Effect of oak acorn level on colostrum composition and plasma immunoglobulin G of late-pregnant goats and their kids

Oak acorn contains high levels of tannins which have capacity to form complexes with proteins and consequently reduce their availability and as a result it could reduce colostrum quality and immunoglobulin (Ig) synthesis. Thus, the aim of this experiment was to investigate the effects of dietary oak (Quercus persica) acorn (OA) level during the last 60 days of pregnancy on colostrum composition and plasma metabolites and IgG level of goats and their kids. In all, 24 multiparous pregnant goats (41.7 +/- 2.3 kg BW) were assigned into one of the three experimental diets consisted of control diet (without OA) and diets containing 20% (OA(20)) or 40% (OA(40)) OA on dry matter basis. Goats fed OA 40 had lower BW change compared with other groups (P <= 0.05). Kids birth weight was not affected by experimental diets (P > 0.05). Goats fed OA containing diets had lower plasma glucose, triglyceride and Fe concentrations compared with those fed the control diet (P < 0.01). Plasma IgG (P < 0.01) and urea (P < 0.05) concentrations were lower in goats fed OA(40) compared with others. Animals fed OA containing diets had higher plasma alanine aminotransferase than those fed the control diet (P <0.05). Goats fed OA(40) produced colostrum with lower fat (P <= 0.05) and lactose (P < 0.01) contents compared with other animals. Goats fed OA containing diets had lower colostrum IgG level than those fed the control diet (P <= 0.05). Kids plasma total protein concentration was not affected by experimental diets (P > 0.05), whereas kids born from goats fed OA containing diets had lower plasma IgG level compared with the control diet (P < 0.01). It is concluded that feeding OA during the last 60 days of pregnancy decreased colostrum quality which may have adverse effect on kid's survival.