PSX-A-4 Late-Breaking: Assessing the antifungal efficacy of EverWildTM D01 against Aspergillus flavus in semi-moist pet treats

Semi-moist pet treats contain moisture levels ranging from 20–30% making them ideal for mold growth and mycotoxin production. To control mold, synthetic mold inhibitors such as potassium sorbate or calcium propionate are used. Synthetic additives are effective, but there is a shift in the pet owner preferences for ‘natural’ products. Fermented and (or) cultured whey has been shown to contain antifungal metabolites and has been used to control fungal growth in bread. EverWildTM D01 is a commercially available cultured whey product. The objective of this study was to assess the efficacy of EverWildTM D01 against Aspergillus flavus in a semi-moist pet treat. A model semi-moist pet treat fortified to be nutritionally complete was produced with three levels of powdered whey fermentate, [1.0%, 3.0% and 5% (w/w)], a negative control with no antifungal and a “positive control” which contained potassium sorbate as a standard industrial mold inhibitor. Treats were produced by baking in 3cm x 3cm squares. Individual squares were inoculated with 0.1 mL of Aspergillus flavus (ATCC 204304) to achieve a final concentration of ~ 5.0 Log CFU/square. The inoculated squares were individually incubated at 250 C. Fungal analysis was performed at day 3, 6, 9, 12, 15, 18, 21, 24 and 28 by surface plating on Potato Dextrose Agar (PDA) followed by incubation at 250 C for 72h. The total log reductions were calculated by subtracting the initial inoculum with the colony counts on day 28. EverWildTM D01 at 1.0%, 3.0%, and 5% (w/w) had a 1.90, 3.89 and 4.58 Log CFU/square log reduction, respectively. The positive control had a 1.19 Log CFU/square log reduction. All treatments differed from the negative control (P < 0.05). In conclusion, EverWildTM D01 may be effective as a natural alternative to synthetic mold inhibitors in semi-moist pet treats.

Effects of Calcium Propionate on Milk Performance and Serum Metabolome of Dairy Cows in Early Lactation

Background: Most of the dairy cows in early lactation suffer from a period of negative energy balance (NEB) and hypocalcemia metabolic disorders. Calcium propionate is a source of energy and calcium for alleviating NEB and hypocalcemia. The objective of the study was to investigate the changes of milk compositions and blood metabolites of postpartum dairy cows fed with calcium propionate for 5 weeks.Methods:Thirty-two multiparous Holstein cows after calving were randomly allocated to control (CON), low calcium propionate (LCaP), medium calcium propionate (MCaP) and high calcium propionate (HCaP) groups with 8 cows per group balanced with parity, milk yield and body weight. The dairy cows in the four groups were oral drenching with 0, 200, 350, 500 g/d calcium propionate per cow from calving to d 35 in early lactation, respectively.Results:The results showed that the milk yield in MCaP group was significantly higher than those in the other groups. At d 35, the somatic cell count (SCC) in MCaP group tended to be lower than those in other groups. Compared with the CON group, serum non-esterified fatty acid (NEFA) in MCaP and HCaP groups tended to decrease. The serum alanine aminotransferase (ALT) concentration in MCaP group was lowest among the four groups. The concentration of aspartate aminotransferase (AST) in HCaP group was significantly higher than the other groups. Feeding calcium propionate had no significant effect on serum calcium, phosphorus and magnesium concentrations. The serum parathyroid hormone (PTH) in HCaP group tended to decrease. The calcium propionate treatments significantly decreased the serum alkaline phosphatase (ALP) level. The MCaP treatment significantly decreased serum total antioxidant capacity (T-AOC), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT) activity, while increased the concentration of malondialdehyde (MDA) when compared with the other groups. The metabolomic results showed that calcium propionate significantly affected the bile acid compositions. Conclusions: It was concluded that the 350 g/d calcium propionate feeding level could significantly improve milk performance, alleviate body fat mobilization and bone calcium utilization, however decrease antioxidant capacity of dairy cows as well. The effect of calcium propionate on milk performance and serum metabolites in early lactation cows may be regulated through the serum bile acids metabolism.

Acute effects of the food preservative propionic acid on glucose metabolism in humans

IntroductionPropionic acid (PA) is a common food preservative generally recognized as safe by the US Food and Drug Administration; however, exogenous PA has effects on glucose metabolism that are not fully understood. Our preclinical studies demonstrated exogenous PA increases glucagon, norepinephrine, and endogenous glucose production (EGP).Research design and methodsWe performed a randomized, placebo-controlled, crossover study in 28 healthy men and women to determine the effect of PA (1500 mg calcium propionate) on these factors. Subjects had two study visits, each preceded by a 1 week, PA-free diet. During each visit, glucose, insulin, glucagon, norepinephrine, epinephrine, and EGP were assessed for 2 hours after oral administration of PA/placebo under resting conditions (protocol 1) and during either a euglycemic (~85–90 mg/dL) or hypoglycemic (~65–70 mg/dL) hyperinsulinemic clamp (protocol 2).ResultsPA, as compared with placebo, significantly increased: (1) glucagon and norepinephrine during protocol 1; (2) glucagon, norepinephrine, and epinephrine under euglycemic conditions in protocol 2; and (3) norepinephrine, epinephrine, and EGP under hypoglycemic conditions in protocol 2.ConclusionOral consumption of PA leads to inappropriate activation of the insulin counterregulatory hormonal network. This inappropriate stimulation highlights PA as a potential metabolic disruptor.