Sheep herders wait for clients in Abidjan, Cote d'Ivoire, ahead of the Eid al-Adha, on Aug. 18, 2018. (Xinhua/Yvan Sonh)

Sheep herders wait for clients in Abidjan, Cote d'Ivoire, ahead of the Eid al-Adha, on Aug. 18, 2018. (Xinhua/Yvan Sonh)

Sheep herders wait for clients in Abidjan, Cote d'Ivoire, ahead of the Eid al-Adha, on Aug. 18, 2018. (Xinhua/Yvan Sonh)

People herd sheep to a market for clients in Abidjan, Cote d'Ivoire, ahead of the Eid al-Adha, on Aug. 18, 2018. (Xinhua/Yvan Sonh)

A livestock merchant exposes the teeth of a goat to determine the age of the animal for a customer ahead of the annual Eid al-Adha festival at a livestock market in Sanaa, Yemen, on Aug. 18, 2018. (Xinhua/Mohammed Mohammed)

A man pulls an ox after he bought it as a sacrifice ahead of the annual Eid al-Adha festival at a livestock market in Sanaa, Yemen, on Aug. 18, 2018. (Xinhua/Mohammed Mohammed)