Reproductive performance of goats treated with free gonadorelin or nanoconjugated gonadorelin at estrus.

The reproductive performance of goats that received a GnRH analog (gonadorelin) fabricated with or without chitosan-sodium tripolyphosphate (TPP) nanoparticles on the day of estrus (day 0) was evaluated. The chitosan-TPP polymer was conjugated with gonadorelin using an ionic gelation method. Thirty-three multiparous Zaraiebi goats were synchronized for estrus with 2 intramuscular (im) injections of 125 µg prostaglandin F2α 14 d apart. Goats showing signs of estrus were divided equally into 3 experimental groups and received a single im injection of 1 mL physiological saline (placebo; control), 50 µg/mL gonadorelin (GnRH), or 12.5 µg (quarter of GnRH dose)/mL chitosan-TPP-conjugated gonadorelin nanoparticles (NGnRH). Each goat underwent ultrasound imaging of their ovaries at day 0 and at day 10 after mating, and pregnancy was diagnosed 28 and 45 d after mating. The concentrations of estradiol (E2) and progesterone (P4) were determined at day 0 and at days 7, 14, 21, and 42 after mating. NGnRH size, polydispersity, and zeta potential were 93.91 nm, 0.302, and 11.6 mV, respectively. Chitosan-TPP nanoparticles showed 91.2% entrapment efficiency for GnRH. No differences in estrus rate, interval to estrus, or ovarian structure at day 0 were observed among the experimental groups, but the GnRH and NGnRH treatments significantly decreased the duration of estrus compared with the control. At day 10 after mating, both GnRH and NGnRH increased (P = 0.011) the number of corpora lutea compared with the control. Treatment with GnRH increased (P = 0.023) serum E2 concentrations from day 7 to 42 after mating compared with NGnRH and control treatments. The highest (P = 0.043) serum P4 concentration was observed in the GnRH group, followed by the NGnRH and control groups. The increase in serum P4 concentration started earlier a on day 7 in the GnRH group but later on day 14 in the NGnRH group. Compared with the control, GnRH resulted in a higher (P = 0.041) P4-to-E2 ratio, followed by NGnRH. Both gonadorelin treatments significantly increased the twinning rate, the number of embryos at days 28 and 42, and prolificacy and decreased pregnancy losses compared with the control. In conclusion, the administration of GnRH at the time of estrus improved the prolificacy of goats by increasing both the ovulation rate and the number of embryos. In addition, the nanoformulation developed in this study allowed a 75% reduction in the conventional dose of gonadorelin without affecting the fertility and prolificacy of goats, indicating the bioavailability of the reduced GnRH dose after conjugation with developed nanoformula.

Soybean isoflavone affects in rabbits: Effects on metabolism, antioxidant capacity, hormonal balance and reproductive performance.

Though soybean isoflavones (SBI) have pharmaceutical properties, the compounds also have endocrine disrupting activities that may adversely affect fertility of mammals. The effects of SBI on metabolism, antioxidant capacity, hormonal balance and reproductive performance of male rabbits were investigated. Adult male rabbits (n = 21) fed an isoflavone-free diet were orally treated with 0 (control; CON), 5 (small; LSBI) or 20 (large; HSBI) mg of SBI/kg body weight/day for 12 weeks. Both SBI doses resulted in lesser blood plasma total protein concentrations, while there were no effects on glucose and cholesterol concentrations compared to CON. The HSBI-treated males had the greatest (P < 0.05) blood plasma total antioxidant capacity and least malondialdehyde. Treatment with both SBI doses induced a 43% increase in triiodothyronine concentrations (P < 0.05) and 82% in reaction times (P < 0.001), while decreased sperm concentrations (P = 0.01) and blood plasma testosterone concentrations (P = 0.017) 26% and 19%, respectively. The total functional sperm fraction was less (P < 0.05) in the HSBI group; however, there was no effect of the LSBI treatment as compared to values for the CON group. The kindling rates of females mated to HSBI-treated males tended to be less (P = 0.081) than those of does mated with LSBI or CON males. In conclusion, only the HSBI treatment improved antioxidant status; whereas, treatment with both LSBI and HSBI doses induced a hormonal imbalance which led to an impaired testis function indicating the sensitivity of the adult male reproductive system to SBI actions.

Prolonged exposure of dietary phytoestrogens on semen characteristics and reproductive performance of rabbit bucks.

The effects of inclusion of different sources of dietary phytoestrogens on antioxidant capacity, hormonal balance, libido, semen quality, and fertility of rabbit bucks were studied. Twenty-one, adult, fertile, V-line bucks were randomly allocated into 3 homogenous groups (n = 7/treatment) and received control diet (phytoestrogens-free diet, CON) or soybean meal isoflavones-containing diet (SMI) or linseed meal lignans-containing diet (LML) for 12 wk. The diets were formulated to be isocaloric and isonitrogenous. The concentrations of isoflavones in the SMI diet were 24.04 mg/100 g dry matter (DM) daidzein and 13.10 mg/100 g DM genistein. The major phytoestrogen detected in the LML diet was secoisolariciresinol (36.80 mg/100 g DM). Treatment had no effects on body weight, feed intake and rectal temperature of bucks. Compared with control, bucks fed the SMI and LML diets had higher (P < 0.001) blood plasma total antioxidant capacity (0.98 ± 0.12, 1.50 ± 0.13, and 2.29 ± 0.17 mM/L for CON, SMI, and LML, respectively), and lower (P < 0.01) blood plasma malondialdehyde (2.76 ± 0.23, 1.76 ± 0.16, and 1.70 ± 0.18 nmol/mL for CON, SMI, and LML, respectively), whereas activities of reduced glutathione and superoxide dismutase (SOD) enzymes were not affected. Bucks fed the SMI and LML diets had greater (P < 0.001) concentrations of blood plasma triiodothyronine. Feeding the SMI and LML diets decreased (P < 0.01) libido (8.26 ± 0.71, 12.18 ± 0.97, and 14.12 ± 1.12 s for CON, SMI, and LML, respectively), sperm concentration (327.7 ± 21.6, 265.8 ± 36.8, and 226.5 ± 20.1 × 106/mL for CON, SMI, and LML, respectively), testosterone (5.16 ± 0.95, 3.91 ± 0.63, and 3.04 ± 0.92 ng/mL for CON, SMI, and LML, respectively), and seminal plasma fructose compared with the CON diet. The percentage of progressive motile sperm was improved (P < 0.001) by both phytoestrogen-containing diets. Feeding the SMI diet increased (P = 0.02) the percentage of live sperm compared with CON, whereas LML resulted in an intermediate value. Dietary treatment of bucks did not affect kindling rates or litter sizes of does, and did not affect birth weights or viabilities of kits. In conclusion, prolonged consumption of dietary isoflavones or lignans did not impair semen fertilizability. This may be due to the benefits of antioxidant activity or due to the benefits of other components in the diet. Dietary phytoestrogens did evoke obvious decreases in libido and steroidogenesis with altered semen parameters.

Effects of Trifolium alexandrinum phytoestrogens on oestrous behaviour, ovarian activity and reproductive performance of ewes during the non-breeding season.

Phytoestrogens are classified as naturally occurring endocrine disrupting chemicals that may affect reproductive performance of farm animals. To investigate the effects of Berseem clover phytoestrogens on reproductive performance of seasonal anoestrus ewes, twenty four late pregnant Rahmani ewes were fed either Berseem clover or maize silage (n = 12/treatment). Treatment started 2 months prepartum and continued until oestrous induction (week 8 postpartum), using the CIDR-eCG based protocol, and early pregnancy. Throughout the 2-8 weeks postpartum, oestrous rate and ovarian activity were not affected by treatment. After oestrous induction, ewes in both groups expressed comparable oestrous rates; however feeding Berseem clover extended (P < 0.05) interval to oestrus (57.00 compared with 42.54 h) and shortened (P < 0.05) oestrous duration (20.0 compared with 34.90 h). Feeding Berseem clover did not affect follicular activity except the number of medium follicles, which was less (P < 0.05) on day of oestrus (Day 0). Feeding maize silage increased (P < 0.05) the total number of follicles and number of small and medium follicles the day before oestrus (Day -1). On Day 0, the greater total number of follicles was due to the greater (P < 0.05) number of medium follicles that was associated with less number of small follicles. Although, the number and diameter of corpora lutea (CLs) were not affected by treatment, serum P4 concentration was greater (P < 0.05) for ewes fed maize silage than for those fed Berseem clover. Fecundity and litter size tended to be greater (about 35%; P = 0.132 and 0.085, respectively) in the maize silage fed ewes. In conclusion, feeding Berseem clover throughout seasonal anoestrus disrupted aspects of behavioural oestrus and there was less luteal P4 synthesis and fecundity of ewes.

Effects of a single administration of different gonadotropins on day 7 post-insemination on pregnancy outcomes of rabbit does.

This study aimed to investigate the effects of a single administration of one of three different gonadotropins on Day 7 post-insemination on ovarian activity, progesterone (P4) concentration and pregnancy outcomes of rabbit does. Multiparous, non-lactating, V-line does were artificially inseminated after synchronization and ovulation induction with equine chorionic gonadotropin (eCG; 25 IU im) and gonadotropin releasing hormone (GnRH; 0.8  µg buserelin im) 48 h later. On Day 7 post-inseminarion, does were randomly allocated into four groups (n = 40/group). Does of each group were intramuscularly injected with a single dose of one of physiological saline (placebo; control), GnRH (0.8  µg buserelin), human chorionic gonadotropin (hCG; 25 IU) or eCG (25 IU). Concentration of serum P4 was determined on Days 6, 9, 11 and 18 post-insemination. On Day 14 post-insemination, the ovaries and reproductive tracts of pregnant does were removed and weighed. Also, numbers of visible follicles, hemorrhagic follicles, corpora lutea of pregnancy (pCLs), new CLs (nCLs; formed after Day 7 post-insemination) and implantation sites were recorded. Conception rate, parturition rate, abortion rate, litter size/weight and litter viability were recorded. The highest (P < 0.05) reproductive tract and ovary weights were for eCG. The highest (P < 0.05) number of visible ovarian follicles was for eCG, whereas the lowest (P < 0.05) was for GnRH. Treatment with eCG increased (P < 0.05) numbers of pCLs and total implantation sites compared to the other groups. Treatment with GnRH or hCG increased (P < 0.05) number of nCLs compared to control and eCG. The highest rate of fetal loss was in does treated with GnRH. The concentration of serum P4 decreased (P < 0.05) following the treatment with GnRH and continued low until Day 18. However, it remained in line for control, hCG and eCG groups up to Day 11, then decreased (P < 0.05) for control and hCG on Day 18, being lower for hCG than control, while continued to increase for eCG up to Day 18. Compared to control, treatment with eCG improved (P < 0.05) conception and parturition rates by 24 and 22%; respectively, while GnRH and hCG treatments decreased (P < 0.05) them by 57 and 47.6%; respectively. Litter size and litter weight at birth were improved by eCG, but were adversely affectd by GnRH and hCG. In conclusion, a single administration of eCG 7 Days post-insemination could be recommended for improving pregnancy outcomes in rabbits.

Genetic screening of FecB, FecXG and FecXI mutations and their linkage with litter size in Barki and Rahmani sheep breeds.

Characterization of fecundity genes offers the opportunity to improve production efficiency, and the consequent increase in litter size in livestock industry, through utilizing them in breeding programs. The main objective of this study was to detect the BMPR-IB, BMP15 and GDF9 gene mutations and to investigate whether these mutations are associated with litter size in Egyptian sheep breeds. To achieve this goal, 73 adult ewes representing Barki (n = 33) and Rahmani (n = 40) breeds were used. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) screening approach was used to detect the presence of FecB, FecXG and FecXI mutations in the two selected breeds. Results of this study showed that the three different candidate gene mutations, namely FecB, FecXG and FecXI are not present among these selected populations of the Egyptian breeds. Further studies regarding other mutations and/or other genes, which may influence ovulation rate, should be carried out to determine the type and mode of inheritance of such genes in Egyptian sheep breeds.

Physiological response and semen quality of rabbit bucks supplemented with Moringa leaves ethanolic extract during summer season.

Exposure of rabbit bucks to summer heat stress reduces their homeostasis and semen quality leading to a temporal subfertility. The potentiality of ethanolic extract of Moringa oleifera leaves (M. oleifera ethanolic extract (MLEE)) to reduce negative impacts of heat stress on physiological and semen quality traits was investigated. A total of 28 adult V-line rabbit bucks were randomly distributed among four experimental groups of seven rabbits each. The first group received water (placebo) and served as a control (M0). The other three groups were given orally MLEE at levels of 50 (M50), 100 (M100) and 150 (M150) mg/kg BW every other day for 12 consecutive weeks during the summer season. Chemical constituents of MLEE were detected by gas chromatography/MS. During the experimental period, ambient temperature and relative humidity were recorded daily and were used to estimate temperature and humidity index. Feed intake, BW, rectal temperature were recorded and blood serum biochemical attributes were determined. Semen samples were collected weekly and were analyzed for semen quality traits. Results showed that MLEE contained high percentages of long-chain fatty acids and antioxidant agents. Feed intake and BW were not affected significantly by the treatment, however rectal temperature was decreased significantly by 0.42°C, 0.24°C and 0.40°C in the M50, M100 and M150 groups, respectively, compared with the M0 group. Treatment with 50 mg/kg BW increased concentration of serum albumin (115%; P<0.05), total antioxidant capacity (132%; P<0.05) and testosterone (160%; P=0.098) as well as seminal plasma initial fructose (127%; P=0.092) compared with the control group. Compared with the control, MLEE supplementation with 50, 100 and 150 mg/kg BW increased significantly sperm concentration by 118%, 151% and 158%, sperm progressive motility by 117%, 120% and 118%, sperm viability by 129%, 137% and 127%, sperm normal morphology by 114%, 113% and 114%, intact acrosome sperm by 109% (on average) and sperm with integrated cell membrane by 109%, 123% and 114%, respectively. In conclusion, MLEE supplementation at a level of 50 mg/kg BW could be effectively used to improve heat tolerance, oxidative status and semen quality of rabbit bucks during summer season.

Evaluation of the Effects of Cypermethrin on Female Reproductive Function by Using Rabbit Model and of the Protective Role of Chinese Propolis.

The prophylactic effects of Chinese propolis against cypermethrin toxicity were evaluated by performing ovary and uterus histopathology, as well as by characterizing ovarian function, embryos, and litters. Cypermethrin induced atypia in the ovary and uterus, and decreased the ovulation sites and the number of embryos. Cypermethrin-induced oxidative stress during pregnancy, decreased the parturition rate as well as the number and weight of offspring and increased the incidence of morphological malformations in the offspring. Administration of propolis to cypermethrin-treated animals mitigated cypermethrin-induced reproductive toxicity.

Hormonal concentrations and reproductive performance of Holstein heifers fed Trifolium alexandrinum as a phytoestrogenic roughage.

Effects of phytoestrogen isoflavones in Berseem clover on hormonal balance during early pregnancy and fertility of heifers were studied. Holstein heifers (n=26) were divided into two equal homogenous groups. Heifers in the first group (Clover-fed group) were fed Egyptian clover (Trifolium alexandrinum) as oestrogenic roughage; whereas the heifers in the second group (Silage-fed group) were fed maize silage. Concentrations of four isoflavone aglycones (genistein. Daidzein, biochanin A and formononetein) were determined in the two roughages. Treatment lasted for 20 consecutive weeks (5 months) during which blood samples were collected biweekly for determining the metabolic profile of heifers. Heifers were subjected to oestrous synchronisation using a double prostaglandin F2α (PGF2α) based protocol, 14days apart (week 10 and 12), and were artificially inseminated 12h following detection of overt signs of oestrus. Concentrations of serum oestradiol (E2) and progesterone (P4) on the day of insemination (Day 0) and on Days 7, 14 and 21 post-insemination (early pregnancy) were determined and P4 to E2 ratio was calculated. Clover had greater total isoflavone content than maize silage. The dominant isoflavone detected in Berseem clover was biochanin A, whereas the least was formononetein. Metabolic profile was not affected (P>0.05) by the type of roughage and was in the same trend in both experimental groups. The overall mean concentration of serum E2 was greater (P<0.05) in the clover-fed group than in the silage-fed group. The overall mean concentration of serum P4 was less (P<0.05) in the clover-fed group than in the silage-fed group. During the period of early pregnancy (from Day 7-21 post-insemination) the concentration of serum P4 increased in the silage-fed group, however, no change was observed in the clover-fed group. The overall mean of P4 to E2 ratio was greater (P<0.001) in the silage-fed group compared with that in the clover-fed group. Heifers fed clover had a lesser (P=0.054) conception rate and a greater (P=0.062) percentage of heifers returning to oestrus than silage-fed heifers. In conclusion, isoflavones in Berseem clover apparently disturbed hormonal balance during early pregnancy leading to a reduction in the fertility of heifers.

Effect of GnRH treatment on ovarian activity and reproductive performance of low-prolific Rahmani ewes.

This study was designed to evaluate the effect of GnRH treatment during different times of the reproductive cycle on ovarian activity, progesterone (P4) concentration, and subsequent fertility of low-prolific, subtropical, Rahmani ewes during breeding season. Forty-five ewes were synchronized for estrus using a double injection of 0.5 mL of PGF2α agonist (125-µg cloprostenol), 11 days apart. Ewes showing estrus (Day 0) were treated with 1 mL of GnRH agonist (4-µg buserelin) on the day of estrus (GnRH0, n = 12) or 7 days post-mating (GnRH7, n = 10) or on both days (GnRH0+7, n = 11) or not (control, n = 12). Ovarian response to the treatment and diagnosis of pregnancy were ultrasonographically monitored. Also, serum P4 concentration was determined weekly throughout 28 days post-mating. Results showed that neither total number of follicles nor their populations were changed on Day 0 or 7 days post-mating by the GnRH treatment. GnRH treatment on Day 0 or Day 7 post-mating or both days did not enhance ovulation rate compared with the control. The mean numbers of accessory CL increased (P < 0.05) in the GnRH7 group than those in the control and GnRH0 groups, whereas it was intermediate in the GnRH0+7 group. The greatest (P < 0.05) overall mean of serum P4 concentration was for the GnRH7 and GnRH0+7 groups, followed by the GnRH0 and control groups. Serum P4 concentration increased (P < 0.05) on Day 14 post-mating and continued higher (P < 0.05) until Day 28 post-mating in the GnRH7 and GnRH0+7 groups compared with the control. Regardless of the time of GnRH administration, GnRH treatment reduced (P < 0.05) pregnancy loss from Day 40 post-mating to parturition and tended to enhance (P < 0.20) lambing rate compared with the control. In conclusion, a single dose of GnRH at the time of estrus or 7 days post-mating could be used as an effective protocol to decrease pregnancy loss from Day 40 after mating to parturition in low-prolific Rahmani ewes.

Effect of short-term supplementation with rumen-protected fat during the late luteal phase on reproduction and metabolism of ewes.

This study was designed to study the effect of short-term supplementation with rumen-protected fat during the late luteal phase on reproduction and metabolism of sheep during breeding season. Seventy-six ewes (Rahmani, Barki and Awassi × Barki) were allocated to two groups considering genotype: the control ewes (C-group) received a maintenance diet, and the fat-supplemented ewes (F-group) received the maintenance diet plus 50 g/head/day of rumen- protected fat (Megalac) for 9 days during which oestrus was synchronized. The latter had been accomplished using double intramuscular injection of prostaglandin F2α (PGF2α ) 11 days apart. Ovarian activity, serum concentration of cholesterol, glucose, insulin and reproductive performance variables were recorded. Data were analysed considering treatment (group) and genotype. Supplementation had positive effects on the overall mean serum concentrations of cholesterol (p < 0.05), glucose (p < 0.05) on day 6 of nutritional treatment and insulin (p = 0.07) on day 8. Fat supplementation did not affect the total number of follicles, follicle populations and ovulation rate. However, fat-supplemented Rahmani ewes tended to have higher ovulation rate compared with other breeds (treatment × breed interaction, p = 0.06). Treatment also did not affect the mean concentration of serum estradiol or progesterone. Supplemented ewes had higher conception (p = 0.06) and lambing rates (p < 0.05) compared with control. In conclusion, short-term supplementation with rumen-protected fat as a source of energy around breeding time improved metabolism, conception and lambing rates of ewes without effects on steroidogenic capacity and ovarian activity being apparent.

Effect of season, month of parturition and lactation on estrus behavior and ovarian activity in Barki x Rahmani crossbred ewes under subtropical conditions.

The correlations between some meteorological parameters and fertility data were evaluated in Barki x Rahmani crossbred ewes using the records of five consecutive years (2003-2007). Additionally, estrus detection and ultrasonic evaluation were applied on eighteen mature dry ewes during breeding and non-breeding seasons. The effect of lactation was evaluated by monitoring estrus behavior in ninety four lactating ewes from 40 to 120 d after parturition. Moreover, ultrasonography was used to identify ovarian activity in six cyclic and six acyclic non-lactating ewes. Results revealed that relative estrus occurrence and fertile mating were positively correlated (P <0.05) with high temperature and long photoperiod (conditions of summer season), and were negatively correlated (P < 0.01) with rainfall (condition of winter season). During breeding season, estrus rate, serum progesterone concentration, and diameter of largest follicle were significantly (P < 0.05) higher than those observed during the non-breeding season. Furthermore, month of parturition had a significant effect (P < 0.05) on estrus rate of lactating ewes where ewes that lambed in August, September, and October recorded higher estrus rate than those lambed in November and December. However, the lactational strength did not exert any deleterious effect on the reproductive performance of lactating ewes. In conclusion, in Egypt under subtropical conditions, Barki x Rahmani crossbred ewes exerted optimum estrus behavior and fertile mating during summer season. The reduction in estrus activity during lactation was due to the seasonal effect rather than lactational stress.