RESUMEN
Copper (Cu) and zinc (Zn) have negative environmental impacts as they accumulate in the soil after pig manure is spread. Cu and Zn are essential elements in pig nutrition but due to their low retention rate, more than 90% of ingested Cu and Zn are excreted. A better understanding of the behaviour of these elements throughout the animal-manure-soil continuum according to feed composition and manure management chain is thus required to propose alternative ways to reduce these environmental impacts. The aim of this study was to determine the fate of Cu and Zn throughout this continuum by studying the effect of Cu and Zn contents in animal feed and in the manure management chain based on anaerobic digestion and composting. Faeces were collected from 24 finishing pigs fed with 4 different Cu and Zn dietary levels and sources of supplementation. Samples of faeces were exposed to mesophilic anaerobic digestion or to 5-week composting with straw. Concentrations of Cu and Zn in the faeces were highly dependent on dietary supplies and ranged from 38 to 188 mg Cu/kg DM and from 191 to 728 mg Zn/kg DM. Degradation of a significant fraction of organic matter during treatment led to a significant increase in Cu and Zn concentration relative to the product's dry matter (DM) content, which. Cu and Zn concentrations relative to DM content were twice as high after treatment whatever the content and the form of Cu and Zn dietary supplementation. Otherwise, effluent treatment tended to reduce the possible availability of Cu and Zn in final organic products according to water-extractible contents. This study clearly shows that feed management is the main lever for reducing the amount of Cu and Zn amount in pig effluents and hence in the soil. Appropriate treatment could also facilitate the supply of organic fertilisers to areas with soil deficiency, but feed strategies need to be adapted to the treatment chain to enable the production of good quality organic products that respect EU regulations.
Asunto(s)
Estiércol , Zinc , Porcinos , Animales , Zinc/análisis , Cobre/análisis , Heces , Suelo , Compuestos Orgánicos , Alimentación AnimalRESUMEN
n-3 polyunsaturated fatty acids (n-3 PUFA) contribute to the normal growth and development of numerous organs in the piglet. The fatty acid composition of piglet tissues is linked to the fatty acid composition of sow milk and, consequently, to the composition of sow diet during the gestation and lactation period. In this study, we investigated the impact of different contents of extruded linseed in the sow diet on the fatty acid composition and desaturase gene expression of piglets. Sows received a diet containing either sunflower oil (low 18:3n-3 with 18:3n-3 representing 3% of total fatty acids) or a mixture of extruded linseed and sunflower oil (medium 18:3n-3 with 9% of 18:3n-3) or extruded linseed (high 18:3n-3 with 27% of 18:3n-3) during gestation and lactation. Fatty acid composition was evaluated on sow milk and on different piglet tissues at days 0, 7, 14, 21 and 28. The postnatal evolution of delta5 (D5D) and delta6 (D6D) desaturase mRNA expression was also measured in the liver of low 18:3n-3 and high 18:3n-3 piglets. The milk of high 18:3n-3 sows had higher proportions of n-3PUFA than that of low 18:3n-3 and medium 18:3n-3 sows. Piglets suckling the high 18:3n-3 sows had greater proportions of 18:3n-3, 20:5n-3, 22:5n-3 and 22:6n-3 in the liver, and of 22:5n-3 and 22:6n-3 in the brain than low 18:3n-3 and medium 18:3n-3 piglets. D5D and D6D mRNA expressions in piglet liver were not affected by the maternal diet at any age. In conclusion, extruded linseed in the sow diet modifies the n-3PUFA status of piglets during the postnatal period. However, a minimal content of 18:3n-3 in the sow diet is necessary to increase the n-3PUFA level in piglet liver and brain. Moreover, modifications in the n-3PUFA fatty acid composition of piglet tissue seem linked to the availability of 18:3n-3 in maternal milk and not to desaturase enzyme expression.
Asunto(s)
Alimentación Animal/análisis , Dieta/veterinaria , Ácido Graso Desaturasas/metabolismo , Ácidos Grasos/metabolismo , Hígado/enzimología , Porcinos/fisiología , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Ácido Graso Desaturasas/genética , Ácidos Grasos/química , Femenino , Regulación del Desarrollo de la Expresión Génica/fisiología , Regulación Enzimológica de la Expresión Génica/fisiología , Fenómenos Fisiologicos Nutricionales MaternosRESUMEN
The intestinal epithelial barrier (IEB) plays a key role in the maintenance of gut homeostasis and the development of the immune system in newborns. The enteric nervous system (ENS), a key regulator of gastrointestinal functions, has been shown to be modulated by nutritional factors. However, it remains currently unknown whether maternal diet, in particular n-3 polyunsaturated fatty acids (n-3PUFAs), can impact upon the IEB in newborn piglets and whether the ENS is involved in this effect. Sows received either a control diet (lard based) or an n-3PUFA diet (linseed oil based) during gestation and lactation. Intestinal paracellular permeability was assessed in Ussing chambers on piglets at birth, 3, 7, 14, 21 and 28 postnatal days (PND). Basal jejunal permeability increased significantly and similarly in both groups until PND14 and decreased thereafter. However, at PND28, permeability was higher in n-3PUFA animals as compared to controls. In addition, a vasoactive intestinal peptide (VIP) receptor antagonist increased paracellular permeability in controls but not in n-3PUFA piglets. Conversely, atropine and hexamethonium decreased paracellular permeability in the n-3PUFA group but not in the control group. Moreover, the n-3PUFA diet increased the proportion of choline acetyltransferase (ChAT)-immunoreactive (IR) neurons and decreased the proportion of VIP-IR neurons in the submucosal plexus of piglet jejunum compared to controls. In addition, in primary culture of rat ENS, we showed that 20:5n-3 but not 18:3n-3 increased the proportion of ChAT-IR neurons and decreased the proportion of VIP-IR neurons. In conclusion, supplementation of the maternal diet with n-3PUFAs modified intestinal permeability probably via diet-induced neuroplastic changes in the ENS of newborn piglets.