Effect of aflatoxin culture on intestinal function and nutrient loss in laying hens

Abstract

The negative effects of aflatoxins (AFLA) on hepatic necrosis and total tract digestibility of energy, N, and amino acids have been well documented. However, the question remains if this is an effect on nutrient metabolizability alone or an effect on the intestine, or both, resulting in increased endogenous nutrient loss or reduced nutrient retention, or both. Therefore, a 2-wk feeding study with a crude AFLA culture was conducted with laying hens to measure endogenous losses and digestive functionality of the intestine. Hy-Line W36 hens were fed 1 of 4 experimental diets containing a crude AFLA culture from 20 to 22 wk of age. Diets were analyzed to contain 0, 0.6, 1.2, or 2.5 mg/kg of AFLA B(1). Dietary AFLA concentration had no effect on BW, egg production, or feed intake. Intestinal crypt depth (but not villus length) increased linearly with increasing AFLA concentration. Similarly, specific activity of the intestinal disaccharidase, maltase, increased quadratically by feeding up to 1.2 mg/kg of AFLA and declined at 2.5 mg/kg of AFLA (P <or= 0.022). Although there was no effect of AFLA on goblet cell number, density, or crude mucin excretion (P > 0.05), sialic acid excretion increased quadradically such that it was increased 12% when 0.6 and 1.2 mg/kg of AFLA was fed versus the control (P <or= 0.025). Digestibility of DM and N per hen per day were unaffected by AFLA. Feeding of 0.6 and 1.2 mg/kg reduced the apparent digestible and AME(n) of the hen by 10 and 4%, respectively (P <or= 0.025). Because intestinal characteristics (intestinal morphology, sialic acid production, and apparent digestible energy) were altered by AFLA feeding, it can be surmised that AFLA can have a direct or indirect effect, or both, on functionality of the gastrointestinal tract.

Aflatoksin İçeren Yumurta Tavuğu Yemlerine Sodyum Bentonit ve Mannan Oligosakkarit İlavesinin Performans, Yumurta Kalitesi, Kan ve Sindirim Özelliklerine Etkileri

“…Ali et al [13] reported that the toxicity of aflatoxin was characterized by reduction in body weight gain as aflatoxins interfere with normal metabolic pathway through the inhibition of protein synthesis and enzyme system that is involved in carbohydrate metabolism and energy release. The results of present study agree with data showing that AF contamination did not affect the liveability, egg production and feed intake of laying hens [5,19,28,29,31] . However, some researchers did report that dietary AF decreased egg production and feed intake [8,32,33] .…”

“…In another study, the inclusion of dietary AFB 1 from 0 to 2.0 ppm resulted in lowered egg weight and nitrogen retention [28] . However, in 2-week a short feeding study, AF contamination did not have any detrimental effect on body weight gain [29] . Aflatoxin appears to exert its negative effect on animal performance chiefly by depressing the DNA and RNA synthesis and eventually protein synthesis [28,30] .…”

Effects of feeding corn naturally contaminated with AFB₁ and AFB₂ on performance and aflatoxin residues in broilers

“…Our results are in agreement with the results of Kermanshahi et al (2007) in broilers and Applegate et al (2009) in laying hens. However, there was a trend that showed a decrease in the apparent digestibility of dry matter, organic matter, crude protein, and gross energy of the broilers feed diets when contaminated with AFB 1 and AFB 2 (P > 0.05).…”

Aflatoxins in Poultry Nutrition

“…Furthermore, the type and specific line of chicken used in various studies may also affect the reaction of intestine towards chronic aflatoxicosis. This hypothesis is supported by the recent observations regarding aflatoxicosis in layers (Hyline W36; exposure age from 140 to 154 days) by Applegate et al (2009). Contrary to the observations in broilers, these authors noted a linear increase in the crypt depth in distal jejunum with the increasing levels of AFB1 in the diet as 0, 0,6, 1,2, and 2,5 mg/kg, but no effect of the toxin on villus height and number of toxins.…”