## 3 Results
The development stages of embryos recovered 48 h post-insemination from does in groups C, HM, and QM were morula and early blastocyst stages. In contrast, \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Variables**} & \multicolumn{5}{c}{**Groups (\(n\) = 4 Does/Group)**} & \multirow{2}{*}{\(p\)**-Value**} \\ \cline{2-2} \cline{5-6}  & **C** & **HM** & **QM** & **HV** & **QV** \\ \hline \multicolumn{6}{c}{Ovarian structure (mean \(\pm\) S.E.M.)} \\ \hline Total ovarian & \(15.5\pm 1.0^{\circ}\) & \(33.0\pm 3.6^{\circ}\) & \(36.5\pm 0.9^{\circ}\) & \(40.2\pm 0.2^{\circ}\) & \(36.5\pm 2.0^{\circ}\) & 0.0001 \\ follicles & \(6.3\pm 0.9^{\circ}\) & \(9.3\pm 1.2^{\circ}\) & \(6.0\pm 1.2^{\circ}\) & \(8.8\pm 1.2^{\circ}\) & \(0.00\pm 0.00^{\circ}\) & 0.001 \\ Total embryos & \(4.0\pm 0.2^{\circ}\) & \(6.2\pm 0.9^{\circ}\) & \(5.2\pm 1.4^{\circ}\) & \(8.0\pm 0.9^{\circ}\) & \(0.00\pm 0.00^{\circ}\) & 0.001 \\ Non-fertil ox & \(0.25\pm 0.3\) & \(0.00\pm 0.0\) & \(0.00\pm 0.0\) & \(0.00\pm 0.0\) & \(0.00\pm 0.00\) & 0.438 \\ \multicolumn{6}{c}{Empy developmental stages (\%)} \\ \multicolumn{6}{c}{Morula} & \(50^{\circ}\)(8/16) & \(48^{\circ}\)(12/25) & \(76.2^{\circ}\)(16/21) & \(25^{\circ}\)(8/32) & - & 0.004 \\ Early blastocyst & \(254\)(16) & \(401\)(0/25) & \(23.85\)(2/51) & \(5016\)(32) & - & 0.175 \\ Blastocyst & \(00\)(16) & \(123\)(25) & \(00\)(21) & \(00\)(3/2) & - & 0.361 \\ Expanded & \(0^{\circ}\)(0/16) & \(0^{\circ}\)(0/16) & \(0^{\circ}\)(0/21) & \(156.4^{\circ}\)(5/32) & - & 0.009 \\ Blastocyst & \(0^{\circ}\)(0/16) & \(0^{\circ}\)(0/16) & \(0^{\circ}\)(0/21) & \(9.4^{\circ}\)(5/32) & - & 0.004 \\ Flatching & \(0^{\circ}\)(0/16) & \(0^{\circ}\)(0/16) & \(0^{\circ}\)(0/21) & \(9.4^{\circ}\)(5/32) & - & 0.044 \\ blastocyst & & & & & & \\ \hline \hline \end{tabular}  
* b, c Within rows, means with different superscripts differ at \(p\) < 0.05.  
\end{table} 
Table 2: Ovarian structure and developmental stages of embryos collected 48 h post-insemination from rabbit does that received two intramuscular doses (HM = 0.4 ug and QM = 0.2 ug) or two intravascular doses (HV = 4 ug and QV = 2 ug) of GnRH-ChNPs compared to control rabbit does that received bare GnRH (0.8 ug). Figure 6: Changes over time in mean (\(\pm\)S.E.M.) serum LH concentrations in rabbit does receiving two i.m. doses (HM = 0.4 ug and QM = 0.2 ug) or two intravascular doses (HV = 4 ug and QV = 2 ug) of GnRH–ChNPs or bare GnRH (C = 0.8 ug). Overall values are included below the figure. P(Tr) accounts for treatment effects, P(Tm) for time effects, and P(Tr \(\times\) Tm) for their interactions. Different uppercase and lowercase superscript letters denote significant differences (\(p\) < 0.05) between or within treatments, respectively. embryo development was advanced in group HV since 15.6 and 9.4% of the embryos were expanded blastocyst and hatching blastocyst, respectively. In Vivo Assessment of Fertility and Productive Traits in Does Treated with GnRH-Loaded Nanoparticles  
The assessment in groups C, HM, and HV of the serum progesterone and estradiol concentrations (P\({}_{4}\) and E\({}_{2}\), respectively) at 10, 17, and 24 days of pregnancy (Figure 7) showed higher P\({}_{4}\) concentrations in group HM than in group HV (\(p<0.05\)), with intermediate values in group C. The interaction of treatment-by-time showed no differences among groups at day 10 but, from days 17 to 24, P\({}_{4}\) concentrations decreased in group HV and increased in group HM (\(p<0.05\)). The E\({}_{2}\) concentrations were also affected by a treatment-by-time interaction (\(p<0.05\)). There were no effects on days 10 and 17, but the E\({}_{2}\) concentrations at day 24 were higher in group HM than in groups HV and C (\(p<0.05\)). In fact, there were no changes over time in these groups whilst E\({}_{2}\) concentrations increased in group HM at day 24 (\(p<0.05\)).