically increased. Urinary total PD excretion quadratically increased. The results indicated that FA supplementation increased ADG, ruminal fermentation and nutrient digestibility with promoted ruminal microbial growth and enzyme activity, and the optimum dose was 7.2 mg FA per kg basal diet for calves.

Evaluation of collection days and times to estimate urinary excretion of purine derivatives and nitrogen compounds in grazing Nellore cattle

ABSTRACT The objectives of this study were to evaluate the effects of collection day and 4-hour collection times on the urinary excretion of creatinine, purine derivatives (PD), and nitrogen compounds in grazing Zebu cattle. Five Nellore heifers (300 ± 15.2 kg body weight [BW]) were used in a 5 × 5 Latin square design. Five treatments were tested: a mineral mixture supplied at 60 g/day (g/d) (control – CON); two treatments higher in salt and urea to achieve a reduced ad libitum intake of supplements: one with 39.7% crude protein (CP) on a dry matter (DM) basis (RI40) and another with 69.4% CP (RI70), both fed ad libitum; and two supplements with restricted feeding rates relative to BW: both with 20.3% of CP fed at 5 g/kg BW (BW5) or 10 g/kg BW (BW10). Each experimental period lasted 17 d (12 used for adaptation and 5 for sample collection). Six collection times at 4-hour intervals were established for each 24-hour collection day. For total urine collection, a Foley catheter was used and the collection bag attached to the animal was emptied every 4 h. Collection day, collection time, treatment or their interactions (P > 0.05) had no effect on urinary excretions of creatinine, allantoin, uric acid, and PD, nor on their ratio with creatinine. However, an interaction between collection times and treatment (P

Effect of corn supplementation on purine derivatives and rumen fermentation in sheep fed PKC and urea-treated rice straw

This study investigated the effect of different levels of corn supplementation as energy source into palm kernel cake–urea-treated rice straw basal diet on urinary excretion of purine derivatives, nitrogen utilization, rumen fermentation, and rumen microorganism populations. Twenty-seven Dorper lambs were randomly assigned to three treatment groups and kept in individual pens for a 120-day period. The animals were subjected to the dietary treatments as follows: T1: 75.3% PKC + 0% corn, T2: 70.3% PKC + 5% corn, and T3: 65.3% PKC + 10% corn. Hypoxanthine and uric acid excretion level were recorded similarly in lambs supplemented with corn. The microbial N yield and butyrate level was higher in corn-supplemented group, but fecal N excretion, T3 has the lowest level than other groups. Lambs fed T3 had a greater rumen protozoa population while the number of R. flavefaciens was recorded highest in T2. No significant differences were observed for total bacteria, F. succinogenes, R. albus, and methanogen population among all treatment. Based on these results, T3 could be fed to lambs without deleterious effect on the VFA and N balance.

Effect of oak (Quercus persica) acorn level on apparent digestibility, ruminal fermentation, nitrogen balance and urinary purine derivatives in pregnant goats.

The aim of this experiment was to investigate the effect of dietary oak (Quercus persica) acorn (OA) level on dry matter intake (DMI), apparent nutrient digestibility, nitrogen (N) utilization, ruminal fermentation, protozoa population and urinary purine derivatives (PD) during the last 60days of goat pregnancy. Twenty-four multiparous pregnant goats (41.7±2.3kg BW) were assigned to one of three experimental diets consisted of control diet (C, without OA) and diets containing 20 (OA20 ) or 40g/100g of OA (OA40 ) on a DM basis in a completely randomized block design. Goats fed OA40 had lower DMI (p<.01), DM (p<.01), OM (p<.01) and NDF (p<.05) digestibility, ruminal NH3 -N concentration (p<.01), N intake (p<.01) and N retention (p<.01). Crude protein digestibility and ruminal acetate and total volatile fatty acid (VFA) concentration were lower in animals fed OA-contained diets (p<.01), whereas ruminal propionate concentration was higher in goats fed the C diet (p<.01). Animals fed OA40 had higher faecal N excretion and lower urinary N excretion (p<.01). Urinary PD was lower in goats fed diets containing OA in relation to those fed the C diet (p<.01). Total protozoa population decreased linearly with increasing OA level in the diet (p<.05). These results suggest that feeding OA, especially high level, has negative impacts on DMI, nutrient digestibility, VFA concentration, N retention and urinary PD excretion that may have adverse effects on metabolism and performance of pregnant goats.

Effects of concentrate-to-forage ratios and 2-methylbutyrate supplementation on ruminal fermentation, bacteria abundance and urinary excretion of purine derivatives in Chinese Simmental steers.

This study evaluated the effects of dietary concentrate levels and 2-methylbutyrate (2MB) supplementation on performance, ruminal fermentation, bacteria abundance, microbial enzyme activity and urinary excretion of purine derivatives (PD) in steers. Eight ruminally cannulated Simmental steers (12months of age; 389±3.7kg of body weight) were used in a replicated 4×4 Latin square design with a 2×2 factorial arrangement. Moderate-concentrate (400g/kg diet [MC]) or high-concentrate (600g/kg diet [HC]) diets were fed with or without 2MB (0g/day [2MB-] or 15.0g/day [2MB+]). Dry matter intake and average daily gain increased, but feed conversion ratio decreased with the HC diet or 2MB supplementation. Ruminal pH decreased, but total volatile fatty acid increased with the HC diet or 2MB supplementation. Molar proportion of acetate and acetate-to-propionate ratio decreased with the HC diet, but increased with 2MB supplementation. Propionate molar proportion and ruminal NH3 -N content increased with the HC diet, but decreased with 2MB supplementation. Neutral detergent fibre degradability decreased with the HC diet, but increased with 2MB supplementation. Crude protein degradability increased with the HC diet or 2MB supplementation. Abundance of Ruminococcus albus, Ruminococcus flavefaciens, Fibrobacter succinogenes and Bufyrivibrio fibrisolvens as well as activities of carboxymethyl cellulase, cellobiase, xylanase and pectinase decreased with the HC diet, but increased with 2MB supplementation. However, abundance of Prevotella ruminicola and Ruminobacter amylophilus as well as activities of α-amylase and protease increased with the HC diet or 2MB supplementation. Total PD excretion also increased with the HC diet or 2MB supplementation. The results suggested that growth performance, ruminal fermentation, CP degradability and total PD excretion increased with increasing dietary concentrate level from 40% to 60% or 2MB supplementation. The observed diet×2MB interaction indicated that supplementation of 2MB was more efficacious for improving growth performance, ruminal fermentation and total PD excretion with promoted ruminal bacteria abundance and enzyme activity in the MC diet than in the HC diet.

Replacing maize silage plus soybean meal with red clover silage plus wheat in diets for lactating dairy cows

The objectives of this study were to evaluate the effects of replacing maize silage plus soybean meal with red clover silage (RCS) plus wheat on feed intake, diet digestibility, N partitioning, urinary excretion of purine derivatives, and milk production in dairy cows. Forty-four lactating German Holstein cows were used in a 4 × 4 Latin square design with 21-d periods composed of a 13-d adaptation phase followed by an 8-d sampling phase. Experimental diets offered as total mixed ration consisted of a constant forage-to-concentrate ratio (75:25) with targeted proportions of RCS-to-maize silage of 15:60 (RCS15), 30:45 (RCS30), 45:30 (RCS45), and 60:15 (RCS60) on a dry matter (DM) basis. Increasing the proportion of RCS plus wheat in the diet decreased linearly the intake of DM from 22.4 to 19.8 kg/d, and of organic matter from 21.1 to 18.1 kg/d. The apparent total tract digestibility (ATTD) of DM and organic matter did not differ across diets and averaged 68.4 and 70.5%, respectively. However, ATTD of N decreased linearly from 68.5 to 63.2%, whereas ATTD of neutral detergent fiber and acid detergent fiber increased linearly from 50.4 to 59.6% and from 48.4 to 57.7%, respectively, when increasing the proportion of RCS plus wheat. Fecal N excretion increased from 31.6 (RCS15) to 37.2% (RCS60) of N intake, whereas urinary N excretion was the lowest (32.8% of N intake) with RCS45. Hence, N efficiency (milk N/N intake) decreased linearly with incremental levels of RCS plus wheat, being the lowest when feeding RCS60 (25.4%), probably due to increased nonprotein N proportion in total dietary N. Urinary excretion of purine derivatives decreased linearly from 378 to 339 mmol/d, which suggests that increasing levels of RCS plus wheat reduced the microbial crude protein flow at the duodenum. Milk yield and milk protein concentration declined linearly from 35.9 to 30.2 kg/d and from 3.20 to 3.01%, respectively, when increasing the proportion of RCS plus wheat. In conclusion, caution should be taken before introducing high levels of RCS plus wheat in diets of high-yielding dairy cows. However, RCS plus wheat can be included up to 30% of the dairy cow diet (DM basis) without a reduction in lactation performance.

Response of rumen bacterial diversity and fermentation parameters in beef cattle to diets containing supplemental daidzein

An experiment was conducted to determine the effects of soy isoflavone daidzein on ruminal fermentation, microbial protein synthesis and rumen bacterial community in beef cattle. Six rumen-cannulated adult beef cattle were assigned to three blocks according to similar body weight in a randomised block design, with two cattle each block. Each block randomly received one of the two dietary treatments: control (basal concentrate) and daidzein (supplementation with 500 mg daidzein/kg basal concentrate). High-throughput sequencing data showed that supplemental daidzein increased the relative abundance of bacteria belonging to phylum Bacteroidetes (p = .050), but reduced and tended to reduce the relative abundance of phylum Spirochaetae (p = .030) and Firmicutes (p = .080). At the genus level, the relative abundance of Prevotella (p = .036), RC9_gut_group (p = .019), Succinivibrio (p = .093) and Ruminobacter (p = .085) were increased or tended to be increased by daidzein supplementation. However, supplemental daidzein reduced or tended to reduce some uncultured and unclassified bacteria genus belonging to Ruminococcaceae (p = .028), Prevotellaceae (p = .088) and Lachnospiraceae (p = .068). The ruminal pH (p = .023) and ammonia-N (p = .031) concentration were lower in the daidzein group than in the control group, but the daidzein group tended to have greater ruminal total VFA (p = .063) concentration. Supplemental daidzein increased urinary excretion of allantoin (p = .005) and total purine derivatives (p = .007). Current results suggest that supplemental daidzein can affect ruminal fermentation by changing ruminal microbial community, increase the production of VFA and enhance microbial protein synthesis in the rumen, showing the potential of daidzein for improving ruminal fermentation in beef cattle.

Effects of dietary protein levels and 2-methylbutyrate on ruminal fermentation, nutrient degradability, bacterial populations and urinary purine derivatives in Simmental steers.

The objective of this study was to evaluate the effects of dietary crude protein (CP) levels and 2-methylbutyrate (MB) supplementation on ruminal fermentation, bacterial populations, microbial enzyme activity and urinary excretion of purine derivatives (PD) in Simmental steers. Eight ruminally cannulated Simmental steers, averaging 18months of age and 465±8.6kg of body weight (BW), were used in a replicated 4×4 Latin square design by a 2×2 factorial arrangement. Low protein (98.5g CP/kg dry matter [LP] or high protein (128.7g CP/kg dry matter [HP]) diets were fed with MB supplementation (0g [MB-] or 16.8gsteer-1 day-1 [MB+]). Steers were fed a total mixed ration with dietary corn straw to concentrate ratio of 50:50 (dry matter [DM] basis). The CP×MB interaction was observed for ruminal total VFA, molar proportions of acetate and propionate, acetate to propionate ratio, ammonia-N, effective degradability of neutral detergent fibre (NDF) and CP, microbial enzyme activity, bacterial populations and total PD excretion (p<.05). Ruminal pH decreased (p<.05), but ruminal total VFA concentration increased (p<.05) with increasing dietary CP level or MB supplementation. Acetate molar proportion increased (p=.043) with MB supplementation, but was not affected by dietary CP level. Propionate molar proportion decreased (p<.05) with increasing dietary CP level or MB supplementation. Consequently, acetate-to-propionate ratio increased (p=.001) with MB supplementation, but was not affected by dietary CP level. Ruminal ammonia-N content increased (p=.034) with increasing dietary CP level, but decreased (p=.012) with MB supplementation. The effective degradability of NDF and CP increased (p<.05) with increasing dietary CP level or MB supplementation. Microbial enzyme activity, bacterial populations and total PD excretion also increased (p<.05) with increasing dietary CP level or MB supplementation. The results indicated that ruminal fermentation, nutrient degradability, microbial enzyme activity, ruminal bacterial populations and microbial protein synthesis improved with increasing dietary CP level or MB supplementation in steers.

Urinary purine derivatives as a tool to estimate dry matter intake in cattle: A meta-analysis

The objectives of this study were to investigate the relationship between dry matter intake (DMI) and urinary purine derivative (PD) excretion, to develop equations to predict DMI and to determine the endogenous excretion of PD for beef and dairy cattle using a meta-analytical approach. To develop the models, 62 published studies for both dairy (45 studies) and beef cattle (17 studies) were compiled. Twenty models were tested using DMI (kg/d) and digestible DMI (dDMI, kg/d) as response variables and PD:creatinine (linear term: PD:C, and quadratic term: PD:C2), allantoin:creatinine (linear term: ALLA:C, and quadratic term: ALLA:C2), metabolic body weight (BW0.75, kg), milk yield (MY, kg/d), and their combination as explanatory variables for dairy and beef (except for MY) cattle. The models developed to predict DMI for dairy cattle were validated using an independent data set from 2 research trials carried out at the University of Wisconsin (trial 1: n = 45; trial 2: n = 50). A second set of models was developed to estimate the endogenous PD excretion. In all evaluated models, the effect of PD (either as PD:C or ALLA:C) was significant, supporting our hypothesis that PD are in fact correlated with DMI. Despite the BW-independent relationship between PD and DMI, the inclusion of BW0.75 in the models with PD:C and ALLA:C as predictors slightly decreased the values of root mean square error (RMSE) and Akaike information criterion for the models of DMI. Our models suggest that both DMI and dDMI can be equally well predicted by PD-related variables; however, predicting DMI seems more useful from a practical and experimental standpoint. The inclusion of MY into the dairy models substantially decreased RMSE and Akaike information criterion values, and further increased the precision of the equations. The model including PD:C, BW0.75, and MY presented greater concordance correlation coefficient (0.93 and 0.63 for trials 1 and 2, respectively) and lower RMSE of prediction (1.90 and 3.35 kg/d for trials 1 and 2, respectively) when tested in the validation data set, emerging as a potentially useful estimator of nutrient intake in dairy cows. Endogenous PD excretion was estimated by the intercept of the linear regression between DMI (g/kg of BW0.75) and PD excretion (mmol/kg of BW0.75) for beef (0.404 mmol/kg of BW0.75) and dairy cattle (0.651 mmol/kg of BW0.75). Based on the very close agreement between our results for beef cattle and the literature, the linear regression appears to be an adequate method to estimate endogenous PD excretion.

Effects of different dietary protein levels and rumen-protected folic acid on ruminal fermentation, degradability, bacterial populations and urinary excretion of purine derivatives in beef steers

SUMMARYThe current experiment was conducted to evaluate the effects of different dietary protein levels and rumen-protected folic acid (RPFA) supplementation on ruminal fermentation, microbial enzyme activity, bacterial populations and urinary excretion of purine derivatives (PD) in growing beef steers. Low-protein (LP) or high-protein (HP) diets were fed to eight ruminally cannulated first-generation cross-bred (Blonde d'Aquitaine × Simmental) beef steers with or without RPFA supplementation. Steers were fed a total mixed ration, and dietary concentrate to maize silage ratio was 50 : 50 (dry matter (DM) basis). No interaction between dietary crude protein (CP) levels and RPFA supplementation was observed during the experiment. Ruminal pH was unaffected by RPFA supplementation, but decreased with increasing dietary CP levels. Ruminal total volatile fatty acid concentration increased with increasing dietary CP levels or RPFA supplementation. Molar proportion of acetate increased with RPFA supplementation, but tended to decrease with increasing dietary CP levels. The proportion of propionate decreased with RPFA supplementation, but was unaffected by dietary CP levels. As a result, the acetate to propionate ratio increased with RPFA supplementation, but tended to be lower for the HP diets than the LP diets. Ammonia-nitrogen content decreased with RPFA supplementation, but increased with increasing dietary CP levels.In situruminal degradability of maize straw and concentrate increased with increasing dietary CP levels or RPFA supplementation. Microbial enzyme (carboxymethyl-cellulase, cellobiase, xylanase, pectinase,α-amylase and protease) activity, bacterial populations (Ruminococcus albus,Ruminococcus flavefaciens,Butyrivibrio fibrisolvens,Prevotella ruminicola,Fibrobacter succinogenesandRuminobacter amylophilus) and urinary PD excretion increased with increasing dietary CP levels or RPFA supplementation. The current study showed that increasing dietary CP levels from 109·1 to 130·7 g/kg DM or supplementing 75 mg RPFA improved ruminal fermentation and microbial protein synthesis by increasing bacterial population and microbial enzyme activity.

Effects of dietary protein levels and rumen-protected pantothenate on ruminal fermentation, microbial enzyme activity and bacteria population in Blonde d'Aquitaine × Simmental beef steers

This study was undertaken to investigate the effects of dietary crude protein (CP) levels and rumen-protected pantothenate (RPP) supplementation on ruminal digestion kinetics, fermentation, microbial enzymatic activity, and selected bacterial species relative abundance in beef steers. Eight ruminally cannulated crossbred beef steers, with 15 months of age and 462±9kg of body weight (BW), were used in a duplicated 4×4 Latin square design by a 2×2 factorial arrangement. Low protein (113.7g/kg of CP [LP] or high protein (133.9g/kg of CP [HP]) diets were fed with or without RPP supplementation (0g [RP-] or 0.48g per kg dietary dry matter (DM) [RP+]). Steers were fed a total mixed ration containing dietary concentrate to corn silage ratio of 50:50 on a DM basis. There were no RPP×CP interactions for ruminal digestion kinetics, fermentation, microbial enzymatic activity, and selected bacterial species relative abundance, except for Ruminobacter amylophilus. Mean ruminal pH decreased with RPP supplementation, but was unaffected by dietary CP levels. Ruminal total VFA concentration increased with increasing dietary CP levels or RPP supplementation. Ruminal acetate percentage was similar among treatments, whereas propionate percentage decreased with increasing dietary CP levels or RPP supplementation. Consequently, the acetate to propionate ratio increased with increasing dietary CP levels or RPP supplementation. Ruminal ammonia-N content was unchanged among treatments. Both in situ ruminal DM degradability of corn silage and CP degradability of concentrate increased with RPP supplementation and tended to increase with increasing dietary CP levels, while NDF degradability of corn silage and DM degradability of concentrate increased with increasing dietary CP levels or RPP supplementation. Activities of carboxymethyl-cellulase, cellobiase, xylanase, pectinase, α-amylase and protease, populations of Ruminococcus albus, Ruminococcus flavefaciens, Butyrivibrio fibrisolvens and Prevotella ruminicola, and urinary excretion of purine derivatives increased with increasing dietary CP levels or RPP supplementation, but populations of Fibrobacter succinogenes and R. amylophilus increased with RPP supplementation, and decreased with increasing dietary CP levels. The results showed that increasing dietary CP levels from 113.7g to 133.9g or with 0.48g RPP supplementation improved ruminal fermentation and microbial protein synthesis by increasing microbial populations and enzymes activities.

Microbial protein estimation in Murrah buffalo calves fed on diets with varying levels of energy and protein

A study was conducted to predict the effect of energy and protein levels in diet on rumen microbial protein production in Murrah buffalo calves. Microbial protein was estimated from urinary excretion of purine derivatives. Six diets were formulated to provide 90% (12.30% CP), 100% (13.70% CP), and 110% (15.15% CP) protein level, and 90% (2.20 Mcal ME/kg DM) and 110% (2.42 Mcal ME/kg DM) energy level of ICAR 2013 recommendations for buffalo calves. Thirty calves (body weight; 254±7.4 kg) were divided into 6 groups and fed in 2×3 factorial designs. Dry matter intake was recorded by feeding animals for experimental period of 150 days. At the end of feeding trial, urine samples were collected. Collection, preservation, analysis and calculation of urinary purine derivatives were performed by methods described by IAEA (1997). Allantoin constituted the principal PD in the urine. Allantoin and uric acid ranged from 19.93 to 21.37 mmol/day and 2.32 to 3.49 mmol/day, respectively. Total PD varied from 23.01 to 24.28 mmol/day, whereas PD per kg BW0.75 was within ranges of 362.77 to 384.23 mmol. The microbial N per kg DOMI or digestible OM retention (DOMR) was significantly higher in lower dietary energy group compared to higher ones. There was no significant effect of the energy and protein levels on allantoin, uric acid, creatinine, total purine derivatives and microbial N production per metabolic body weight (kg) in buffaloes. But microbial N production per digestible organic matter intake increased with decreased energy levels, whereas there was no significant effect of protein levels on it. Thus there was efficient conversion of feed N to microbial protein at CP of 12.3% and ME of 2.20 Mcal/kg DM in 250 kg BW Murrah buffaloes.

Effect of condensed tannins from Ficus infectoria and Psidium guajava leaf meal mixture on nutrient metabolism, methane emission and performance of lambs.

ObjectiveThe study examined the effect of condensed tannins (CT) containing Ficus infectoria and Psidium guajava leaf meal mixture (LMM) supplementation on nutrient metabolism, methane emission and performance of lambs.MethodsTwenty four lambs of ~6 months age (average body weight 10.1±0.60 kg) were randomly divided into 4 dietary treatments (CT-0, CT-1, CT-1.5, and CT-2 containing 0, 1.0, 1.5, and 2.0 percent CT through LMM, respectively) consisting of 6 lambs each in a completely randomized design. All the lambs were offered a basal diet of wheat straw ad libitum, oat hay (100 g/d) along with required amount of concentrate mixture to meet their nutrient requirements for a period of 6 months. After 3 months of experimental feeding, a metabolism trial of 6 days duration was conducted on all 24 lambs to determine nutrient digestibility and nitrogen balance. Urinary excretion of purine derivatives and microbial protein synthesis were determined using high performance liquid chromatography. Respiration chamber study was started at the mid of 5th month of experimental feeding trial. Whole energy balance trials were conducted on individual lamb one after the other, in an open circuit respiration calorimeter.ResultsIntake of dry matter and organic matter (g/d) was significantly (p<0.05) higher in CT-1.5 than control. Digestibility of various nutrients did not differ irrespective of treatments. Nitrogen retention and microbial nitrogen synthesis (g/d) was significantly (p<0.01) higher in CT-1.5 and CT-2 groups relative to CT-0. Total body weight gain (kg) and average daily gain (g) were significantly (linear, p<0.01) higher in CT-1.5 followed by CT-1 and CT-0, respectively. Feed conversion ratio (FCR) by lambs was significantly (linear, p<0.01) better in CT-1.5 followed by CT-2 and CT-0, respectively. Total wool yield (g; g/d) was linearly (p<0.05) higher for CT-1.5 than CT-0. Methane emission was linearly decreased (p<0.05) in CT groups and reduction was highest (p<0.01) in CT-2 followed by CT-1.5 and CT-1. Methane energy (kcal/d) was linearly decreased (p<0.05) in CT groups.ConclusionThe CT supplementation at 1% to 2% of the diet through Ficus infectoria and Psidium guajava LMM significantly improved nitrogen metabolism, growth performance, wool yield, FCR and reduced methane emission by lambs.

Effects of rumen-protected pantothenate on ruminal fermentation, microbial enzyme activity, cellulolytic bacteria and urinary excretion of purine derivatives in growing beef steers

This experiment was to evaluate the effects of rumen-protected pantothenate (RPP) on ruminal fermentation, microbial enzyme activity, bacteria population and urinary excretion of purine derivatives in growing beef steers. Eight ruminally cannulated first-generation crossbred (Blonde d′Aquitaine × Simmental) beef steers, averaging 12 months of age and 363 ± 7kg of body weight (BW), were allocated into a replicated 4 × 4 Latin square design. Four treatments were control, low-RPP (LRPP), medium-RPP (MRPP) and high-RPP (HRPP) with 0, 0.32, 0.48 and 0.64g RPP per kg dietary DM, respectively. Steers were fed a total mixed ration and dietary concentrate to corn silage ratio was 50:50 based on a dry matter (DM) basis. The experiment included four periods and lasted for 96 days, each period contained 14 days of adaptation and 10 days of data collection. Ruminal pH decreased linearly with increasing RPP supplementation and was lower for MRPP than for control. Ruminal total VFA concentration increased linearly with increasing RPP supplementation and was higher for MRPP than for control. The acetate to propionate ratio increased linearly due to the unchanged acetate molar proportion and the tendency towards decreased propionate proportion. Ruminal DM and neutral detergent fibre degradability of corn silage increased quadratically, whereas DM and crude protein degradability of concentrate mix increased linearly with increasing RPP supplementation. Activities of carboxymethyl-cellulase, cellobiase, xylanase and α-amylase increased linearly and was higher for MRPP than for control. Populations of R. albus, R. flavefaciens, F. succinogenes, B. fibrisolvens, P. ruminicola and R. amylophilus increased linearly and quadratically with increasing RPP supplementation. Urinary excretion of purine derivatives increased linearly with increasing RPP supplementation and was higher for HRPP and MRPP than for LRPP and control. The results indicated that dietary supplementary RPP improved ruminal fermentation, in situ ruminal degradation and urinary excretion of purine derivatives by stimulating bacteria growth and microbial enzymes secretion. It is suggested that supplementary RPP regulated bacteria growth and microbial enzymes secretion in a dose-dependent manner. Under the current experimental condition, the appropriate dose of RPP was at 0.48g per dietary DM for growing crossbred beef steer.

Production and nitrogen utilization in lactating dairy cows fed ground field peas with or without ruminally protected lysine and methionine.

Previous research has shown that cows fed ≥24% of the diet dry matter (DM) as field peas decreased milk yield as well as concentration and yield of milk protein, possibly due to reduced DM intake and limited supply of Lys and Met. Twelve multiparous and 4 primiparous lactating Holstein cows were randomly assigned to 1 of 4 diets in a replicated 4 × 4 Latin square design. The diets contained (DM basis) 34.8% corn silage, 15.2% grass-legume silage, 5.9% roasted soybean, 2.4% mineral-vitamin premix, 2.0% alfalfa pellets, and either (1) 36% ground corn, 2.4% soybean meal, and 1.3% urea (UR), (2) 29.7% ground corn, 9.8% soybean meal, 0.13% ruminally protected (RP) Lys, and 0.07% RP-Met (CSBAA), (3) 25% ground field peas, 12.3% ground corn, and 2.4% soybean meal (FP), or (4) FP supplemented with 0.15% RP-Lys and 0.05% RP-Met (FPAA). Our objective was to test the effects of FP versus UR, FPAA versus CSBAA, and FPAA versus FP on milk yield and composition, N utilization, nutrient digestibility, ruminal fermentation profile, and plasma concentration of AA. Milk yield did not differ across diets. Compared with cows fed UR, those fed FP had greater DM intake, concentration and yield of milk true protein, apparent total-tract digestibility of fiber, urinary excretion of purine derivatives, and concentrations of total volatile fatty acids in the rumen and Lys in plasma, and less milk urea N and ruminal NH3-N. The concentration of milk urea N, as well as the concentration and yield of milk fat increased in cows fed FPAA versus CSBAA. Moreover, cows fed FPAA had greater ruminal concentration of total volatile fatty acids, increased proportions of acetate and isobutyrate, and decreased proportions of propionate and valerate than those fed CSBAA. The plasma concentrations of His, Leu, and Phe decreased, whereas plasma Met increased and plasma Lys tended to increase in cows fed FPAA versus CSBAA. Concentration of milk true protein, but not yield, was increased in cows fed FPAA versus FP. However, cows fed FPAA showed decreased concentrations of His and Leu in plasma compared with those fed FP. Overall, compared with the CSBAA diet, feeding FPAA did not negatively affect milk yield and milk protein synthesis. Furthermore, RP-Lys and RP-Met supplementation of the FP diet did not improve milk yield or milk protein synthesis, but decreased urinary urea N excretion.

Feed intake and urinary excretion of nitrogen and purine derivatives in pregnant suckler cows fed alternative roughage-based diets

This study compared intake of alternative roughage-based diets and of common late-cut grass silage and related intake to urinary nitrogen (N), urea-N and purine derivative (PD) excretion, where PD is an indicator of rumen microbial crude protein (MCP) synthesis. Total urine was collected from 36 Hereford cows, blocked into three groups based on expected calving date. Cows within calving groups were randomly assigned to one of four roughage diets: common mixed grass silage (MGS), festulolium silage plus urea (FLS), reed canarygrass silage (RCS) and barley straw plus urea and rapeseed meal (BRM). Diet crude protein (CP) content was classified into five fractions (A, B1, B2, B3 and C), based on degradability characteristics. Feed intake and urinary excretion data were analysed by ANOVA in a randomised block design. To further explain the ANOVA results, multiple regression analyses were conducted to study relationships between intakes of total N (g/d); sum of the CP fractions A, B1 and B2 (AB1B2; g/d), most of which is considered rumen-degradable; digestible organic matter (DOMI; kg/d); protein balance in the rumen (g/kg dry matter); and urinary excretion of N, urea-N (g/d) and PD (mmol/d). Urinary N and urea-N excretion was positively related to N intake and was better explained by N intake than intake of AB1B2. Feeding BRM resulted in the lowest N intake and urinary N output (P < 0.001). Cows fed MGS, FLS and RCS had similar N intake, but urinary N and urea-N excretion was significantly higher (P < 0.001) in cows fed RCS, which probably was attributable to the significantly lower DOMI of this diet (P < 0.001). Furthermore, addition of DOMI to N intake in the multiple regression analysis increased the proportion of explained variation in urinary N and urea-N excretion. The MGS and FLS diets stimulated rumen MCP production to a greater extent than the BRM diet, as indicated by the higher urinary output of PD in cows fed the grass silage-based diets (P < 0.001). Diet had no significant effect on urinary PD excretion when expressed per kg DOMI. Overall mean urinary creatinine excretion was 0.197 ± 0.047mmol/kg body weight, with no significant effect of diet. This study showed that intake of both N and DOM need to be assessed when choosing a suitable alternative roughage diet for suckler cows, in order to prevent undesirable losses of urinary N.

Excreción de Derivados de Purinas en Función de la Relación Fibra/Proteína en la Dieta de Alpacas (Vicugna pacos)

El objetivo del presente estudio fue evaluar la relación de la fibra detergente neutro/ proteína cruda sobre la excreción urinaria de derivados de purinas (DP) en alpacas. El diseño experimental fue un Cuadrado Latino 3x3. Se utilizaron tres alpacas Huacaya machos de 2.5 años de edad, confinados en corrales individuales. El alimento fue suministrado una vez al día y con agua ad libitum. Se trabajó con tres tratamientos a base de heno de avena, donde las relaciones de fibra/proteína se obtuvieron de acuerdo a las proporciones de tallos y hojas. Los tratamientos fueron: T1, hojas de heno de avena, 58.24% de fibra detergente neutro (FDN) y 6.8% proteína cruda (PC); T2, hojas y tallo de avena, 66.31% FDN y 6.36% PC; T3, tallos de avena, 70.22% FDN y 5.75% PC. Cada periodo experimental tuvo una duración de 14 días (10 de acostumbramiento y 4 de evaluación). Los niveles de DP en orina se analizaron mediante Cromatografía Líquida de Alto Performance (HPLC). La excreción diaria total de DP fue de 25.51 (T1), 28.07 (T2) y 14.21 (T3) mg/d. La excreción diaria de alantoína, hipoxantina, xantina y la excreción total de DP fue similar entre tratamientos. Los resultados muestran que la relación FDN/PC en los niveles utilizados no tiene influencia sobre la excreción de DP en la orina de alpacas.

Microbial nitrogen production, nitrogen balance and excretion of urinary purine derivatives in Corriedale ewes under water deprivation

Abstract The objective of this study was to determine microbial N production, and urinary excretion of PDs in Corriedale ewes under water deprivation. Nine Corriedale ewes (average BW=45±4.5 kg) were individually fed diets based on maintenance requirements in metabolic crates. Ewes were assigned to three treatment groups according to a 3×3 Latin square design for 3 periods of 21 days duration. The treatments were free access to water (FAW ), 2h water deprivation (2hWD), and 3h water deprivation (3hWD) following feeding. Daily water intake decreased linearly as water deprivation time following feeding increased. Feed intake and fecal excretion were not different among the treatment groups. Urine weight and volume were higher in FAW than water deprived groups. Nitrogen balance including urinary N, retained N, urinary N/intake N, and retained N/intake N were lower in FAW group than other treatment groups, whereas no differences were observed in intake N, fecal N, digestible N, and fecal N/intake N among the treatment groups. Allantoin concentration tended to be higher in FAW group than 2hWD and 3hWD groups while no differences were observed in uric acid, xanthine+hypoxanthine and creatinine concentrations. Microbial N production per DOMR was higher in 2hWD and 3hWD groups than FAW group whereas no differences were observed between 2hWD and 3hWD groups. Index of PDC decreased linearly with water deprivation. It is concluded that water deprivation following feeding, especially 2 h water deprivation in ewes improved microbial N production.

Can by-products replace conventional ingredients in concentrate of dairy goat diet?

Intensive dairy goat production in the Mediterranean basin is based on imported conventional ingredients to be included in concentrates. Fourteen Murciano-Granadina goats in the middle of the third lactation were allocated into 2 groups of 7 animals each fed, respectively, a control diet based on alfalfa hay and concentrate in a 40:60 ratio, and a diet in which the concentrate included tomato fruits, citrus pulp, brewer's grain and brewer's yeast (T100CBY) to study the effect of diet on nutrient utilization, ruminal fermentation, purine derivatives excretion in urine, milk yield and composition, and methane emissions. No effect of the diet on total dry matter intake was observed. Digestibility of neutral detergent fiber and acid detergent fiber were higher for T100CBY compared with the control diet. The N in feces and urine was lower and balance and retained N were higher in animals fed T100CBY than the control diet. Milk protein N and energy were similar for both diets. Metabolizable energy per energy intake and metabolizable energy per digestible energy were higher and energy in methane was lower with diet T100CBY than with the control. Milk yield and composition were not affected by diet, with the exception of protein, casein, and total solids, which were higher for diet T100CBY than the control. Diet T100CBY promoted less saturated fatty acids and higher mono- and polyunsaturated fatty acids in milk than the control diet. Diet T100CBY produced less methane and NH3 concentration in the rumen, higher propionate, and a lower acetate-to-propionate ratio without an effect on the volatile fatty acid concentration. The concentrate with by-products did not affect urinary excretion of total purine derivatives, reduced feeding costs, and increased profit margin by 14 and 16% compared with the control. The mixture of tomato fruits, citrus pulp, brewer's grain, and brewer's yeast could replace 47% of conventional ingredients (corn, wheat bran, sunflower meal, and soy flour) in the concentrate of the dairy goat diet, reducing feeding cost and methane production, leading to a healthier fatty acids profile in milk without compromising nutrient utilization or milk yield.

Intake, nutrient utilization and growth performance of lambs fed detoxified Jatropha curcas meal

The study assessed the effect of dietary supplementation of detoxified Jatropha meal (DJM) on feed intake, nutrient utilization and growth performance of lambs. Growing lambs (24) of similar age and body weight (15.76±1.92kg) were selected for this study. The experimental lambs were allocated in four groups i.e. control group (CG) without DJM and replacing soybean meal (SBM) of CG with DJM on iso-nitrogenous basis in treatment groups (TG) by 12.5% (T1), 25% (T2) and 37.5% (T3). The feeding cum growth trial was conducted for a period of 180 days. The intake of dry matter (DM), organic matter (OM) and digestibility coefficients of DM, OM, CP, NDF and ADF were comparable between CG and TGs. Nutrient intake, DCP, TDN, Nitrogen (N) intake, excretion and retention were comparable between CG and TGs. Replacement of SBM with DJM even up to 37.5% did not show any significant impact on urinary excretion of total purine derivatives (PD), creatinine (C) and their ratio. Microbial N synthesis (g/d) and efficiency of microbial N synthesis of CG were comparable irrespective of DJM%. The initial and final body weights (BW) of lambs between CG and TGs were also comparable. Total BW gain (kg), average daily gain (ADG; g d-1) and feed conversion ratio (kg DM/kg gain) by lambs did not differ significantly between CG and TGs. The study concluded that SBM in the diet of lambs could be replaced by DJM up to 37.5% without any adverse impact on nutrient intake, digestibility, rumen microflora and growth of the lambs.