Pathological Effects of Formalin (37% Formaldehyde) Mixed in Feed or Administered into the Crops of White Leghorn Cockerels

A comparison of formic acid or monoglycerides to formaldehyde on production efficiency, nutrient absorption, and meat yield and quality of Cobb 700 broilers

After being banned by the European Commission in 2018, the use of formaldehyde as a feed amendment in the United States has come into question. Therefore, this study was conducted to explore alternatives to formaldehyde, such as formic acid and monoglycerides, and their effects on poultry production. In total, 1,728 Cobb 700 broilers were randomly assigned to 96-floor pens on day of hatch (18 birds/pen). Using a randomized complete block design (4 blocks), treatments were assigned to pens with blocking based on location within the barn, with the eastern half of the barn designated for digestibility and the western half designated for production (per experiment: 8 control pens and 10 pens per treatment). All diets were based on a negative control (NC), basal diet. Dietary treatments consisted of: NC, NC + 0.25% formalin (F), NC + 0.25 and 0.50% Amasil NA (AML and AMH; 61% formic acid and 20.5% Na-formate), and NC + SILO Health 104L (SILO; mixture of monoglycerides; 0.5% from 0 to 14 d, 0.4% from 14 to 28 d, and 0.2% from 28 to 42 d). Water and feed were provided ad libitum. Performance data were collected during feed changes on d 0, 14, 28, and 42, with digestibility data collected at d 14 (2 per pen) and carcass quality (6 per pen) assessed at d 46 with a randomly selected group of broilers. A one-way ANOVA followed by Dunnett's multiple comparison, where treatments were evaluated against F were conducted using JMP 14.0 (P ≤ 0.05). Main effect of treatment was significant for performance, nutrient digestibility, and carcass quality. Differences in body weight and ADG were observed from d 14 to d 28, resulting in a trending improvement in lysine digestibility on d 14 and carcass quality on d 46 of birds fed AML and AMH in comparison to those fed F (P < 0.05). Whereas birds fed SILO had reduced digestibility of methionine on d 14 and a decrease in meat quality on d 46 in comparison to those fed F (P < 0.05). Therefore, Amasil NA at 0.25 or 0.50% may be an effective alternative to formaldehyde as a feed amendment for poultry production.

Reproductive and developmental toxicity of formaldehyde: a systematic review

Formaldehyde, the recently classified carcinogen and ubiquitous environmental contaminant, has long been suspected of causing adverse reproductive and developmental effects, but previous reviews were inconclusive, due in part, to limitations in the design of many of the human population studies. In the current review, we systematically evaluated evidence of an association between formaldehyde exposure and adverse reproductive and developmental effects, in human populations and in vivo animal studies, in the peer-reviewed literature. The mostly retrospective human studies provided evidence of an association of maternal exposure with adverse reproductive and developmental effects. Further assessment of this association by meta-analysis revealed an increased risk of spontaneous abortion (1.76, 95% CI 1.20-2.59, p=0.002) and of all adverse pregnancy outcomes combined (1.54, 95% CI 1.27-1.88, p<0.001), in formaldehyde-exposed women, although differential recall, selection bias, or confounding cannot be ruled out. Evaluation of the animal studies including all routes of exposure, doses and dosing regimens studied, suggested positive associations between formaldehyde exposure and reproductive toxicity, mostly in males. Potential mechanisms underlying formaldehyde-induced reproductive and developmental toxicities, including chromosome and DNA damage (genotoxicity), oxidative stress, altered level and/or function of enzymes, hormones and proteins, apoptosis, toxicogenomic and epigenomic effects (such as DNA methylation), were identified. To clarify these associations, well-designed molecular epidemiologic studies, that include quantitative exposure assessment and diminish confounding factors, should examine both reproductive and developmental outcomes associated with exposure in males and females. Together with mechanistic and animal studies, this will allow us to better understand the systemic effect of formaldehyde exposure.

Chemical treatment of animal feed and water for the control of Salmonella

The control of Salmonella in animal feedstuffs is important, principally to protect the human food chain from contamination by Salmonella derived from infected animals. The transmission of Salmonella from animal feeds to animals, and onward to human food products, has been convincingly documented. This is especially important for chicken breeding and laying flocks and pigs, in view of the consequences of recent or imminent control legislation in the European Union. Animal feed ingredients, particularly animal and plant-derived protein meals, are frequently contaminated with Salmonella either from source or from processing plant, and recontamination in compounding mills is an additional problem. Several complementary strategies have been used to control this feed contamination, and these include a range of chemical treatments. The principal agents used are as follows: organic acids and their salts, formaldehyde, and bacterial membrane disruptors such as terpenes and essential oils. Experimental agents include chlorate compounds. Many products use blends of agents from the same or different chemical groups to achieve synergistic or combination effects. The present review draws upon published and company data to describe the various modes of action and efficacies of different chemical agents delivered in feed or in drinking water against Salmonella occurring in feed or in livestock environments. Reasons for the failure of protection are explored, along with problems in usage such as corrosion and reduced palatability. Given the wide array of products available with contrasting modes of action, the need for standardized tests of efficacy is also discussed.

Organic acid and formaldehyde treatment of animal feeds to control Salmonella: efficacy and masking during culture

AIMS

To investigate whether treatment of animals feeds with organic acids/formaldehyde may mask the presence of Salmonella, when assessed by standard cultural methods.

METHODS AND RESULTS

Four commercial treatments were applied at the manufacturers' recommended rates on feeds artificially inoculated with Salmonella. The recovery of Salmonella from these treated feeds was assessed after specific antagonists were added to the treatments during culture. A control group of treated feed received no antagonist. Masking of Salmonella was demonstrated when the addition of antagonists resulted in recovery of Salmonella from the treated feed, compared with a negative recovery when no antagonists were added. There were large variations in the efficacy of treatments, and masking was demonstrated with all four tested treatments. One formaldehyde-based product showed greater efficacy and less masking. Masking was greater when high levels of Salmonella were present in the feed.

CONCLUSIONS

Some organic acid or formaldehyde-based feed treatments may mask the presence of Salmonella.

SIGNIFICANCE AND IMPACT OF THE STUDY

Feeds may be deemed safe despite being contaminated with Salmonella. The use of antagonists during culture may help assess the level of Salmonella contamination when organic acid or formaldehyde treatments have been applied to feed ingredients.

Effects of Formalin Feeding or Administering into the Crops of White Leghorn Cockerels on Hematological and Biochemical Parameters

Formalin administered (15 and 20 mL) into the crops of White Leghorn cockerels resulted in behavioral alterations, included depression, dullness, staggering, somnolence, anorexia, and decreased frequency of crowing. A significant decrease was observed in red blood cell counts, hemoglobin concentration, packed cell volume, and leukocyte counts in birds fed higher levels of formalin. Decreasing and increasing trends in concentrations of serum proteins and enzymes, respectively, were observed with increases in formalin doses. Significantly lower blood glucose and testosterone levels and significantly (P < 0.05) higher blood urea and creatinine concentrations were observed in birds fed higher formalin levels. No gross or microscopic lesions were observed in the birds fed different levels of formalin mixed in feed. These changes suggested that the formalin mixed in feed might have evaporated, and, hence, the amount ingested might have been too low to induce pathological changes. It was concluded from the present study that formalin mixed up to 5 mL/kg of feed, corresponding to 10 mL/bird of 3% formalin in drinking water by crop tube had no adverse effects on the health of White Leghorn cockerels.