Effect of breeding season and pregnancy status on serum progesterone, sodium, potassium, copper and iron of estrous synchronized Aradi goat does

Eighteen out of 88 estrous synchronized Aradi goat does were randomly chosen to be bled during May–July (Out breeding season, n= 9) and during September–December (Within breeding season, n =9). Estrous synchronization was applied by using a control internal drug release (CIDR) as a reproductive management regimen throughout the year. Nineteen days after CIDR insertion, a 500 IU eCG was injected (i.m.) and CIDR was removed. Does were subjected to fertile bucks 48-60 h after CIDR removal. Jugular blood samples were collected in non-heparinized Vacutainer tubes at 0 h just before CIDR insertion, every 3 days during CIDR insert, at day of CIDR removal, at incidence of estrus and mating, at day 1, 8 and 30 post mating. Data on pregnancy were recorded and serum levels of progesterone (P), sodium (Na), potassium (K), copper (Cu) and iron (Fe) were determined. Progesterone concentration was higher (p 0.05) within (2.85 ±0.15 ng/ml) than outside (2.37± 0.13 ng/ml) the breeding season. Pregnant does exhibited higher (p 0.05) levels of progesterone (2.76± 0.17 ng/ml) than non-pregnant does (2.37 ± 0.10 ng/ml). No significant interaction was found between season and pregnancy status on progesterone concentration. A typical progesterone profile was found during treatment days, as levels of P increased during CIDR insertion and declined at CIDR removal and thereafter. Neither breeding season nor pregnancy status affected Na^+ concentration. Contrariwise, mean levels of K^+ was higher (p 0.05) outside (148.34±3.91 mg/L) than within (136.27 ± 3.91 mg/L) the breeding season. Pregnancy status did not influence K concentration. Sodium/potassium (Na^+/K^+) ratio was significantly (p 0.01) higher within (30.29 ±0.44) than outside (27.62 ± 0.44) the breeding season. On the contrary, pregnancy status did not affect this ratio. Iron concentrations neither affected by season nor pregnancy. Likewise, Cu concentrations were not affected by season, however Cu levels were higher (p 0.05) in pregnant (147.75 ± 7.24 μg/L) than in non-pregnant (127.31 ± 5.03 μg/L) does.