Abstract
Simple SummaryEgg production is one of the most vital axes in the poultry industry. During the late laying period, the egg production continuously decreases, and pauses among the sequence of egg laying increases; however, the feed costs remain constant. Several attempts were carried out to improve the reproductive performance of laying hens by decreasing the prolactin level in the blood; an increase in this hormone initiates the onset of incubation behavior in chickens. In this study, we investigated the potential use of nano-bromocriptine to the improve egg production performance in laying hens. The use of alginate-bromocriptine leads to a significant reduction in the prolactin expression in the pituitary gland, which in turn allows the elongation in sequences and reduction in pauses, as well as the feed per dozen egg in laying hens. Further studies are needed to assess the impacts of nano-bromocriptine on other performance parameters. Thus, the improvement of egg production persistency must also go hand in hand with sustainable egg quality and the maintenance of the birds’ health.The current study aimed to investigate the potential use of nano-bromocriptine in improving the laying performance of late laying hens by modulating the prolactin gene expression. A total of 150 NOVOgen brown laying hens aged 70 weeks were randomly allocated into three groups of 50 birds each. The first group was kept as a control, while the second and the third groups were treated with bromocriptine and nano-bromocriptine, respectively, at a dose of 100 µg/kg body weight per week. The pause days, egg production, feed per dozen egg, and Haugh unit were determined on a monthly basis. Also, the relative prolactin gene expression in the pituitary gland was quantified using qPCR and the number of the ovarian follicles was determined after slaughtering at the 84th week of age. It was found that nano-bromocriptine and bromocriptine improved egg laying performance with minimal pause days, reduced feed per dozen egg, and depressed the relative prolactin gene expression; however, nano-bromocriptine treatment was significantly effective compared to bromocriptine. In conclusion, nano-bromocriptine might be beneficial for elongating sequences and reducing pauses.
Highlights
The global table eggs production has increased over the past decade to 76.7 million tonnes in 2018 [1], further improvement of egg production performance is urgently needed to fulfill the high demand for animal proteins
The Fourier Transform Infrared Spectrophotometer (FTIR) spectroscopy pattern of the alginate-bromocriptine nanocomposite revealed a band at 700 cm−1, corresponding to -CH bending; this confirms a bond formation between alginate and bromocriptine (Figure 1)
There is a huge demand for animal protein supply that could be covered with eggs [23]
Summary
The global table eggs production has increased over the past decade to 76.7 million tonnes in 2018 [1], further improvement of egg production performance is urgently needed to fulfill the high demand for animal proteins. The extreme efforts which have been done to keep the persistency of egg production, a reduction in egg production accompanied by a deterioration of egg quality are usually common at or around 72 weeks of age [2] During this period, the egg production continuously decreased and pauses among the sequence of egg laying increased with constant feed costs, causing huge economic losses. Prolactin belongs to adenohypophysis hormones, is one of the most blamed factors accompanied by a progressive reduction of egg laying performance during the late laying period. This hormone is progressively increased by the time in plasma of late laying hens. Subcutaneous injection of bromocriptine in laying hens during the 17th to 36th week of life increases the egg production and depresses the prolactin production during the laying cycle up to the 72nd week of age [3]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
