Enzyme supplementation of wheat-based diets for broilers: 2. Effect on apparent metabolisable energy content and nutrient digestibility

Two experiments were conducted to determine the effect of enzyme supplementation on the nitrogen-corrected apparent metabolisable energy (AME_n) and apparent nutrient digestibilities in ileum and excreta from male broiler chickens fed diets containing high amounts of wheat (>80%). Four different enzyme preparations were added to the wheat-based diets in varying levels and combinations. The difference between Experiments 1 and 2 consisted in the addition of different enzymes and enzyme levels. Excreta and ileal content were collected from broiler chickens at 3 and 6 weeks of age. At 3 weeks of age enzyme supplementation increased (P<0.0001) the AME_n from an average value of 13.86 MJ kg⁻¹ dry matter (DM) to an average of 14.60 MJ kg⁻¹ DM in the two experiments. The apparent digestibility of protein (APD) and fat (AFD) were improved significantly as a result of enzyme addition in both experiments. At 3 weeks of age, improvements (P<0.05) in the ileal AFD and APD were on average 13% and 6%, respectively. The effect of enzyme supplementation on AFD measured in excreta from broiler chickens showed the same pattern. The positive effect of enzyme addition on the overall nutrient digestibility and AME_n was reflected in weight gain and feed conversion efficiency (FCE). Significant improvements in AME_n, APD, and AFD were still present in most of the groups fed with enzyme-supplemented diets at 6 weeks of age. The effect of enzyme addition, however, was less pronounced, especially in Experiment 1 where the ileal APD of broiler chickens did not differ significantly from the control group. Apparent starch digestibility (ASD), measured in Experiment 2, was very high in all groups, including the control; however, enzyme supplementation increased ASD (P<0.001) in ileum and excreta at both 3 and 6 weeks of age. The digestibility of total non-starch polysaccharides (NSP) in excreta was improved significantly (P<0.01) as a result of enzyme supplementation (Experiment 2). In addition, pH of caeca content decreased (P<0.02) in broiler chickens fed with enzyme-supplemented diets when compared with the control group. Decreased pH could indicate microbial fermentation of unabsorbed NSP residues and nitrogenous compounds. Overall, the results demonstrated that the nutritive value of wheat-based diets to broiler chickens improve enzyme supplementation. The apparent digestibility of total NSP and of arabinose and xylose residues improved (P<0.02) in the enzyme-supplemented diets indicating that the enzymes were able to break down the cell wall NSP to a certain extent.     

Application of a method to determine ileal digestibility in broilers of amino acids in wheat

Growing male chickens (Ross) were fed diets of increasing wheat content (250, 500 and 750 g/kg) in which wheat was the only protein source. Other dietary ingredients were: oil (50 g/kg), a vitamin and mineral premix (50 g/kg) and a 50 : 50 mixture of pure maize starch and glucose to make diets up to 1000 g/kg. Titanium dioxide was included at 5 g/kg as an inert marker. Four wheat samples were evaluated: varieties B and H each with a low and high crude protein content (102 and 130, respectively ; 96 and 128 g CP/kg at 880 g DM/kg. Experimental diets were fed ad libitum for 3 days from 18 days of age to birds housed in pairs in cages in a fully randomised design comprising 6 replicates per diet. Samples of ileal digesta were obtained from the birds following slaughter at 21 days of age and analysed for titanium and amino acid content. For each amino acid, the amount of apparently digestible amino acid in the diet was regressed against the dietary wheat content and the linear regression thus derived extrapolated to 1000 and 0 g wheat/kg, allowing the estimation of the apparently digestible amino acid content of the wheat sample and the endogenous loss of amino acids, respectively. Dividing the former by the total amino acid content of the wheat allowed calculation of the coefficient of apparent amino acid digestibility (CAD). Addition of the intercept to the amount of apparently digestible amino acid in the wheat sample and dividing this by the total amount of amino acid in the wheat allowed the determination of the coefficient of true digestibility (CTD). Values for methionine for the four wheat samples ranged between 0.749 to 0.842 (CAD) and 0.719 to 0.892 (CTD), and for lysine from 0.531 to 0.697 (CAD) and 0.510 to 0.793 (CTD). Results revealed that an increase in crude protein in the wheat varieties resulted in a significant increase in apparently digestible amino acid content (P < 0.001), for example, the digestible cystine contents of wheat were 1.54 and 2.22 g/kg for wheat H at the low and high crude protein contents, respectively. Coefficients of digestibility also appeared to increase as the crude protein increased.     

Nutrient digestibility in Atlantic salmon and broiler chickens related to viscosity and non-starch polysaccharide content in different soyabean products

Total tract digestibility in Atlantic salmon and ileal digestibility in chicken were assessed from diets with different soyabean products (hulled, toasted, extracted, SBM; reduced oligosaccharide content, ROM; ethanol-extracted protein concentrate, SPC; isolated protein, ISP). The concentration of dietary fibre was highest in SBM and ROM, while it was low in ISP. In vitro viscosity was also higher in SBM than in the other soyabean products. The diets for the salmon and chickens were based on the same feed ingredients, with the exception that fish meal provided half the crude protein in the salmon diets. For each species, the diets were isonitrogenous, contained similar amounts of fat (fish oil), and were balanced with dextrin, thus substituting soyabean non-starch polysaccharides (NSP) and other non-proteinous components by dextrin.In the salmon, total tract digestibility of nitrogen and dry matter were lower (p < 0.05) with the SBM and ROM diets than with the ISP diet. In the chickens, ileal digestibility of dry matter differed among all treatments (p < 0.05). Digestibility of nitrogen, starch, phosphorus and calcium in the chickens was lower (p < 0.05) with the SBM diet than with the ISP and SPC diets, and fat digestibility was lower (p < 0.05) with the SBM and ROM diets than with the SPC diet. Also, the SBM diet gave lower (p < 0.05) digestibility of nitrogen, phosphorus and calcium than the ROM diet, while the ROM diets gave lower (p < 0.05) digestibilities of nitrogen, fat and starch than the ISP and SPC diets. Intestinal viscosity was higher (p < 0.05) and cholesterol content in the blood was lower (p < 0.05) for the chickens fed the SBM-based diet than those fed the other diets. There was a similar response to the different soy products in salmon and chickens with regard to digestibility of nitrogen and fat (p < 0.05). The negative effects of soyabean meals with a low protein content could indicate antinutritive effects of NSP fractions in soyabean meal, as indicated by the elevated viscosity and the decrease in blood cholesterol content.     

Feed formulations to reduce N excretion and ammonia emission from poultry manure

This summary focuses on reducing nitrogen (N) and ammonia emissions from poultry manure through the use of improved amino acid digestibilities and enzyme supplementation. Proper feed processing techniques, phase feeding, and the minimization of feed and water waste can contribute to additional minor reductions in these emissions. Reductions in environmental pollution can be achieved through improved diet formulation based on available nutrients in the ingredients, reducing crude protein (CP) levels and adding synthetic amino acids. Use of amino acid and CP digestibilities can reduce N excretion up to 40% and a 25% increase in N digestibility can be achieved with enzyme supplementation in broiler diets. Digestibilities can be measured by two methods: the excreta and ileal amino acid digestibilities. Both methods allow amino acid levels to be reduced by 10% or more. Enzyme supplementation decreases intestinal viscosity, improves metabolizable energy levels, and increases amino acid digestibilities. Many feed manufacturers still use total amino acid content to formulate feeds. To meet amino acid requirements, crystalline amino acids are needed. The use of feather, meat and bone meal must not be overestimated or underestimated and the limiting amino acids such as cystine, tryptophan, and threonine must be carefully analyzed.     

Effect of feeding schedule on apparent energy and amino acid digestibility by growing pigs

An experiment was conducted to investigate the effects of feeding schedule on dry matter (DM), gross energy (GE), crude protein (CP), and amino acid (AA) digestibility by growing pigs. Six growing castrates (initial body weight: 40.5 ± 2.25 kg) were equipped with a T-cannula in the distal ileum and allotted to a repeated 3 × 3 Latin square design with three animals and three periods in each square. A maize–soybean meal based diet (181 g CP/kg) was formulated and fed to the pigs in three different feeding schedules; i.e., one meal per day, two meals per day, or free access to feed. Pigs fed one or two meals per day were allotted a daily amount of feed equivalent to three times the maintenance energy requirement. Fecal and ileal samples were collected from all pigs in each period. The coefficients of ileal apparent digestibility (CIAD) for DM, GE, CP, and AA were calculated as were the coefficients of total tract apparent digestibility (CTTAD) of DM and GE. Results of the experiment showed that there were no differences in the CIAD for DM, GE, or for any of the AA among the three feeding schedules. In contrast, pigs given free access to the diet had lower (P<0.002) CTTAD for DM and GE compared with pigs fed a restricted amount of feed either once or twice daily. Therefore, the concentration of digestible energy in the diet was lower if calculated from pigs given free access to the diet compared with pigs fed the diet once or twice daily (14.38 MJ/kg versus 14.83 MJ/kg and 15.13 MJ/kg). It is concluded that the feeding schedule does not influence the CIAD for DM, GE, CP, or AA by pigs. Therefore, any of the three feeding schedules that were used in the current experiment may be used in experiments aimed at measuring CIAD in pigs. However, if the CTTAD of DM and GE are measured, it is recommended that pigs are given free access to feed.     

Nutritional value of white lupins (Lupinus albus) for broilers: apparent metabolisable energy, apparent ileal amino acid digestibility and production performance

Two experiments were conducted to evaluate the nutritional value of three cultivars (Promore, Kiev mutant and Ultra) of white lupins (Lupinus albus L.) for broilers. In experiment 1, the apparent metabolisable energy (AME) and ileal amino acid digestibility coefficients of the three cultivars were determined. The cultivar effects were significant (P < 0.05) for AME, but the ileal amino acid digestibility coefficients were similar (P > 0.05) between cultivars. The AME value of Ultra cultivar was lower (P < 0.05) than those of Promore and Kiev mutant cultivars. In Experiment 2, using the AME and ileal digestible amino acid values determined in Experiment 1, diets containing 200 g/kg of lupin were formulated and the effects of feeding these diets on performance, digestive tract development and excreta quality of broiler starters were investigated. Weight gain, feed intake and feed per gain of broilers fed diets containing white lupins were similar (P > 0.05) to those fed the maize-soybean meal diet. The performance of birds fed diets containing different cultivars of white lupins was similar (P > 0.05). Several digestive tract parameters were influenced by the dietary inclusion of white lupins. In particular, the relative liver weight and the relative empty weights of small intestine and caeca in birds fed diets containing white lupins were higher (P < 0.05) than those fed the maize-soybean meal diet. No differences (P > 0.05) were observed in the excreta quality scores between the birds fed the maize-soybean meal diet and those fed diets containing white lupins.     

Enzyme supplementation of wheat-based diets for broilers: 1. Effect on growth performance and intestinal viscosity

The influence of enzyme supplementation on performance and intestinal viscosity of male broiler chickens fed with diets containing high amount of wheat was examined in three experiments. In the first experiment, addition with an enzyme preparation including different cell wall degrading enzymes to diets containing 63 g kg⁻¹ and 72 g kg⁻¹ of wheat improved (P<0.05) feed conversion efficiency in the 72 g kg⁻¹ wheat diet. In addition, intestinal viscosity of chickens fed with the 72 g kg⁻¹ wheat diet was reduced (P<0.05). Weight gain and feed intake were not influenced by enzyme addition. In Experiments 2 and 3, the inclusion level of wheat in the diets was more than 80 g kg⁻¹ and four different enzyme preparations were used (two xylanase preparations, two mixed preparations). Overall, a significant effect on performance and intestinal viscosity of chickens was obtained as a result of enzyme supplementation in both experiments. In the first 21 days, improvements (P<0.05) in weight gain and feed conversion efficiency were found to be on average 5% and 6% in Experiment 2 and 7% and 8% in Experiment 3, respectively. When weight gain and feed conversion efficiency were examined on a weekly basis it was shown that the significant response of enzyme addition was confined to the first 4 weeks. However, the effect of enzyme supplementation was still significant in the whole period from 21–42 days. Feed intake was not influenced by enzyme addition. The viscosity of intestinal content in both the jejunum and ileum was in general reduced (P<0.05) with enzyme supplementation, the xylanase preparations proving to be the most efficient. It was concluded that enzyme supplementation of wheat-based diets resulted in improved performance of broiler chickens, which was related to a concomitant reduction in intestinal viscosity. However, the response of enzyme supplementation was most pronounced in diets with a wheat content higher than 80 g kg⁻¹.     

Ileal and total tract nutrient digestibility in blue foxes (Alopex lagopus) fed extruded diets containing different protein sources

This study compared apparent ileal and total tract digestibility of macronutrients and amino acids in blue foxes (Alopex lagopus) fed dry extruded diets. The control diet contained fish meal as the main protein source, while in the other diets 50% of the fish meal protein was replaced by not de-hulled solvent-extracted soybean meal, meat meal or bacterial protein meal. Ileal digestibility was obtained with animals modified with ileorectal anastomosis (IRA method). There were no significant differences in the average digestibility of CP, Lys, Trp, Val, Ala or Glu between IRA modified and intact animals. Average ileal digestibilities of His, Thr, Asp, Cys, Gly, Hyp, Pro, Ser, starch and total carbohydrates (CHO) were significantly lower compared with total tract values. Average ileal digestibility of Arg, Ile, Leu, Met, Phe, Tyr and crude fat was significantly higher than total tract digestibility. Digestibility measured in IRA modified animals showed less variability compared with values from intact animals. There were significant differences among diets in ileal as well as total tract digestibility of orude protein, most amino acids, starch and CHO, and in ileal digestibility of crude fat. Ileal crude protein digestibility of the diets ranged from 81.0-86.4% and total tract digestibility from 82.5-86.4%. Ileal amino acid digestibilities ranged from 70.1 (Asp) to 93.3% (Arg) and total tract values ranged from 72.8 (Cys) to 92.2% (Arg). Both ileal and total tract digestibilities of crude protein and most amino acids were significantly lower for diets containing meat meal or bacterial protein meal compared with the control fish meal-based diet and the diet with soybean meal. Although ileal digestibility may be more accurate than total tract digestibility in estimating the protein and amino acid supply in blue foxes, total tract digestibility may be acceptable because of numerically small differences between ileal and total tract digestibilities for protein and most amino acids. It was further concluded that ileal digestibilities of starch and CHO in the blue fox are lower than corresponding total tract digestibilities.     

Effects of inclusion with blue lupins (Lupinus angustifolius) in broiler diets and enzyme supplementation on production performance, digestibility and dietary AME content

An experiment with broiler chickens was conducted to study the effect of inclusion of blue lupins and exogenous enzyme to broiler diets on the apparent metabolisable energy (AME), digestibility and performance. Two basal diets were formulated: a non-lupin diet A based on soya bean meal and maize, and a diet B where parts of soya bean meal and maize were substituted with blue lupin (200 g/kg). The two basal diets were fed either alone or, for diet B in combination with different enzyme preparations (Bio-Feed Plus, lactase, two galactanases (Gal-I and Gal-II)). The experiment was performed in battery cages with 648 male broiler chickens, where eight experimental diets were fed to the chickens from 7 to 21 days of age and weight gain and feed intake were measured during the period. At the end of the experiment, three chickens from each pen were slaughtered and the content from jejunum and ileum was separately collected and pooled and used for measurement on intestinal viscosity. For measurements of the apparent metabolisable energy and the apparent digestibility, excreta were collected at 22–24 days of age and ileal contents collected at 25–26 days from the remaining chickens.

Substitution of soya bean meal and maize with blue lupin depressed weight gain (9%) and feed conversion ratio (12%) significantly. Feed intake of the lupin-based diets was not decreased. The protein in lupin was digested to the same extent as the protein from soya bean meal, the coefficient of ileal apparent digestibility being on average 0.75. However, the high content of the non-starch polysaccharides (NSP; 450 g/kg) in lupin depressed the apparent digestibility of the organic matter by approximately 10%. The AME_n of the non-lupin diet was 14.01 MJ/kg dry matter (DM) compared to a value of 13.11 MJ/kg DM in the lupin control diet. Improvements in the measured parameters were seen with some of the enzymes. Gal-I, and Gal-II in combination with lactase were the most efficient enzymes concerning improvement in AME_n and performance. Weight gain was increased by 3.5–5.5% by addition with these enzymes. Gal-I increased the AME_n significantly to 13.65 MJ/kg, a value not significantly different from the AME_n of the non-lupin diet. There was no effect of addition with the different enzymes on the coefficients of apparent digestibility of organic matter measured in the ileum, whereas addition with Gal-I to the lupin diet increased the apparent digestibility of organic matter over the total tract by 3%. The mode of action of the galactanases has been to hydrolyse the galactan in the NSP cell wall of lupins to galactose and dimers of galactose, which are energy-yielding to poultry. From the results obtained, it can be indicated that Gal-I increased the energy utilisation of the lupin-based diet, confirmed by the improved AME_n content and performance.     

Effect of microbial phytase on apparent ileal amino acid digestibility of phosphorus-adequate diets in growing pigs

Six ileally cannulated pigs (mean initial body weight 34.8 kg) were used to study the effect of microbial phytase on apparent ileal digestibility of P, total N and amino acids. Three P-adequate diets (digestible P concentration 2.3 g kg(- )l) containing barley (B), soyabean meal (S) or a mixture of the two (BS) with or without phytase supplement (1000 FTU x kg(-1)) were fed to pigs using a 6 x 6 Latin square design. The addition of phytase increased (p < 0.05) apparent ileal P digestibility of diets B, S and BS by 16.5, 19.2 and 19.2%, respectively. There was no effect of phytase on the ileal digestibility of total N. Apparent ileal digestibility of amino acids tended to increase in the BS diet supplemented with phytase (mean improvement of 2.2%); but no significant difference was found for any amino acid as compared with the unsupplemented diet. To asses the additivity of apparent amino acid digestibility, the determined values for the BS diet were compared to those calculated from digestibilities found in diets B and S. There were no significant differences between the determined and calculated values. It is concluded that the addition of microbial phytase to P-adequate diets does not affect ileal amino acid digestibility in growing pigs and that the apparent amino acid digestibility values determined in single ingredients may be additive when included into a complex diet.     

Effects of supplementing pig diets with tryptophan and acidifier on protein digestion and deposition,and on brain serotonin concentration in young pigs

The objective of the study was to find out whether feeding acidifying preparation with diets containing crystalline tryptophan (Trp) affects availability of this amino acid for protein and serotonin (5-HT) synthesis in young pigs. Two experiments were performed. Supplementation of Trp-deficient diet with 3 g/kg of acidifier (A) (mixture of phosphoric, citric and fumaric acids) did not affect the coefficients of ileal apparent digestibility (CIAD) of protein and protein-bound amino acids except CIAD of Trp which was increased from about 0.65 to 0.73. In pigs of initial body weight 16 kg, the increase of digestible dietary Trp level from 0.77 to 1.39 and 1.85 g/kg improved growth performance, nitrogen retention and utilization of nitrogen absorbed, while the increase from 0.77 to 1.39 g/kg enhanced 5-HT concentration in all six analyzed brain structures. Supplementation with A did not affect blood Trp level in animals fed on Trp-deficient diet while it decreased it considerably on diet supplemented with Trp to 1.85 g/kg. Feeding A affected 5-HT metabolism: decreased its level in five of six brain structures in pigs fed on Trp-deficient diet, changed 5-HT metabolite 5-hydroxy-indolo-3-acetic acid (5-HIAA) and 5-HIAA/5-HT ratio, and modified response of 5-HT to Trp supplementation.It is concluded that feeding A both with Trp-deficient and Trp-supplemented diets has positive net effect on growth and protein deposition in pigs while it seems to affect negatively 5-HT synthesis and, probably, accelerates its turnover. The mechanism of this action is not known, and it was not proved that it is related to destructive effect of acids on crystalline Trp.     

Effect of feeding different levels of wilted cassava foliage (Manihot esculenta,Crantz) on the performance of growing goats

The effects of feeding different levels of wilted cassava foliage (Manihot esculenta, Crantz) on growth and diet digestibility were studied using local male growing goats with an average body weight of 14.5 kg. Thirty-two animals were randomly allocated to four groups of eight animals in a growth experiment, and four animals were assigned to a 4 × 4 Latin Square design to study digestibility. The four diets in both the growth and the digestibility studies were Gamba grass (Andropogon gayanus) as a sole diet offered ad libitum (control) or supplemented with wilted cassava foliage (WCF) at 20%, 30% and 40% of an expected daily DM intake of 3% of BW. Dry matter (DM) intake was significantly lower in the control group and increased with the level of WCF in the diet, while the DM intake of Gamba grass was not significantly changed. Total DM intake and DM intakes from Gamba grass were 472, 546, 584 and 616 g/d and 472, 457, 457 and 470 g/d for the control and treatments with 20%, 30% and 40% of WCF in the diet, respectively. The inclusion of WCF in the diet increased the apparent digestibility of DM, organic matter, N, Neutral detergent Fibre and Acid Detergent Fibre, and resulted in a higher N-retention. The average daily gains of animals fed diets with WCF were significantly higher than in the control group. The highest gain was recorded in goats with 40% of WCF in the diet (55.0 g/d) and lowest for the control (28.9 g/d). In conclusion, supplementing a basal diet of Gamba grass (Andropogon gayanus) with WCF improved DM intake, digestibility, N-retention and weight gain. The inclusion level of WCF in the diet can be up to 30%–40% of diet DM (21%–24% of total DM intake).     

Effects of dietary Bacillus subtilis and inulin supplementation on performance,eggshell quality,intestinal morphology and microflora composition of laying hens in the late phase of production

Eighty Lohmann White laying hens were used to investigate the effect of dietary inclusion of Bacillus subtilis and inulin, individually or in combination, on egg production, eggshell quality, tibia traits, Ca retention, and small intestine morphology and microflora composition from 64 to 75 weeks of age. Hens were randomly distributed into 4 treatment groups, with 5 replicates per treatment and 4 hens per replicate. Treatment groups were fed basal diet (control), basal diet plus 1 g/kg B. subtilis (2.3 × 10⁸ cfu/g), basal diet plus 1 g/kg inulin, or basal diet plus a synbiotic combination of 1 g/kg B. subtilis (2.3 × 10⁸ cfu/g) and 1 g/kg inulin. Dietary supplementation of B. subtilis, inulin or synbiotic improved (P<0.05) feed conversion, egg performance, eggshell quality and calcium retention compared with the control. B. subtilis and synbiotic groups exhibited the highest (P<0.05) increase in egg production and egg weight. Inulin and synbiotic groups exhibited the highest (P<0.05) increase in eggshell thickness and eggshell calcium content, and the lowest (P<0.05) eggshell deformations. Unmarketable eggs were 8.4% (P<0.05) of the total eggs produced by the control group compared to 3.5%, 1.7%, and 1.5% for the B. subtilis, inulin and synbiotic groups, respectively. Tibia density, ash, and Ca content increased (P<0.05) by inulin and synbiotic inclusions, compared with the control. B. subtilis, inulin, and their synbiotic combination increased (P<0.05) villus height and crypt depth in all intestinal segments, compared with the control. B. subtilis and inulin modulated the ileal and caecal microflora composition by decreasing (P<0.05) numbers of Clostridium and Coliforms and increasing (P<0.05) numbers of bifidobacteria and lactobacilli, compared with the control. Colonization of the beneficial microflora along with increasing the villi–crypts absorptive area were directly associated with the improvements in performance and eggshell quality. It can be concluded that egg production and eggshell quality of laying hens can be improved (P<0.05) in the late phase of production by dietary inclusion of B. subtilis and inulin.     

Effects of non-enzymatic browning reaction intensity on in vitro ruminal protein degradation and intestinal protein digestion of soybean and cottonseed meals

The effects of non-enzymatic browning reactions on in vitro ruminal gas production and in vitro ruminal and intestinal crude protein (CP) digestibilities of soybean (SBM) and cottonseed (CSM) meals were investigated. Non-enzymatically browned SBM and CSM samples were prepared using two xylose levels (10 or 30 g/kg dry matter), two heating lengths (30 or 60 min) and two heating temperatures (120 or 150 °C) for a total of one untreated (commercially solvent-extracted, Control) and eight treated samples for each protein source. The control SBM had higher (P<0.001) in vitro ruminal CP degradability values than the treated samples. Intestinal protein digestibility and total-tract CP digestibility of CSM and SBM were affected by the treatment (P<0.01). The results of the study indicate that not only ruminal CP degradability is reduced but also intestinal and total-tract CP digestibilities may be lowered depending on protein source and intensity of the non-enzymatic browning reaction.     

Effect of fat type and lysophosphatidylcholine addition to broiler diets on performance,apparent digestibility of fatty acids,and apparent metabolizable energy content

A completely randomized design study with a 3 × 2 factorial arrangement was conducted to evaluate the effects of three different fat sources (soybean oil, tallow, and poultry fat) with or without emulsifier supplementation on performance, coefficient of total tract apparent digestibility (CTTAD) of fatty acids, and apparent metabolizable energy (AME) content in broiler chickens. Two hundred and fifty-two one-day-old male Arbor Acres broiler chickens were randomly divided into 6 different treatments: (T1) basal diet containing soybean oil without lysophosphatidylcholine (LPC) supplementation, (T2) basal diet containing soybean oil with LPC supplementation, (T3) basal diet containing tallow without LPC supplementation, (T4) basal diet containing tallow with LPC supplementation, (T5) basal diet containing poultry fat without LPC supplementation, and (T6) basal diet containing poultry fat with LPC supplementation. Body weight gains from broiler chicks fed diets containing tallow were lower (P<0.05) than the body weight gains from chicks that were fed diets containing soybean oil or poultry fat in both the starter and grower periods. Birds fed diets containing tallow had the highest FCR (P<0.05), followed by the birds that were fed diets containing poultry fat, and soybean oil. The CTTAD of C16:0, C18:2, and C18:3n3 was greater (P<0.05) for broilers fed diets containing soybean oil than for those fed diets containing tallow or poultry fat in the starter period. The addition of LPC increased (P<0.05) body weight gain of broiler chickens in the starter period and the AME of the diets in the grower period, and tended to reduce FCR (P=0.072) in the starter period. LPC supplementation increased (P<0.05) the CTTAD of C16:0, C18:1n7 and C18:1n9 in the starter period, and of C18:2, and C18:3n3 in the grower period (P<0.05). There were no significant interactions between fat sources and the addition of LPC. These data indicated that LPC supplementation can improve body weight gain of broiler chickens in the starter period. This effect may be associated with an increase of CTTAD of FA due to LPC activity.     

Effects of fibre level and dietary mannanoligosaccharides on digestibility,caecal volatile fatty acids and performances of growing rabbits

The current experiment with 3 trials aimed to study the effect of two levels of dietary fibre – high fibre (HF; 323 g aNDFom/kg) and low fibre (LF; 248 g aNDFom/kg) – and the effect of mannanoligosaccharides (MOS) addition (1 g/kg) to the LF diet (LFM) on the performances and health status of growing rabbits, digestibility and caecal fermentative characteristics. In the growth trial 132 rabbits of both sexes were used (11 cages with 4 rabbits per treatment) from weaning (32 days of age) to slaughter (67 days of age). Rabbits fed HF diet showed a significantly higher weight gain and live weight at 67 days than rabbits fed LF diet (2032 g vs. 1935 g) (P<0.05). Feed and digestible energy intake increased with dietary fibre level (P<0.05). During the growing period rabbits fed HF diet had a feed intake 26% higher than those fed LF diet. Feed efficiency ratio was worse in HF animals (0.334 vs. 0.385; P<0.05). Addition of MOS to LF diet did not affect growth performance parameters (P>0.05). Mortality and morbidity rate were not affected by treatments. In the digestibility 24 rabbits from 46 to 51 days of age trial were used. The HF diet resulted in a significant (P<0.05) decrease in digestibility of dry matter, organic matter and protein while the aNDFom digestibility was not significantly different between diets (P>0.05). Supplementation with MOS had no effects on digestibility (P>0.05). In the 3rd trial the caecal traits were measured in 30 rabbits with 46 days of age that received the experimental diets in the previous 14 days. Caecal production of total volatile fatty acids (VFA), acetate and propionate were significantly higher (P>0.05) on rabbits fed HF diets than on rabbits fed LF diets. The total VFA concentration increased 64% (from 5.01 to 8.20 mmol/100 ml) and acetate increased 73% (from 3.73 to 6.44 mmol/100 ml). Butyrate production was not different between diets (P>0.05). Fibre level did not affect proportions of VFA and caecal contents and caecal weights. Addition of MOS to LF diet did not affect any caecal trait (P>0.05). It was concluded that the reduction of dietary fibre level increases feed digestibility but worsens rabbit growth performances. Supplementation of low fibre diet with 1 g MOS/kg is not enough to reduce its negative effects on growth performances.     

Intake,digestibility and nitrogen utilization of Robinia pseudoacacia foliage fed to growing goat wethers

Black locust (BL; Robinia pseudoacacia L.), a native tree of southeastern USA known to contain substantial levels of condensed tannins (CT), was fed to 32, 4 month old (20.4 kg BW) Boer cross wether goats in two randomized complete block design trials. The objectives were to examine the effects of feeding hay diets containing several levels of fresh BL foliage on intake, digestibility, and N metabolism. First year (1999) diets were H_E (100% Eastern gamagrass [EGH; Tripsacum dactyloides L.] hay), H_EG (70% EGH and a 30% mixture of 59% ground corn [GC; Zea mays L.], 36% soybean meal [SBM; Glycine max L.], and 5% minerals), 25BL99 (75% EGH and 25% BL leaves), and 50BL99 (50% EGH and 50% BL leaves). Second year (2000) diets were H_O (100% orchardgrass [OGH; Dactylis glomerata L.] hay), H_OG (70% OGH and a 30% mixture of 63% GC, 37% SBM, and 5% minerals), 50BL00 (50% OGH and 50% BL leaves), and 75BL00 (25% OGH and 75% BL leaves). In 1999, apparent digestibilities of the diets in the order listed above were 62.4, 68.2, 58.0, and 60.6% (P = 0.001) for DM and 62.8, 72.5, 56.0, and 59.1% (P = 0.001) for crude protein (CP). Acid detergent lignin digestibilities were negative for diets 25BL99 (−56.7%) and 50BL99 (−49.3%), apparently due to the formation of insoluble tannin and lignin complexes during passage through the digestive tract. Intakes of DM were similar across diets. In 2000, apparent digestibilities of diet DM (64.4, 71.7, 64.8 and 65.4%) and CP (70.0, 76.0, 66.6, and 66.5%) did not differ. Lignin digestibilities were positive for diets 50BL00 (9.4%) and 75BL00 (29.6%) unlike those for year 1999. Overall, BL contained 10% CT and 18–34% hydrolyzable tannins. In 1999, N intake, urinary N (UN) excretion and N retained were higher for diet H_EG (P = 0.01) than diet H_E whereas fecal N excretion (FN) was similar for diets H_EG, 25BL99 and 50BL99. In 1999, FN excretion as a percentage of N intake was higher (P < 0.02) in the BL diets, although UN as a percentage of N intake did not differ among diets. In 2000, N intake and FN output were higher for BL diets compared to diets H_O (P = 0.01) and H_OG (P = 0.02). Fecal N as a percentage of N intake was lower (P = 0.01) for diet H_OG (24.0%) than for diets 50BL00 (33.4%) and 75BL00 (33.5%). Conversely, urinary N as a percentage of N intake was higher for diets H_O and H_OG compared to the BL diets (P = 0.02). Increased levels of dietary BL increased FN, suggesting that tannins formed insoluble protein complexes thus hindering digestibility.     

Effect of elemental nano-selenium on feed digestibility,rumen fermentation,and purine derivatives in sheep

The objective of this experiment was to study the effect of elemental nano-selenium (NS) on feed digestibility, rumen fermentation, and urinary purine derivatives in sheep. Eight male ruminally cannulated sheep (42.5 ± 3.2 kg of body weight, BW) were used in a replicated 4×4 Latin square experiment in four 20 day periods. Depending on treatment designation, sheep were fed the basal diet supplemented with 0 (control), 0.3, 3 and 6 g of nano-Se/kg dry matter (DM). Ruminal pH (range of 6.68–6.80) and ammonia N concentration (range of 9.95–12.49 mg/100 mL) was decreased (P<0.01), and total VFA concentration (range of 73.63–77.72 mM) was increased linearly (P<0.01) and quadratically (P<0.01) with increasing nano-Se supplementation. The ratio of acetate to propionate was linearly (P<0.01) and quadratically (P<0.01) decreased due to the increasing of propionate concentration. In situ ruminal neutral detergent fiber (aNDF) degradation of Leymus chinensis and crude protein (CP) of soybean meal were linearly (P<0.01) and quadratically (P<0.01) improved by feeding nano-Se. Similarly, nutrients digestibility in the total tract and urinary excretion of purine derivatives were also quadratically (P<0.01) changed by increasing nano-Se supplementation. The present results indicated that nano-Se supplementation in basal diet improved rumen fermentation and feed utilization. Nano-Se could also stimulate rumen microbial activity, digestive microorganisms or enzyme activity. The optimum dose of nano-Se was about 3.0 g/kg dietary DM in sheep.     

Effects of dietary inclusion of triticale,rye and wheat and xylanase supplementation on growth performance of broiler chickens and fermentation in the gastrointestinal tract

An experiment was performed over a period of 5 weeks with 576 one-day-old cockerels (Cobb 500), which were randomly divided into 6 experimental groups (12 replicate cages with 8 birds/cage). The objective of the experiment was to estimate whether different grain types (wheat, rye or triticale) and exogenous xylanase inclusion influence the performance and the gastrointestinal ecosystems of broiler chickens as regards intestinal viscosity, pH as well as the concentration of short-chain fatty acids (SCFA) and lactic acid (LA). The rye-based diets resulted in the poorest production results followed by wheat and triticale-based diets. Ileal viscosity decreased in the range: rye (140 cps), triticale (6.1 cps) and wheat (2.5 cps). Xylanase supplementation reduced ileal viscosity significantly only in birds fed with rye. The cereal type influenced the fermentation process in the broiler gastrointestinal tract more than the xylanase supplementation. The total concentration of organic acids was highest in the caeca, followed by the crop, ileum and gizzard. Lactic acid concentrations were highest in the content of the crop followed by ileum, gizzard and caeca. Propionate was only detected in caecal contents, whereas butyrate was also found in small amounts in the contents of the crop of birds from all treatments. The concentrations of acetate, butyrate and total organic acid concentration in caecal contents of chickens receiving the rye-based diets were lower than in birds fed the other cereals (P<0.001). Enzyme supplementation reduced the relative weight of the caeca in rye-fed birds (P=0.001).     

Fermented soybean meal increases nutrient digestibility via the improvement of intestinal function,anti-oxidative capacity and immune function of weaned pigs

The nutritional components of fermented soybean meal (FSBM) vary because of the complex process of microbial fermentation. The objective of this study was to investigate the nutritional value of FSBM from two sources and explore the mode of actions of FSBM on the improvement of nutrient digestibility with the measurements of digestive enzymes and serum biomarkers. Eight weaned barrows (initial BW: 14.12 ± 0.24 kg) equipped with T-cannula in the distal ileum were allotted to a duplicated 4 × 4 Latin-square design with four experimental diets and four periods. Four experimental diets included a soybean meal control diet, two FSBM diets, and a nitrogen-free diet. The two sources of FSBM increased the contents of CP, amino acid and lactic acid, while decreased the levels of anti-nutritional factors, including glycinin, β-conglycinin and trypsin inhibitors. Compared to soybean meal control diet, both FSBM diets significantly increased the apparent and standardised ileal digestibility of CP and amino acids (P < 0.05), increased the activities of lipase, maltase and invertase in digesta (P < 0.05), increased total antioxidant capacity, activities of glutathione peroxidase and superoxide dismutase, the levels of interleukin-4, IgA, IgG and IgM in serum (P < 0.05), while decreased the levels of diamine oxidase, malondialdehyde, interleukin-6, and interleukin-2 in serum (P < 0.05). Additionally, the standardised ileal digestibility of amino acids were highly correlated with the aforementioned digestive enzymes and health-related serum biomarkers. In summary, FSBM diets showed an improved nutritional value evidenced by the higher nutrient digestibility, which may be partially derived from its beneficial effects on intestinal integrity, anti-oxidative capacity and immune function.