Limestone Solubility: What Can You Do About It?

Calcium (Ca) is essential for bone development mineralisation, as well as for eggshell formation, muscle and neural functions. Depending on the type of diets (veggie vs. non-veggie), species (turkey, chicken, duck), and age of animal (young vs. adult), limestone can contribute up to 95% total Ca in the final diet, with more Ca from limestone for younger animals with veggie diet. Despite the significant contribution of limestone to total diet Ca levels, the bioavailability variation of limestone Ca is rarely considered. Phosphorus (P) is a limited resource and is the third most costly ingredient in poultry diets. Improving P utilization in poultry diets will decrease the amount of inorganic P needed, reduce P excretion and feed costs, as well as increase the sustainability of poultry production. Studies in the past two decades have clearly demonstrated that Ca can be detrimental to P utilization. Some recent studies suggested that phytase, if used correctly can partially or even completely alleviate such detrimental effect. In addition, recent evidences also showed that formulating on bioavailability of Ca, instead of total Ca, could be more favourable in regard to feed cost, animal performance, and sustainability. The global limestone survey started in 2018, primarily to understand the variation of: 1) Ca concentration from the most significant Ca source and probably the cheapest ingredient limestone; 2) solubility and potentially bioavailability of the Ca from limestone. In parallel, a series animal studies were carried out to determine: 1) correlation of in vitro limestone solubility and in vitro Ca digestibility; 2) the impact of solubility profile on P digestion and phytase efficacy. It has been four years since the survey started, with over 1500 samples collected globally. It is a good time to review the results from and learnings so far

Recent Findings on Phosphorus Digestibility of Feed Ingredients in Broilers

Accurately meeting the dietary P needs of broilers is critical to ensure optimal bird performance, health, and welfare without causing undue environmental burdens associated with excess dietary P excretion. Phosphorus is commonly supplied in broiler diets from inorganic phosphates derived from non-renewable sources, but it has been estimated that peak P production will occur between 2030-2040 and that the global supply of P could be depleted within this century (Cordell and Drangert, 2009; Nest and Cordell, 2012). To address these concerns, inorganic P use in agriculture, including use in broiler diet formulation, requires careful stewardship. To this end, the dietary inclusion of animal protein meals can help reduce or eliminate the need for inorganic phosphate use, especially when paired with phytase (van Harn et al., 2017). However, the proportion of P available to the bird within commonly used inorganic phosphate and animal protein sources is often not well-defined.With increasing adoption of ileal digestibility of P in feed formulation, additional data are needed to develop robust databases for commonly used and important sources of P. Therefore, the aim of this study was to generate values of AID and SID of P for different inorganic phosphates and meat and bone meal sources using the direct method. In addition, relative P digestibility of these sources was determined using monosodium phosphate as the reference ingredient to provide a basis for comparing quantitative digestibility results with relative values

Productive performance of commercial growing and finishing pigs supplemented with a Buttiauxella phytase as a total replacement of inorganic phosphate

The objective of this study was to test if a novel phytase from Buttiauxella sp. can replace all added inorganic phosphate in a diet with reduced Ca and metabolizable energy (ME) fed to commercial pigs from 12 kg body weight (BW) until slaughter, whilst maintaining performance and carcass quality parameters. Four dietary treatments were tested in a completely randomized design with 9 replicate pens, each containing 31 mixed sex Newsham Choice pigs. Diets included a positive control (PC) based on corn, soybean meal, wheat middling and bakery meal, meeting all nutrient requirement of pigs; a negative control (NC) excluded inorganic phosphate and with reduced Ca (−0.13%) and ME (−0.15 MJ/kg); and NC supplemented with Buttiauxella phytase at 500 or 1,000 FTU/kg feed. Diets were fed ad libitum in mash form in 5 phases: starter (12 to 25 kg BW), grower 1 (25 to 50 kg BW) and 2 (50 to 75 kg BW), and finisher 1 (75 to 100 kg BW) and 2 (100 kg BW to slaughter). The NC group showed lower (P < 0.05) average daily feed intake (ADFI) and average daily gain (ADG) in starter and grower phases, lower gain to feed ratio (G:F) in starter and grower 1 compared with PC. Pigs receiving the high dose of phytase of 1,000 FTU/kg had improved performance vs. the 500 FTU/kg phytase treatment in starter and grower 1 phase compared with the PC in grower 1 phase. Increasing phytase dose resulted in a linear increase in ADG (12 to 120 kg BW) and G:F (50 to 75 kg BW). A comparison of treatment groups over the full production period from 12 kg BW until slaughter showed that both 500 and 1,000 FTU/kg phytase treatments were able to maintain growth performance and carcass characteristics compared with PC. The application of Buttiauxella phytase could therefore be used as an effective strategy to replace all inorganic phosphate in diets of pigs fed corn, soybean meal, wheat middling and bakery meal based diets from 12 kg BW. An economic analysis showed greater return from both phytase treatments vs. the PC and favored the higher phytase dose at 1,000 FTU/kg vs. the traditional dose of 500 FTU/kg. The latter was mainly related to the improved performance of the higher dose in younger pigs to 75 kg BW. Keywords: Buttiauxella phytase, Carcass, Pigs, Phosphorus, Productive performanc

Panel 2A

In this panel, Janet Alexander served as commenter while the other three faculty shared the following papers: Zachary Clopton - Public-Private Enforcement Jaime Dodge - Shadow Judges Dana Remus & Adam Zimmerman - The Corporate Settlement Mil

Effects of once-weekly exenatide on cardiovascular outcomes in type 2 diabetes

BACKGROUND: The cardiovascular effects of adding once-weekly treatment with exenatide to usual care in patients with type 2 diabetes are unknown. METHODS: We randomly assigned patients with type 2 diabetes, with or without previous cardiovascular disease, to receive subcutaneous injections of extended-release exenatide at a dose of 2 mg or matching placebo once weekly. The primary composite outcome was the first occurrence of death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke. The coprimary hypotheses were that exenatide, administered once weekly, would be noninferior to placebo with respect to safety and superior to placebo with respect to efficacy. RESULTS: In all, 14,752 patients (of whom 10,782 [73.1%] had previous cardiovascular disease) were followed for a median of 3.2 years (interquartile range, 2.2 to 4.4). A primary composite outcome event occurred in 839 of 7356 patients (11.4%; 3.7 events per 100 person-years) in the exenatide group and in 905 of 7396 patients (12.2%; 4.0 events per 100 person-years) in the placebo group (hazard ratio, 0.91; 95% confidence interval [CI], 0.83 to 1.00), with the intention-to-treat analysis indicating that exenatide, administered once weekly, was noninferior to placebo with respect to safety (P<0.001 for noninferiority) but was not superior to placebo with respect to efficacy (P=0.06 for superiority). The rates of death from cardiovascular causes, fatal or nonfatal myocardial infarction, fatal or nonfatal stroke, hospitalization for heart failure, and hospitalization for acute coronary syndrome, and the incidence of acute pancreatitis, pancreatic cancer, medullary thyroid carcinoma, and serious adverse events did not differ significantly between the two groups. CONCLUSIONS: Among patients with type 2 diabetes with or without previous cardiovascular disease, the incidence of major adverse cardiovascular events did not differ significantly between patients who received exenatide and those who received placebo