Confirmation of phosphorus availability in low-phytate and high-protein corn to growing-finishing large white toms

A 115-d (16.5-wk) experiment was conducted to validate the estimated availability of P in a high nutrient-dense (amino acids and calories), low-phytic acid (NDLP) corn variety as compared with conventional yellow dent (YD) corn when fed to commercial toms. The NDLP corn contained 0.32% P and 90% of this was nonphytate P (NPP) compared with YD corn, which had 0.25% P and 32% of the total P was NPP. Toms consuming NDLP corn were fed diets formulated to have the same dietary NPP level as the control diet with reduced levels of total P. Phosphorus was successfully formulated at 90% availability for NDLP corn with no compromise to growth performance or bone integrity measurements compared with the control diet with YD corn. Ulna breaking strength was the most sensitive measurement of dietary P adequacy under the conditions of the experiment. Excretion of P from toms was decreased by 30% when NDLP corn was fed in place of YD corn during the finishing phase, and litter P was decreased by 19% by replacement of YD corn with NDLP corn

Benefit of feeding dietary calcium and nonphytate phosphorus levels above National Research Council recommendations to tom turkeys in the growing-finishing phases

This experiment evaluated the effects of feeding various dietary Ca and nonphytate P (nPP) levels to Large White male turkeys from 3 to 17 wk of age. After consuming a common prestarter diet, poults were fed approximate NRC (1994) levels of dietary Ca and nPP from 3 to 9 wk of age or levels approximately 25% higher. From 9 to 17 wk of age, each starter group was fed approximately 75 (low P), 100 (medium P), or 145% (high P) of the NRC (1994) requirements for Ca and nPP. Diets were fed as crumbles to 6 wk of age and as pellets from 6 to 17 wk of age. There were no effects on BW or feed efficiency to 9 wk of age. Litter P was increased by 21% when high Ca and nPP were fed from 3 to 9 wk. High dietary Ca and nPP fed during the growing-finishing period generally improved bone strength and ash. Tibia strength and ash were higher in the medium P group compared with in the low P group. Wing bone strength was greater in the high P group than in both the birds fed low or medium P. Litter P was increased by 23% when High P was fed in the growing-finishing period compared to the birds fed the Medium P diet during the same period. The results show there is a benefit to bone strength and mineralization when Ca and nPP are fed at levels higher than NRC (1994) recommendations

Evaluation of phytase concentration needed for growing–finishing commercial turkey toms

1. Growth performance, serum bone markers, and bone strength and mineralisation were determined in tom turkeys grown from 9 to 17 weeks of age. 2. Dietary non-phytate phosphorus was formulated to be reduced by 1·0 g/kg in the low phosphorus diet compared to a control diet and phytase was added to provide 0, 150, 300, 450 or 600 units/kg activity to the low phosphorus diet. 3. From 9 to 12 weeks of age, body weight and gain:food were reduced by the low phosphorus diet without added phytase, compared to the adequate phosphorus diet. Increasing the concentration of phytase linearly increased these growth parameters. There were no significant growth responses at 17 weeks of age. 4. Serum osteocalcin was reduced by increasing dietary phosphorus at 12 weeks of age when growth was affected, but not at later ages. Serum pyridinoline was reduced by higher dietary phosphorus and decreased linearly with increasing phytase activity at 17 weeks of age. 5. Fracture force of the ulna and femur increased linearly with increasing phytase activity but bone strength was not affected when corrected for bone cross-sectional area. Bone strength of the ulna and ash concentration of the ulna and tibia were increased by higher dietary phosphorus. Humerus and ulna ash increased linearly with increasing phytase activity. 6. Water-soluble phosphorus content of the litter was increased by higher dietary phosphorus and addition of phytase to the low phosphorus diet. The increase in water-soluble phosphorus content of the litter when phytase was fed may indicate that phosphorus could be fed at a lower concentration than used in this trial, at least in the finisher diet when phytase is added to the food. 7. Bone fracture force, strength and ash were generally optimised when 450 units/kg phytase activity was added to the low phosphorus diet. However, growth performance was best in the grower I (9 to 12 weeks) phase when 600 units/kg phytase was added to the diet

Effects of low-phytic acid corn on growth performance, bone strength, and serum osteocalcin concentration in growing-finishing pigs

A 91-d experiment was conducted to evaluate whether low-phytic acid corn (NDLP, Exseed Genetics) (90% phosphorus (P) availability) could replace dent corn (DC) without adversely affecting growth performance or bone parameters in growing-finishing pigs. Total Pand phytate P were 0.24 and 0.16% in DC; 0.32 and 0.03% in NDLP, by analysis. Pigs were blocked by initial BW (18.5 to 22.5 kg) into four pens per treatment (trt) of eight crossbred pigs per pen. Two trts were fed; trt 1 contained DC and trt 2 contained NDLP. Three phases were fed; each was four wks in length. Dietary calcium and non-phytate Pw ere computed to provide 0.75 and 0.36, 0.63 and 0.30, or 0.55 and 0.28% in phases I, II, and III, respectively. Total Pw as computed to provide 0.57, 0.50, or 0.47% for trt 1; and 0.47, 0.40, or 0.36% for trt 2, in phases I, II, and III, respectively. Dicalcium phosphate concentration was decreased by 0.73, 0.78, and 0.85% units in trt 2, for phases I, II, and III, respectively. One gilt per pen was chosen, based on average pen BW (92 to 106 kg), for slaughter at 91d. All third and fourth metacarpals (MC) and metatarsals (MT) were used to analyze bone-breaking strength. Blood was collected from two pigs per pen at 90d for serum osteocalcin (OC) analysis (an indicator of bone turnover). Gain/feed (trt 1 = 316, trt 2 = 350, P > 0.09), BW (trt 1 = 97.3 kg, trt 2 = 98.7 kg, P > 0.71), and ADG (trt 1 = 840 g/d, trt 2 = 860 g, P > 0.57) were not affected. There were no differences in bone strength of third and fourth MC and fourth MT bones (P > 0.28). Overall, MC and MT bone strength was higher (15.04 vs. 12.83 MPa, P 0.92), suggesting no difference in bone turnover. This study proposes that NDLPcorn can be formulated with 90% Pa vailability and replace dent corn without adversely affecting pig performance

Effects of protease enzyme supplementation and varying levels of amino acid inclusion on productive performance, egg quality, and amino acid digestibility in laying hens from 30 to 50 weeks of age

ABSTRACT: An experiment was conducted to evaluate the effects of protease supplementation and reduced digestible amino acid (dAA)/ crude protein (CP) level on productive performance, AA digestibility, and egg quality parameters in Hy-Line W-36 laying hen from 30 to 50 wk of age. A total of 768 hens (12 replicates of 8 hens per treatment) were equally and randomly allocated into 8 experimental diets in a 4 × 2 factorial arrangement of dAA/CP level (100, 95, 90, and 85% of breeder recommendation) and protease (exclusion or inclusion). Protease was added at 60 g/metric ton of feed in the inclusion group. Hens were housed in raised-wire cages with a stocking density of 870 cm2/bird. The adequate (100%) diet was based on corn and soybean meal and formulated based on the digestible (d) Lys and dAAs (dMet, dThr, dTrp, dTSAA, dIle, and dVal) to meet 100% of the current management guide recommendation. Variations in dAA/CP (95, 90, and 85% diets) were accomplished by reducing the 100% dAA by 5, 10, and 15%, respectively. All diets were supplemented with phytase at 500 phytase units (FTU)/kg. Data were analyzed using PROC GLM of SAS 9.4. There was a main effect of dAA/CP level on 85% diet where it had a lower mean hen-day egg production (HDEP, P < 0.01), egg mass (EM, P < 0.01), and higher feed conversion ratio (FCR, P < 0.001). Higher egg weight (P < 0.01) was observed in 95 and 100% dAA/CP level diets. However, Haugh unit (P < 0.01) and albumen height (P < 0.01) were higher in 85 and 90% diets. The inclusion of protease reduced the feed consumption (P = 0.0247), FCR for dozens of eggs (P = 0.0049) from 30 to 49 wk of age without affecting the HDEP or EM. Protease supplementation and dAA/CP level had an effect on the apparent ileal digestibility (AID) of CP (P = 0.019), Lys (P < 0.01), Thr (P < 0.01), Trp (P = 0.017), and Val (P < 0.01). Addition of protease significantly increased egg income (P = 0.033) and return on investment (P = 0.00223) from 30 to 37 wk of age. At 38 to 50 wk of age, dAA/CP level had a significant effect on egg income (P < 0.001), feed cost (P < 0.001), and return on investment (P < 0.001). This experiment indicates that the inclusion of protease in 90 and 95% lower dAA/CP diets could help improve the digestibility of CP, and key amino acids and maintain productive performance of corn and soybean meal-based diets in Hy-Line W-36 laying hen from 30 to 50 wk of age

Effect of increasing dietary calcium and phosphorus on bone development in growing turkeys

In the turkey production industry (IND, it is standard practice to feed higher levels of Ca and non-phytate Phosphorus (npP) than the National Research Council (NRC) recommendations, in order to promote the growth of a stronger skeleton. Elevated dietary npP leads to an increase in P content in the manure, which is undesirable due to resulting environmental contamination, particularly eutrification of the water. The purpose of this study was to determine the effect of varying concentrations of dietary Ca and npP on bone size, density and breaking strength in turkeys

Effects of dietary calcium and phosphorus regimen on growth performance, bone strength and carcass quality and yield of large white tom turkeys

An experiment was conducted to estimate the calcium (Ca) and nonphytate phosphorus (npP) levels needed for toms in the starter (ST) (3-9 wk of age) and the grower/finisher (G/F) (9-15/15-17 wk of age) periods to support growth performance, bone breaking strength and carcass parameters. After 3 wk of group brooding, poults (B.U.T.) were divided into treatment (trt) pens and fed pellets containing Ca and npP at approximately NRC requirements (3 wk interval basis) or at typical industry (IND) levels (breeder recommendations). At 9 wk of age, birds from each ST trt were fed either a low npP (75% of NRC requirement) diet, the NRC recommended level, or an IND level of npP (Ca:npP=2:1 for all trts) until marketed at 17 wk of age. The birds were weighed every 3 wks and at 17 wk of age. Feed intake was estimated by feed disappearance to calculate feed efficiency. There were 15 pens of 31 birds/pen for each trt in the ST period and 5 pens for each of the 6 trt combinations during the G/F period. Three toms/pen were selected at 15 and 17 wk for bone and component yield measurements. All birds from 3 pens/trt were judged for a walking score (range 1-5, 5 best) during the 17th wk. There was no difference in body weight or feed intake in the ST period. Body weight was decreased when the NRC ST-low npP G/F trt was fed relative to the products in this experiment, especially, for FTM. There was an average moisture reduction of 2.4% for both PBMs and FTMs used in this experiment