black seed

Black seeds can affect the productive and physiological performance of birds and laboratory animals. This research aimed to study the effect of black seed levels on production and reproduction parameters in Japanese quail.

The experiment was conducted on 400 pieces of adult 12-week-old quails in 20 experimental units with four treatments and five replications for 6 weeks. Experimental treatments were control (without black seeds, feeding with a basic diet), a basic diet with 1% of black seeds, the basic diet with 2% of black seeds, and the basic diet with 3% of black seeds. At the end of the experimental period, blood was taken from one randomly selected male bird from each replicate for testosterone measurement, and they were killed to examine reproductive components. The produced quail eggs of each experimental replication were collected daily and their number was recorded and weighed separately every week. At the end of the test period, 30 quail eggs from each replication were collected for 4 days and placed in the egg combs. The selected quail eggs were arranged in the setter combs and incubated in an automatic incubator at 37.7 °C and 55% humidity. For 15 days of the setter stage, the temperature was 37.2°C and 70% humidity for 3 days of the hatcher stage. The number of chickens in each replication and their weight and losses were recorded after hatching. Reproductive parameters, including fertility rate, total hatch, and the hatch of fertile eggs, were examined at the end of the incubation period.

The reproductive components and male Japanese quail testosterone were not affected by different levels of black seed (p < 0.05). Mansour et al. (2003) showed that treated groups (olive oil, black seed oil, and pomegranate extract) slightly affected testosterone, LH, FSH, and Inhibin-B compared to the control group. Considering that black seed has many properties, it did not show an effect on testosterone levels in the treatments compared to the control treatment; however, it did not have a harmful effect on the hormone levels. Egg production was affected by experimental treatments (p < 0.05). Egg weight parameters were not affected by experimental treatments (p < 0.05). The highest percentage of egg production was recorded in the treatments with 2 and 3% of black seeds, and the lowest percentage of egg production belonged to the treatment with 1% of black seeds. Aydin et al. (2008) added black seeds to the diet of Leghorn laying hens of line strains and reported that black seeds at the levels of 2 and 3% positively affected egg production and shell quality and reduced cholesterol in the yolk. Hasankhah et al., (2021) investigated different black seed levels on the safety and performance of laying hens and reported that using 4% and 5% black seeds positively influenced egg production. Fertility and overall hatching were affected by experimental treatments (p < 0.05), but fertile eggs and the weight of hatched chicks were not affected by experimental treatments (p < 0.05). The highest and the lowest fertility and hatch belonged to the treatments with 2% and 1% of black seeds, respectively. Madrasi and Pournaji (2018) studies on the effect of black seed hydroalcoholic extract on female reproductive factors in small laboratory mice showed that this extract increased the follicle graph and corpus luteum, which could have a positive result in female fertility. Except for mid-embryonic losses, other embryonic parameters were not affected by experimental treatments (p < 0.05). Blood parameters were not affected by experimental treatments (p < 0.05). Taghiani et al. (2010) investigated the effect of black seeds (2 and 4 g/kg) in the basic diet of broiler chickens on blood parameters. Their results showed that serum biochemical parameters, including albumin, triglyceride, LDL, HDL, and total cholesterol, were not significantly affected by dietary treatments.

Based on the results of the present research, black seed can have an effect on fertility, hatchability, and egg production due to the presence of compounds such as thymoquinone, fatty acids, and piscimen, and resulting in better reproductive performance in mother quails. In general, the use of black seeds at a 2% level in the Japanese quail diet can positively affect fertility and egg production.

Oxidative stress is inevitable in broiler chicken production, and it affects the physiological, behavioral, and biochemical status of growing chicken which ultimately deteriorates meat quality. The imbalance among free radicals and antioxidant enzymes within living cells or tissues leads to the oxidation of lipids, proteins, and nucleic acids and is a fundamental cause of oxidative stress. When the antioxidant mechanism within living cells weakens, the production of free radicals increases under physiological oxygen metabolism, and reactive species (i.e., reactive oxygen species and reactive nitrogen species) are needed in cells in small quantities because they function as signaling molecules during homeostasis. However, excessive production of these species leads to oxidative stress. There is a mechanism in living cells to reduce the number of oxidative species through physiological scavenging. Numerous reactive oxygen species such assuperoxide and hydrogen peroxide are produced during oxygen metabolism. In addition, some reports showed that after the occurrence of oxidative stress, there are severe inflammatory reactions in the cells involved, which can lead to greater tissue damage and activate tissue apoptosis. Oxidative stress plays an essential role in the emergence of a number of chronic disorders such as diabetes and cancer by inducing inflammation. To protect against free radicals, living organisms have a combined antioxidant defense system including enzymatic system (such as glutathione peroxidase, superoxide dismutase, and catalase enzymes in the cytosol and cell membrane structure) and a non-enzymatic system (such as glutathione, polyphenol, carotenoids, special dipeptides, proteins containing thiol group, polyamines, ubiquinol, flavonoids, bilirubin, uric acid, vitamin E with selenium, and vitamin C) in tissues. Black cumin seeds (Nigella sativa) have been used as alternative medicine for more than 2000 years due to their multisystemic positive effects. Many active components of black cumin have been identified, including dithymoquinone, thymoquinone, nigellone, thymohydroquinone, nigilline, melanthin, nigelamine, damascenone, pinene, and p-cymene. Black cumin contains minerals such as calcium, magnesium, potassium, iron, phosphorus, cobalt, zinc, and manganese, and vitamins A, B, C, D, and E. Moreover, black cumin is rich in essential oils, proteins, alkaloids, saponins, flavonoids, and polyphenols. The black cumin has anti-inflammatory, analgesic, anthelmintic, hypocholesteremia, appetite stimulant, antidiarrheal, diuretic, antiulcer, spasmolytic and bronchodilatory, antimicrobial, antihypertensive, antidiabetic, anticancer, hepatoprotective, and renal protective activities and has antioxidant properties. This study was conducted to investigate the effects of black cumin on growth performance, antioxidant status, inflammatory responses, and biochemical and hematological changes in broilers under oxidative stress induced by hydrogen peroxide.

A total of 200 one-day-old chickens (Ross 308) were reared in the form of a completelyrandomized design with four treatments and five replications (10 chickens per replicate). Experimental treatments included: 1. Control group (fed with basic diet), and groups 2, 3, and 4 had levels of 50, 100, and 150 g of black seed per kg of diet. To induce oxidative stress, all birds received 1% hydrogen peroxide per liter of drinking water from 14 to 42 days of age. At 42 d, two birds were randomly selected from each cage and after blood sampling from the wing vein, were killed and dissected for liver and spleen tissue sampling. Growth performance, blood and biochemical parameters such as the number of red and white blood cells, hemoglobin, hematocrit, heterophil and lymphocyte, serum triglyceride, and cholesterol, as well as serum antioxidant parameters including the level of malondialdehyde (MDA) and the activity of antioxidant enzymes including glutathione peroxidase, superoxide dismutase, and catalase, were determined. In addition, liver enzymes present in the serum including alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) were measured. Also, to evaluate the effect of black cumin on the inflammatory response of broiler chickens under induced oxidative stress, serum interleukins including IL-10, IL-6, and TNF-α were measured.

The results showed that black seed supplementation in chickens under induced oxidative stress significantly improved the growth performance, increased the activity of antioxidant enzymes, and decreased MDA in serum, liver tissue, and spleen (P<0.05). Black seed supplementation significantly decreased serum levels of inflammatory cytokines of IL-6 and TNF-α, and increased anti-inflammatory cytokine of IL-10 (P<0.05). Also, black seed supplementation did not affect red blood cells, hematocrit, or hemoglobin, but increased white blood cells, lymphocytes, and decreased blood heterophils (P<0.05). Serum levels of triglycerides, cholesterol, ALT, AST, and ALP also decreased significantly under the influence of black seed.

Based on the results of this experiment, it appears that black cumin (Nigella sativa) seed supplement can improve the growth performance of broiler chickens due to its antioxidant and anti-inflammatory effects.

The Japanese quail is a species known for its short production period and high productivity. Due to their small size and low feed requirements, they are considered a cost-effective option for egg production compared to other poultry species. Additionally, quail eggs are recognized for their superior nutritional value compared to regular chicken eggs. However, there is a need for effective methods to enhance productivity, especially in stressful situations. Previous research has indicated that the use of certain dietary supplements can address this issue and improve the productive traits of birds. Therefore, there is considerable scientific interest in studying the effects of natural compounds such as black seed and L-carnitine on the productive performance of laying Japanese quails, both under normal conditions and during heat stress. Investigating these factors can provide valuable insights into the development of strategies to effectively manage and optimize egg production in laying Japanese quails. This, in turn, would contribute to the sustainability and profitability of the poultry industry. In this study, we aimed to examine the effects of black seed, L-carnitine, and vitamin E on the productive performance, carcass characteristics, blood biochemical parameters, and immune responses of Japanese laying quails.

A total of 500 Japanese laying quails were included in this study. They were divided into two temperature conditions: normal temperature and high temperature (36 degrees Celsius for 6 hours per day). Additionally, there were five experimental treatments: control diet (without any additives), black seed (1.5% black seed diet), L-carnitine (250 ppm + control diet), 1.5% black seed + 250 ppm L-carnitine diet, and Vitamin E diet (200 ppm + control diet). This resulted in a 5x2 factorial experiment with a total of 10 treatments, 5 replications, and 10 quails per replication. The study consisted of three phases: an adaptation period to the experimental diets lasting two weeks, exposure to the designated temperature conditions for five weeks, and a three-week recovery period. During these phases, various parameters were measured and recorded, including productive performance, carcass characteristics, and blood biochemical and immune indicators (such as triglyceride, cholesterol, LDL, HDL concentrations, heterophil, and lymphocyte percentages) under both heat stress and recovery periods in Japanese laying quails. Data analysis was performed using the Generalized Linear Model (GLM) method with the assistance of SAS software. Mean comparisons were conducted using Tukey's multiple range tests.

The results of this study revealed several important findings. During the initial two weeks of the experiment, the consumption of feed containing black seed + L-carnitine led to the highest feed intake, while diets containing black seed, black seed + L-carnitine, and vitamin E demonstrated the highest egg mass compared to the control group (P<0.05). During the heat stress period, high temperatures caused a decrease in feed intake, egg weight, egg production, and egg mass. However, the consumption of feed containing black seed + L-carnitine resulted in increased feed intake, and diets containing black seed, black seed + L-carnitine, and vitamin E showed increased egg production and mass compared to the control group. Furthermore, vitamin E exhibited a better conversion coefficient (P<0.05). During the recovery period, high temperatures led to a decrease in feed intake but an increase in bird body weight. The control group exhibited the lowest feed intake and body weight, whereas diets containing black seed, black seed + L-carnitine, and vitamin E demonstrated the highest egg production and egg mass compared to the control group. Birds fed diets with black seed and vitamin E exhibited a better conversion coefficient (P<0.05). Regarding carcass yield and relative liver weight, the effect of environmental temperature and experimental treatments during both heat stress and recovery periods was not significant. However, the consumption of black seed, L-carnitine, and vitamin E was found to increase carcass yield and relative heart weight. Additionally, high temperatures increased the relative liver weight (P<0.05). Moreover, birds fed control and black seed diets at normal and high temperatures exhibited higher blood cholesterol levels compared to other experimental treatments. In normal temperature conditions and diets containing vitamin E and L-carnitine, a higher percentage of lymphocytes was observed in the blood. In high temperature conditions and diets containing L-carnitine and vitamin E, the heterophil to lymphocyte ratio was also higher (P<0.05).

Finally, the findings of this study highlight the beneficial effects of incorporating black seed, L-carnitine, and vitamin E into the diet of Japanese laying quails, both under normal and high-temperature conditions. These dietary interventions have shown positive impacts on the performance of the quails. Consequently, these results can serve as valuable guidance for quail breeders and producers in selecting suitable feed regimens to manage heat stress in Japanese quail layers, thereby enhancing performance efficiency, carcass characteristics, and blood lipid and immune parameters.