Rapeseed meal‐glucosinolates and their antinutritional effects Part 5. Animal reproduction

Abstract

Although there is no clear evidence to fully describe the mechanism involved in glucosinolate-related effects on animal reproduction, lowered fertility in animals fed diets with rapeseed meal (RSM) inclusion is related to glucosinolate content in the diet. Negative effects can result both from multidirectional action of glucosinolates, malnutrition of mother due to the thyroid dysfunction, transfer of goitrogenic compounds to foetus and reduced transfer of nutritive compounds (e.g. iodine) through the placenta. The degree of reproduction impairment depends both on glucosinolate content and on the type of animal. Pregnant female rats are sensitive to the presence of glucosinolates, and the first symptoms of fertility impairment and lowering of offspring survival rate may occur at low glucosinolate levels, e.g. with diets containing low glucosinolate rapeseed meal (LG-RSM). In the case of swine, the limiting value above which sows fertility may be impaired is 4 mumol of total glucosinolates per g diet and 8 mmol of daily intake of these compounds. Opinions on the permitted RSM inclusion in diet for hens are very divergent. Some authors recommend limiting of the RSM inclusion to 10%, while others did not find any lowering of egg production in hens fed with two- or three-fold greater RSM inclusion rates. Most long-term experiments with heifers, cows and ewes indicate that ruminants tolerate the level of glucosinolate in LG-RSM although feeding this fodder as the only high-protein concentrate component may lead to impaired fertility.

Chemical and biological characterisation of nutraceutical compounds of broccoli

“…On the other hand, GLSs have traditionally been condemned because of their goitrogenic and growth retardation activities [61]. Glucosinolate breakdown products (oxazolidine-2-thiones) found in several oil meals may induce morphological and histological abnormalities of internal organs in animals [61,62], as exemplified in increased thyroid weight in pigs and poultry, as well as depressed growth, goiters, poor egg production, and liver damage.…”

Effects of dietary purified rapeseed protein concentrate on hepatic gene expression in juvenile turbot (Psetta maxima)

“…. . Aquaculture Nutrition calcium or copper) and positively charged proteins (Francis et al 2001), hence, potentially inflicting malnutrition (Mawson et al 1994). Likewise, tannins interfere with the digestive processes by binding to feed components such as proteins or minerals or to digestive enzymes, directly.…”

Detoxification of Rapeseed Meals by Steam Explosion

“…Among them, glucosinolates, whose metabolites are toxic, were the primary limiting factor before the double low varieties, especially canola, were successfully developed. Although glucosinolate content was considerably decreased in contemporary commercial varieties, low levels still influence palatability, growth performance, reproduction, thyroid function, liver and kidney function of non-ruminant animals and fish [2][3][4][5][6][7][8]. Therefore, it is necessary to further reduce the glucosinolate content to improve the feeding value of rapeseed meals.…”