Intestinal development of bovine foetuses during gestation is affected by foetal sex and maternal nutrition.

We aimed to evaluate the effects of maternal nutrition (MN) and foetal sex on the intestinal development of bovine foetuses throughout different days of gestation (DG). Forty-four multiparous, dry Holstein × Gyr cows with average initial body weight of 480 ± 10 kg were fed the same diet of either restricted feeding at 1.15% of body weight (CO, n = 24) or fed ad libitum (overnourished, ON, n = 20). Six cows from CO group and five cows from ON group were slaughtered at 139, 199, 241 and 268 DG, and foetuses were necropsied to evaluate the intestinal development. The mass, length and density of foetal intestines were not affected by MN (p ≥ 0.260). An interaction between MN and DG was observed for the villi length of jejunum (p = 0.006) and ileum (p < 0.001). Villi length of jejunum and ileum was higher (p < 0.10) in foetuses from ON-fed cows than in foetuses from CO-fed cows at 139 DG. However, at 199 DG, the villi length of jejunum and ileum of foetuses from CO-fed cows was higher than in foetuses from ON-fed cows. Despite these differences, MN did not affect the villi length of jejunum and ileum at 268 DG (p > 0.10). Female foetuses had greater small intestine mass (p = 0.093), large intestine mass (p = 0.022), small intestine mass in proportion to body mass (p = 0.017) and large intestine mass in proportion to body mass (p < 0.001) than male foetuses. Female foetuses had also longer small intestine (p = 0.077) and greater small intestine density (p = 0.021) and villi length of jejunum (p = 0.001) and ileum (p = 0.010) than males. We conclude that MN affects the pathway for the development of foetal villi length throughout the gestation in bovine foetuses without changing the final villi length. Female foetuses had higher intestinal mass, density and villi length than males during the foetal phase in bovines.

Pesticide application to agricultural fields: effects on the reproduction and avoidance behaviour of Folsomia candida and Eisenia andrei.

The objective of this work was to assess the impact of pesticide application to non-target soil organisms simulating what happens following pesticide application in agricultural fields and thus obtaining higher realism on results obtained. For that purpose, three commercial formulations containing the insecticides chlorpyrifos and endosulfan and the herbicide glyphosate were applied to a Mediterranean agricultural field. The soil was collected after spraying and dilution series were prepared with untreated soil to determine the impact of the pesticides on the avoidance behaviour and reproduction of the earthworm Eisenia andrei and the collembolan Folsomia candida. A significant avoidance was observed at the recommended field dose in case of endosulfan by earthworms (60 %) and in case of chlorpyrifos by collembolans (64 %). In addition, both insecticides affected the number of juveniles produced by the earthworms (EC(50) were below the recommended field dose). Glyphosate did not seem to affect either earthworms or collembolans in the recommended field dose. Folsomia candida was more sensitive to pesticide application than Eisenia andrei, what was corroborated by the EC(50) and LC(50) values. In conclusion, insecticides may affect the structure of the soil community by reducing the survival of collembolans and the reproductive capacity of collembolans and earthworms.