Nutrient deficiencies in broiler chicks: a demonstration project for undergraduate students

A demonstration project is described that proved to be popular with undergraduate students enrolled in a senior level course on animal and poultry nutrition. A total of 100 male, day-old broiler chicks were housed in a Petersime battery brooder and used in a 3-week test. Students were responsible for the management and care of the birds throughout the test. The birds were allotted to 5 groups (4 replicates each of 5 birds per group) and the test involved the omission of calcium, phosphorus, vitamin D3, or sodium chloride from a nutritionally adequate diet for a period of 2 weeks. After that period, one pen of each group was repleted with the control diet. Feed consumption, liveweight, feed conversion efficiency, and tibia bone ash content were measured weekly. Deficiency signs of the nutrients were observed, and it was noted that sodium chloride had the most marked effect on growth. Phosphorus deficiency had the most severe effect on bone development and resulted in a high incidence of rickets. Repletion resulted in a marked response in all parameters measured and was most marked in the group deficient in sodium chloride.