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Age negatively affects reproductive success of broiler breeder flocks. One of the main hormones involved in the change of fertility with the age is testosterone (TT). The introduction of young males at later production stages of broiler flocks is known as spiking and is expected to reduce the fertility decline with age. The aim of this study was to determine the effect of injection of different levels of TT and the effect of spiking on reproductive fitness of broiler breeder flocks. Two experiments were conducted on Ross 308 breeder flocks for 10 weeks (41–50 weeks of age). The experiment 1 included a control and three treatments corresponding to three doses of TT (0.1, 0.2 and 0.3 cc), while the experiment 2 included a control and one treatment corresponding to spiking. The lower dose of TT (0.1 cc) and the spiking clearly slowed down the decline in hatchability. Therefore, either the external administration of TT to the males when the natural concentration of TT starts to decline or spiking the breeder flock with young roosters could contribute to improve reproductive success in later stages of the production cycle in broiler breeder flocks.  相似文献   
2.
This experiment was conducted to evaluate the effects of different levels of sweet orange (Citrus sinensis) peel extract (SOPE) on humoral immune system responses in broiler chickens. Three hundred 1‐day broilers (Ross‐308) were randomly allocated to treatments varying in supplemental SOPE added in the drinking water. The experimental groups consisted of three treatments fed for 42 days as follows: a control treatment without feed extract, a treatment containing 1000 ppm of SOPE and a treatment containing 1250 ppm of SOPE. All treatments were isocaloric and isonitrogenous. Broilers were vaccinated with Newcastle disease virus (NDV), avian influenza (AI), infectious bursal disease (IBD) and infectious bronchitis virus (IBV) vaccines. Antibody titer response to sheep red blood cells (SRBC) was higher in the group fed 1250 ppm of SOPE (P < 0.05) as well as for immunoglobulin G (IgG) and IgM. Similarly, antibody titer responses to all vaccines were constantly elevated (P < 0.05) by SOPE enrichment in a dose‐dependent manner. Relative weights of spleen and bursa of Fabricius were unaffected by treatments. Dietary SOPE supplementation may improve the immune response and diseases resistance, indicating that it can constitute a useful additive in broiler feeding. Thus, supplying SOPE in rations may help to improve relative immune response in broiler chickens.  相似文献   
3.
L‐ascorbyl‐2‐monophosphate‐Na/Ca (AMP‐Na/Ca) was used as a vitamin C source to investigate its ascorbic acid (L‐AA) enrichment and retention in boosted Artemia biomass (AB) and squid mantle muscle (SM). Different doses of AMP‐Na/Ca (500, 1000, and 1500 AMP‐Na/Ca mg/kg) were gradually dissolved into the culture tanks at time 0 (T0) and at each hour until Hour 6 (T6). Samples of AB and SM were taken for AMP‐Na/Ca and L‐AA analysis at T0, T1, T2, T3, T4, T5, T6, T12, and T24. There were no significant differences (P > 0.05) among the AB groups at T1. The T6 enrichment analysis for AB resulted in significant differences (P < 0.05) in the AMP‐Na/Ca content for the 1500 mg/kg treatment, in which the initial concentration (0.001 ± 0.002 mg/kg) increased by more than 16‐fold. For all AB enrichment treatments, the AMP‐Na/Ca content demonstrated a decrease (32–11%) for the T6, T12 and T24 analysis. The T1 analysis for SM at the higher AMP‐Na/Ca enrichment concentration registered 30 mg/kg of L‐AA and decreased (27.6%) at T6. This study demonstrated that AB and SM can be boosted with AMP‐Na/Ca.  相似文献   
4.
Tropical Animal Health and Production - The aim of this study was to evaluate the effect of different dietary energy and protein supplements on performance, weekly body sizes or body frame size,...  相似文献   
5.
The effects of three climates (hot and dry, mild and humid and Alpine) and three flock densities (<100, 100–300 and >300 m2) on ostrich reproductive and productive traits were studied. Data were compared with the benchmark target sets by the World Ostrich Association (Ostrich benchmark Performance Targets. Version 2, May, 2008) for reproductive qualifications of ostrich. No significant difference was observed on egg production, weight, fertility, hatchability and day‐old chicks weight among the three climate conditions; however, the Alpine climate had a lower performance trend. Mild and humid climates had a significant effect of age at sexual maturity for both males and females as well as on the duration of egg production season. Stocking density did not show significant difference on egg production, hatchability, age of male and female at sexual maturity and on duration of egg production season, while an area >300 m2 showed a reduction in egg weight and day‐old chick weight. Further, an area <100 m2 led to a weaker ostrich fertility rate. Results showed that the ostrich would have a better performance under hot and dry and mild and humid climates as compared to Alpine climate with a stocking density of 100–300 m2 area per breeder bird. Thus, climatic intervention strategies at Alpine regions may be carried out for maintaining optimal reproductive qualification of ostrich so as to improve the productivity in this sector.  相似文献   
6.

The pivotal aim of the present context was to determine the effect of probiotic (superzist) and medicinal plants (R. coriaria, H. persicum, and M. piperita) powder on growth performance, carcass characteristics, blood parameters, immunity response, and microflora counts of broilers over a 42-day feeding period. One hundred and fifty one-day-old chickens were randomly allocated to the following five treatments: (1) Control diets; (2) control diets?+?0.03% w/v superzist; (3) control diets?+?0.5% w/v R. coriaria; (4) control diets?+?0.5% w/v H. persicum; and (5) control diets?+?0.5% w/v M. piperita. No significant differences among treatments on broiler performance during 29th to 35th days of age, whereas a gradual reduction (P?<?0.05) in the feed efficiency and economic index values between 36th to 42nd days of age, across the treatments versus control diet. Supplementations were increased (P?<?0.05), the colon weight, colon length, and right cecum weight versus control. However, the superzist and phytogenic supplementation slightly increased the jejunum length, ileum length, and left cecum length. The supplementation showed reduced heterophils, increased lymphocytes and monocytes percentage, and decreased heterophils/lymphocytes ratio. Additions of superzist and medicinal plants reduced (P?<?0.05) the total counts of E. coli and improved (P?<?0.05) the cecal lactobacilli. In conclusion, under the appropriate conditions of this investigation, the superzist and tested medicinal plants could undoubtedly be ideal alternatives to the use of existing antibiotics as growth promoters in poultry industry.

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7.
Tropical Animal Health and Production - This study investigated the effect of different levels and consumption periods of Aspergillus oryzae meal on performance, carcass characteristics, blood...  相似文献   
8.
Routine use of the antibiotic flavomycin in broiler production may lead to resistance, and alternative growth promoters are used to enhance performance. Two hundred day-old male Ross 308 broiler chicks were allocated to five dietary supplements included from d 1–42: flavomycin, three possible alternatives, a probiotic, prebiotic and a synbiotic, as well as a control treatment. There were four replicate cages of 10 birds each in each treatment. Compared with the control and antibiotics treatments, the probiotic, prebiotic and synbiotic treatments increased (p?=?0.001) weight gain (64, 66, 73, 70 and 74 g/d, respectively). The synbiotic treatment reduced (p?=?0.004) the feed conversion ratio, compared with the control and antibiotic treatments (1.70, 1.84, 1.83, respectively). Compared with the control and antibiotic treatments, the birds fed the synbiotic treatment had greater relative gizzard (+47%) and spleen weights (+115%), and lighter kidneys (?47%). The birds fed the symbiotic treatment also had thinner walls of the caudal gut segments. The prebiotic had the most beneficial effect on cecal microbiota, stimulating aerobic and lactic acid producing bacteria and reducing Escherichia coli bacteria. Enterococci were increased in the antibiotic treatment. We conclude that there were significant performance and health benefits of using prebiotics, probiotics and synbiotics for broilers, rather than antibiotics.  相似文献   
9.
The present study is aimed to evaluate the effects of different levels of earthworm (EW) powder and vermihumus (VH) on the growth performance, humoral immunity response, plasma constituents and reproductive performance of Japanese breeder quails. A total of 336 birds were assigned to seven treatments in a completely randomized design from day 30 to 90 of age. The dietary treatments were carried out, one without any addition of EW and VH, the second had a standard rate of VH at 0.8%, while a range of EW additions was supplied from 0%, 0.5%, 1%, 1.5%, 2% and 2.5%. The effects of treatments on body weight and mortality were not significant (p > .05). The highest feed intake was observed in birds fed the diets supplemented with 1% and 1.5% EW (p < .05). The highest titre of antibodies against influenza virus and sheep red blood cells belonged to the EW and VH treatments (p < .05). The antibody titre against Newcastle disease virus vaccine was not affected by the treatments. In general, the birds receiving EW and VH had the highest egg weight, egg production and egg mass weight (p < .05). Nonetheless, various levels of EW powder negatively affected hatchability and increased mortality and leg disorders (p < .05). The results showed that the levels of dietary 1% and 1.5% of EW powder gave the best growth and reproductive performance to birds respectively.  相似文献   
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