Nutrition and Digestive Physiology of the Broiler Chick: State of the Art and Outlook
Monogastric Research Centre, School of Agriculture and Environment, Massey University, Palmerston North 4442, New Zealand
Author to whom correspondence should be addressed.
Academic Editors: Anna Arczewska-Włosek and Sylwester Świątkiewicz
Received: 8 September 2021
Revised: 23 September 2021
Accepted: 23 September 2021
Published: 25 September 2021
The first week after hatch is the most challenging period in the life of broilers. The digestive tract of the newly hatched chick is immature and must undergo dramatic changes before it can efficiently digest and absorb nutrients. The gut is the vital organ where nutrient digestion and absorption take place. Ontogenic changes that accompany improved digestion and absorption include increased secretion of digestive enzymes, increase in the gut absorptive surface area, and enhanced nutrient transporters. The obvious limiting factors are the secretion and activities of digestive enzymes, and the surface area for absorption. These limitations are overcome as the birds grow older, with concurrent improvements in nutrient utilization. In addition, substantial changes also take place in the physical and functional development of the immune system and intestinal microbial ecology. However, the focus of the current review was on nutrition-related challenges and nutritional approaches to assist the chick during this highly demanding period.