Digestibility Of Calcium Research Articles

The effect of 25-hydroxyvitamin D3 and phytase inclusion on pig performance, bone parameters and pork quality in finisher pigs.

The objective of this study was to investigate the effects of supplementing both phytase and 25-hydroxyvitamin D3 (25-OH-D₃) on pig performance, nutrient digestibility, carcass characteristics, bone parameters and pork quality in finisher pigs. The experimental design was a 2×2 factorial comprising of four dietary treatments. One hundred and twenty pigs (60 male, 60 female) were blocked according to live weight and sex and allocated to the following dietary treatments: low P (4.81g/kg) diet (basal) (T1); low P diet + phytase (T2); low P diet + 25-OH-D₃ (T3) and low P diet + phytase + 25-OH-D₃ (T4). Pigs supplemented with phytase had a lower average daily feed intake (ADFI) (2.45kg vs. 2.59kg; p<0.05) and lower feed conversion ratio (FCR) (2.74kg/kg vs. 2.85kg/kg; p<0.05) compared to pigs offered the nonphytase diets. Pigs offered phytase diets had a higher (p<0.05) coefficient of apparent total tract digestibility (CATTD) of ash, phosphorous (P) and calcium (Ca) compared with pigs offered the nonphytase supplemented diets. Pigs offered the 25-OH-D3 diets had a higher CATTD of N and ash. Pigs offered the phytase diets had increased (p<0.05) bone DM, ash, Ca, P and density compared to the nonphytase diets. There was a significant interaction (p<0.05) between phytase and 25-OH-D3 on cook loss. Pigs offered 25-OH-D3 had increased cook loss over the basal diet; however, there was no effect on cook loss when phytase and 25-OH-D3 were offered in combination compared to the phytase only diet. Pigs offered 25-OH-D3 exhibited higher (p<0.05) Warner Bratzler shear force values and lower (p<0.05) pork lightness (L*) surface colorimeter values. In conclusion, there was no benefit to offering a combination of phytase and 25-OH-D3 on pig performance, bone parameters or pork quality.

Improving effects of dietary rumen protected γ-aminobutyric acid additive on apparent nutrient digestibility, growth performance and health status in heat-stressed beef cattle.

This study was aimed to investigate the effects of rumen-protected γ-aminobutyric acid (RP-GABA) on apparent nutrient digestibility, growth performance and health status in heat stressed beef cattle. Fifty Jinjiang Yellow cattle were randomly assigned to 5 treatments (10 animals/treatment). Treatments 1 to 5 were basal diets affixed with 0 (control), 8, 16, 24 and 32mg of RP-GABA/kg of body weight (BW) respectively. The trial lasted 45days. Apparent digestibility of crude protein (CP), crude fiber (CF) and calcium (Ca) quadratically increased with increasing RP-GABA (p<.01), while apparent digestibility of phosphorus (P) tended to quadratically increase (p=.09). Dietary supplementation with increasing RP-GABA linearly increased DM digestibility and average daily gain (ADG) (p<.01), whereas the feed to gain (F:G) ratio linearly decreased with increasing RP-GABA (p<.01). The average daily feed intake (ADFI) value tended to linearly increase with RP-GABA supplementation (p=.08). Total protein (TP), blood urea nitrogen (BUN) and malondialdehyde (MDA) levels quadratically decreased (p<.01) with increasing RP-GABA, however albumin (ALB), glucose (GLU), superoxide dismutase (SOD), triiodothyronine (T3) and thyroxine (T4) levels quadratically increased (p≤.01). In conclusion, the present results indicated that dietary supplementation with RP-GABA led to improved nutrient digestibility, growth performance and antioxidant status in heat stressed beef cattle.

Phytase supplementation in diets rich in fiber from rapeseed enhances phosphorus and calcium digestibility but not retention in broiler chickens

Two experiments were conducted on broilers to assess the effect of dietary fiber from 00-rapeseed meal (RSM) on phosphorus (P) and calcium (Ca) apparent ileal digestibility (AID) and retention (AR) during the growing (Exp1: 10 to 21 d) or finishing period (Exp2: 21 to 31 d) in diets supplemented or not with microbial phytase. Each experiment involved 144 male Cobb 500 fed one of 8 diets. Fiber content was modulated by incorporating whole RSM, RSM from dehulled rapeseeds, either raw or supplemented with 2 levels of defatted rapeseed hulls. Diets were supplemented or not with 750 phytase units of microbial phytase per kg. Excreta were collected from d 14 to d 17 (Exp1) and from d 27 to d 30 (Exp2) to measure AR. At the end of experiments, digestive tracts were sampled and weighed. The distal ileum and tibias were collected to measure AID and bone mineralization, respectively. Age did not significantly alter the response of birds to the addition of dietary fiber. Inclusion of hulls decreased growth performance (P < 0.05). The weight of the proventriculus-gizzard (PG) increased with the dietary fiber content in Exp1: The decreased weight observed using dehulled RSM was reversed following the inclusion of hulls. In both trials, while the presence of phytase increased the AID of P (P < 0.001) but not Ca, the inclusion of hulls with phytase improved the AID of P and Ca [linear (Lin), P < 0.05]. This effect could depend on the effect of fiber on PG development and physiology. Hulls decreased the moisture content of excreta (P < 0.01), suggesting higher water retention or lower water consumption with fiber. The AR of P was lower than AID of P with hulls, contrary to Ca, suggesting a metabolic imbalance. The decrease of AR together with the decrease of bone characteristics indicates a lack of Ca in diets with hulls and suggests that P and Ca provision should be adapted to the level and the origin of fiber inclusion.

Determination of true ileal phosphorus digestibility of maize and soybean meal and true ileal calcium digestibility of soybean meal for broiler chickens

Two experiments were conducted, using the regression method, to determine the true ileal phosphorus (P) digestibility of maize and soybean meal (SBM), and true ileal calcium (Ca) digestibility of SBM for broiler chickens. The aim of Experiment 1 was to determine true ileal P digestibility of maize and SBM. The experimental diets were formulated with four inclusion levels of each test ingredient to achieve graded concentrations of total P (2.5, 3.0, 3.5 and 4.0 g/kg, respectively). The P concentrations in maize-based diets were adjusted by the inclusion of monosodium phosphate. The Ca:total P ratio in all diets was maintained at 1.35 by the addition of limestone. Experiment 2 was conducted to determine true ileal Ca digestibility of SBM. Experimental diets were formulated to contain four levels of SBM to achieve graded concentrations of Ca (2.5, 3.0, 3.5 and 4.0 g/kg, respectively). Because of the low concentration of Ca in SBM, all diets were supplemented with a similar level of limestone to prevent any Ca deficiency. The Ca:total P ratio in all diets was adjusted to be equal by the addition of monosodium phosphate. In both experiments, titanium dioxide (3 g/kg) was used as the indigestible marker. One-day-old male broiler chicks were fed a commercial starter diet from 1 to 21 days of age. On Day 22, a total of 240 and 120 birds were assigned to eight and four dietary treatments in Experiments 1 and 2, respectively, with five replicate cages and six birds per cage. Birds were fed the experimental diets for 7 days. On Day 29, ileal digesta were collected from the posterior half of ileum, and the true P and Ca digestibility of test ingredients were calculated by linear regression analysis. True P digestibility of maize and SBM were determined to be 33.8% and 42.3%, respectively. True Ca digestibility of SBM was determined to be 45.9%.

157 Comparative Digestibility and Retention of Calcium and Phosphorus By Gestating Sows and Growing Pigs Fed Low- and High-Phytate Diets without or with Microbial Phytase.

157 Comparative Digestibility and Retention of Calcium and Phosphorus By Gestating Sows and Growing Pigs Fed Low- and High-Phytate Diets without or with Microbial Phytase.

HUSK OF KOREAN PINE CONES IN DIETS OF LAYING QUAILS

There was studied effectiveness of introduction Korean pine (Pinus koraiensis) cone husks into diets of laying quails of Japanese breed as a source of natural amino acids, microelements and other biologically active substances. Experiment of 182 days duration was carried out according to the standard technique in four groups of 50 birds each kept in a cell battery under required microclimate conditions. Quails of all groups received the basic diet (feed), developed taking into account their age and physiological characteristics. Quails of 1st to 3rd experimental groups, unlike the control one were additionally fed with Korean pine cone husks in the amount of 1.5; 2.0 and 2.5 kg/t of feed respectively. There was studied influence of different doses of the additive on laying quails egg productivity, eggs chemical composition and incubation qualities, diet nutrients digestibility, the balance and use of nitrogen, calcium and phosphorus and hematological parameters. It was found that adding a new supplement in amount of 1.5–2.5 kg/t into combined feeds increased poultry egg production by 2.9 and 5.8 %, the intensity of oviposition by 2.0 to 4.0 %, egg weight by 2.70–4.71 %, total egg mass by 5.69 – of 10.83 %, yield of hatching eggs by 2.19–8.58 % and the hatchability of chicks from eggs laid by 6.3 and 8.2 %. At the same time, feed consumption per unit of production decreased by 7.95 – 18.18 %, incubation waste by 33.3 %. Feeding with pine cone husks in the indicated doses increased the digestibility of the diet dry matter by 1.63–2.16 %, crude protein by 1.28 –1.82 %, crude fiber by 0.76 – 3.03 %, the efficiency of nitrogen use for egg formation in 1.12–1.23 times. It was also revealed that feeding with the addition of Korean pine cone husks at the rate of 2.5 kg / t feed had a maximum positive impact on the zootechnic and economic indicators of productive use of laying quails.

Observation about phosphorus and protein supply in cats and dogs prior to the diagnosis of chronic kidney disease.

There is evidence that nutritional phosphorus (P) excess may be a risk factor for chronic kidney disease (CKD) in humans and pets (Advances in Nutrition: An International Review Journal (2014), 5, 104; The American Journal of Clinical Nutrition, (2013), 98, 6; Journal of Feline Medicine and Surgery, (2017); The source of phosphorus influences serum PTH, apparent digestibility and blood levels of calcium and phosphorus in dogs fed high phosphorus diets with balanced Ca/P ratio. Proc. Waltham International Nutritional Sciences Symposium, USA; Clinical aspects of natural and added phosphorus in foods, 2017, Springer Science+Business, Media). A retrospective study was conducted in order to gather data about P and protein intake in the feeding history of dogs and cats prior to the diagnosis of CKD. Cases of 75 dogs and 16 cats with CKD with comprehensive nutritional history presented to the nutrition consultation service of the Chair of Animal Nutrition and Dietetics, Ludwig-Maximilians-University Munich, between October 2009 and March 2016, were evaluated. Cases of age-matched dogs (n=57) and cats (n=18) without diagnosed or suspected CKD served as controls. The most frequent type of diet used in the four groups (cats CKD, cats control, dogs CKD and dogs control) was home-made. In all groups, P and protein supply was in excess (>150%) of the recommended daily allowances (RDA; Nutrient requirements of dogs and cats (2006), National Research Council, National Academy Press). Between the dog groups, no differences regarding P and protein intake existed. The P and protein intake relative to the RDA was altogether higher in cats than in dogs. Cats with CKD showed significantly higher P and protein intakes prior to diagnosis than the control cats (170±36 vs. 123±34mg P/kg BW0.67 ; p<.05). These observations call for further investigations into the long-term effects of P excess.

Responses in digestibilities of macro-minerals, trace minerals and amino acids generated by exogenous phytase and xylanase in canola meal diets offered to broiler chickens

Atypical diets based on canola meal (584 g/kg) and dextrose, supplemented with phytase and xylanase individually and in combination, were offered to 120 male Ross 308 broiler chicks with six replicates for each of the four treatments. The objective was to determine the effects of phytase and xylanase on the apparent digestibility coefficients of macro-minerals, trace minerals and amino acids along the small intestine of broiler chickens. The combination increased phosphorus digestibility by a two-fold factor (0.694 versus 0.324), calcium digestibility by a three-fold factor (0.527 versus 0.178), increased zinc from -0.141 to 0.324 and increased sodium digestibility coefficients from -1.402 to -0.359 in comparison to the control diet. Similarly, phytase and xylanase in tandem generated better responses in the apparent ileal digestibility coefficients of amino acids. The enzyme combination significantly increased the digestibility of nine essential amino acids by from 5.47% (methionine) to 35.4% (threonine), and seven non-essential amino acids by from 13.9% (glutamic acid) to 32.9% (proline). The better responses in apparent ileal digestibilities of phosphorus, calcium, sodium, zinc and five other trace minerals in broiler chickens offered the combination diet was confounded by its higher enzyme recovery activities in comparison to the individual supplemented diets and the study may suggest that the inclusions of phytase and xylanase in tandem should be considered in diets containing canola meal for broiler chickens.

The interactive influence of dietary nutrient density and feed form on the performance of broiler chickens

The present study investigates the interactions between dietary nutrient density and feed form on the growth performance, coefficient of apparent ileal digestibility (CAID) of dry matter (DM), nitrogen (N), starch, fat, calcium (Ca) and phosphorus (P), and N-corrected apparent metabolisable energy (AMEn) in broiler chickens to 21d post-hatch. Maize-soybean meal diets with five tiers of nutrient density were formulated and mixed. The diets were then divided into two equal batches; the first batch was offered as unprocessed mash and the second batch was steam-pelleted at a conditioning temperature of 75 °C. A 5 × 2 factorial array of ten dietary treatments were offered to a total of 480, day-old male broiler (Ross 308) chicks accommodated in 60 cages (eight birds per cage). Significant (P < 0.001) interactions between nutrient density and feed form were observed for weight gain, feed intake and feed per unit gain. While birds fed pelleted diets outperformed those fed mash diets at each nutrient density level, the pellet-associated benefits were more pronounced at the lowest nutrient density. Increasing nutrient density increased (P < 0.001) N digestibility from 0.772 to 0.811, but decreased (P < 0.001) that of starch from 0.969 in very low density diets to 0.943 in very high density diets. No significant (P > 0.05) effect of nutrient density on the CAID of DM and fat was found. Feeding pelleted diets, regardless of nutrient density, reduced (P < 0.001) the CAID of DM, N, starch and fat. Significant nutrient density × feed form interactions were observed for the CAID of Ca (P < 0.001) and P (P < 0.01). Pelleting enhanced (P < 0.05) the CAID of Ca and P in the diet with lowest nutrient density but reduced (P < 0.05) the digestibility of these minerals in all other nutrient density diets. Increasing dietary nutrient density progressively increased the AMEn, but feeding of pelleted diets, regardless of nutrient density, reduced (P < 0.001) the AMEn. Overall, the present data showed that the magnitude of pelleting-induced benefits on broiler performance varied depending on dietary nutrient density, with responses to pelleting decreasing with increasing dietary nutrient density. The present study highlights that dietary nutrient density must be taken into consideration if the full benefits associated with feeding pelleted diets are to be achieved.

Digestibility of calcium and digestible calcium from inorganic sources evaluated in swine by two methods

SUMMARY The objective of the study was to determine the digestible calcium from different sources by direct and indirect methods. Thirty castrated male pigs were used, distributed in randomized blocks, in six treatments: 1- Calcitic limestone; 2-Dicalcium phosphate powder 18%; 3- Dicalcium phosphate powder 20%; 4- Dicalcium microgranulated phosphate 18%; 5- Monodicalcium microgranulated phosphate 20%; 6- Monodicalcium microgranulated phosphate 21%, with six replicates and one animal per experimental unit. A basal diet was formulated to meet the nutritional requirements of the animals, except for calcium (0.06%) and the evaluated sources replaced the basal diet in order to provide 0.45% of total Ca. At the same time, two stool collection methods were evaluated: total collection and fecal indicator. The animals were housed in metabolism cages for 12 days to collect feces and urine to determine the calcium values used to estimate digestibility coefficients and digestible calcium. The total collection method and the faecal indicator method did not affect the true digestibility coefficient of calcium. The calcium digestibility of the microgranulated dicalcium phosphate 21% (MM21) was superior in comparison with the other calcium sources evaluated by the indirect method in the present study. The average values of true digestibility of the calcium sources, in percentage, were: calcitic limestone: 82.47; dicalcium phosphate powder 18%: 80.87; dicalcium phosphate powder 20%: 85.65; dicalcium microgranulated phosphate 18%: 81.65; monodicalcium microgranulated phosphate 20%: 84.15; and monodicalcium microgranulated phosphate 21%: 88.35. The two methodologies can be used to determine the digestibility of calcium.

Effects of chito-oligosaccharide supplementation with low or medium molecular weight and high degree of deacetylation on growth performance, nutrient digestibility and small intestinal morphology in weaned pigs

Chito-oligosaccharide (COS) supplementation in nursery diets has been found to improve piglets’ performance. However, little is known on which COS characteristics are responsible for its effect. The present study was designed to further study how COS characteristics: molecular weight (MW) and degree of deacetylation (DD); affect the growth performance, nutrient digestibility, and small intestinal modifications in weaning pigs. For this purpose, 48 weanling pigs were divided into 4 groups (12 animals per group) and received either a basal diet or a basal diet supplemented with 150 mg/kg of COS which differed in MW and DD: 8 kDa and ~90% DD (8 kDa~90%), 65 kDa and ~80% DD (65 kDa~80%), and 65 kDa and ~90% DD (65 kDa~90%). The experiment lasted 56 days. There were treatment effects on pigs’ body weight gain (BWG), average daily gain (ADG), average daily feed intake (ADFI), blood urea nitrogen (BUN), digestibility of crude protein, fat and calcium, small intestinal morphology and crypt cell proliferation (P < .05, respectively). Throughout the study, pigs supplemented with 8 kDa~90% COS showed significantly enhanced BWG, ADG, and ADFI when compared to those supplemented with 65 kDa~80% COS (P < .05, respectively). The enhanced growth performances in pigs supplemented with 8 kDa~90% COS was supported by an increase in ADFI (P < .05), and improved ileal digestibility of crude protein and crude fat (P < .01, respectively). Pigs supplemented with 8 kDa~90% COS also had increased absorption capacity as indicated by elongated villus height and increased villus height to crypt depth ratio of the small intestinal segments (P < .05, respectively), and more active cell division as indicated by increased Ki-67 marker at jejunal crypt cells (P < .05) on day 28 and 56 of the experiment. These data suggest that 8 kDa~90% might be the most effective form of COS to improve feed intake, and promote nutrient digestibility and absorption when supplemented at 150 mg/kg in the diet.

Measurement of the true ileal calcium digestibility of some feed ingredients for broiler chickens

Results from three experiments relating to the measurement of ileal calcium (Ca) digestibility in feed ingredients for broiler chickens are presented herein. The first experiment was conducted to determine the true ileal Ca digestibility of dicalcium phosphate (DCP), monocalcium phosphate (MCP), poultry by-product meal (PBPM), fish meal (FM) and canola meal (CM). Five semi-purified diets containing DCP, MCP, PBPM and FM with a dietary Ca concentration of 9 g/kg, and CM with a dietary Ca concentration of 5.71 g/kg were generated. A Ca- and phosphorus (P)-free diet was used to determine the basal ileal endogenous Ca losses. Titanium dioxide was incorporated in all diets as an indigestible marker. Each diet was randomly allotted to six replicate cages (eight birds per cage) and fed from 21 to 24 days post-hatch. True Ca digestibility coefficients of DCP, MCP, PBPM, FM and CM were determined to be 0.28, 0.33, 0.29, 0.24 and 0.31, respectively. These lower digestibility coefficients were unexpected and it was speculated that this finding may be due to the length of adaptation to assay diets and/or assay methodology. To investigate these possibilities, two more experiments were conducted. In the second experiment, the influence of dietary adaptation length was examined with DCP and MCP. The assay diets with DCP and MCP, and the Ca- and P-free diet were similar to those used in Experiment 1. Each diet was randomly allocated to four replicate cages (15 birds per cage) and fed from 21 to 24 days post-hatch. Digesta samples of five birds from each replicate were collected after 24, 48 and 72 h of feeding. Dietary adaptation length had no influence (P > 0.05) on the true Ca digestibility of MCP, but increased that of DCP at 24 h. True ileal Ca digestibility of DCP and MCP after 24, 48 and 72 h of adaptation were 0.45, 0.36, and 0.35, and 0.30, 0.32 and 0.34, respectively. The third experiment was conducted to determine the effect of assay methodology (direct, regression and difference methods) and Ca:non-phytate P ratio (2:1 and 1.16:1) on the Ca digestibility of DCP. The true Ca digestibility coefficients of DCP determined by the direct, difference and regression methods with Ca:non-phytate P ratio of 1.16:1 were 0.34, 0.21 and 0.13, respectively. The true Ca digestibility of DCP determined by the direct method was higher (P < 0.05) than those determined by difference and regression methods The true Ca digestibility coefficient of DCP with Ca:non-phytate P ratios of 2:1 and 1.16:1 were 0.25 and 0.21, respectively, and was not influenced (P > 0.05) by the Ca to non-phytate P ratio.

Effects of rapeseed meal fiber content on phosphorus and calcium digestibility in growing pigs fed diets without or with microbial phytase

The optimization of dietary phosphorus (P) and calcium (Ca) supply requires a better understanding of the effect of dietary fiber content of co-products on the digestive utilization of minerals. This study was designed to evaluate the effects of dietary fiber content from 00-rapeseed meal (RSM) on P and Ca digestibility throughout the gastrointestinal tract in growing pigs fed diets without or with microbial phytase. In total, 48 castrated male pigs (initial BW=36.1±0.4 kg) were housed in metabolic crates for 29 days. After an 8-day adaptation period, pigs were allocated to one of the eight treatments. The impact of dietary fiber was modulated by adding whole RSM (wRSM), dehulled RSM (dRSM) or dRSM supplemented with 4.5% or 9.0% rapeseed hulls (dRSMh1 and dRSMh2). Diets contained 0 or 500 phytase unit of microbial phytase per kg. From day 14 to day 23, feces and urine were collected separately to determine apparent total tract digestibility (ATTD) and apparent retention (AR) of P and Ca. At the end of the experiment, femurs and digestive contents were sampled. No effect of variables of interest was observed on growth performance. Microbial phytase increased ATTD and AR of P (P<0.001) but the P equivalency with the wRSM diet was lower than expected. Moreover, stomach inorganic P (iP) solubility was improved by microbial phytase (P<0.001). The ATTD of Ca was not affected by microbial phytase which increased AR of Ca and femur characteristics (P<0.05). Ileal recovery of P was not affected by microbial phytase but cecal recovery was considerably reduced by microbial phytase (P<0.001). The decrease in digesta pH between the distal ileum and cecum (7.6 v. 5.9) enhanced the solubility of iP and may have improved its absorption, as supported by the negative relationship between soluble iP and pH (R2=0.40, P<0.001 without microbial phytase and R2=0.24, P=0.026 with microbial phytase). The inclusion of hulls improved the solubility of iP (P<0.05). In conclusion, dehulling does not largely increase nutrient digestibility although dRSM seems to improve the efficacy of microbial phytase in releasing phosphate in the stomach. Moreover, dietary fiber may affect solubilization process in the cecum which potentiates the effect of microbial phytase on P digestibility.

The effect of phytase, xylanase and their combination on growth performance and nutrient utilization in Nile tilapia

Increasing the inclusion rate of plant ingredients will increase the content of non-starch polysaccharides (NSP) and phytate in the fish feed. Both NSP and phytate are undesired in fish feed due to their anti-nutritional properties. The main objective of the present study was to assess the impact of exogenous enzyme supplementation on growth, body composition, digestibility and the energy, nitrogen and phosphorus balances in Nile tilapia. Four experimental diets were tested in a 2×2 factorial arrangement of treatments. The first factor was phytase supplementation at a dose of either 0 or 1000 FTU/kg and the second factor was xylanase supplementation at a dose of 0 or 4000U/kg. This resulted in a control diet (CON-CON) without enzymes, phytase diet (PHY-CON), xylanase diet (CON-XYL) and a diet with both xylanase and phytase (PHY-XYL). In total 24 tanks (6 replicates/treatment) were used with 30 (mean initial body weight 42g) fish each. Fish were restrictively (80% of expected satiation) fed the experimental diets for 38days. Growth was significantly affected by the interaction between phytase and xylanase supplementation (P<0.05), showing a synergism between both enzymes. Growth at the CON-CON and CON-XYL diets were similar, whereas fish fed the PHY-CON had an improved growth. The effect of phytase supplementation on growth was further enhanced when xyalanse was supplemented (PHY-XYL diet). Phytase significantly improved the digestibility of dry matter, crude protein, carbohydrates, energy, ash, phosphorus and calcium (P<0.001). Xylanase enhanced the digestibility of dry matter, crude protein, carbohydrates and energy significantly (P<0.05). In contrast to growth, there was no significant synergetic effect of the combination of phytase and xylanase on the digestibility (P>0.05). The significant synergetic effect of the combination of phytase and xylanase on growth was not reflected on the digestibility (P>0.05). The nitrogen balance showed that the synergism on growth was predominantly due the significant synergistic effect of phytase and xylanase on the protein retention (P=0.005). Both xylanase and phytase showed to be an effective tool to improve the nutrient availability and growth in Nile tilapia. Fish fed the diet supplemented with both phytase and xylanase had a significantly higher growth than all other treatments.

Addition of phytogenic blend in different nutrient density diets of meat-type ducks

ABSTRACTA total of 160 1-d-old ducklings (mixed gender) were used to evaluate the effects of dietary phytogenic supplementation on growth performance, carcass characteristics, and nutrient digestibility. Each treatment consisted of eight replications and five birds/replication. Treatments were: (T1) high nutrient diet; (T2) T1+phytobiotics; (T3) low nutrient diet; (T4) T3+phytobiotics. The results indicated that inclusion of phytobiotics and nutrients’ density of diets influenced body weight gain and feed conversion ratio (P < .05). Feeding low nutrient diets had a negative effect on drip loss percentage. Cooking loss percentage increased (P < .05) by reducing nutrient density. Relative weights of breast muscle, abdominal fat and body organs, pH value, and colour of breast muscle were not affected by treatment diets. Supplementing the diets reduced TBARS value on d 14 post-slaughter (P < .05). Density of nutrients and phytogenic blend (P < .05) improved the digestibility of dry matter and energy, but the digestibility of calcium and phosphorous were not affected by treatments.

True is more additive than apparent total tract digestibility of calcium in limestone and dicalcium phosphate for twenty-kilogram pigs fed semipurified diets.

Two experiments were conducted to determine the Ca digestibility of limestone and dicalcium phosphate (DCP) and if values for Ca digestibility are additive in mixed diets for pigs. In Exp. 1, 48 barrows with an average initial BW of 19.2 ± 1.1 kg were assigned to 1 of 6 dietary treatments in a 2 × 3 factorial arrangement of 2 Ca sources, including limestone or DCP, and 3 dietary Ca concentrations of 0.54, 0.74, or 0.94%. Diets were fed for a 5-d adjustment period followed by a total collection period of 5 d with chromic oxide and ferric oxide as markers to determine the initiation and termination of fecal collection, respectively. Results indicated that the increased dietary Ca concentration linearly increased ( < 0.01) Ca intake, digested Ca, and retained Ca but did not affect the apparent total tract digestibility (ATTD) of Ca or Ca retention of intake (%). The ATTD of P and P retention of intake were linearly increased ( < 0.05) as dietary Ca and P increased. In Exp. 2, 72 barrows with an average initial BW of 20.8 ± 1.3 kg were assigned to 1 of 9 dietary treatments in a 3 × 3 factorial arrangement of 3 Ca sources, including limestone, DCP, or the mixture of the 2 at a ratio of 1:1, and dietary Ca concentrations of 0.40, 0.50, or 0.60%. Feeding and sample collection procedures were as in Exp. 1. The results also showed that increased Ca concentration linearly increased ( < 0.001) Ca intake, fecal Ca output, and Ca absorbed but did not affect the ATTD of Ca within each Ca source. The average ATTD were 66.46, 70.34, and 69.32% for the limestone, DCP, and mixed diets, respectively. By regressing daily digested Ca against daily Ca intake, the true total tract digestibility (TTTD) of Ca was determined to be 70.06, 76.42, and 73.72% for the limestone, DCP, and mixed diets, respectively. The predicted TTTD for Ca in the mixed diets of limestone and DCP was calculated to be 72.67% based on the Ca contribution coefficient of 0.59 for limestone and 0.41 for DCP. The predicted Ca TTTD (72.67%) in the mixed diets was not different from the Ca TTTD (73.72%) determined using the regression method. It is concluded that although the ATTD of limestone and DCP were not affected by the Ca concentration in the diet, TTTD is recommended for evaluation of Ca digestibility because of its additivity in a mixed diet.

Faecal calcium excretion does not decrease during long-term feeding of a low-calcium diet in adult dogs.

According to a previous meta-analysis, adult dogs do not notably increase calcium absorption from the gastrointestinal tract when calcium intake is decreased. This results in a negative calcium balance even with a moderate calcium reduction. In this study we wanted to verify (i) whether a negative calcium balance occurs at a calcium intake equivalent to NRC (2006) (Nutrient requirements of dogs and cats, 2006, The National Academies Press, Washington, DC) minimal requirements, and if so (ii) whether the negative calcium balance will persist for up to 6months on a low-calcium diet. After a pre-feeding period of at least 18weeks with calcium intake slightly exceeding maintenance requirements (200mg/kg body weight0.75 ), 12 dogs (6 Beagles, 6 Foxhound crossbreds) were fed a low-calcium diet for 28weeks. One dog was removed from the trial for reasons unrelated to the study at week 23. Calcium intake amounted to 60mg/kg body weight0.75 corresponding to the minimal requirement for maintenance in dogs (NRC, 2006 (Nutrient requirements of dogs and cats, 2006, The National Academies Press, Washington, DC)). Digestion trials were carried out at week 7, 14, 21 and 28 of the low calcium feeding period. At these time points, and at week 18 of the pre-trial, blood samples were taken and analysed for calcium, ionised calcium, phosphorus, parathyroid hormone, vitamin D, serum crosslaps and bone alkaline phosphatase. Apparent calcium digestibility was negative throughout the study, suggesting a negative calcium balance. There was no systematic decrease in faecal calcium excretion. Serum calcium, ionised calcium and phosphorus remained within the reference range. Serum crosslaps increased continuously from baseline to week 28 of trial, with averages increasing from 0.102ng/ml to 0.279ng/ml, suggesting osteoclastic activity, indicative of calcium mobilisation from the skeleton. The study supports the theory of a lack of adaptation of intestinal calcium absorption from diets with relatively low calcium content in dogs. This agrees with clinical findings in dogs eating low-calcium diet.

Effect of organic acids and essential oils on performance, intestinal health and digestive enzyme activities of weaned pigs

This experiment was conducted to evaluate the effects of organic acid (OA) and essential oil (EO) used individually or combination on performance, fecal microbiota, intestinal morphology and digestive enzymes of weaned pigs. A total of 210 weaned piglets [Duroc×(Landrace×Yorkshire)] with initial body weight (8.64±0.33kg) were randomly allocated to 1 of 5 treatments with 7 replicate pens (3 barrows and 3 gilts per pen) per treatment according to sex and weight in randomized complete block design. The treatments consist of NC (negative control, corn-soybean meal basal diet), PC (positive control, NC+15mg/kg Colistin sulfate, 2mg/kg Nosiheptide and 50mg/kg Olaquindox), OA (NC+1.5g/kg OA), EO diet (NC+30mg/kg EO), OA+EO diet (NC+1.5g/kg OA+30mg/kg EO). The experiment lasted 28 d (d 0–14 as for early period and d 14–28 as for later period). From d 0 to 14, EO had greater (P<0.05) average daily gain (ADG) compared with NC, EO and OA+EO had a trend to improve ADG compared with PC. From d 14 to 28, OA improved (P<0.05) ADG compared with NC and OA+EO had a trend to improve ADG compared with PC. From d 0 to 28, supplementation of OA or EO individually increased (P<0.05) ADG compared with NC and OA+EO had a trend to increase ADG compared with PC. EO improved apparent digestibility of dry matter, calcium, phosphorus, crude protein and gross energy (P<0.05). OA improved digestibility of calcium, phosphorus and crude protein (P<0.05). Compared with NC, OA tended to decrease (P<0.10) fecal score from d 0 to 7. OA, EO and OA+EO had greater Lactobacilli counts of feces (P<0.05) than PC. OA and EO increased villous height of duodenum and OA increased villous height of jejunum (P<0.05). OA increased butyric acid concentration of cecum and valeric acid concentration of colon (P<0.05). Trypsin and chymotrypsin activities of jejunum were improved (P<0.05) by EO supplementation. Overall, OA and EO had no interactive effects, but it improved performance by the different positive effects on intestinal health and digestive enzymes of weaned pigs.

Effect of suboptimal levels of non-phytate phosphorus and exogenous phytase on precaecal digestibility of phosphorus and calcium in laying hens

The precaecal digestibility of phosphorus and calcium in laying hens was evaluated at two dietary levels of non-phytate phosphorus (NPP; 1.58 and 2.03 g/kg) and two levels of exogenous 3-phytase (F; 0 and 300 phytase units (FTU)/kg). A total of 192 ISA Brown hens were used for the study, and were housed in enriched cages (8 per cage). At the end of the experiment, which was the peak of the egg production, the content of the posterior half of the ileum from each hen was collected. The lower level of NPP significantly (P &amp;lt; 0.05) improved the precaecal phosphorus digestibility coefficient. There was no significant difference in the amount of absorbed phosphorus between the lower and the higher level of NPP. The level of NPP with supplementation of exo-genous phytase had a significant effect (P &amp;lt; 0.001) on the concentration of phosphorus in ileum, while the higher level of NPP increased phosphorus concentration in the ileum and phytase decreased phosphorus content in the ileal digesta. The phytase had no significant effect on phosphorus precaecal digestibility. There was no significant effect of the both factors, level of NPP, and exogenous phytase on the daily calcium intake, the amount of absorbed calcium, the content of calcium in ileal digesta, and on the precaecal digestibility of calcium. However a significant effect (P &amp;lt; 0.05) of the interaction between NPP and phytase was observed on the amount of absorbed calcium and on the precaecal digestibility coefficient. It can be concluded that the estimation of phosphorus ileal digestibility depends on the level of dietary phosphorus.

Sesame meal as the first protein source in piglet starter diets and advantages of a phytase: a digestive study

Soybean meal (SBM) is the protein source that is used most in feeding piglets, but its high price has prompted a search for alternatives. One option is sesame meal (SM), a by-product of sesame oil. This study evaluated the effects of SM and phytase on the intestinal morphology, total trypsin activity (TTA) and specific trypsin activity (STA), apparent ileal digestibility (AID) of amino acids (AAs), and apparent total tract digestibility (ATTD) of phosphorus (P), calcium (Ca), and energy (E) in weaned piglets. Twenty piglets weaned at 17 days old were placed in metabolic cages in a temperature-controlled room. When the piglets were 21 days old, cannulas were fitted at the terminal ileum. From the fourth day after surgery, piglets received the experimental treatments for nine days, namely an SM or SBM diet, each with or without phytase. The protein source or phytase did not affect villus height, crypt depth, or TTA. However, phytase increased STA. The AID of dry matter (DM), E, crude protein (CP), and AA was similar among treatments, except for arginine, which was more digestible in the SM diets (85.8) than in the SBM ones (81.6). The ATTD of DM and E was higher in the SM than in the SBM diets. Phytase increased the ATTD of Ca (22.7 %) and P (27.9 %). The findings showed that SM can be used as a protein source for piglets and that its consumption increases arginine intake. The addition of phytase to the diet increases the ATTD of P and Ca. Keywords : Amino acids digestibility, arginine, piglets weaning, phosphorus digestibility