Effect of combination vitamin E and single long-acting progesterone dose on enhancing pregnancy outcomes in the first two parities of young rabbit does

Effect of vitamin E, D-limonene, and their combination on nulliparous rabbit reproductive performance

Oxidative status is important in reproductive performance and using two natural antioxidants is more beneficial than one in nulliparous rabbits. The goal, effect of vitamin E (VitE), D-limonene (DL), and VitE+DL on maternal LBW (MLBW), conception (CR), pregnancy (PR), and kindling rates (KR), gestation length (GL), total litter size at birth (TLSB) and weaning (TLSW), live kits at birth (LKB) and weaning (LKW), dead kits at birth (DKB) and weaning (DKW), kits mortality rate at weaning (KMRW), Kit weight at birth (KWB) and weaning (KWW), total kit weight at birth (TKWB) and weaning (TKWW), and concentrations of progesterone (P4) and Malondialdehyde (MDA), during first two pregnancies. A total of 24 healthy female WNZ rabbits were randomly selected and assigned into four groups (6/each). Control (animals injected with 1.0 mL propylene glycol), VitE (60 mg IM injection/animal, 2X/week pre-mating and 3X post-mating until mid-pregnancy, DL (20 mg IM injection/animal, 2X/week pre-mating and 1X at mating, and VitE+DL (IM injection/animal with the same doses and times applied in VitE and DL groups. All animals were treated during 1st pregnancy only. The results confirmed that animals treated with VitE+DL gained significant maternal LBW in 1st pregnancy, reduced dead kit number at birth and kit mortality rate at weaning, increased live kits and total kit weight at birth and weaning in the two pregnancies, and also increased significantly kit weight at birth and weaning in the treatments than controls in the two pregnancies, and DL was greater in 1st pregnancy. Progesterone concentrations in mid-pregnancy rose significantly in VitE+DL during 1st pregnancy and DL in 2nd pregnancy. Malondialdehyde concentrations dropped significantly in VitE and VitE+DL in mid-pregnancy in the two pregnancies. Eventually, the integration of VitE and DL displayed their unique properties for improving productive and reproductive performance in nulliparous rabbits.

Effect of punicalagin and human chorionic gonadotropin on body weight and reproductive traits in maiden rabbit does

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Punicalagin as a potential antioxidant against free radicals in combination with human chorionic gonadotropin as an auxiliary factor in increasing progesterone levels from accessory corpus luteum enhance reproductive and pregnancy health in young does.

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Free radicals produced from reproductive processes may disturb oocyte and embryo growth.

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Injection of punicalagin (PL) alone or in combination with human chorionic gonadotropin (HCG) had significant impacts on maternal body weight (MBW), conception rate (CR), gestation length (GL), kindling rate (KR), total litter size (TLS), live litter size (LLS), kit weight (KW) and progesterone (P4) concentrations during 1st/2nd gestation periods.

Little is known about the effect of punicalagin extracted from pomegranate or in combination with human chorionic gonadotropin on enhancing the productive and reproductive performance in rabbits that gestate for the first time. The impact of punicalagin alone or in combination with human chorionic gonadotropin on maiden doe body weight, progesterone concentrations, conception rate, gestation rate, litter size, and kit weight was investigated in this study. A completely randomized and balanced experimental design was used to allocate 21 naturally mated maiden does at 6 months of age into the following three treatment groups of 7 does each: Control - intramuscular injection with sterilized water only; Treatment 1 - pre-mating intramuscular injection with punicalagin (100 µg/doe) twice a week and once 3 days post-mating; and Treatment 2 - pre-mating intramuscular injection with punicalagin twice a week and human chorionic gonadotropin (25 IU/doe) once 3 days post-mating. Progesterone was assayed from blood samples taken from the ear marginal vein at mating, post-mating, gestation, and post-kindling phases when all does were weighed. Results indicated significantly positive impacts of punicalagin alone or in combination with human chorionic gonadotropin on all doe reproductive traits, birth, and weaning weights of kits. The study clearly demonstrated an improvement in doe fertility, reproductive performance, and kit survival to weaning. In conclusion, PL and PL+HCG improved maternal body weights and their offspring as well as pregnancy outcomes of young rabbits particularly in the 2nd pregnancy, hence findings of this study could be recommended for improving reproductive health and fertility in maiden rabbit does.

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.