Alleviation of thermoregulatory responses of Baladi does by chromium and Selenium-E supplementation in subtropical areas

الملخص EN

This experiment was conducted to study the effect of the treating Baladi female goats with chromium and selenium-E during estrous cycle, pregnancy and postpartum periods to alleviate thermoregulatory responses of animals under hot conditions in Egypt to improve their performance throughout these stages.

It has been used in this research 72 mature Baladi does (36 animal / season) with an average age of 2-3 years and an average body weight of 25 Kg, the experiment lasted for two seasons (mild and hot).

Animals were divided randomly into three similar groups, the 1st group was kept without any treatments (control), the 2nd group was supplemented by chromium (chromium chloride, Cr).

The 3rd group was injected intramuscularly twice a week with 2ml viteselen®, contained 0.5 mg selenium and 10.7 IU vitamin E (Se-E).

Animals were kept in semi-open pens during the experimental period and allowed to graze for five hours daily at least.

Thermoregulatory responses of the animal were estimated in terms of rectal temperature (RT), skin temperature (ST) and respiratory rate (RR).

Results showed significant decrease in RT during the estrous cycle due to Cr and Se-E treatments.

Also, Selenium-E injection showed lower ST during most of the different stages of estrous cycle.

Under hot season, each of chromium and selenium-E reduced ST during estrous cycle while this effect was only due to Se-E for RR without chromium .Both Cr and Se-E treatments decreased RT and ST throughout different stages of pregnancy, except at late pregnancy of Se-E group.

Under hot season conditions, does injected with Se-E were the lowest in RR during the mid and late pregnancy compared with other groups.

While Cr group did not reveal significant effect on RR.

During postpartum period Cr and Se-E supplementation under hot condition showed significant decrease in RT and ST.

Both treatments decreased (P<0.05) RR during the postpartum period, only Se-E exhibited this decline under hot season