Document Type : Research Paper
Extended Abstract
Introduction
Since the concentration of vitamins and minerals in common poultry feed items varies and the accessibility of vitamins and minerals to these items is low, all these factors lead to uncertainty about the adequate supply of vitamins and minerals through the diet. In poultry nutrition, the contribution of vitamins and trace minerals of feed ingredients is rarely considered in the formulation of the diet. In fact, the supply of vitamins and trace minerals required by birds is achieved by adding vitamin and mineral supplements, which are generally in the form of premixes. These premixes contain vitamins and trace minerals and sometimes micronutrients and other additives. The question is, which recommended requirements tables should be used as the basis for the formulation of these supplements? On the other hand, these recommended requirements tables are often diverse and sometimes very different from each other, and require continuous and ongoing evaluation. Therefore, the purpose of this study was to investigate the effects of using different levels of vitamins and trace minerals in the diet on performance, immunity, hatchability, and vitamin and mineral adequacy indices in Ross 308 broiler breeder hens at 50 weeks of age.
A total of 520 Ross broiler breeder hens were housed in 52 pens, with each pen containing 10 hens and 1 rooster. The birds were maintained from week 50 onwards (the breeder hens and roosters were obtained from Taha Morgh Malekan Company, Iran). From week 50 to week 62, the breeder groups were fed a diet containing a relatively low level of vitamins and trace minerals through a premix (referred to as the "breeder low mix"). Fertilized eggs were collected from the 62-week-old breeder hens and divided into 13 batches, corresponding to 13 different treatments. These eggs were incubated separately. In this experiment, the effects of different levels of vitamins and minerals in the diet of broiler breeder hens on the hatchability and chick quality were evaluated.
For this experiment, 520 Ross 308 broiler breeder hens, aged 50 weeks, were utilized in a completely randomized design comprising 13 treatments with 4 replicates, each replicate consisting of 10 broiler breeder hens. Additionally, one young rooster was included for every 10 hens and was fed the experimental diets for 12 weeks. The experimental treatments included two dietary standards based on Ross 308 and Brazilian recommended tables. These treatments involved three levels of vitamins (100%, 80%, and 60%) and three levels of trace minerals (100%, 80%, and 60%) according to Ross recommendations, as well as two levels of vitamins (100% and 80%) and two levels of trace minerals (100% and 80%) based on Brazilian tables. For the purpose of this experiment, an empty hall was divided in to 52 pens of equal size using chicken netting, with each pen equipped with a separate waterer and feeder for both hens and the rooster. A two-week adaptation period was provided to all experimental units prior to the start of the trial. The experimental diets were formulated based on the nutritional requirements of broiler breeders as per the Ross 308 Parent Stock Nutrition guide (2021) throughout the experimental period. Birds had free access to water during the experimental period, and the amount of feed consumed was calculated and allocated based on their energy requirements (Honar Bakhsh et al., 2013). Disease control and herd vaccination were carried out according to the plan proposed by the regional veterinary office and the veterinarian of the relevant poultry unit, and the lighting program of the hall was 16 hours of light and 8 hours of darkness per day, with an intensity of 80 lux.
The effects of using different levels of vitamins and minerals in the diet of broiler breeders on the average production performance from the age of 50 to 62 weeks showed that using different levels of vitamins and minerals in the diet had a significant effect on the average number of eggs produced (P<0.05). In addition, comparing treatment 5 (RM80, RV80) with treatment 10 (BM100, BV100), it was observed that levels of 80% of vitamins and minerals based on the Ross requirement better than the level of 100 recommended by the Brazilian tables affected the number of eggs produced. Similarly, the results of the present experiment showed that using different levels of vitamins and trace minerals in the diet of broiler breeder hens for 12 weeks had no significant effect on egg weight produced, feed conversion ratio (FCR) (P>0.05). The results of the present experiment showed that the use of different levels of vitamins and trace minerals in the diet of broiler breeder hens significantly affected the egg mass produced, so that treatments 1 (RM100, RV100), 2 (RM80, RV100), 4 (RM100, RV80) and 5 (RM80, RV80) had higher egg mass produced than treatments 3 (RM60, RV100), 6 (RM60, RV80), 7 (RM100, RV60), 8 (RM80, RV60), 9 (RM60, RV60), 10 (BM100, BV100), 11 (BM80, BV100), 12 (BM100, BV80) and 13 (BM80, BV80). The results of this experiment also showed that the experimental diets had a significant effect on the amount of feed consumed per chick produced (P<0.05), so that treatments 1 (RM100, RV100), 2 (RM80, RV100), 4 (RM100, RV80) and 5 (RM80, RV80) had less feed per chick produced than treatments 3 (RM60, RV100), 6 (RM60, RV80), 7 (RM100, RV60), 8 (RM80, RV60), 9 (RM60, RV60), 10 (BM100, BV100), 11 (BM80, BV100), 12 (BM100, BV80) and 13 (BM80, BV80) (P<0.05). The results also showed that the number of chicks produced per hen per week did not have a significant effect between the experimental diets (P>0.05), but in the entire experimental period, the effect of the experimental diets on the number of chicks produced per hen in 12 weeks was significant (P<0.05), so that treatments 1 (RM100, RV100), 2 (RM80, RV100), 4 (RM100, RV80) and 5 (RM80, RV80) had a higher number of chicks per hen in 12 weeks than treatments 3 (RM60, RV100), 6 (RM60, RV80), 7 (RM100, RV60), 8 (RM80, RV60), 9 (RM60, RV60), 10 (BM100, BV100), 11 (BM80, BV100), 12 (BM100, BV80) and 13 (BM80, BV80). Also, comparing treatment 1 (RM100, RV100) with treatment 10 (BM100, BV100), the results showed that treatment 1 (RM100, RV100) produced more chicks in 12 weeks than treatment 10 (BM100, BV100). According to the information obtained, it seems that treatment 5 (RM80, RV80) could be a suitable and economical option in order to produce more chicks per hen, which is an important economic parameter in broiler breeder farms. Similarly, the results showed that the hatching percentage of treatment 1 (RM100, RV100) was significantly higher compared to treatment 10 (BM100, BV100) (P<0.05). Also, treatment 4 (RM100, RV80) had a better hatching percentage than treatments 3 (RM60, RV100), 9 (RM60, RV60), 11 (BM80, BV100), 12 (BM100, BV80) and 13 (BM80, BV80) (P<0.05). According to the results obtained from this experiment, it seems that treatment 4 (RM100, RV80) could be a suitable option based on hatchability percentage. The effects of using different levels of vitamins and minerals in the diet for 12 weeks on production traits in broiler breeders showed that the percentage of Settable eggs was significantly different between the experimental diets (P<0.05), so that treatments 1 (RM100, RV100), 2 (RM80, RV100), 3 (RM60, RV100), 4 (RM100, RV80), 5 (RM80, RV80) and 6 (RM60, RV80) had a higher percentage of Unsettable eggs than treatments 7 (RM100, RV60), 8 (RM80, RV60), 9 (RM60, RV60), 10 (BM100, BV100), 11 (BM80, BV100), 12 (BM100, BV80) and 13 (BM80, BV80). Also, a significant difference was observed in the percentage of Settable eggs when comparing treatments 1 (RM100, RV100) with 10 (BM100, BV100) (P<0.05). Also, according to the results obtained from the following experiment, it was observed that the percentage of Unsettable eggs had a significant difference between the experimental diets (P<0.05), so that treatments 7 (RM100, RV60), 8 (RM80, RV60), 9 (RM60, RV60), 11 (BM80, BV100), 12 (BM100, BV80) and 13 (BM80, BV80) had a higher percentage of Unsettable eggs than treatments 1 (RM100, RV100), 4 (RM100, RV80) and 6 (RM60, RV80) (P<0.05). Also, in comparing treatments 1 (RM100, RV100) with 10 (BM100, BV100), the results showed that there was a statistically significant difference between these two treatments in the percentage of Unsettable eggs. According to the information obtained, it seems that the reason for this could be due to the significant increase in the number of edible eggs between treatments 1 (RM100, RV100) and 10 (BM100, BV100). The results also showed that the energy consumed to produce each chick in treatments 1 (RM100, RV100), 2 (RM80, RV100), 4 (RM100, RV80) and 5 (RM80, RV80) was lower than the other treatments (P<0.05). The results showed that the use of experimental diets had no significant effect on influenza and Newcastle disease titers in broiler breeders (P>0.05). The highest level of immunoglobulin M was observed numerically in treatment 6 (RM60, RV80), but the effect of experimental diets on immunoglobulin G and T titers was not significant (P>0.05). The results of vitamin and mineral adequacy indices in poultry showed that the amount of T4 in the serum of broiler breeder hens, as an indicator for examining the iodine status in the diet of broiler breeder hens, was not significantly affected by the experimental diets. The results of the present experiment show that the experimental diets had a significant effect on the amount of glutathione peroxidase (GPX) (P<0.05). Also, treatment 3 showed the highest concentration of glutathione peroxidase (GPX) among the experimental diets in serum. The results showed that the effects of experimental diets on the amount of superoxide dismutase (SOD) in the serum of broiler breeder hens had no significant effects (P>0.05). The results of this experiment showed that the experimental diets caused significant changes in serum alanine amino transferase (ALT) levels, with treatment 3 having the highest ALT (P<0.05). The results also showed that the experimental diets had no significant effect on blood lactate levels in broiler breeders (P<0.05). Similarly, the results showed that the serum iron level, as an indicator of iron adequacy in the diet, was not significantly affected between the different treatments (P>0.05). The results also showed that the concentration of copper in the blood serum of the broiler breeder hens, as an indicator of copper adequacy, was not significantly affected between the experimental diets (P>0.05). The results showed that blood alkaline phosphatase (ALP) levels had significant changes between experimental treatments (P<0.05).
The results showed that, based on the production of more chicks per hen, treatment 5 (RM80, RV80) could be a suitable and economical option for providing vitamin and mineral supplements. Also, based on the hatchability percentage, treatment 4 (RM100, RV80) could be a suitable option. Similarly, based on the energy consumption for producing each chick, treatment 5 (RM80, RV80) could be the most suitable and economical option possible. Also, based on immunity, treatment 6 (RM60, RV80) is the most suitable option for broiler breeders. In general, considering that the need for hatchability percentage covers most of the needs of broiler breeders, therefore, based on hatchability percentage, treatment 4 (RM100, RV80) is the best option for providing vitamin and mineral supplements for broiler breeders.
Author Contributions
All authors contributed equally to the conceptualization, review, and analysis of the article, and to the writing of initial and subsequent drafts, and approved the final version for submission.
Data Availability Statement
Data will be available upon reasonable request.
Acknowledgements
The authors would like to sincerely thank Taha Morgh Malekan, Mina Toyoor, and Kowsar Hatchery, as well as all those who helped us in conducting this research.
Ethical considerations
The research procedures were conducted in accordance with institutional and national ethical guidelines.
Conflict of interest
The author declares no conflict of interest.
