Effects of high concentrations of dietary vitamin e and ethoxyquin on the performance of laying hens1

Abstract

1. Three experiments were carried out with light strain laying hens to evaluate the effects of relatively high doses of dietary vitamin E (125 mg/kg food) or ethoxyquin (EQ) (250 mg/kg food) on their laying performance. The control diet contained 5 and 125 mg/kg vitamin E and EQ, respectively. The experimental diets were fed either from one or 32 weeks until 88 or 89 weeks of age. 2. The two antioxidants did not affect the growth of the pullets, age at first egg, final body weight, average egg weight or relative abdominal fat pad size and liver weight at the termination of the experiments. In two out of three experiments, vitamin E and EQ did not affect egg production, food efficiency or mortality; in the third experiment vitamin E significantly (P less than 0.05) improved egg production and food efficiency after an outbreak of Newcastle disease which occurred at 34 weeks of age. EQ significantly reduced mortality during the course of this experiment, but did affect the variables of performance. In two experiments vitamin E consistently improved shell density, although a significant effect was observed in only one of the eight determinations carried out. EQ did not affect this variable. 3. The uterine muscle was more susceptible to oxidation than the drumstick meat, as evaluated by TBA values. In both tissues, vitamin E significantly and consistently decreased TBA values and restricted their increase during incubation, while EQ was less effective, particularly in the drumstick meat. 4. It is concluded that increasing vitamin E and EQ concentrations in diets of laying hens have no effect on the decrease in egg production due to aging. However, vitamin E may minimize the decline in egg production and food efficiency following the outbreaks of some diseases and slightly improve--under certain yet undefined conditions--shell density.

Effects of supplemental vitamin E during the laying period on the reproductive performance of Taiwan native chickens

“…3 g). These data are partly in agreement with Bartov et al (1991), who found that dietary concentration of vitamin E (125 mg/kg food) fed from either one or 32 weeks of age did not affect pullet growth rate, age at first egg or average EW.…”

“…Bartov et al (1991) observed a similar result, in that dietary vitamin E, at 125 mg/kg, could Values in a row not sharing a common superscript are significantly different (P < 0 . 05).…”

Effect of hens fed dietary flaxseed with and without a fatty liver supplement on hepatic, plasma and production characteristics relevant to fatty liver haemorrhagic syndrome in laying hens

“…Antioxidants have improved immunity response against stress, including challenges such as coccidiosis (Colnago et al, 1984) and may improve egg production in flocks challenged by some diseases (Bartov et al, 1991). However, supplementation of the diet with ascorbic acid (200 mg/kg) or -tocopherol (75 mg/kg) to adult layers in full production did not change liver malondialdehyde content, glutathione content or liver haemorrhage score in birds predisposed to FLHS (Diaz et al, 1994).…”

Vitamin E in young turkeys: a reassessment of the requirement

“…In chickens, published data dealing with changes in BW with VE supplementation has been also divergent. Decreased (March eta!., 1973;Nockels et al, 1976) or unchanged (McCuaig and Motzok, 1970;Bartov et al, 1991;Sheehy et a!., 1991;Bartov and Frigg, 1992) BW of chickens with high dietary concentrations of VE has been reported in the literature. In other species, high dietary concentrations of VE have been reported to increase BW of calves (Reddy et al, 1987), pigs (Asghar et al, 1991a), and rats (Meydani et al, 1986), and to maintain BW of calves (Arnold etal., 1992), laying hens (Butcher ef al., 1993), and trout (Furones et al, 1992).…”

“…Similarly, Bartov et al (1991) found that performance of laying hens did not change when the dietary VE increased from 5 to 125 mg/kg of diet. In contrast, after feeding sunflower oil-based diets containing 200 mg of VE/kg for different periods of time, Lin et al (1989) reported that VE supplementation increased BW and improved FE of chickens from 1 to 7 wk of age, compared with giving the VE only during the last 10 d of the experiment.…”