Evaluation of novel protease enzymes on growth performance and apparent ileal digestibility of amino acids in poultry: enzyme screening

Three experiments were conducted to evaluate eight neutral and six acid proteases on growth performance and apparent ileal amino acid digestibility (AID) of poults (Experiment 1) or chicks (Experiments 2 and 3). Two basal diets were formulated: a nutrient adequate positive control (PC), which met or exceeded the nutrient requirements for poults (Experiment 1) or chicks (Experiments 2 and 3) and a negative control (NC) formulated to achieve 85% (Experiments 1 and 2) or 80% (Experiments 3) of the requirement for protein and amino acids. Phytase was included in all diets to provide 500 phytase units (FTU)/kg and xylanase was included in all diets to provide 10,000 (Experiments 1 and 2) or 16,000 (Experiments 3) xylanase units (BXU)/kg. Proteases were supplemented in the NC diet at an equivalent amount of enzyme protein to create 16 experimental diets. There were five birds/pen and 10 replicate pens per treatment in each experiment. In experiment 1, birds fed the PC diet gained more (P < 0.05) than birds fed the NC. There were no differences in growth performance in birds fed the PC or NC in experiments 2 or 3. In all three experiments, birds fed the NC supplemented with neutral protease 1 had reduced (P < 0.05) feed intake (FI) or body weight gain (BWG) and increased (P < 0.05) feed conversion ratio (FCR) compared with birds fed the NC. Birds fed the NC diet supplemented with neutral protease 3, 7 (Experiment 1), or acid protease 4 (Experiment 3) had increased (P < 0.05) FCR and birds fed neutral protease 6 (Experiment 2) had reduced (P < 0.05) BWG compared with birds fed the NC. Apparent ileal amino acid digestibility was improved (P < 0.05) with protease supplementation to the NC diets (Experiment 1 or 3), but this was dependent on the protease and the amino acid. In conclusion, novel protease supplementation improved AID of amino acids but this was not reflected in improvements in growth performance of poults or chicks

The effect of dietary calcium inclusion on broiler gastrointestinal pH: quantification and method optimization

There is little consensus as to the most appropriate methodology for the measurement of gastrointestinal pH in chickens. An experiment was conducted to establish the optimum sampling method for the determination of broiler digesta pH in birds fed differing levels of dietary calcium. Ross 308 broilers (n = 60) were fed one of two experimental diets, one containing 0.8% monocalcium phosphate and 2% limestone and one containing 0.4% monocalcium phosphate and 1% limestone. Four factors were investigated to determine the most appropriate method of measuring broiler gastrointestinal digesta pH: removal from the tract, prolonged air exposure, altering the temperature of the assay, and controlling the water content of the digesta. The conditions were assessed at bird ages from 7 to 42 d post hatch. Dietary Ca content had no significant effect on in situ pH, but it contributed towards variance in ex situ pH of both gizzard and duodenum digesta

Digestible calcium equivalency of phytase and nutrient utilization of broiler chickens fed graded levels of limestone or phytase during the starter phase

ABSTRACT: The current study aimed to quantify the digestible calcium (Ca) equivalency of a new phytase (HiPhorius) in broiler chickens. A total of 1,152 male Cobb 500 broiler chickens were used in an experiment in which 8 diets consisting of graded levels of Ca supplied with limestone or graded levels of the phytase were fed. The 8 dietary treatments were based on a corn-soybean meal diet containing 5.1 g/kg of Ca and 5.1 g/kg of phosphorus (P) as negative control (NC); the NC + 1.3, 2.6, or 3.9 g/kg of Ca from limestone; and the NC + 500, 1,000, 2,000, or 4,000 FYT/kg of phytase. Birds were fed the experimental diets for 3 d (from d 7 to 10) or 14 d (from d 7 to 21) to determine apparent ileal digestibility (AID) and apparent total tract retention (ATTR) of dry matter (DM), CP, Ca, and P. In the 10-day-old birds, increasing the levels of Ca decreased the AID of P and Ca (linear, P < 0.05). Increasing the levels of phytase quadratically improved (P < 0.05) the AID of Ca and P. The AID of DM and CP in the younger birds quadratically increased (P < 0.05) as the levels of Ca increased. There were linear and quadratic effects (P < 0.05) of increasing phytase level for the AID of DM and a linear effect (P < 0.05) for the AID of CP. In the 21-day-old birds, increasing Ca levels resulted in a linear decrease (P < 0.05) in the AID of CP and P, and a quadratic decrease (P < 0.05) in the ATTR of CP. Increasing phytase levels linearly and quadratically (P < 0.05) improved the AID and ATTR of CP, P, and the ATTR of Ca. The analyzed phytase activity in the diets supplemented with phytase ranged from 1,520 to 7,661 FYT/kg. The digestible Ca equivalence for dietary phytase at 1,520 to 7,661 FYT/kg ranged from 1.55 to 2.02 g/kg in the 10-day-old birds fed for 3 d and from 0.52 to 0.64 g/kg in 21-day-old birds fed for 14 d. The results showed the reduction in Ca level that could be accommodated by phytase supplementation, which is markedly different between the younger and older birds. Feeding duration influenced the impact of phytase supplementation on Ca and P digestibility, with better efficacy of phytase observed in the 10-day-old birds fed for 3 d. Also, the results showed the extra-phosphoric effects of phytase on the utilization of other essential nutrients such as protein and Ca

Dietary muramidase improved growth performance, feed efficiency, breast meat yield, and welfare of turkeys from hatch to market

ABSTRACT: Muramidase is an enzyme that hydrolyzes peptidoglycans of bacterial cell walls and improves performance of broilers in a dose-dependent manner. An experiment was conducted to evaluate muramidase supplementation, at a high or step-down dose, in turkeys from hatch to market. Male, B.U.T. 6 turkey poults were placed in 24 floor pens at 32 birds per pen. Poults were fed 1 of 3 diets from d 1 to 126 of age. There were 8 replicate pens per treatment. The treatments were a control (CTL) diet, the CTL plus muramidase at 45,000 LSU(F)/kg from phase 1 to 6 (BAL45), and the CTL plus muramidase at 45,000 LSU(F)/kg from phase 1 to 3 and decreased to 25,000 LSU(F)/kg from phase 4 to 6 (BAL45-25). Data were analyzed using SAS. The model included treatment and block and means were separated by Fisher LSD test. Birds fed BAL45 were heavier (P < 0.05) and had a greater (P < 0.05) average daily gain compared with birds fed the CTL from hatch to d 126 of age. Birds fed BAL45-25 had a final BW and average daily gain intermediate to or equivalent to birds fed BAL45 at the same phases. Feed conversion ratio was improved (P < 0.05) in birds fed BAL45 compared with birds fed the CTL and intermediate in birds fed BAL45-25. Breast meat yield was greater (P < 0.05) in turkeys fed muramidase, regardless of dose, compared with birds fed the CTL. There was no effect of treatment on muramic acid content in the jejunum digesta or litter scores. The frequency of pododermatitis score 1 was greater (P < 0.05) and score 2 was lower (P < 0.05) in birds fed muramidase, regardless of dose, compared with birds fed the CTL diet. In conclusion, muramidase supplementation improved performance, breast meat yield, feed efficiency and some markers of welfare, proportional to the dose in the diets

Wave overtopping field data collected at the sea walls in Dawlish and Penzance (southwest UK) between March 2021 and March 2022.

WireWall wave overtopping measurement systems were deployed around the sea walls at Dawlish and Penzance (southwest of England) to monitor overtopping during a period from the 10th of March 2021 to the 17th of March 2022. The systems were programmed to operate for every tide from 3 hours before predicted high tide to 3 hours after. Located at various distances inland of the sea wall crest at Dawlish and Penzance, the systems had varying configurations of capacitance sensors that measured the total depth of aerated water (both solid flow and spray). All overtopping times were recorded in UTC. These data were collected as part of the Coastal REsistance: Alerts and Monitoring Technologies (CreamT) project, NE/V002538/1