Ca Digestibility Research Articles

Meta-analysis-based estimates of efficiency of calcium utilisation by ruminants

The most abundant mineral in the body of animals is Ca, which has crucial importance for the regulation of various processes. The maintenance of Ca balance has become more challenging, especially in lactating ruminants, owing to the increased milk yields and thus Ca requirement. To determine the Ca requirement, factors such as Ca secretion via milk or Ca deposition in body tissues and conception products are summed up to the net Ca requirement. Nevertheless, dietary Ca cannot be completely utilised by the animal to cover the net Ca requirement, therefore a value for the efficiency of Ca utilisation is applied, which is the maximum proportion of Ca from the feed that the animal can use for covering the net requirement. However, current estimates for the efficiency of Ca utilisation are inconsistent. Therefore, the objective of the present meta-analysis was to estimate the efficiency of Ca utilisation for ruminants, considering the Ca supply of the animal. A data set of 223 observations was compiled from 37 studies, including data on cattle and small ruminants. Standardised Ca digestibility was calculated from data on Ca intake and faecal Ca excretion, corrected for faecal endogenous losses. Furthermore, a data subset on only lactating ruminants was created. For this subset, Ca excretion via faeces and urine and standardised Ca digestibility were related to the Ca supply of the animal. An exponential function was fitted to standardised digestibility data in response to Ca concentration in the diet and Ca supply, revealing that standardised Ca digestibility decreased with increasing dietary Ca concentration and Ca supply. The median for standardised Ca digestibility was 40%, with a remarkable variation between 9% and 88%. In response to Ca supply, faecal Ca excretion increased in a strong linear manner (slope = 0.76, R2 = 0.96). Excretion of Ca via urine was very low even when Ca supply was very high. To conclude, Ca digestibility is a suitable indicator for the efficiency of Ca utilisation, since excessive Ca is almost completely excreted in faeces; however, Ca digestibility has to be determined at a Ca supply level below the requirement of the animal. To date, only very limited number of data have been reported for such supply conditions. Comparative studies using various Ca sources are suggested for future studies but should be conducted using a marginal Ca supply level.

Healthy Ageing Is Associated with Preserved or Enhanced Nutrient and Mineral Apparent Digestibility in Dogs and Cats Fed Commercially Relevant Extruded Diets.

Simple SummaryPreventative healthcare and provision of optimal nutrition from early ages is increasing the life expectancy of companion animals today. However, as part of the normal ageing process, changes in the capacity to digest and use dietary nutrients may occur, which could contribute to deficiency in energy and/or essential nutrients. Based on previous studies, an effect of ageing on nutrient digestibility has primarily been observed when feeding low-fat or high-fibre diets. In this study, we evaluated the effect of age on nutrient digestibility using healthy dogs and cats up to 14 years old by feeding diets differing in fat and fibre contents. Older dogs and cats had a preserved nutrient digestibility, in some cases showed an enhanced digestibility of fibre and calcium. Interestingly, older cats had a lower nutrient digestibility with one of the diets, which was unrelated to fat and fibre levels, but was possibly associated with other ingredients in the formulation. Our findings support the use of a wide range of fat and fibre levels in healthy older dogs and cats within the studied ages. However, ingredient sources should be considered in the formulation of senior diets.Age-related changes in gastrointestinal function have been reported in companion animals, but the impact on digestive efficiency remains uncertain. Healthy dogs (n = 37; 2.6–14.2 years) received four diets varying in total dietary fibre (TDF; 6–29%, as fed). Healthy cats (n = 28; 1–13 years) received four diets with two fat (10–12%; 17–18%) and TDF (9 and 12%) levels. In a crossover design, diets were provided over four consecutive 10-day cycles, including a 4-day faecal collection. Apparent crude protein (CP), ether extract (EE), TDF, calcium (Ca), and phosphorus (P) digestibilities were determined. The effect of age was analysed as a continuous variable in dogs and as differences between adult (1–5 years) and senior (7–13 years) cats. In dogs, EE digestibility was unaffected by age (p > 0.10). Dogs of 6–12 years had higher digestibility of CP (p = 0.032), TDF (p = 0.019), Ca (p = 0.019), and P (p = 0.024) when fed the 6% TDF diet. Senior cats had greater digestibility of TDF (p < 0.01) and Ca (p = 0.024) but had lower EE and CP digestibility with one diet (17% fat; 9%TDF) (age, p > 0.10; diet × age, p < 0.001). Healthy ageing was associated with preserved nutrient digestibility in dogs and cats within the age ranges studied. The effect of ingredient sources in senior cats warrants further investigation.

Influence of a novel consensus bacterial 6-phytase variant on mineral digestibility and bone ash in young growing pigs fed diets with different concentrations of phytate-bound phosphorus

A 20-d experiment was conducted to test the hypothesis that phytase increases nutrient digestibility, bone ash, and growth performance of pigs fed diets containing 0.23%, 0.29%, or 0.35% phytate-bound P. Within each level of phytate, five diets were formulated to contain 0, 500, 1,000, 2,000, or 4,000 phytase units (FTU)/kg of a novel phytase (PhyG). Three reference diets were formulated by adding a commercial Buttiauxella phytase (PhyB) at 1,000 FTU/kg to diets containing 0.23%, 0.29%, or 0.35% phytate-bound P. A randomized complete block design with 144 individually housed pigs (12.70 ± 4.01 kg), 18 diets, and 8 replicate pigs per diet was used. Pigs were adapted to diets for 15 d followed by 4 d of fecal collection. Femurs were collected on the last day of the experiment. Results indicated that diets containing 0.35% phytate-bound P had reduced (P < 0.01) digestibility of Ca, P, Mg, and K compared with diets containing less phytate-bound P. Due to increased concentration of total P in diets with high phytate, apparent total tract digestible P and bone ash were increased by PhyG to a greater extent in diets with 0.29% or 0.35% phytate-bound P than in diets with 0.23% phytate-bound P (interaction, P < 0.05). At 1,000 FTU/kg, PhyG increased P digestibility and bone P more (P < 0.05) than PhyB. The PhyG increased (P < 0.01) pig growth performance, and pigs fed diets containing 0.35% or 0.29% phytate-bound P performed better (P < 0.01) than pigs fed the 0.23% phytate-bound P diets. In conclusion, the novel phytase (i.e., PhyG) is effective in increasing bone ash, mineral digestibility, and growth performance of pigs regardless of dietary phytate level.

Prediction of calcium and phosphorus requirements for pigs in different bodyweight ranges using a meta-analysis.

Several studies have focused on Ca and P requirements for pigs. These requirements are estimated from their retention and bone formation. However, modern pig breeds have different responses to dietary Ca and P than traditional breeds, and their requirements are expected to change on an annual basis. Besides individual Ca and P needs, the Ca to P ratio (Ca/P) is an important factor in determining requirements. This study aimed to implement a linear and quadratic regression analysis to estimate Ca and P requirements based on average daily gain (ADG), apparent total tract digestibility (ATTD) of Ca (ATTD-Ca), ATTD of P (ATTD-P), and crude protein (CP) digestibility. Results show that Ca/P had linear and quadratic effects on ADG in the phytase-supplemented (PS) group in both the 6–11 kg and 11–25 kg categories. In the latter category, the CP digestibility was linearly increased in response to increasing Ca/P in the without-phytase (WP) group. In the 25–50 kg category, there was a linear response of ADG and linear and quadratic responses of CP digestibility to Ca/P in the PS group, while a linear and quadratic increase in CP digestibility and a quadratic effect on ATTD-Ca were observed in the WP group. In the 50–75 kg category, Ca/P had significant quadratic effects on ADG in the PS and WP groups, along with significant linear and quadratic effects on ATTD-Ca. In addition, Ca/P had significant quadratic effects on ATTD-P and led to a significant linear and quadratic increase in the CP digestibility in the WP group. In the 75–100 kg category, analysis showed a significant decrease in ATTD-Ca and ATTD-P in the PS and WP groups; in the latter, ATTD-P and ATTD-Ca were linearly decreased by increasing Ca/P. In conclusion, our equations predicted a higher Ca/P in the 6–25 kg bodyweight categories and a lower Ca/P in the 50-100 kg category than that recommended in the literature.

Comparison of the apparent ileal calcium digestibility of limestone in broilers and layers

ABSTRACT 1. The apparent ileal calcium (Ca) digestibility coefficients of two limestone sources in growing broilers and layers were determined in two separate experiments. 2. In each experiment, two maize-based diets were developed with two limestone sources (A, experiment 1 and B, experiment 2) to contain either 8.0 g/kg Ca for broilers or 40 g/kg Ca for layers. The two sources differed in particle size, with limestone A being finer and limestone B being coarser. Each experimental diet was randomly allotted to six replicate cages and offered for 3 days from 19 to 21-day post-hatch to broilers and during 40 weeks of age to layers. The total tract Ca retention was also measured using the indicator ratios in the diet and excreta. 3. In both experiments, the apparent ileal Ca digestibility, gizzard pH and gizzard Ca concentration were higher (P < 0.05) in layers than in broilers. The apparent ileal digestibility coefficient of limestone A for broilers and layers was 0.50 and 0.62, respectively. The corresponding values for limestone B were 0.43 and 0.70, respectively. The apparent total tract retention of Ca was similar (P > 0.05) between broilers and layers in both experiments, and between the two sources. 4. The data show that the layers are more efficient in absorbing Ca from limestone than broilers.

The effect of short-term phytase supplementation on the apparent total tract digestibility of calcium and phosphorus and the reproductive performance of late gestation and lactating sows fed diets without mineral phosphorus.

The objective of this study was to measure apparent total tract digestibility (ATTD) of Ca and P as well as reproductive performance in late gestation and lactating sows supplemented with a novel phytase and to compare the response to phytase supplementation between late gestation and lactating sows. A total of 45 late gestation sows and 45 lactating sows were used in experiments 1 and 2, respectively, in a completely randomized design. The sows were provided with a control diet or the control diet supplemented with 187.5 or 375 FYT phytase/kg feed for 10 days. The diets were prepared according to the formulas in use for production but without any inorganic P supplement. Titanium dioxide was included at 3 g/kg feed as an indigestible marker. Each dietary treatment was replicated with 15 sows individually housed in farrowing stalls. The sows were allowed to adapt to the experimental diets for 5 days before a 5-d fecal collection by grab sampling, and the performance of the sows and their litters were measured until weaning. The results showed that the ATTD of Ca increased linearly (P < 0.001), while the ATTD of P increased both linearly and quadratically (P < 0.01) with increasing supplementation of phytase in both late gestation and lactating sows. There was no significant effect of phytase on the ATTD of dry matter, crude protein, and gross energy, and the performance of the sows and their progenies. The phytase added at 187.5 and 375 FYT/kg feed released 0.07% and 0.10% digested P, respectively, in late gestation sows, which compared with 0.09% and 0.12% digested P in lactating sows. In conclusion, a novel phytase at 187.5-375 FYT/kg feed could release 0.07-0.12% digestible P for sows. It appeared that using the P digestibility values of feed ingredients listed by NRC to formulate a diet for sows might overestimate dietary P supply and a greater response to phytase supplementation could be expected in lactating sows than in late gestation sows.

No Observed Adverse Effects on Health Were Detected in Adult Beagle Dogs When Fed a High-Calcium Diet for 40 Weeks.

Simple SummaryCalcium (Ca) is an essential mineral that plays a vital role in many bodily functions. There is evidence that high levels of dietary Ca for puppies and growing dogs can result in adverse growth and health effects, with certain breeds and dog size categories being most susceptible, for example, large breed sizes or beagles. Until recently, little was known about the health consequences of high Ca diets to adult dog, however, a study in the large sized breed Labrador retriever found no adverse health consequences when feeding diets containing levels of Ca near maximum levels set by pet food regulators (2.5 g per 100 g dry matter) for 40 weeks. This current study fed a similar high Ca diet to adult beagles, a medium sized breed for 40 weeks and monitored the dogs’ health using an extensive suite of health parameters. All dogs remained healthy and did not display any clinically relevant signs of adverse health relating to diet at any point during or following completion of the study.The implications of long-term high calcium (Ca) intake are well documented in growing dogs and in adult dogs of large breed size, however, the consequences on other breeds and breed sizes are yet to be determined. Eighteen neutered adult beagles, nine males and nine females aged 1.4–4.4 years, were randomized to control or test diets providing in g∙4184 kJ−1 (1000 kcal−1): 1.44 and 7.19 total Ca balanced with 1.05 and 4.25 total phosphorus, respectively, for 40 weeks. Health parameters, ultrasound scans, radiographs, glomerular filtration rate, and mineral balance were measured at eight-week intervals. All dogs remained healthy with no measured evidence of orthopedic, urinary, or renal disease. The test diet resulted in a 5.2 fold increase in fecal Ca excretion. Apparent Ca digestibility (%) and Ca balance (g/d) did not significantly (p > 0.05) change from baseline in the test diet group, although dogs displayed a positive Ca balance (maximum at week 8, 1.11 g/d with 95% CI (0.41, 1.80)) before a neutral Ca balance was restored at week 32. Despite an initial positive Ca balance, we can conclude that no measurable adverse health effects were observed as a result of the test diet fed in this study in beagles over a period of 40 weeks.

Effects of dietary cation-anion differences at the early stage of transitional period on dry matter intake and plasma Ca metabolism in beef cows

The present study investigated the effects of dietary cation-anion differences (DCADs) on dry matter intake (DMI), nutrient digestibility, body condition score (BCS), body fat, plasma ion metabolism, and relative hormone levels through a perinatal feeding experiment. Eighteen healthy Simmental crossbred cows (Simmental ♂ × native Yunnan Yellow ♀; body weight, 325.4 ± 27.63 kg) were allocated to one of three treatment groups with six replicates each. The control (CON) group received basal diet without anionic salt supplementation, with a DCAD of 127.56 mEq kg−1 DM. The T2% and T4% groups received basal diet supplemented with 2% and 4% anionic salts, with DCADs of −1.60 and −129.10 mEq kg−1 DM, respectively. All groups received isoenergetic and isonitrogenous diets. Blood samples were collected on prepartum days 7 and 3; on the day of calving; and on postpartum days 1, 3, 7, 14, and 42. Prenatal urine pH decreased with decreasing DCAD (P < 0.001). Compared with that in the CON group, DMI in the T2% and T4% groups was decreased by respectively 11.4 % and 17.8 % (P = 0.005) at the early stages of perinatal period (−21 to 0 days), but DMI in the T2% group was increased by 9.4 % (P < 0.046) at the later stages of perinatal period (0–21 days). The postpartum BCS in the T2% and T4% groups was 25 % lower than that in the CON group (P = 0.038). Prepartum apparent P digestibility was increased in the T2% and T4% groups (P = 0.017) and prepartum apparent Ca digestibility was increased in the T2% group (P = 0.022). The content of colostrum fat, Ca, lactose, and immunoglobulin G was increased in the T2% group (P < 0.05). On postpartum day 1, the plasma ionized (i) Ca concentrations were increased by 20.4 % and 19.4 % (P < 0.05), the plasma 1,25(OH)2D3 concentrations were increased by 15.6 % and 12.7 % (P < 0.05), and the plasma iK concentrations were decreased by 8.8 % and 9.8 % (P = 0.003) in the T2% and T4% groups, respectively, compared with values in the CON group. In addition, the iMg, iP, and parathyroid hormone levels in the T2% group were increased (P < 0.05). On prepartum day 7, the plasma glucose concentration in the T2% group was higher than that in the CON group (P = 0.010), and on the day of calving, the plasma glucose concentration in the T4% group was higher than that in the T2% group (P = 0.041). On postpartum day 1, the plasma non-esterified fatty acid (NEFA) concentration in the T2% group was lower than that in the CON group (P = 0.021), but there was no significant difference in this concentration between the T4% and CON groups (P > 0.05). The postpartum plasma β-hydroxybutyric acid (BHB) concentrations in the T2% and T4% groups were lower than those in the CON group (P < 0.001). On postpartum day 42, progesterone levels in the T2% and T4% groups were respectively 27.3 % and 16.7 % lower than those in the CON group (P < 0.001). Therefore, the addition of anionic salts to reduce DCAD accelerated the recovery of postpartum DMI, decreased plasma NEFA and BHB concentrations, and increased plasma iCa concentration. Under the present experimental conditions, 2% anionic salt supplementation was more appropriate.

Effect of Dietary Mineral Content and Phytase Dose on Nutrient Utilization, Performance, Egg Traits and Bone Mineralization in Laying Hens from 22 to 31 Weeks of Age.

Simple SummaryThe aim of this work was to elucidate how the dietary inclusion of phytase, at a normal dose and overdosed, could affect the utilization of nutrients and performance in young laying hens. When a diet deficient in Ca and P was applied, the dietary inclusion of phytase at low doses (500 FTU/kg) led to an improvement in the digestive efficiency of P in the first weeks after introduction. However, when these deficient diets were maintained in the long term, laying hens improved their digestive utilization of both Ca and P, a higher dose of phytase (1000 FTU/kg) being required to achieve greater P availability. This overdosage also provided additional extraphosphoric advantages, slightly improving access to other nutrients and the feed conversion rate of the hens.A total of 192 laying hens were used to evaluate the effect of dietary mineral content and phytase dose on nutrient utilization, egg production and quality and bone mineralization of young laying hens. Four dietary treatments were studied: PC, positive control with no added phytase, 4.07% Ca and 0.61% P; NC, negative control with no added phytase, 2.97% Ca and 0.37% P; and P500 and P1000, where NC diet was supplemented with phytase at 500 and 1000 FTU/kg, respectively. Hens’ performance and egg traits were controlled from 22 to 31 weeks of age. Coefficients of total tract apparent digestibility (CTTAD) of nutrients were determined at 25 and 31 weeks of age. Apparent ileal digestibility (AID) and blood content of Ca and P, as well as bone traits, were determined at 31 weeks of age. Ca and P retention was higher in birds on PC diet at 25 weeks, but not at 31 weeks of age compared to those on NC diet (p < 0.05). P1000 birds had the highest CTTAD values for dry and organic matter at both ages (p < 0.001). CTTAD of Ca was significantly higher in P1000 diet than in NC diet at 31 weeks of age (p < 0.001). Birds fed with P500 diet at 25 weeks of age and P1000 at 31 weeks of age showed higher CTTAD and retention of P, but lower excretion of P than those fed NC diet (p < 0.05). Phytase inclusion linearly increased AID of dry matter and P (p < 0.001). P500 hens fed had the greatest body weight at the end of the trial (p < 0.05) and P1000 birds had the best feed conversion ratio (p < 0.05). Fowl fed a PC diet produced eggs with higher shell thickness and yolk color than those fed on NC diet (p < 0.05). Phytase inclusion linearly increased the yolk color (p < 0.05). Tibia of laying hens fed with PC had significantly higher ash content than those on NC diet (p < 0.05), and birds fed with P1000 presented intermediate values. It can be concluded that it would be advisable to increase the dose of phytase in the feed of laying hens to obtain long-term benefits.

Effect of feeding acidified or fermented barley using Limosilactobacillus reuteri with or without supplemental phytase on diet nutrient digestibility in growing pigs.

Fermentation of cereal grains may degrade myo-inositol 1,2,3,4,5,6-hexakis (dihydrogen phosphate) (InsP6) thereby increasing nutrient digestibility. Effects of chemical acidification or fermentation with Limosilactobacillus (L.) reuteri with or without phytase of high β-glucan hull-less barley grain on apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of nutrients and gross energy (GE), standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AAs), and standardized total tract digestibility (STTD) of P were assessed in growing pigs. Pigs were fed four mash barley-based diets balanced for water content: 1) unfermented barley (Control); 2) chemically acidified barley (ACD) with lactic acid and acidic acid (0.019 L/kg barley grain at a ratio of 4:1 [vol/vol]); 3) barley fermented with L. reuteri TMW 1.656 (Fermented without phytase); and 4) barley fermented with L. reuteri TMW 1.656 and phytase (Fermented with phytase; 500 FYT/kg barley grain). The acidification and fermentation treatments occurred for 24 h at 37 °C in a water bath. The four diets were fed to eight ileal-cannulated barrows (initial body weight [BW], 17.4 kg) for four 11-d periods in a double 4 × 4 Latin square. Barley grain InsP6 content of Control, ACD, Fermented without phytase, or Fermented with phytase was 1.12%, 0.59%, 0.52% dry matter (DM), or not detectable, respectively. Diet ATTD of DM, CP, Ca, and GE, digestible energy (DE), predicted net energy (NE) value, and urinary excretion of P were greater (P < 0.05) for ACD than Control. Diet ATTD of DM, CP, Ca, GE, DE and predicted NE value, urinary excretion of P was greater (P < 0.05), and diet AID of Ca and ATTD and STTD of P tended to be greater (P < 0.10) for Fermented without phytase than Control. Diet ATTD of GE was lower (P < 0.05) and diet ATTD and STTD of P, AID and ATTD of Ca was greater (P < 0.05) for Fermented with phytase than Fermented without phytase. Acidification or fermentation with/without phytase did not affect diet SID of CP and AA. In conclusion, ACD or Fermented without phytase partially degraded InsP6 in barley grain and increased diet ATTD of DM, CP, and GE, but not SID of CP and most AA in growing pigs. Fermentation with phytase entirely degraded InsP6 in barley grain and maximized P and Ca digestibility, thereby reducing the need to provide inorganic dietary P to meet P requirements of growing pigs.

95 Growth Performance, Bone Mineralization, and Nutrient Digestibility of Nursery-grower Pigs Fed Phytase-supplemented Calcium and Phosphorus-deficient Diets

Abstract A 36-d experiment evaluated effects of supplemental OptiPhos Plus phytase (Huvepharma, Peachtree City, GA) on growth, bone mineralization, Ca and P digestibility of nursery-grower pigs. Individually housed crossbred pigs (n = 42; initial body weight [BW], 16.1 ± 0.4 kg) were randomly allotted to 7 dietary treatments based on BW and sex. A positive control (PC) diet was formulated to contain 0.601% Ca and 0.296% standardized total tract digestible (STTD) P, which were marginally lower than NRC (2012) requirement estimates for 25–50 kg pigs. A negative control (NC) diet (0.431% Ca and 0.164% STTD P) was developed by the removal of dicalcium phosphate from the PC diet and replacement with limestone and sand. Diets were: 1) PC, 2) NC, and 3–7) NC + 250, 500, 750, 1,000 and 1,500 FTU phytase/kg diet. On d 36, all pigs were euthanized for femur and metacarpal measures. Compared with NC, pigs fed the PC diet provided greater (P &amp;lt; 0.05) response for ADG (966 vs. 730 g/d), ADFI (1,660 vs. 1,329 g/d); bone measures (37.1 vs. 17.4 g ash/femur and 71.9 vs. 29.3 kg for metacarpal strength), and apparent total tract digestibility (ATTD) of Ca (69.5 vs. 63.5%) and P (62.5 vs. 49.3%). As supplemental phytase increased from 0 to 1,500 FTU/kg of diet, linear and quadratic increases (P &amp;lt; 0.002) occurred in overall ADG and ADFI, femur mineral content, metacarpal breaking strength, and ATTD of Ca and P. Responses statistically similar to PC were achieved at 250 or 500 FTU/kg and peak responses occurred at 750 to 1,500 FTU/kg that were numerically greater than PC for all but metacarpal strength. In conclusion, supplemental OptiPhos Plus improved growth, bone mineralization, Ca and P digestibility of pigs fed Ca and P-deficient diets, demonstrating enhanced Ca and P utilization of corn-soybean meal-based diets by nursery-grower pigs.

60 Effect of a Novel Consensus Bacterial 6-phytase Variant on Mineral Digestibility and Bone Ash in Young Growing Pigs Fed Diets with Different Concentrations of Phytate

Abstract An experiment was conducted to test the hypothesis that increasing levels of phytase increases mineral digestibility and bone ash by pigs fed diets containing 0.23%, 0.29%, or 0.35% phytate-P. Within each level of phytate, 5 diets were formulated based on corn, soybean meal, and canola meal to contain 0, 500, 1,000, 2,000, or 4,000 phytase units (FTU)/kg of a novel consensus bacterial 6-phytase variant (PhyG). In addition, 3 reference diets were formulated by adding a commercial Buttiauxella phytase (PhyB) at 1,000 FTU/kg to the 3 diets containing no PhyG. A randomized complete block design with 144 pigs (12.70 ± 4.01 kg), 18 diets, and 8 replicate pigs per diet was used. Pigs adapted to diets for 15 d followed by 4 d of fecal collection. Femurs were collected on the last day. Data were analyzed as a 3 × 5 factorial with 3 levels of phytate-P and 5 levels of phytase, and contrast statements were used to compare 1,000 FTU of PhyG with PhyB. Pig was the experimental unit. Diets containing 0.35% phytate-P had reduced (P &amp;lt; 0.01) apparent total tract digestibility (ATTD) of Ca, P, Mg, and K compared with diets containing 0.23% or 0.29% phytate-P, but inclusion of phytase increased (P &amp;lt; 0.01) ATTD of Ca, Na, and K (Table 1). Phytase increased ATTD of P and Mg, but to a greater extent in diets with 0.23 or 0.29% phytate-P than in diets with 0.35% phytate-P (interaction, P &amp;lt; 0.05). Phytase increased bone ash, but to a greater extent if there was 0.35 rather than 0.23 or 0.29% phytate-P in the diets (interaction, P &amp;lt; 0.05). PhyG increased ATTD of P more (P &amp;lt; 0.05) than PhyB. In conclusion, the novel consensus phytase is effective in increasing bone ash and ATTD of Ca, P, Na, Mg and K.

PSIII-18 Super Dose Phytase and Carbohydrase Cocktail Enhance Ileal Nutrient and Energy Digestibility of Corn-soybean Diets in Nursery Pigs

Abstract Feed enzymes may ameliorate reduced nutrient and energy digestibility in nursery pigs. The objective was to test effects of super-dosing phytase and fiber-degrading enzymes on digestibility of DM, GE, CP, AA, and Ca. We tested supplementing a super dose (added 1,500 FYT/kg) of phytase (Ronozyme Hi-Phos) with or without carbohydrase cocktail that contained 85 FXU β-xylanase/kg, 587 U/g endo-1,4-β-glucanase, 513 U/g endo-1,3(4)-β-glucanase, 15,000 U/g hemicellulases, and 3,000 U/g pectinases in corn-soybean meal diets in a 2 × 2 factorial arrangement. Diets included 68% corn, 17% SBM, and a basal level of 500 FTU/kg of phytase, and were formulated to contain 2.50 Mcal/kg NE and 5.10 gSID Lys/Mcal NE. Eight ileal-cannulated nursery pigs (initial BW 10 kg) were fed 4 diets at 3.0 × maintenance DE (110 kcal per kg of BW0.75) for four 9-day periods in a double 4 × 4 Latin square. Apparent hindgut fermentation (AHF) was calculated as apparent total tract digestibility (ATTD) minus apparent ileal digestibility (AID). Interactions between super-dosing phytase and carbohydrase cocktail were observed. Supplementing either carbohydrase cocktail or super dose phytase, but not their combination, increased (P &amp;lt; 0.05) diet AID of DM, GE, CP, and most AA by 4–5%-units. Supplementing super dose phytase increased (P &amp;lt; 0.05) AID of P by 16%-units and ATTD of P by 10%-units. Supplementing super dose phytase or carbohydrase cocktail did not affect AID of Ca and ATTD of GE, CP, and Ca, and diet DE value. Supplementing carbohydrase cocktail without super dose phytase decreased (P &amp;lt; 0.05) diet AHF of DM, GE, and CP. In conclusion, dietary inclusion of super dose phytase or carbohydrase cocktail increased ileal digestibility of nutrients in nursery pigs, and thereby reduced protein entering the large intestine. Additive or synergistic effects of carbohydrase cocktail and super dose phytase were not detected.

Formulation of diets for pigs based on a ratio between digestible calcium and digestible phosphorus results in reduced excretion of calcium in urine without affecting retention of calcium and phosphorus compared with formulation based on values for total calcium.

An experiment was conducted to test the hypothesis that formulating diets for pigs based on a ratio between standardized total tract digestible (STTD) Ca and STTD P instead of total Ca and STTD P does not decrease Ca retention, but increases P utilization. Forty barrows (59.4 ± 3.8 kg) were individually housed in metabolism crates and allotted to four corn-soybean meal-based diets in a randomized complete block design with two blocks and five pigs per diet in each block. Diets were formulated using a 2 × 2 factorial design with two diet formulation principles (total Ca or STTD Ca) and two inclusion levels of microbial phytase (0 or 500 units per kg of feed). Phytase was assumed to release 0.11% STTD P and 0.16% total Ca. Diets were formulated based on requirements for total Ca and STTD P or a ratio between STTD Ca and STTD P of 1.25:1. Diets were fed for 11 d and fecal and urine samples were collected from feed provided from day 6 to day 10. Interactions (P < 0.05) between diet formulation principle and phytase level were observed for Ca intake, Ca in feces, Ca absorbed, Ca retained, P digestibility, P absorbed, and P in urine. Phytase increased (P < 0.05) the digestibility of Ca in both total Ca and STTD Ca diets. Without phytase, Ca intake, Ca in feces, and Ca absorbed was greater (P < 0.05) from pigs fed total Ca diets than from pigs fed STTD Ca diets, but P absorbed, P digestibility, and P in urine was greater (P < 0.05) from pigs fed STTD Ca diets than from pigs fed total Ca diets. However, in the presence of phytase, no differences between diet formulation principles were observed in these variables. Regardless of phytase, Ca in urine was lower (P < 0.05) from pigs fed STTD Ca diets than from pigs fed total Ca diets. There were no differences in Ca retention between pigs fed STTD Ca diets and total Ca diets, but pigs fed total Ca diets retained less (P < 0.05) Ca if diets contained phytase. No differences in P retention were observed between diet formulation principles, but pigs fed non-phytase diets retained more (P < 0.05) P than pigs fed diets with phytase. In conclusion, because diets formulated based on STTD Ca contain less Ca than total Ca diets, pigs fed STTD Ca diets excreted less Ca in urine, but retention of Ca was not affected. Formulating non-phytase diets based on STTD Ca instead of total Ca increased P absorption, which confirms the detrimental effect of excess Ca on P digestibility. However, P retention was not improved if pigs were fed STTD Ca diets.

Interactive effect of corn particle size and insoluble fiber source on performance, nutrient utilization and intestine morphology in broilers fed pelleted diets.

The effects of corn particle size and dietary fibre on the performance, coefficient of apparent ileal digestibility (CAID) and intestinal characteristics in broiler starters fed pelleted diets were studied. The experiment included 10 treatments arranged as a 2×5 factorial with two corn particle sizes (GMD of 1071 [CGC] vs. 534 [FGC]) and five diets that consisted in a low-fibre diet and four extra diets resulting from the inclusion of insoluble fibre sources (10g/kg of lignocellulose (LC), and 30g/kg of oat hulls; OH, rice hulls; RH, and sunflower hulls; SFH). In coarse grinding, all-fibre sources improved body weight gain and feed intake compared to the control diet (p<0.01). Feed conversion ratio (FCR) improved with fibre supplementation (p<0.01) and fine grinding of corn (FGC) (p<0.01). Coarse grinding of corn (CGC) and inclusion of RH, SFH and OH reduced gizzard pH (p<0.01). Fibre inclusion increased ileal fat and Ca digestibility (p<0.01), gizzard weight (p<0.01), digesta transit time (p<0.01) and length of duodenum and small intestine (p<0.01). The CAID of phosphorus increased in CGC fed birds and inclusion of RH, SFH and OH (p<0.05). The weight of gizzard, proventriculus and pancreas (p<0.01) was greater in CGC fed birds. Feeding SFH, RH and OH (p<0.01), and CGC (p<0.01) increased the villus height (VH) of the duodenum. The OH, RH and SFH supplementation increased the caecal population of Lactobacillus spp. and total anaerobic bacteria (p<0.01) only in FGC fed birds. Overall, birds fed pelleted diets containing RH, OH and SFH (3%) exhibited improved performance, and increased nutrient digestibility, which may be caused by developed gizzards and intestine. Furthermore, coarse grinding of corn is beneficial to gizzard development.

Intestinal digestibility of selected minerals, growth performance and meat quality in turkeys fed diets supplemented with different sources and levels of zinc

Abstract The aim of this study was to determine whether dietary supplementation with zinc oxide nanoparticales (NP-ZnO) as a substitute for the conventional ZnO affects the intestinal digestibility of selected minerals, growth performance and meat quality in turkeys. The replacement of ZnO with NP-ZnO had no effect on the intestinal digestibility of Zn, Cu, Fe and Ca, whereas the lowest dose of supplemental Zn reduced Zn digestibility. The applied inclusion levels and sources of Zn had no effect on the growth performance (except the feed intake) of turkeys, including liveability. No differences in the relative weights of the heart, spleen and bursa of Fabricius (except the liver), or the weights of the femur and tibia were found between the dietary treatments. Neither the dose nor the source of supplemental Zn influenced carcass dressing percentage or the share of breast, thigh and drumstick muscles in the carcass. In comparison with the highest and moderate doses of Zn, the lowest inclusion level of Zn contributed to increased yellowness of breast meat (P=0.005). The analyzed doses and sources of supplemental Zn exerted varied effects on the redox status of fresh and frozen breast meat. In conclusion, the growth performance of turkeys, carcass yield and composition as well as the redox status of fresh and frozen breast meat were generally similar, regardless of the dietary source and level of Zn. The beneficial effect of Zn addition at 100 mg/kg was improved Zn and Ca digestibility, and increased redness of breast meat.

The effect of reduced feed pH, phytase addition and their interaction on mineral utilization in pigs

An experiment with a 2 × 2-factorial arrangement of treatments was carried out to assess the effect of reduced feed pH and addition of phytase and their interactions on performance, mineral retention (Ca, P, Mg, Zn, Fe and Cu) and bone mineralization. A wheat-based diet with a high phytate-P content and no inorganic P added, or the same diet with either 1.4 % formic acid, 500 FTU C. braakii-derived phytase or both added, were used. Thirty-two piglets, with a mean weight of 21.06 ± 0.83 kg were distributed in eight pens. Individual feed intake was recorded, and all treatments were represented in all pens. The experimental period was 28 days. Performance was recorded, pH in stomach, jejunum and ileum was measured and content from jejunum and ileum was collected for assessment of P digestibility. In addition, feces were collected for total digestibility measurements and left third and fourth metacarpal were analyzed for bone mineralization. No interaction effects between phytase and acid addition were found. Phytase addition increased growth (P=0.046), jejunal P digestibility (P=0.004), total tract digestibility of P (P<0.001) and Ca (P<0.001) and bone mineralization (P<0.001). Acid addition improved growth (P=0.002) and FCR (P=0.033) in addition to total tract digestibility of Mg (P=0.04), Fe (P<0.001) and Ca (P=0.001).The experiment confirmed that phytase addition improved P digestibility. However, no increased phytase efficacy was seen with acid addition.

Effect of two phytases at two doses on performance and phytate degradation in broilers during 1-21 days of age.

The effect of two microbial phytases at two dose-levels on performance and apparent ileal digestibility (AID) of nutrients in broilers fed European-type diets was studied. A total of 1,200 d-old Ross 308 male broilers were randomly assigned to 5 treatments with 30 birds/pen and 8 pens/treatment. A nutritionally adequate positive control (PC) diet was tested against 4 experimental diets containing reduced total P, retainable P, Ca and Na as per the recommended nutritional contribution for Buttiauxella phytase (Phy B) at 1,000 FTU/kg (-1.87 g/kg, -1.59 g/kg, -1.99 g/kg and -0.4 g/kg vs. PC, respectively). Experimental diets were supplemented with Phy B at 500 FTU/kg or 1,000 FTU/kg, or Citrobacter phytase (Phy C) at 1,000 FTU/kg or 2,000 FTU/kg. Diets were based on corn, soybean meal, rapeseed meal and sunflower meal and formulated by phase (starter 1–10 d, grower 11–21 d) in crumbled or pelleted form. Overall (d 1–21), at 1,000 FTU/kg, birds fed Phy C exhibited lower BWG (-2.7%), FI (-3.4%) and tibia ash (-2.2%) vs. PC (P < 0.05), and reduced BWG (-3.6%), FI (-3.9%) and tibia ash (-1.8%) vs. Phy B (P < 0.05). Phy B at 1,000 FTU/kg and Phy C at 2,000 FTU/kg maintained performance equivalent to the PC. Digestibility of Ca did not differ among phytase treatments but at 1,000 FTU/kg AID P was greater with Phy B than Phy C (72.3% vs. 62.7%, P < 0.05). Ileal phytate (myo-inositol hexakisphosphate, IP6) digestibility was greatest with Phy B at 1,000 FTU/kg which was higher than Phy C at 1,000 FTU/kg (87.6 vs. 60.6%, P < 0.05). The findings indicate a higher phytate degradation rate of Phy B than Phy C at equivalent dose-level and this is correlated to the performance of the broilers.

Impact of combined α-galactosidase and xylanase enzymes on growth performance, nutrients digestibility, chyme viscosity, and enzymes activity of broilers fed corn-soybean diets.

Two experiments were conducted to investigate the effects of a combined α-galactosidase and xylanase preparation on nutrients digestibility and growth performance in broiler chickens. Experiment 1 had 240 broilers allocated to 3 treatments with the dietary supplementation of 0, 300, and 500 g/t of the enzyme combination. Diet and amino acid (AA) digestibility were assessed. Experiment 2 was a 2 × 3 (enzyme × diet) factorial arrangement with 10 replicates of 12 male broilers per replicate. Diets were based on corn-soybean meal (SBM) diet and had 3 nutritional levels (normal, 2% apparent metabolizable energy (AME) and crude protein (CP) reduction, and 4% AME and CP reduction). Each of these diets was fed with or without enzyme supplementation. Growth performance, chyme viscosity, nutrients digestibility, and endogenous enzymes activity were assessed. In experiment 1, enzyme supplementation improved the digestibility of Ca (P = 0.025) and ileal digestibility of total AA, Pro, Alu, Ile, Lys, His, Thr, Glu, Val, Leu, Tyr, and Phe (P < 0.05), and also tended to increase the AME of diets (P < 0.10). In experiment 2, broilers fed the corn-SBM diet with 4% nutrient reduction had better growth performance (P < 0.05), jejunal digesta viscosity at 42 d (P < 0.01), and lower digestibility of gross energy (GE; P < 0.05) when compared with those fed the normal nutrient diet. Enzyme inclusion increased digestibility of CP (P = 0.044), GE (P = 0.009), raffinose (P < 0.001) and stachyose (P < 0.001), improved average daily gain (P = 0.031), and reduced jejunal digesta viscosity at 42 d (P = 0.011). Besides, similar improvements trend in amylase, trypsin, sucrase, and maltase activity with enzyme inclusion were observed as with energy. These data support that the enzyme supplementation increased nutrients and ileal AA digestibility, improved performance and endogenous enzymes activity.

Effects of calcium level and source, formic acid, and phytase on phytate degradation and the microbiota in the digestive tract of broiler chickens

BackgroundDiet acidification, dietary calcium (Ca) level, and phytase supplementation are known influences on the microbial community in the digestive tract and on phosphorus (P) utilization of broiler chickens. Effects of dietary factors and microbiota on P utilization may be linked because microorganisms produce enzymes that release P from phytate (InsP6), the main source of P in plant feedstuffs. This study aimed to detect linkages between microbiota and InsP6 degradation by acidifying diets (i.e., replacing Ca carbonate (CaCO3) by Ca formate or adding formic acid to CaCO3-containing diets), varying Ca levels, and supplementing phytase in a three-factorial design. We investigated i) the microbial community and pH in the digestive tract, ii) prececal (pc) P and Ca digestibility, and iii) InsP6 degradation.ResultsAll factors under investigation influenced digesta pH and the microbiota composition. Predicted functionality and relative abundance of microorganisms indicated that diets influenced the potential contribution of the microbiota on InsP degradation. Values of InsP6 degradation and relative abundance of the strains Lactobacillus johnsonii and Lactobacillus reuteri were correlated. Phytase supplementation increased pc InsP6 disappearance, with differences between Ca levels, and influenced concentrations of lower inositol phosphate isomers in the digestive tract. Formic acid supplementation increased pc InsP6 degradation to myo-inositol. Replacing CaCO3 by Ca-formate and the high level of these Ca sources reduced pc InsP6 disappearance, except when the combination of CaCO3 + formic acid was used. Supplementing phytase to CaCO3 + formic acid led to the highest InsP6 disappearance (52%) in the crop and increased myo-inositol concentration in the ileum digesta. Supplementing phytase leveled the effect of high Ca content on pc InsP6 disappearance.ConclusionsThe results point towards a contribution of changing microbial community on InsP6 degradation in the crop and up to the terminal ileum. This is indicated by relationships between InsP6 degradation and relative abundance of phosphatase-producing strains. Functional predictions supported influences of microbiota on InsP6 degradation. The extent of such effects remains to be clarified. InsP6 degradation may also be influenced by variation of pH caused by dietary concentration and solubility of the Ca in the feed.