Nitrogen Balance Trials Research Articles

Effects of dietary niacinamide and CP concentrations on the nitrogen excretion, growth performance, and meat quality of pigs.

Reducing the dietary CP concentration in the formulation of low-protein diets without adverse effects on animal growth performance and meat quality remains challenging. In this study, we investigated the effects of nicotinamide (NAM) on the nitrogen excretion, growth performance, and meat quality of growing-finishing pigs fed low-protein diets. To measure the nitrogen balance, we conducted two trials: in nitrogen balance trial 1, four crossbred (Duroc×Landrace×Large White) barrows (40±0.5kg BW) were used in a 4×4 Latin square design with four diets and periods. The diets consisted of a basal diet+30mg/kg NAM (a control dose), basal diet+90mg/kg NAM, basal diet+210mg/kg NAM, and basal diet+360mg/kg NAM. In nitrogen balance trial 2, another four barrows (40±0.5kg BW) were used in a 4×4 Latin square design. The diets consisted of a basal diet+including 30mg/kg NAM (control), basal diet+360mg/kg NAM, low-protein diet+30mg/kg NAM, and low-protein diet+360mg/kg NAM. To measure growth performance, two trials were conducted. In growth performance trial 1, 40 barrows (37.0±1.0kg) were randomly allocated to one of four dietary treatments (n=10 per group), whereas in growth performance trial 2, 300 barrows (41.4±2.0kg) were randomly allocated to one of four dietary treatments, with each dietary treatment conducted in five repetitions with 15 pigs each. The four diets in the two growth performance trials were similar to those in nitrogen balance trial 2. Supplementing the diet with 210 or 360mg/kg NAM reduced urinary nitrogen excretion and total nitrogen excretion and increased nitrogen retention comparted with the control diet (P<0.05). Compared with the control diet, the low-protein diet with 360mg/kg NAM reduced faecal, urinary, and total nitrogen excretion (P<0.05) without affecting nitrogen retention and average daily gain (P>0.05). Pigs fed the low-protein diet with 360mg/kg NAM showed a decreased intramuscular fat content in the longissimus thoracis muscle when compared with pigs fed the control diet (P>0.05). Our results suggest NAM as a suitable dietary additive to reduce dietary CP concentration, maximise nitrogen retention and growth performance, and decrease fat deposition in pigs.

Effect of feeding varying levels of dietary crude protein and digestible energy levels on nitrogen retention, urinary and blood plasma constituents in pigs fed from 9 to 60kg

This study was designed to investigate the effects and possible interactions of varying crude protein (CP) and digestible energy levels (DE) on Nitrogen Retention, (NR), Urinary and blood plasma constituents in pigs reared from 6 to 60 kg liveweight. One hundred and twenty eight Large White x Landrace pigs weighing 9+1.5kg were assigned to sixteen groups of eight pigs, comprising four females and four castrated males in a 4x4 factorial design, the factors were four crude protein levels: (18, 21, 24 and 27%) and four digestible energy levels: (3,000; 3,300: 3,600 and 3,900 kcal/kg) nitrogen retention studies were conducted during the 4 week after the animals were 4 weeks on test diets. There were 6 pigs (3 females and 3 males) in the nitrogen balance trials. Apparent protein digestibility was calculated from the faecal collection. Urinary urea, citrulline and allocation were also determined. Six out of the eight experimental pigs per diet were selected for bleeding and the plasma urea concentrations were determined. There was a significant ( 0.05) Protein x Energy, Energy X Sex and Protein x Energy x Sex interactions. Females retained significantly higher proportions of their nitrogen intake than the castrated males, the lowest nitrogen retention was obtained on the lowest protein and lowest energy combination. The best nitrogen retention in males was obtained on the 21% protein diet with 3,600 kcal DE/kg, while in females; the best was obtained on the diet containing 24% Protein. Total urinary urea concentration was significantly (p 0.01) influenced by both protein and energy levels and significant Protein x Energy interactions also occurred. Dietary protein, expectedly, significantly influenced plasma urea concentrations tending to be lowest on the two intermediate energy levels; 3,300 and 3,600 kcal DE /kg. Nitrogen retention was optimum between 18 and 21% protein levels and castrated males tended to show optimum nitrogen economy on lower protein levels than female pigs. Total urea concentration paralleled nitrogen retention profile. The Kiriyama Index(A/U x IP) may be a precise method to determine protein requirement for pigs in the humid tropical environment. Digestible energy levels of between 3,300 and 3,600 kcal/kg would be adequate for maximum nitrogen economy.

Improvement in enzymolysis efficiency and bioavailability of rapeseed meal protein concentrate by sequential dual frequency ultrasound pretreatment

In order to improve the bioavailability of rapeseed meal protein concentrate (RPC), sequential dual frequency (50/28 kHz) ultrasound was applied to pretreat RPC and its protein bioavailability was investigated by in-vivo nitrogen-balance trials. Based on Box-Behnken experimental design, a set of preferred ultrasound pretreatment condition was determined to be at power density of 65.6 W/L for 38.6 min with an incubation temperature of 39.0 °C. Under these conditions, degree of hydrolysis and protein conversion rate of RPC respectively increased by 26.6 % and 32.9 % compared to the control. Meanwhile, the macromolecular protein of sonicated RPC was converted into more small molecular peptides with a molecular weight of 200∼1000 Da by enzymolysis, accompanied by the changes of amino acid composition in supernatant. Furthermore, the rats fed with hydrolysates (including supernatant and precipitate) derived from ultrasound pretreatment coupled with enzymolysis rather than traditional enzymolysis showed higher weight gain, protein efficiency ratio, net protein ratio, apparent digestibility and true digestibility. These findings revealed that ultrasound could be considered as a promising pretreatment technology for preparing enzymatic hydrolysates with high bioavailability and thus realize the maximum utilization of rapeseed meal protein.

Effects of Leucaena leucocephala supplementation to basal hay on Energy and Protein metabolism in West African. Dwarf sheep

Energy and protein utilization and quantitative retention of protein, fat and energy was investigated with twelve castrated West African Dwarf (WAD) sheep averaging (23.0 h 2.4 kg BW) in nitrogen and energy balance trials. Dried leaves of Leucaena leucocephala were offered as supplement at two levels 25% (diet 2) and 50% (diet 3) of dry matter intake (DM1), replacing hay in the basal hay diet. The basal hay diet without supplementation was the control. Measurements were performed by means of nitrogen and carbon balances and with the use of indirect calorimetry The digestibility and utilization of protein were influenced (P&lt;0.05) by supplementation. Metabolisability of energy (ME/ GE) was on the average 42.9 (SEM 4.3)% being significantly (P&lt;0.05) different among treatments. Diet 2 had a higher (P&lt;0.05) retained protein (9.6 g/d) compared with the control diet and hence a superior (P&lt;0.05) protein utilization than the control and diet 3, respectively. It was concluded that Leucaena leuccocephala improved protein utilization and retention in WAD sheep.

20 Assessment of lysine requirement in lipopolysaccharide-challenged pigs

Abstract This study was conducted to investigate the effect of immune challenge (IC) on digestible lysine (Lys) requirement of growing pigs using the Goettingen approach. Twenty-four 19kg-pigs were used in three nitrogen balance (NB) trials. The trials were performed in a complete randomized block design, with six nitrogen levels (NL), two sanitary status (control and IC) and two individual replicates per treatment (6 x 2 x 6). Dietary NL concentration ranged from 1.06 to 4.48 % in DM, being Lys limiting in all the levels assessed. For two consecutive days, Escherichia coli lipopolyssacharide (LPS) was intramuscular injected in challenged pigs at 30 and 34μg/kg. Data were fitted to nonlinear models to estimate nitrogen requirement for maintenance (NMR) and the maximum nitrogen deposition (NDmaxT). Both information were associated with the maximum nitrogen retention (NRmaxT), Lys efficiency (bc-1) and nitrogen retention (NR) to determine Lys requirements as follows: Lys = (lnNRmaxT-ln(NRmaxT-NR))/(16×bc−1). The NRM of pigs from control group was estimated in 152mg of N/kg of BW0,75/day, whereas LPS-challenged pigs had such requirements estimated in 197 N/kg of BW0,75/day. NDmaxT was estimated in 3525 and 2078mg of N/kg BW0,75/day in for pigs form control and LPS-challenged group, respectively. Requirements for Lys were estimated based on 68% and 54% of NDmaxT, being such percentage based on the mean value of ND for each group. Pigs from control group had the requirements for Lys estimated in 1.42 and 1.58%, based on a feed intake of 1000 and 900g/day, respectively, whereas Lys requirements of LPS-challenged pigs were estimated in 0.76 and 0.84%, based 893 and 803g/day of feed intake, respectively. Compared with control, LPS group exhibited a reduction of approximately 11% in feed intake. The model enables to estimate Lys requirement, taking into account protein deposition potential, feed intake, and immune challenge.

Alternative procedure for determining lysine maintenance requirement in poultry

ABSTRACT The objective with this study was to determine the lysine maintenance requirements (LMR) of male and female broilers as animal models. A total of 252 birds were used for nitrogen balance trials during three periods (I: 6-21, II: 22-37, and III: 38-53 days). Six lysine levels were used (2.76, 5.88, 8.99, 12.1, 15.2, and 18.3 g kg−1) with six replications. A control group also included, totalizing seven treatments for males and females for each assay. The experimental period was [...]

Arginine requirements for maintenance and egg production for broiler breeder hens

Two studies were conducted with objective of determine the specific requirements of arginine (Arg) for maintenance using different unit systems; evaluate the response of broiler breeder hens of Ross 308AP genotype to different intakes of arginine, determine amino acid utilization efficiency (k), and develop a factorial model. One nitrogen balance trial (Experiment 1) was performed using 42 roosters and another dose response trial was performed using 64 broiler breeder hens (Experiment 2). The nitrogen balance trial lasted five days with 48 h of fasting (with roosters receiving only water + sucrose) and the last 72 h for feeding and excreta collection. Forty grams of each diet first-limiting in arginine was fed by tube each day (three days) to give a range of intakes from 0 to 18.5 g/kg BW d of arginine. Excreta were collected during the last 3 days of the balance period and the nitrogen content of the excreta was analyzed. A linear regression between nitrogen retention (NR) and arginine intake was performed. The studies were conducted in a complete random design. Were used with 6 treatments, 6 replicates for Experiment 1 and, 8 treatments with 6 replicates for Experiment 2, and one bird per cage. To confirm that the amino acid studied was indeed limiting and that the responses were due to the limitation of the test amino acid and not protein, we added one more treatment consisting of a control diet (totaling 7 treatments for Experiment 1 and 8 treatments for Experiment 2). The diets were formulated by dilution technique using one summit diet and one nitrogen (N)-free diet, resulting in AA levels that ranged from 2.37 to 10.27 g of arginine/kg. The data obtained were AA intake (AAI), body weight (BW), and egg output (EO). Broken line model was used to evaluate the responses. The equation from linear regression was: NR = -39.9 (± 4.5) + 1.8 (± 0.1) × Arg. The arginine required to maintain the body at zero NR were calculated to be 23 mg/kg body weight per day, respectively. For the system unit mg per kg of metabolic weight, the intake of arginine was 36. Considering the degree of maturity of the animal and body protein content the amounts of arginine required for maintenance was calculated to be 151 mg per unit of maintenance protein (BP m0.73 × u) per day. The values estimated by the model for utilization efficiency was 62 %. The arginine requirement estimated by the model at 30 weeks was 753 mg/day. The prediction of the model was improved using the coefficients estimated here with physiologically relevant units.

Comparative Effects of Stovers of Four Varieties of Common Vetch on Growth Performance, Ruminal Fermentation, and Nutrient Digestibility of Growing Lambs.

Simple SummaryCommon vetch is an important legume crop of mixed crop-livestock systems, and it has the ability to satisfy food, fodder, and fertilizer demands through grain, stover, and nitrogen fixation. The aim of this study was to evaluate common vetch varietal differences in stover nutritive value, ruminal fermentation properties, nutrient digestibility, nitrogen retention, and animal performance in fattening lambs consuming a diet comprising 20% common vetch. The results showed that the substitution of alfalfa hay by varieties Lanjian No. 1 and Lanjian No. 2 stovers in ruminant diets could be advantageous in reducing dependence on imported alfalfa hay, thereby enhancing sustainability of small holder farmers on the Tibetan Plateau.This study evaluated common vetch stover as a feed in mixed rations for growing lambs. Four common vetch varieties were compared with alfalfa (control) for their effects on growth performance, ruminal fermentation, nutrient digestibility, and nitrogen retention. Male Hu lambs (n = 50) aged 3 months, with a mean body weight of 17.5 ± 0.34 kg were allocated randomly to one of the five dietary treatments, making 10 lambs per treatment. The experiment lasted 67 days with a 10-day adaptation period and a 50-day fattening period, and with the final 7 days used for a nutrient digestibility and nitrogen balance trial. All diets contained 30.0% maize straw and 50.0% concentrate, with different forage sources (on a fed basis): 20.0% alfalfa hay (control), 20.0% local common vetch variety 333A (C333A) stover, or 20.0% stover of one of three improved common vetch varieties: Lanjian No. 1 (CLJ1), Lanjian No. 2 (CLJ2), or Lanjian No. 3 (CLJ3). For stover quality, CLJ1 stover had the greatest crude protein (CP), in vitro organic matter digestibility (IVOMD), and metabolizable energy (ME) content and the least cell wall contents, while C333A stover had the least CP, IVOMD, and ME contents and the greatest cell wall contents. Sheep fed the control diet had a greater average daily gain (ADG), apparent digestibility of organic matter (DOM), neutral detergent fiber, acid detergent fiber, and nitrogen retention, and greater ruminal total volatile fatty acids concentration than lambs fed the C333A or CLJ3 diet, but similar performance to lambs fed the CLJ1 and CLJ2 diets. The feed conversion ratio and predicted CH4 emission per unit of DOM intake and ADG of the control, CLJ1, and CLJ2 diets was significantly lower (p < 0.05) than for the other diets. Based on these results, stovers of varieties CLJ1 and CLJ2 can be recommended as an alternative to alfalfa hay and for use in a legume crop rotation with cereals on the Tibetan plateau.

Ileal and total tract digestibility and nitrogen utilisation in blue fox (Vulpes lagopus) fed low-protein diets supplemented with DL-methionine and L-histidine

ABSTRACTTo formulate low-protein diets for blue foxes with sufficient amounts of amino acids (AA), AA digestibility and AA requirements of the animals are crucial information. Therefore, a digestibility and nitrogen (N) balance trial was conducted with 20 blue foxes to determine the macronutrient and AA digestibility and N utilisation in low-protein diets supplemented with DL-methionine (Met) and L-histidine (His). In addition, plasma urea and plasma AA were measured. The diets were designated as P24 (control), P20, P20M, P16M and P16MH and contained energy from digestible crude protein (DCP) at 24%, 20% or 16% of total dietary metabolisable energy (ME). The 20% protein level was fed with or without Met and the 16% protein level was fed with Met and with or without His. The apparent total-tract digestibility (ATTD) of crude protein linearly decreased with decreasing dietary protein level. The ATTD of dry matter, organic matter and crude carbohydrates increased when wheat starch was added as a replacement for protein. The apparent ileal digestibility (AID) and ATTD methods were compared to determine the AA digestibility. The decreasing dietary protein supply decreased the ATTD of most of the AA: threonine, tryptophan (Trp), valine, alanine (Ala), aspartic acid (Asp), glutamic acid, glycine (Gly), proline (Pro), serine (Ser) and total AA. The AID of the AA was constant between diets. Diverging AA showed higher or lower digestibility when determined in the AID or ATTD methods. Isoleucine, lysine, Met, Ala and tyrosine showed higher levels of AID. Arginine, His, cysteine (Cys), Trp, Asp, Gly, Pro and Ser showed higher levels of ATTD, which may reflect the net loss of these AA in the large intestine. Met and His supplementation improved the ATTD and AID of the AA in question, respectively, but did not affect the other variables examined. N retention did not differ between diets and renal N excretion decreased with decreasing protein level; thus N utilisation improved. It was concluded that the protein supply and AA composition in low-protein diets with supplemented Met were adequate for adult blue foxes, since the lower protein supply improved N utilisation and did not affect N retention. However, His supplementation failed to reach the designed level and therefore showed no clear results.

Estimation of the net energy and protein requirements for maintenance of male arctic foxes (Alopex lagopus) during the growth period1,2.

The maintenance requirements of net energy and net protein were assumed to represent the most accurate and important values totally for the animal's utilization. The objective of this experiment was to determine the net energy and net protein requirements for maintenance of growing arctic foxes. The experiments was evaluated using regression models estimated from data collected by means of indirect calorimetry, nitrogen balance trials, and digestion and metabolism experiments. Thirty-six growing arctic foxes (3 487 ± 261.7 g) at the age of 85 days were randomly assigned to four groups with 9 animals in each group. Arctic foxes were fed a complete formula diet at four intake levels (100%, or 80%, 60%, and 40% of feed requirements) from 24 July 2017 to 23 September 2017. Arctic foxes in each treatment were kept individually in respiration chambers after 1-d adaptation at day 2 for a 3-d balance trial and then at day 5 followed by a 3-d fasting period. The metabolizable energy intake (MEI), heat production in the fed state (HP), and retained energy (RE) of arctic foxes significantly decreased (P < 0.01) as the feed intake level decreased. Fasting heat production (FHP) of arctic foxes was not influenced by feed intake level (P > 0.05). The metabolizable energy maintenance requirement (MEm) and net energy maintenance requirement (NEm) estimated from the linear relationship between RE and MEI were 230 and 217 kJ/kg of body weight BW0.75/d, respectively. The MEm and NEm estimated by logarithmic regression of HP on MEI were 225 and 209 kJ/kg BW0.75/d, respectively. The net N maintenance requirement (NNm) and net protein maintenance requirement (NPm) estimated from the linear relationship between retained nitrogen (RN) and daily nitrogen intake (NI) were 179.6 mg/kg BW0.75/d and 1.123 g/kg BW0.75/d, respectively. It is concluded that NEm and NPm values obtained fill the net energy and protein requirements shortage, and provide the basic data for establishing the standard of nutrition demand of breeding arctic foxes in China.

Effect of vitamin D3 supplementation on lysine utilization in growing rabbits

The effect of vitamin D3 (VD3) on lysine utilization in growing rabbits was studied in two experiments (Exp.). In Exp. 1, 162 growing rabbits (491 ± 38 g) were fed basal diets containing 16% crude protein ad libitum. The treatments were varying levels of VD3 (0, 500, and 1000 IU) and lysine (5.5, 6, and 6.5 g/kg dry matter; DM) in a 3 × 3 factorial design with six replicates in each treatment occurring for 5 weeks, and the experimental units were the cages (3 rabbits/cage). Nine experimental VD3+lysine diets, (0 + 0), (0 + 0.5), (0 + 1), (500 + 0), (500 + 0.5), (500 + 1), (1000 + 0), (1000 + 0.5) and (1000 + 1), were formulated. A basal diet (0 + 0) was formulated to be deficient in lysine (5.5 g/kg DM) and VD3 (0.0 IU). Lysine significantly (P < 0.01) affected the final body weight (FBW), average daily gain (ADG) and feed conversion ratio (FCR) but did not affect feed intake. VD3 tended (P = 0.06) to improve the FCR with no significant effect on FBW and ADG. VD3 and lysine exhibited no effect on feed intake. The highest mortality rate (38.9%, 7/18) was observed for the 0 + 0 (control) treatment, and the lowest mortality rates of 5.6% and 0.0% were observed for the 1000 + 0 and 1000 + 0.5 treatments, respectively. Exp. 2, the nutrient digestibility and nitrogen balance trial, was conducted with 45 rabbits (n = 5/treatment) randomly chosen from Exp. 1. Rabbits were housed in metabolic cages for 8 d and offered 180 g/d of each respective diet described in Exp. 1. A significant VD3 × lysine interaction was observed for N intake (P < 0.05). VD3 tended to increase N intake (P = 0.08) and improved (P < 0.05) dry matter digestibility (DMD) and organic matter digestibility (OMD). Lysine increased (P < 0.05) N intake and retained N (P < 0.01), decreased (P < 0.01) urine N, and tended to improve crude protein digestibility (CPD) (P = 0.08) and OMD (P = 0.10). Lysine increased the plasma total protein (TP), albumin (Alb; P < 0.05) and calcium (Ca; P < 0.01) contents and decreased plasma cholesterol (Cho), while VD3 and lysine decreased the urea concentration. A significant (P < 0.01) VD3 × lysine interaction was observed for plasma phosphorus (P) and growth hormones (GHs). VD3 increased P (P < 0.01) and tended (P = 0.08) to increase GHs, whereas lysine decreased (P < 0.05) P at the 1.0 g level but caused a linear and quadratic (P < 0.05) increase in GHs. Overall, the supplementation of diets with VD3 did not improve lysine utilization in growing rabbits; however, lysine increased N intake, retained N, the FBW, and the ADG and improved the FCR.

Nitrogen maintenance requirements and potential for nitrogen retention of pullets in growth phase.

Experiments were conducted to estimate daily N maintenance requirements (NMRs) and the genetic potential for daily N retention (NRmax T) of pullets in growth phase. Three nitrogen balance trials were conducted, and a total of 48 Hy-line W-36 pullets were used in each trial in age periods (starter: 14-28, grower: 56-70 and developer: 98-112days). The treatments consisted of six graded levels of nitrogen in the diets (L1=8, L2=16, L3=24, L4=32, L5=40 and L6=48gN/kg of feed), formulated using the dilution technique. The regression analyses between nitrogen intake and nitrogen excretion were performed to fit the exponential function and to determine the NMR. The daily NMRs that were estimated at 294, 331 and 355mg/BWkg 0.67 for the initial, grower and developer periods, respectively, were applied for further calculation of NRmax T as the threshold value of the function between N intake and daily N balance. The NRmax T was estimated by a statistical procedure following several iteration steps by the Levenberg-Marquardt algorithm until the sum of the squares of the residual was minimized. The NRmax T was estimated at 3,200, 2,633 and 1,826mg/BWkg 0.67 for starter, grower and developer periods respectively. The determined model parameters were the precondition for modelling of the amino acid requirement based on an exponential N-utilization model and depended on performance and dietary amino acid efficiency. This procedure will be further developed and applied in the subsequent study.

Buffalo is more environmentally friendly than cattle based on N excretion

Cattle and buffalo have different characteristic in utilizing of feed protein. The differences of utilization will impact on N excretion in feces and urine which are potential to increase environmental contamination. Therefore, it was necessary to evaluate the N emission factor and to determine the specific management that suitable for each commodity species. Total of 26 individual data were obtained from 2 studies in nitrogen balance trials (11 heads of cattle and 15 heads of buffalo). All data were observed from total collection method. The value of nitrogen content in feces and urine were analyzed by Kjedhal method. The parameters observed in this study were nitrogen intake, nitrogen faeces and urine. The data were analyzed using t-test. The results showed that higher N intake/metabolic BW, the higher N excretion, both of urine and feces on buffalo and cattle. In the same intake/metabolic BW, buffalo excreted higher feces than cattle. However, different result was shown in N urine excretion. N urine excretion on buffalo was lower than cattle. N intake/metabolic BW has positive and strong correlation with all N feces excretion (r = 0.89) but low correlation with all N urine excretion (r = 0.36). It can be concluded that buffalo was more environmentally friendly than cattle due to lower nitrogen urine excretion.

Potential to mitigate ammonia emission from slurry by increasing dietary fermentable fiber through inclusion of tropical byproducts in practical diets for growing pigs

ObjectiveResearch was conducted to test the effect of including fiber-rich feedstuffs in practical pig diets on nutrient digestibility, nitrogen balance and ammonia emissions from slurry.MethodsThree Vietnamese fiber sources were screened, namely cassava leaf meal (CL), cassava root residue (CR), and tofu by-product (TF). Accordingly, a control diet (Con) with 10% of dietary non-starch polysaccharides (NSP) and three test diets including one of the three fiber-rich feedstuffs to reach 15% of NSP were formulated. All formulated diets had the same level of crude protein (CP), in vitro ileal protein digestible and metabolisable energy, whereas the in vitro hindgut volatile fatty acid (VFA) production of the test diets was 12% to 20% higher than the control diet. Forty growing barrows with initial body weight at 28.6±1.93 kg (mean±standard deviation) were allocated to the four treatments. When pigs reached about 50 kg of body weight, four pigs from each treatment were used for a nitrogen balance trial and ammonia emission assessment, the remaining six pigs continued the second period of the feeding trial.ResultsThe TF treatment increased fecal VFA by 33% as compared with the control treatment (p = 0.07), suggesting stimulation of the hindgut fermentation. However, urinary N was not significantly reduced or shifted to fecal N, nor was slurry pH decreased. Accordingly, ammonia emissions were not mitigated. CR and CL treatments failed to enhance in vivo hindgut fermentation, as assessed by fecal VFA and purine bases. On the contrary, the reduction of CP digestibility in the CL treatment enhanced ammonia emissions from slurry.ConclusionDietary inclusion of cassava and tofu byproducts through an increase of dietary NSP from 10% to 15% might stimulate fecal VFA excretion but this does not guarantee a reduction in ammonia emissions from slurry, while its interaction with protein digestibility even might enhance enhanced ammonia emission.

Comparative effects of Moringa oleifera root bark and monensin supplementations on ruminal fermentation, nutrient digestibility and growth performance of growing lambs

Two comparative in vitro and in vivo experiments were accomplished to assess the effects of Moringa oleifera root bark (MRB) and ionophore antibiotic monensin as dietary feed additives for ruminants' diets. In the in vitro experiment, the effects of graded levels of MRB (0, 25 and 50g/kg DM) and monensin (40mg/kg DM) on ruminal fermentation and degradability parameters were evaluated using the semi-automatic gas production (GP) system. Results were subjected to regression analysis (dose-response analysis) and ANOVA to select the MRB effective dose. In the in vivo experiment, eighteen Barki lambs (BW; 25±3.1kg) were randomly allotted into three dietary treatments (n=6/treatment) as: control (basal diet without additive), monensin (40mg/kg DM) and MRB (25g/kg DM). The experiment lasted for 70 days to collect ruminal samples and evaluate lamb performance, while the subsequent 7 days were assigned for the nutrient digestibility and nitrogen balance trial. The GC–MS analysis of MRB showed that the most abundant phytochemicals were organosilicons, alkaloids and benzoic acid ester. Results of the in vitro assay showed that both MRB doses inhibited (P<0.01) CH4 production (ml/g DM) without adverse effects on GP and degradability compared to control. Diet supplemented with 25gMRB/kg DM resulted in the highest increase (P=0.03) of propionate compared to control. Ammonia concentration was decreased (P<0.01) by monensin, while protozoal counts were not affected by all experimental diets. The in vivo effects of MRB on ruminal fermentation profile were different from those of in vitro assay. MRB enhanced (P<0.05) the total short chain fatty acids, acetate production and nutrients digestibility, while monensin enhanced propionate (P<0.01) compared to other diets. Both monensin and MRB exhibited similar reductions (P<0.01) in protozoal counts, urine N excretions and estimated CH4 produced per unit of body weight gain while enhanced (P<0.05) the body N retention, average daily gain, and feed efficiency compared to control. These results suggested that, although MRB was less effective than monensin, it favourably modified the ruminal fermentation process and nutrients digestibility, thus it could be used as a novel dietary feed additive for ruminant diets.

Modelling of lysine requirement in broiler breeder hens based on daily nitrogen retention and efficiency of dietary lysine utilization

The current feeding programs used for broiler breeder hens need information on how to make use of the genetic potential more efficiently by modelling the amino acid (AA) requirements. Thus, this study aimed to determine the model parameters for maximum nitrogen retention (NRmaxT), nitrogen maintenance requirement (NMR) and the efficiency of lysine utilization (bc−1) to determine the lysine (Lys) requirements of broiler breeder hens. Nitrogen balance trials were performed in two periods (I: 31–35 wks and II: 46–50 wks). Seven dietary treatments were used with eight replicates and one hen per cage; the treatments consisted of seven diets with protein levels ranging from 58.8 to 311.9g/kg of feed, with Lys being limiting in the dietary protein (c=3.91g of Lys in 100g of CP). For each period, nitrogen intake (NI), nitrogen excretion (NEX), nitrogen in egg mass (NEM), nitrogen deposition (ND) and nitrogen retention (NR, NR=ND+NEM+NMR) were obtained in a N balance trial of 25days. The NMR was calculated as the intersection point of the exponential curve between NEX and NI at NI=0. The NRmaxT and b (slope related to protein quality) were estimated by the exponential fit between NR and NI. The Lys efficiency bc−1 was obtained dividing b by c. The likelihood ratio test for the model parameters yielded 255mg/BWkg0.67 for NMR, 0.000117 for b and 1684mg/BWkg0.67 (period I) and 1484mg/BWkg0.67 (period II) for NRmaxT. The necessary Lys intake dependent on NR and Lys efficiency was derived by the equation Lys=(lnNRmaxT-ln(NRmaxT-NR))/(16×bc−1). Lys intakes required to achieve 0.80 times the maximum potential (NRmaxT) were 915mg and 876mg in the period I and II, respectively. For broiler breeder hens, assuming 0.80 times the NRmaxT value and average efficiency of Lys utilization, 6.02g/kg (31–35 wk) and 5.96g/kg (46–50 wk) digestible dietary Lys were observed as optimal digestible Lys concentration in the diet (corresponding to 152 and 147g of daily feed intake, respectively). Results of model calculations need verification in performance trials with evaluation of nitrogen deposition and varying dietary Lys efficiencies.

Optimal in-feed amino acid ratio for broiler breeder hens based on deletion studies.

An ideal amino acid ratio (IAAR) for breeder hens is needed for maximum nitrogen retention (NR) taking into account nitrogen deposition in body (NDB ), feathers (NDF ) and egg mass (NEM) to improve dietary protein efficiency. Thus, the aim of this study was to apply the deletion method to derive the IAAR for broiler breeder hens. The nitrogen balance trials were performed from 31 to 35weeks and from 46 to 50weeks. Twelve treatments with eight replicates and one hen per cage were used. A balanced diet (BD) was formulated to meet the requirement of all nutrients. The other diets were formulated diluting 55% of BD with corn starch and refilled with amino acids (AAs) and other ingredients, except the AA tested. Each trial lasted 25days. Feather losses, egg production and egg weight were recorded daily, and the samples were stored to further determine NEM and nitrogen in feather losses (NDFL ). At the start and the end of each period, a group of birds were slaughtered to further determine NDB and NDF . The NR was calculated as the sum of NDB , NDF , NDFL , NEM and the nitrogen maintenance requirement (NMR). The deletion of valine greatly depressed the NR in peak production (31 to 35weeks) while the deletion of the isoleucine greatly depressed the NR of the hens from 46 to 50weeks of age. The percentual reduction in NR and the per cent of the AA to delete from the BD were used to calculate the AA requirement. The average IAAR was Lys 100, Met+Cys 86, Trp 23, Thr 80, Arg 113, Val 90, Ile 91, Leu 133, Phe+Tyr 108, Gly+Ser 94 and His 35. The IAAR was in line with the recommendation from the literature, validating deletion method with the advantages from a rapid and low-cost procedure.

Maintenance valine, isoleucine, and tryptophan requirements for poultry

Poultry maintenance requirements for valine, isoleucine, and tryptophan were measured by nitrogen balance using different unit systems. The nitrogen balance trial lasted 5 d with 48 h of fasting (with roosters receiving only water+sucrose) and the last 72 h for feeding and excreta collection. Forty grams of each diet first-limiting in valine, isoleucine, or tryptophan was fed by tube each day (3 d) to give a range of intakes from 0 to 101, 0 to 119, and 0 to 34 mg/kg BW d of valine, isoleucine, and tryptophan, respectively. A nitrogen-free diet containing energy, vitamins, and minerals, meeting the rooster requirements, was offered ad libitum during these three d. To confirm that the amino acids studied were limiting, a treatment was added with a control diet formulated by adding 0.24 g/kg of L-valine, 0.21 g/kg of L-isoleucine, and 0.10 g/kg of L-tryptophan to the diets with lower amino acid level. Excreta were collected during the last 3 d of the balance period and the nitrogen content of the excreta was analyzed. For each amino acid, a linear regression between nitrogen retention (NR) and amino acid intake was performed. The equations from linear regression were: NR=-98.6 (±10.1)+2.4 (±0.2)×Val, NR=-46.9 (±7.1)+2.3 (±0.1)×Ile, NR=-39.5 (±7.7)+7.3 (±0.4)×Trp; where Val, Ile, and Trp are the intakes of valine, isoleucine, and tryptophan in mg/kg body weight per d, respectively. The valine, isoleucine, and tryptophan required to maintain the body at zero NR were calculated to be 41, 20, and 5 mg/kg body weight per d, respectively. For the system unit mg per kg of metabolic weight, the intake of valine, isoleucine, and tryptophan was 59, 32, and 9, respectively. Considering the degree of maturity of the animal and body protein content (BPm (0.73)×u), the amounts of valine, isoleucine, and tryptophan required for maintenance were calculated to be 247, 134, and 37 mg per unit of maintenance protein (BPm (0.73)×u) per d. Maintenance requirement is more adequately expressed as body protein content.

Effect of tree forage supplementation on growth performance of goats

An experiment with 25 growing goats (in 5 groups) were fed four different tree forage based diets (B,C,D,E) and control A showed that there were significant (p&lt;0.05) differences in DM , ME and DCP intakes. Although there were no significant differences in the digestibility of DM, OM, CP and ADF but intake of these nutrients were significantly (p&lt;0.05) differed among the treatments. There were no significant differences in the digestibility of diets having different forages but they were significantly higher than that of grass based control diet. Feeding of tree forages had significant (p&lt;0.05) effect on live weight gain of goats. Animals fed tree forage based diets significantly (p&lt;0.05) increased weight gain (60.03, 59.10, 57.75 and 55.57 g/d for Sesbania grandiflora, Leucaena leucocephala, Erythrina orientalis and Morus alba, respectively) compared to that of control group (39.25 g/d) . However, there were no significant differences in weight gain of the animals fed different tree forage based diets. Feed conversion efficiency (kg feed/kg gain) also showed that animals fed tree forage based diets presented significantly (p&lt;0.01) higher efficiency (11.74, 12.05, 12.21 and 12.02) for L. leucocephala, E. orientalis, S. grandiflora and M. alba compared to that (16.00) of fed control diet. Nitrogen balance trial showed that there were significant (p&lt;0.05) differences among the mean values in terms of total N intake (g/d), nitrogen retention (%) and nitrogen balance (g/d). It may be concluded that supplementation of diets with tree forages resulted in better weight gain, digestibility and nitrogen balance compared to green grass. So, the diets of goats may be supplemented with tree forages of S. grandiflora, L. leucocephala, E. orientalis and M. alba for improved growth performance.Asian J. Med. Biol. Res. June 2015, 1(2): 209-215

Reevaluation of the digestible lysine requirement for broilers based on genetic potential

Broiler strains available in the poultry industry present different requirements for dietary lysine due to their different growth potentials as a result of their genetic makeup. This study aimed to determine the model parameters for maximum nitrogen retention (NRmaxT), the nitrogen maintenance requirement (NMR) and the efficiency of lysine utilization (bc-1) to reevaluate the lysine (Lys) requirements of male and female broilers. Nitrogen balance trials were performed during three periods (I: 6-21 days, II: 22-37 days, and III: 38-53 days). Seven treatments were used for males and females; the treatments consisted of seven diets with protein levels ranging from 61 to 364 g kg-1 dry matter, with Lys being limiting in the dietary nitrogen (4.91 g of Lys in 16 g of N). Nitrogen intake (NI), excretion (NEX), deposition (ND, ND=NI-NEX) and retention (NR, NR=ND+NMR) values were obtained. The NMR was represented by the exponential relationship between NEX and NI. The NRmax T and bc-1 were estimated by the exponential fit between ND and NI. The NRmax T, bc-1, and NMR values were combined in a model to estimate Lys intake by simulating different percentages of the NRmaxT. The Lys intake estimates were 581, 1,538, and 2,171 mg day-1 for males and 512, 1,340, and 1674 mg day-1 for females during periods I, II, and III, respectively. Due to the flexibility of the model, it is possible to calculate the Lys intake for percentages of NR in the range of practical performance data.