Document Type : Research Paper
Authors
1 Department of Animal Sciences, Faculty of Agriculture, University of Tabriz, East Azerbaijan, Tabriz City
2 , Department of Animal Sciences, Faculty of Agriculture, University of Tabriz, Iran.
3 Department of Animal Sciences, Faculty of Agriculture, University of Tabriz, Iran
4 Department of Animal Sciences, Faculty of Agriculture, University of Tehran, Iran.
5 Department of Animal Sciences, Faculty of Agriculture, University of Tabriz, Iran.
Abstract
Keywords
Main Subjects
Extended Abstract
Introduction
Background
The provision of soluble and water-soluble vitamins, as well as micro-essential minerals such as Cu, Fe, Mn, Zn, Se, and I, to meet the nutritional requirements of birds is typically achieved by incorporating vitamin and mineral premixes into their diets. However, the formulation of these vitamin and trace mineral premixes is often based on varying recommendations, which can result in additional costs for broiler breeder hen producers. Significant differences exist among these recommendations for supplying vitamins and trace minerals, with effective dose ranges that vary widely for different nutrients. This variation makes it unclear which doses are optimal or what specific combinations might enhance production performance. There is considerable diversity in vitamin and trace mineral recommendations for poultry (Leeson and Summers, 1991; Whitehead, 2002), and the large discrepancies in the vitamin and mineral content of commercial premixes underscore the lack of scientific consensus, highlighting the need for continuous evaluation. The objective of the present study was to evaluate the effects of different levels of vitamins and minerals in the diets of broiler breeder hens, based on the recommendations of the Ross and Brazilian tables, on progeny performance, humoral immunity, antibody titers against Newcastle disease and influenza, as well as the physical and chemical criteria for bone mineralization.
Methods
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 Margh Malkan 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 performance of their progeny were evaluated. The progeny were fed a basal diet consisting of corn and soybean meal, the composition of which is detailed in Table 2. No growth promoters or coccidiostats were included in the diet.
Experiment 1
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).
Experiment 2
A total of 416 one-day-old mixed-sex chicks, hatched from the first experiment, were used in a completely randomized design with 13 treatments, 4 replicates per treatment, and 8 chicks per replicate. The progeny were raised for 35 days at the Khalat Pushan Research Station of the University of Tabriz, following a diet formulated according to the Ross 308 broiler strain standards. To sensitize the broilers’ responses, the levels of vitamins and minerals provided in this experiment were set at 50% of the Ross 308 (2022) recommendations for the starter and grower periods. During this period, the birds were raised under standard environmental conditions. The chickens were housed on a litter floor, with feed and water provided ad libitum. Routine vaccination protocols were followed, with the progeny vaccinated on day 1 against infectious bronchitis (IB) (B1 + H120), on day 10 against Newcastle disease (strain B1, Razi), and on day 15 against infectious bursal disease (IBD) (Nobilis D78, Intervet).
Results
The results of weekly weighing of the progeny (offspring) and analysis of the resulting data showed that during the experimental period, only the first and third week weights were significantly affected by the experimental diets (P<0.05). The results showed that there was a significant difference between the experimental diets in the average daily weight gain (ADG) up to day 21 of the experimental period (P<0.05). The results also showed that there was a significant difference between the different treatments in the feed conversion ratio corrected for initial weight (FCRC) up to 21 days of age (P<0.05). So that the lowest FCRC (0.863) was observed in treatment 2 (RM80, RV100) and the highest FCRC (1.128) was observed in treatment 3 (RM60, RV100). The results showed that the average daily weight gain (ADG) up to 35 days of age showed a statistically significant difference between the experimental diets (P<0.05). The highest (42.33 g) and lowest (36.66 g) ADG was observed in treatments 12 (BM100, RV80) and 5 (RM80, RV80), respectively. Also, the average daily feed intake (ADFI) up to 35 days of age was significantly different between the experimental diets (P<0.05). The highest (63 g) and lowest (51.66 g) ADFI up to 35 days of age were observed in treatments 9 (RM60, RV60) and 1 (RM100, RV100), respectively. In general, the results of this research work showed that the effects of using different levels of vitamins and trace minerals in the diet of broiler breeder hens on the performance of the offspring (progeny) up to 35 days of age are significant (P<0.05). The results also showed that in treatments whose diets of the broiler breeder hens had higher levels of vitamins and minerals, the titers of immunoglobulins M and T in the blood serum of their offspring were higher. According to the results, it seems that higher levels of vitamins and minerals in the diet of broiler breeder hens improve the influenza titer in the offspring. In other words, chicks that were hatched from parents that received high levels of minerals and vitamins in the diet showed a better response against influenza disease during the growth stage. The results also showed that the amount of iron in femur ash changed significantly in response to the experimental diets (P<0.05). Also, the amount of iron in femur ash showed a positive response in response to higher levels of iron in the diet. There was also a high correlation (0.87) between iron in the diet and iron in femur ash. Similarly, the highest (4847 mg/kg) and lowest (486 mg/kg) iron in femur ash were observed in treatments 1 (RM100, RV100) and 13 (BM80, BV80), respectively. Also, a strong and positive correlation (0.86) was observed between the content of zinc in the diet of broiler breeder and the amount of zinc in the progeny femur ash. However, among the experimental treatments, the highest (1692 mg/kg) and lowest (275 mg/kg) zinc content in femur ash was observed in treatments 1 (RM100, RV100) and 11 (BM80, BV100), respectively. These results indicate that the amount of elements in femur or tibia ash can be used, along with other parameters such as the amount of elements in the liver and feces, as an indicator of the status of mineral elements in poultry (El-Husseiny et al., 2012). The results also showed that the femoral cortical surface index had a significant relationship between the experimental groups (P<0.05), such that the highest (61%) and lowest (18%) cortical surface index were observed in treatment 2 (RM80, RV100) and 12 (BM100, BV80), respectively. The results also showed that the bone strength index was significantly different between the experimental treatments (P<0.05).
Conclusion
The results showed that based on FCRC up to 21 days of age, the best response in the progeny was observed in treatment 2 (RM80, RV100). However, based on FCRC in the entire experimental period, the best response in the progeny was observed in treatment 13 (BM80, BV80). Also, based on the amount of force required to break the femur, the best response was observed in treatment 7 (RM100, RV60). Similarly, based on the femur strength index, the best response (102) in the progeny was observed in treatment 2 (RM80, RV100). Also, based on Newcastle titer, the best response (7.67) in the progeny was observed in treatment 3 (RM60, RV100). Similarly, based on influenza titer, the best response (9) was observed in treatments 3 (RM60, RV100) and 4 (RM100, RV80). Similarly, based on the humoral immune response, the best response in the progeny was observed in treatment 3 (RM60, RV100). According the total results obtained from the present study, it can be concluded that different responses are obtained based on different parameters, so it seems that the immune response is a parameter that can cover all responses in a way. Therefore, based on the immune response, treatment 3 (RM60, RV100) is the optimal level of nutrition of vitamins and minerals in the diet of broiler breeders and is recommended as the best possible option for use in supplementation factories, considering economic calculations.
This article contains all the data that were created or evaluated during the research.
The authors would like to sincerely thank the members of the Faculty of Animal Sciences, University of Tabriz Research Council for the approval and support of this research.
The author declares no conflict of interest.
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