Effect of feeding powdered Nigella sativa L. seeds on poultry egg production and their suitability for human consumption.

The effect of Kalongi (Nigella sativa, L.) seeds was studied on the performance of layers and cholesterol contents of their egg-yolks. A total of 96 White-Leghorn birds of 40 weeks of age and at the egg-laying stage were randomly divided into 12 experimental units, eight birds in each unit. These units were randomly allotted to four treatments in such a way that each treatment received 3 experimental units. Four test rations were prepared by supplementing a commercial layer-ration with powdered Kalongi seeds at the rates of 0.0, 0.5, 1.0 and 1.5%. Effects of feeding these rations on feed intake, egg production, egg mass, egg shell thickness, Haugh unit, yolk index, blood spots, meat spots and total cholesterol in eggs were determined after a period of 12 weeks. Blood samples of the two birds selected at random from each replicate were taken at 0, 6 and 12 weeks. The serum obtained from these samples was analyzed for total cholesterol, low-density lipoproteins, high-density lipoproteins and triglycerides. Data on feed intake, feed refused and egg production were used to calculate the feed conversion ratio. Results showed that Nigella sativa seeds significantly (P<0.05) increased egg production, egg mass, eggshell thickness and Haugh unit. However, there was no significant (P>0.05) change in yolk index, blood and meat spots. The Nigella sativa seeds also significantly (P<0.05) reduced yolk cholesterol contents. The serum triglycerides, low-density lipoprotein, cholesterol and total cholesterol levels were also reduced, while serum high-density lipoprotein cholesterol level was increased by supplementing the commercial layer-ration with Nigella sativa seeds. Introduction The poultry industry has been considered as the second largest industry in Pakistan. This sector has not only provided best quality, low cholesterol meat but also highly nutritious eggs to consumers. Poultry meat is lower in cholesterol than red meat but poultry eggs have a high concentration of cholesterol, i.e. 213 mg per egg (ANONYMOUS, 1989). Normally, a person is able to consume about 300 mg. of dietary cholesterol per day to avoid the risks associated with coronary heart disease (ANONYMOUS, 1986). This has necessitated a drastic reduction or even elimination of egg intake in the human diet in order to stay below the recommended level. The high cholesterol level in eggs has been a possible contributory factor to the decrease their consumption. There is a well-known religious instruction which goes as follows: “There exists in the black seed (Kalongi) health and a cure for …