Endocrine correlates of female reproductive activity in the roan antelope (Hippotragus equinus)

Although ovarian endocrine activity has been described in most members of the tribe Hippotragini, little is known about the reproductive endocrine correlates of the roan antelope (Hippotragus equinus), an endangered antelope species of southern Africa. This study characterised the endocrine pattern of the reproductive activity (oestrous cycle, pregnancy and post-partum period) in the female roan antelope by monitoring faecal progestogen metabolite (fPM) concentrations and oestrogen metabolite (fEM) concentrations for cyclicity and observing reproductive behaviours. The study was carried out over the course of 12 months. At the beginning of this study, all 18 focal females (nulliparous, primiparous and multiparous) were monitored for cyclicity (for between 3 and 4 months). Following observed copulation, pregnancy in multiparous females (n = 10) was subsequently monitored until parturition and 21 days post-partum. Individual faecal samples were collected three times per week during the presumed period of cyclicity, twice per week during pregnancy and daily for 21 days post-partum. Mating births, courtship events, and copulations were recorded when observed. In eight of the 18 females monitored, the patterns of fPM and fEM concentrations indicated oestrous cycle lengths (n = 10) of approximately 30.8 ± 2.1 days. The determined lengths of luteal and follicular phases were approximately 15.8 ± 1.5 days and 14.6 ± 2.1 respectively. Pregnancy was marked by a pronounced increase in fPM concentrations until parturition, and lasted approximately 280.4 ± 4.8 days; whereas the intercalving period ranged between 306 and 380 days (n = 9; mean: 333.2 ± 7.4 days). Twenty-one day after parturition, 78% of the focal females (n = 5) did not show a resumption of the ovarian activity. This study demonstrated that monitoring faecal reproductive hormone metabolite patterns is a valuable approach for estimating ovarian activity in roan antelope and may be used to assist respective conservation breeding programmes by improving management practices.National Research Foundation, South Africa.https://zslpublications.onlinelibrary.wiley.com/journal/14697998hj2023Mammal Research InstituteZoology and Entomolog

Patterns of faecal glucocorticoid metabolite levels in captive roan antelope (Hippotragus equinus) in relation to reproductive status and season

DATA BASE : The data generated and subsequently analysed during this study are available on the repository of the University of Pretoria. The digital object identifier assigned to the data is https://doi.org/10.25403/UPresearchdata.14073662.Populations of roan antelope (Hippotragus equinus) in southern Africa have experienced a drastic decline over the past few decades and this situation has led to the development of intensive breeding programmes to support conservation efforts. However, little is known about related welfare aspects, including stress-related physiological biomarkers. The present study set out to establish a non-invasive method to monitor faecal glucocorticoid metabolite (fGCM) concentrations as a measure of stress and determine fGCM concentrations in relation to male reproductive activity and female reproductive status in the roan antelope. An adrenocorticotrophic hormone challenge was performed using two adult roan antelope (one male and one female) at Lapalala Wilderness Nature Reserve, South Africa, to determine the suitability of five enzyme immunoassays (EIA) for monitoring adrenocortical function in roan antelope. An 11-oxoaetiocholanolone I EIA detecting 11,17 dioxoandrostanes performed best showing 17–20 folds increases in fGCM concentrations after 12 h-17 h post-injection. The identified EIA was then used to monitor fGCM concentrations during active and non-active reproductive periods in males (n = 3), and during periods of cyclicity, gestation, and postpartum in females (n = 10). Males showed an overall 80% increase in fGCM concentrations when reproductively active and females showed a progressively significant increase in fGCM levels throughout pregnancy, with overall fGCM concentrations being 1.5 to 2.6-fold higher than the respective fGCM concentrations during periods of postpartum and cyclicity, respectively. Furthermore, fGCM concentrations remained above baseline for up to 21 days post-partum. A correlation between ecological parameters (rainfall and temperature) and fGCM concentrations revealed elevated fGCM concentrations during the dry season for males, but not females. The non-invasive method validated in this study provides a valuable tool to quantify stress-related biomarkers in roan antelope, and findings can be used to support management decisions in conservation breeding facilities.The National Research Foundation through the SARChI Chair for Mammal Behavioural Ecology and Physiology.https://www.elsevier.com/locate/ygcenhj2023Mammal Research InstituteZoology and Entomolog

Therapeutic effects of avocado (Persea americana Mill.) seed powder against reproductive toxicity induced by Mancozeb (herbicide) in female rabbits

DATA AVAILABILITY STATEMENT : The authors declare no competing interests.Pesticides like Mancozeb are being increasingly indispensable in the control of crop pests. Unfortunately, they have been implicated in genotoxicity due to their ubiquity, toxicological properties, persistence and presence in the food chain. This study sought to evaluate the efficacy of powdered avocado seed on reproductive parameters in the management of oxidative stress in female rabbits caused by the herbicide Mancozeb. Twenty-eight female rabbits aged 7–8 months and weighing between 2780.4 g and 3143.7 g were randomly divided into four groups of seven rabbits each. Each group received for 90 consecutive days distilled water or Mancozeb associated or not with avocado seed powder orally as follows: T1: 10 ml distilled water; T2, T3 and T4: 100 mg/kg bw Mancozeb. This was followed by oral administration of 250, 500, and 0 mg/kg of avocado seed powder for T2, T3, and T4, respectively. Water and feed were distributed ad libitum. Collected data concerned growth, carcass and reproductive performances, hematological and biochemistry characteristics. Results demonstrated that pregnant and lactating female rabbits administered Mancozeb exhibited a significant decrease (P < 0.05) in food intake, body weight, and body weight gain. Female rabbits exposed to Mancozeb had a decrease in litter size and weight from birth to weaning, as well as in weaning body weight and weight increase, fertility and prolificacy rate, milk yield, and daily milk efficiency. However, administration of avocado seed powder reversed (P < 0.05) the trends in these parameters in a dose-dependent manner. The increase in relative weight of the kidney and liver, concentrations of urea, creatinine, alanine and aspartate aminotransferases, mean cell volume, white blood cells, and lymphocytes were all associated with increased Mancozeb rates (P < 0.05). On the contrary, administration of the Mancozeb caused decrease in hemoglobin (Hb), Red blood Cell (RBC) and protein content. Administration of avocado seed powder significantly (P < 0.05) ameliorated the Mancozeb effects on these parameters. Applying 500 mg/kg b.w Avocado seed powder may be suggested as an alternative therapy for reproductive defects induced by Mancozeb in female rabbits.https://www.cell.com/heliyon/homeZoology and Entomolog

Thesis

The knowledge of the reproductive biology of the roan antelope (Hippotragus equinus) is crucial to improve management practices in conservation breeding programmes for this species. In this study, I studied the reproductive behaviours of male and female roan antelope in captivity and determined the respective endocrine correlates and the stress-related hormone patterns in both sexes. Fifteen pre-defined sexual behaviours are exhibited by males, with the precopulatory behaviours being prominent. In females, receptivity lasts up to 72 h and eight pre-defined oestrus-related sexual behaviours are usually exhibited, with homosexual mounts being observed prior to oestrus for the first time for this species, and in the tribe Hippotragini. In male roan antelope, faecal androgen metabolite (fAM) concentrations increased during the breeding periods and were low during the non-breeding periods. Breeding males showed a 73% increase in fAM concentrations during the breeding period compared to the non-breeding periods, and those were 85% higher when compared to the lactation/gestation periods. Results also revealed that fAM production in male roan antelope increase with reducing daylight duration but is not influenced by ecological seasons. These endocrine changes in males followed the same pattern as the frequencies of sexual behaviours observed. In females, faecal progestagen metabolite (fPM) and faecal oestrogen metabolite (fEM) analyses, revealed oestrous cycle length of between 16 to 37 days in multiparous females, 16 days in pluriparous females, and 37 days in nulliparous females, with the length of luteal and follicular phases of between 14.0 ± 0.7 days and 16.0 ± 2.4 days in multiparous females, 17.1 ± 1.1 and 16.8 ± 2.3 in nulliparous females and 9.0 days and 6.0 days for the nulliparous female. Results further showed that the length of gestation is approximately 280.4 ± 4.8 days and the longitudinal profile of fPM levels showed a significant increase from three months post-conception persisting until parturition. Findings of this study revealed that in female roan antelope, the resumption of the ovarian activity may occur between 16 to 62 days after parturition. Results demonstrated that a 11-oxoaeticholanolone I enzyme immunoassay (EIA) detecting 11,17 dioxoandrostanes is an adequate EIA to use when quantifying faecal glucocorticoids metabolite (fGCM) in the roan antelope. In males, fGCM concentrations increased by 80 % during active reproductive periods compared to respective concentrations for the non-active reproductive periods. In females, fGCM levels did not vary significantly between the phases of the oestrous cycle, however, a slight increase above baseline was noted prior to ovulation. During the gestation period, fGCM concentrations were significantly high compared to respective levels during the lactation and mating periods. Both males and females showed higher fGCM concentrations during the dry season compared to the wet season. However, fGCM concentrations were not correlated with rainfall and temperature. The detailed description of the reproductive behaviours and respective correlates along with the newly developed non-invasive methods for monitoring reproductive and stress-related hormones has provided new insights into the reproductive biology of the roan antelope which can be used to assist management decisions in breeding programmes for this iconic antelope.Thesis (PhD (Zoology))--University of Pretoria, 2021.DST-NRF SARChI chair for Mammal Behavioural Ecology and Physiology , Gun 46756Zoology and EntomologyPhD (Zoology)Unrestricte

Reproductive events and respective faecal androgen metabolite concentrations in captive male roan antelope (Hippotragus equinus)

Understanding the reproductive biology of the roan antelope (Hippotragus equinus) (É. Geoffroy Saint-Hilaire, 1803) is crucial to optimise breeding success in captive breeding programmes of this threatened species. In this study, the pattern of faecal androgen metabolite (fAM) production related to reproductive events (calving or birthing, mating, gestation, and lactation), sexual behaviours as well as environmental cues were studied in captive adult male roan antelope. Faecal sample collection and behavioural observations were carried out from August 2017 to July 2018 for three reproductive males participating in a conservation breeding programme at the Lapalala Wilderness Nature Reserve in South Africa. As a prerequisite, the enzyme immunoassay used in this study was biologically validated for the species by demonstrating a significant difference between fAM concentrations in non-breeding adults, breeding adults and juvenile males. Results revealed that in adults males, the overall mean fAM levels were 73% higher during the breeding period compared to the non-breeding periods, and 85% higher when exclusively compared to the lactation/gestation periods, but only 5.3% higher when compared to the birthing period. Simultaneously, fAM concentrations were lower during the wet season compared to the dry season, increasing with a reduction in photoperiod. With the exception of courtship, frequencies of sexual behaviours monitored changed in accordance with individual mean fAM concentrations in male roan antelope, the findings suggest that androgen production varies with the occurrence of mating activity and may be influenced by photoperiod but not with rainfall.S1 Dataset. fAM concentrations measured in all males according to weeks, ecological seasons and reproductive events.S2 Dataset. Monthly fAM, photoperiod, temperature and rainfall.S3 Dataset. Average fam, mounts, anogenital smelling, laufschlag, courtship circling per week for male 1 and male 2.A DST-NRF SARChI chair for Mammal Behavioural Ecology and Physiologyhttp://www.plosone.orgam2021Mammal Research InstituteZoology and Entomolog

Effects of coat color pattern and sex on physiological traits and heat tolerance of indigenous goats exposed to solar radiation

In this century, climate change is one of the major problems affecting livestock productivity. This study aimed at evaluating the effect of body coat color pattern and sex on heat regulation and heat stress tolerance in indigenous goat breeds exposed to solar radiation. In the experiment, 4 bucks and 4 does (8 to 9 months age) with black, white, grey and brown coat color were selected and exposed to solar radiation during 12 days during the summer period. Water and feed were served add libitum. The consumption were measured daily at 17:00 for each animal. Rectal temperature (RT) and rate pulse (PR) were measured three-time (7:00, 12:00, and 17:00) every day on each animal during the experimental period. At the end of the experiment, blood samples were collected from the jugular vein and immediately delivered to the lab to determine biochemical (serum protein: albumin and globulin), and hematological parameters. Exposing goats to temperature variation affected the physiological, hematological as well as biochemical parameters in all subjects. The female with a black body coat color was mostly affected. The heat stress induced an increase of RT and PR, an increase in water consumption while depression in food intake was observed. Blood platelets, hematocrits, red cell distribution, white blood cell and albumin were damaged in goats with black coat color compared to goats with white coat color. These variations in physiological, hematological and biochemical parameters in female black goat could affect its productive and reproductive performances in high-temperature environments.The Université Evangélique en Afriquehttps://www.jabbnet.comam2021Mammal Research InstituteZoology and Entomolog