Use of GnRH-Encapsulated Chitosan Nanoparticles as an Alternative to eCG for Induction of Estrus and Ovulation during Non-Breeding Season in Sheep

Abstract

This study is aimed at determining the reproductive performance of anestrous ewes treated with nanoencapsulated GnRH after a progesterone-based protocol for estrus induction was proposed as a way of replacing eCG. A total of sixty anestrous, multiparous, non-lactating Barki ewes were randomly allocated into three homogenous groups and subjected to a CIDR-based estrus induction protocol. The first group (eCG) received an intramuscular (i.m.) injection of 350 IU of eCG at CIDR removal. The second (LNGnRH) and third (HLNGnR) groups received either 25 µg or 50 µg of encapsulated GnRH nanoparticles by the i.m. route in the form of spherical GnRH-encapsulated chitosan–TPP nanoparticles (which were 490.8 nm and had a 13.6 mV positive charge) 48 h after CIDR removal. Follicular dynamics, estrous behavior, luteal activity, and pregnancy outcomes were evaluated. Three days after CIDR removal, the number of large follicles increased by similar amounts in the LNGnRH and eCG groups and were significantly higher in both groups than in the HNGnRH group. However, no differences were observed in the numbers and diameters of CLs among the experimental groups and, on the other hand, treatment with HNGnRH significantly increased blood serum progesterone levels compared with eCG and LNGnRH. Treatment with HNGnRH increased conception, lambing, and fecundity rates (p < 0.05), with the trend of a higher litter size (p = 0.081) compared with eCG, whereas LNGnRH resulted in intermediate values. In conclusion, a dose of 50 µg of GnRH encapsulated in chitosan-TPP nanoparticles can be used as an alternative to eCG in progesterone-based estrus induction protocols in sheep.

Use of Short-Term CIDR-Based Protocols for Oestrus Synchronisation in Goats at Tropical and Subtropical Latitudes

“…In response to this, a recent study in goats synchronised with the ovsynch protocol during the non-breeding season applied GnRH using the nano-delivery system ( Figure 3 ), which induced a tighter synchrony of ovulation and better luteal function [ 69 ]. The authors also compared nano-GnRH to eCG in a long-term CIDR-based oestrus synchronisation protocol in sheep and observed an increase in conception, lambing, and fecundity rates ( p < 0.05), when a high dosage of 50 µg was used [ 70 ]. In addition, a tendency of a higher litter size ( p = 0.081) compared with eCG was obtained.…”

“… Schematic representation of an ES protocol to compare 2 doses of nano-GnRH with eCG in a long-term CIDR-based protocol applied to anoestrus ewes. (Based on the study of Hashem et al 2023 [ 70 ]). …”

Application of Exogenous GnRH in Food Animal Production

“…Following a progesterone-based protocol for estrus induction, the reproductive performance of anestrous ewes receiving treatment with nanoencapsulated GnRH was evaluated as a potential alternative to eCG [ 131 ]. The authors developed a nano-GnRH formulation with distinct physicochemical features that yielded favorable outcomes on ovulation and luteal function in various animal species, including goats, sheep, and rabbits [ 132 , 133 ].…”

“…For instance, in Chios-breed ewes, the use of eCG for superovulation, and, to a lesser extent, for estrus synchronization, can impact glycosidase activity in the genital tract, potentially leading to adverse effects on embryo survival and pregnancy maintenance before the maternal recognition of pregnancy [ 134 ]. As a substitute for eCG, nanoencapsulated GnRH can be employed in progesterone (CIDR)-based estrus induction regimens for sheep [ 131 ].…”

An effective and sustainable dye removal via sunlight-based photocatalysis and adsorption using eco-friendly and low-cost ZnS nanoparticles: Experiments, modelling, and mechanism

“…Nanotechnology, also known as nanoscience, is based on the study of the preparation routes, application, and property characterization of different materials of nanometric dimensions. It is of great interest in several application elds, including electronics (Khan et al 2022), photocatalysis (Chakroborty et al 2023), biology (Hashem et al 2023) and medicine (Yusuf et al 2023), and is considered to be the origin of a fourth industrial revolution. During the last twenty years, the quantum dots, which are uorescent semiconductor nanoparticles, have been classi ed as promising materials because of their interesting electronic, optical and structural properties, which depend on their size and quantum con nement, size and surface-to-volume ratio (Li and He 2021).…”