High Carbohydrate, Fat, and Protein Diets Have a Critical Role in Folliculogenesis and Oocyte Development in Rats

To date, there is no comparative data on the effects of carbohydrates, fat, and proteins, which are macronutrients, on female reproductive functions. Therefore, in this study, we investigated the effects of diets enriched with carbohydrates, fats, and proteins on folliculogenesis and oocyte development in female rats. 21-day-old rats that were just weaned were divided into 4 groups: control, carbohydrate, fat, and protein. The control group was fed with standard chow and the carbohydrate, fat, and protein groups were fed diets enriched with 75% carbohydrate, 60% fat, and 50% protein for 11 weeks, respectively. It was found that high-fat and high-protein diets caused an increase in the estrous cycle length compared to carbohydrate group (p < 0.05). Graafian follicle number decreased in the protein group compared to the control (p < 0.05). However, the atretic follicle number was higher in the fat group compared to the control group (p < 0.05). In the carbohydrate group, Zp1 was found to be lower than the control and protein groups, Zp2 was found to be lower than the control, and Zp3 was found to be lower than the fat group (p < 0.05). While BMP15 was similar between groups (p > 0.05), GDF9 was lower in all diet groups compared to the control (p < 0.05). Foxo3a was lower in the protein group compared to carbohydrate and control (p < 0.05). GAS2 was found to be higher in the control group than the fat group, and higher in the carbohydrate group than the fat and protein groups (p < 0.05). FSH, LH, Progesterone, and E2 levels were higher in all three diet groups than in the control (p < 0.05). Also, significant differences were observed between the groups regarding adiponectin, resistin, and leptin levels. Taken together, high carbohydrate, fat, and protein intake are associated with impairment of the menstrual cycle, depletion of the developing follicle types, and altered expression of folliculogenesis-specific genes and hormones. Therefore, long-term macronutrient diets may result in shortened reproductive periods and reduced fertilization potential in females in the long run.

The curse of the firstborn: Effects of dam primiparity on developmental programming in ruminant offspring

The first parity, or first pregnancy, of ruminant females has negative effects on offspring during fetal, perinatal, and pre-weaning periods which ultimately lead to diminished pre-weaning productivity. Offspring born to primiparous ruminant females can have decreased fetal and pre-weaning growth, resulting in lower body weights at birth and weaning in cattle, sheep, and goats. Moreover, mortality is greater during both neonatal and pre-weaning periods. Insults during these critical developmental windows likely also have long-term consequences on first-parity offspring through developmental programming, but less research has been done to investigate effects in the post-weaning period. Many potential physiological, metabolic, and behavioral mechanisms exist for the outcomes of dam primiparity. Although competition for nutrient partitioning between maternal and fetal growth or lactation is often cited as a major contributor, we hypothesize that the most important mechanism causing most first-parity outcomes is the relative physiological inexperience of reproductive tissues such as the uterus and mammary gland during the first pregnancy and lactation, or a "first use theory" of tissues. More research is necessary to explore these areas, as well as if primiparous dams respond differently to stressors than multiparous dams, and if stress during the first parity affects subsequent parities.

Weak coupling between energetic status and the timing of reproduction in an Arctic ungulate

Bioenergetic constraints are the ultimate determinant of the timing of reproduction, and seasonal breeding is consequently a widely observed trait. Consistent with this, attention has focused on plasticity in reproductive phenology conceptualized as a response to concomitant advances in the phenology of the environmental energy supply caused by climate change. Few studies, however, have directly compared timing of reproduction with energetic status in free-living wild animals. Here we demonstrate that neither body mass nor adiposity are strong proximate predictors of date of conception in wild reindeer (Rangifer tarandus). Weak coupling between energetic status and the phenology of reproduction accounts for the increasing discrepancy between the phenology of forage (energy supply) and the phenology of reproduction (energy demand) observed across the last 2-4 decades in two populations of this species. The results emphasise that phenological plasticity is not a passive response to changes in energy supply but derives from the way in which environmental factors interact with the core control mechanisms that govern timing. Central in this respect is integration, within the rheostatic centres of the hypothalamus, of information on nutritional status with the circannual life-history calendar.

Stress Factors and Their Effects on Productivity in Sheep

Products obtained from sheep have an economically important place in the world. Their adaptability to different climatic conditions, their ease of care and feeding, their high utilization of poor pasture areas with low yield and quality, the ease of flock management, their high twinning rate, and their short intergenerational period are some of the advantages of sheep production. Sheep production has the ability to adapt better to environmental stress factors, as can be understood from the presence of sheep in different geographical regions at a global level. However, the changes in environmental conditions and production cause some negative results in animals. All these negative results expose animals to various stress factors (heat, cold, transport, treatment, nutritional, shearing, weaning, etc.). All stress factors that directly and indirectly affect sheep production ultimately lead to compromised performance, decreased productivity, increased mortality, and adverse effects on the immune system. In order to cope with the current stress parameters in animals and to achieve optimum production, a holistic approach is needed according to the environmental conditions and available resources. It is important to consider the factors involved in these responses in order to manage these processes correctly and to develop adequate strategies and improve sheep welfare. This review aimed to reveal the importance of some stress factors in sheep and their effects on sheep productivity.

GnRH and the photoperiodic control of seasonal reproduction: Delegating the task to kisspeptin and RFRP-3

Synchronization of mammalian breeding activity to the annual change of photoperiod and environmental conditions is of the utmost importance for individual survival and species perpetuation. Subsequent to the early 1960s, when the central role of melatonin in this adaptive process was demonstrated, our comprehension of the mechanisms through which light regulates gonadal activity has increased considerably. The current model for the photoperiodic neuroendocrine system points to pivotal roles for the melatonin-sensitive pars tuberalis (PT) and its seasonally-regulated production of thyroid-stimulating hormone (TSH), as well as for TSH-sensitive hypothalamic tanycytes, radial glia-like cells located in the basal part of the third ventricle. Tanycytes respond to TSH through increased expression of thyroid hormone (TH) deiodinase 2 (Dio2), which leads to heightened production of intrahypothalamic triiodothyronine (T3) during longer days of spring and summer. There is strong evidence that this local, long-day driven, increase in T3 links melatonin input at the PT to gonadotropin-releasing hormone (GnRH) output, to align breeding with the seasons. The mechanism(s) through which T3 impinges upon GnRH remain(s) unclear. However, two distinct neuronal populations of the medio-basal hypothalamus, which express the (Arg)(Phe)-amide peptides kisspeptin and RFamide-related peptide-3, appear to be well-positioned to relay this seasonal T3 message towards GnRH neurons. Here, we summarize our current understanding of the cellular, molecular and neuroendocrine players, which keep track of photoperiod and ultimately govern GnRH output and seasonal breeding.

Genetic Variations and Differential DNA Methylation to Face Contrasted Climates in Small Ruminants: An Analysis on Traditionally-Managed Sheep and Goats

The way in which living organisms mobilize a combination of long-term adaptive mechanisms and short-term phenotypic plasticity to face environmental variations is still largely unknown. In the context of climate change, understanding the genetic and epigenetic bases for adaptation and plasticity is a major stake for preserving genomic resources and the resilience capacity of livestock populations. We characterized both epigenetic and genetic variations by contrasting 22 sheep and 21 goats from both sides of a climate gradient, focusing on free-ranging populations from Morocco. We produced for each individual Whole-Genome Sequence at 12X coverage and MeDIP-Seq data, to identify regions under selection and those differentially methylated. For both species, the analysis of genetic differences (F_ST) along the genome between animals from localities with high vs. low temperature annual variations detected candidate genes under selection in relation to environmental perception (5 genes), immunity (4 genes), reproduction (8 genes) and production (11 genes). Moreover, we found for each species one differentially methylated gene, namely AGPTA4 in goat and SLIT3 in sheep, which were both related, among other functions, to milk production and muscle development. In both sheep and goats, the comparison between genomic regions impacted by genetic and epigenetic variations suggests that climatic variations impacted similar biological pathways but different genes.

Reproductive Management of Rams and Ram Lambs during the Pre-Breeding Season in US Sheep Farms

Simple Summary

Pre-breeding management of rams and their ram lambs is critical for viable, sustainable and profitable farms. A further understanding of the management and selection criteria of the males during pre-breeding enables producers to efficiently use animal resources to maximize the reproductive potential of the animals. The reproductive management of mature rams and their lambs is complex, varying across breeds, farms, and regions of the world. It involves different aspects of animal husbandry, such as genetics, health, nutrition, behavior, economy and physiological and anatomical changes during the non-breeding season. Sound flock management must include an integrative and complete management plan for males and females that provides adequate conditions for the sheep to express their genetic potential and production level. This review article examines some of the key aspects to consider when managing mature rams and ram lambs during the pre-breeding season to ensure proper condition of the males for optimal function during the breeding season.

Abstract

In sheep farms, achieving economic and productive efficiency and sustainability goals is directly related with the reproductive management of the animals. Genetically, the male contribution to the offspring is 50%, but in practical terms, there is a greater potential impact of the ram on reproductive results, because one male has the potential to affect a large group of females and therefore greatly affects the entire flock. Unfortunately, the selection of males for breeding in the US sheep industry has been traditionally conducted based on phenotypical traits, without a genetic/reproductive evaluation, and/or health assessment or records. Therefore, it is important to establish integrative management practices to select the rams and ram lambs to be used in the breeding season. Among these practices are genomic testing, a comprehensive breeding soundness evaluation and assessment of health status and records of the males before the breeding season, to detect and correct potential issues.

Fucoidans and Bowel Health

Fucoidans are cell wall polysaccharides found in various species of brown seaweeds. They are fucose-containing sulfated polysaccharides (FCSPs) and comprise 5-20% of the algal dry weight. Fucoidans possess multiple bioactivities, including antioxidant, anticoagulant, antithrombotic, anti-inflammatory, antiviral, anti-lipidemic, anti-metastatic, anti-diabetic and anti-cancer effects. Dietary fucoidans provide small but constant amounts of FCSPs to the intestinal tract, which can reorganize the composition of commensal microbiota altered by FCSPs, and consequently control inflammation symptoms in the intestine. Although the bioactivities of fucoidans have been well described, there is limited evidence to implicate their effect on gut microbiota and bowel health. In this review, we summarize the recent studies that introduce the fundamental characteristics of various kinds of fucoidans and discuss their potential in altering commensal microorganisms and influencing intestinal diseases.

Gene duplication and loss of AANAT in mammals driven by rhythmic adaptations

Arylalkylamine N-acetyltransferase (AANAT) plays a crucial role in synchronizing internal biological functions to circadian and circannual changes. Generally speaking, only one copy of AANAT gene has been found in mammals, however, three independent duplications of this gene were detected in several cetartiodactyl lineages (i.e., Suidae, Hippopotamidae, and Pecora), which originated in the middle Eocene, a geological period characterized with the increased climate seasonality. Lineage-specific expansions of AANAT and the associated functional enhancement in these lineages strongly suggest an improvement in regulating photoperiodic response to adapt to seasonal climate changes. In contrast, independent inactivating mutations or deletions of the AANAT locus were identified in the four pineal-deficient clades (cetaceans, sirenians, xenarthrans, and pangolins). Loss of AANAT function in cetaceans and sirenians could disrupt the sleep-promoting effects of pineal melatonin, which might contribute to increasing wakefulness, adapting these clades to underwater sleep. The absence of AANAT and pineal glands in xenarthrans and pangolins may be associated with their body temperature maintenance. The present work demonstrates a far more complex and intriguing evolutionary pattern and functional diversity of mammalian AANAT genes than previously thought and provides further evidence for understanding AANAT evolution as driven by rhythmic adaptations in mammals.

MicroRNAs as Biomarkers for Animal Health and Welfare in Livestock

MicroRNAs (miRNAs) are small and highly conserved non-coding RNA molecules that orchestrate a wide range of biological processes through the post-transcriptional regulation of gene expression. An intriguing aspect in identifying these molecules as biomarkers is derived from their role in cell-to-cell communication, their active secretion from cells into the extracellular environment, their high stability in body fluids, and their ease of collection. All these features confer on miRNAs the potential to become a non-invasive tool to score animal welfare. There is growing interest in the importance of miRNAs as biomarkers for assessing the welfare of livestock during metabolic, environmental, and management stress, particularly in ruminants, pigs, and poultry. This review provides an overview of the current knowledge regarding the potential use of tissue and/or circulating miRNAs as biomarkers for the assessment of the health and welfare status in these livestock species.

Partitioning of fatty acids into tissues and fluids from reproductive organs of ewes as affected by dietary phenolic extracts

Evaluation of dietary interventions with regard to fertility problems often observed in ruminant livestock is of global interest. Though the effects of polyphenol supplementation in ruminants on digestion and food quality are well described, the impact on reproductive tissues and fluids remains scarcely investigated. These compounds protect dietary unsaturated fatty acids (FA) from oxidation and biohydrogenation and thus saturation. In addition, modification of the expression of genes associated with FA metabolism may occur. Therefore, we characterized for the first time the FA profiles of reproductive tissues and fluids and investigated their potential modification by dietary polyphenols in 22 cyclic ewes. The animals were randomly divided into four groups and fed a basal diet of meadow hay and one of four concentrate types either non-supplemented (control) or supplemented with grape seed extract, Acacia mearnsii bark extract (13 g/kg dry matter (DM) each) or a combination of both (26 g/kg DM). After 10 weeks of feeding, the animals were slaughtered. Samples of reproductive (oviduct, uterus) and metabolically differently active tissues (liver, muscle, adipose) as well as of plasma and fluids from oviduct and uterus were analysed for their FA composition. In addition, the expression of lipid metabolic and antioxidant genes was analysed in all tissues except the adipose tissue. Fatty acid profiles in tissues and fluids as well as gene expression in tissues significantly differed between the different fluids and tissues. In contrast, only a few diet and matrix (fluid or tissue) × diet interactions were observed. Still, the FA profile of the uterus was the only one not at all affected by the diet. The mRNA expression was not affected by the diet for most of the genes investigated, which might in part be explained by the similar plasma polyphenol concentrations found at slaughter. Overall, our findings contribute to an improved understanding of the characteristic FA composition of reproductive tissues and fluids in sheep. In addition, the effect of polyphenols on different tissues, fluids and tissue gene expression has been confirmed as described in other animal species.

Nutritional status affects the microRNA profile of the hypothalamus of female sheep

Recent studies on the seasonal regulation of the oestrous cycle in sheep have focussed mainly on the responses to photoperiod. However, the brain systems that control reproductive activity also respond to nutritional inputs, although the molecular mechanisms involved are not completely understood. One possibility is that small, non-coding RNAs, such as micro-RNAs (miRNAs), have significant influence. In the present study, the amounts and characteristics of miRNAs in hypothalamus from oestrous and anestrous ewes, fed low- or high-nutrient diets, were compared using Illumina HiSeq sequencing technology. In total, 398 miRNAs, including 261 novel miRNAs, were identified in ewes with an enhanced nutritional status (HEN), whereas 384 miRNAs, including 247 novel miRNAs, were identified in the ewes with a lesser nutritional status (HAN). There were eight conserved and 140 novel miRNAs expressed differentially between the two libraries. Based on quantitative real-time polymerase chain reaction, six miRNAs were assessed to verify the accuracy of the library database. Moreover, the correlation between the miRNA target and several upstream and downstream genes in the oestrus-related pathways were also verified in hypothalamus nerve cells. According to the results, nutritional status plays an important role in oestrous regulation in sheep, and the hypothalamic processes and pathways induced by nutritional signals (folic acid and tyrosine) are different from those induced by photoperiodic regulation of oestrus. We have expanded the repertoire of sheep miRNAs that could contribute to the molecular mechanisms that regulate the initiation of oestrous cycles in anestrous ewes in response to the influence of nutritional status.

The Opuntia effect and the Reactivation of Ovarian Function and Blood Metabolite Concentrations of Anestrous Goats Exposed to Active Males

Simple Summary

We evaluated the potential supplementation effect of protein enriched Opuntia cladodes, the flat leaf-like steam of cactus species (PEO), upon changes of blood metabolites, estrus induction, estrus latency, and ovulation rate in anestrous goats exposed to sexually active males. We observed that PEO positively influenced reproductive outcomes without changes in blood metabolites. Our results highlight the importance that bio-fortified Opuntia cladodes supplementation exerts on anestrous goats exposed to the male effect as an option to improve not only the out-of-season reproductive efficiency of goats but to enhance the sustainability of marginal, extensive and semi-arid goat production systems.

Abstract

The effect of protein enriched Opuntia cladodes supplementation upon changes of serum total protein, urea, cholesterol, glucose as related to estrus induction (EI%), estrus latency (EL, h), and ovulation rate (OR, units) in adult anestrous goats exposed to the male effect was evaluated. In late April, anestrus goats (n = 45, 25° N) homogeneous regarding live weight (LE; 43.8 ± 1.6 kg) and body condition score (BCS; 2.3 ± 0.1 units) were randomly assigned to: (1). Protein-enriched Opuntia (PEO; n = 15; 29.8% CP, 2.2 Mcal ME kg⁻¹), (2). Non-enriched Opuntia (NEO; n = 15; 6.4% CP, 2.1 Mcal ME kg⁻¹), and (3). Control (CON; n = 15). NEO and PEO goats were individually supplemented with cladodes (160 g d⁻¹; 0900–1000 h), thereafter all groups grazed in a marginal rangeland (1000–1800 h). Neither LW (p > 0.05) nor BCS (p > 0.05) differed among groups, yet an increased (p < 0.05) EI % (100, 57, 42 ± 0.16%), EL h (62, 60, 32 ± 4.2 h), and OR (1.33, 0.71, 0.43 ± 0.23 units) occurred in PEO and NEO vs. CONT, respectively. However, neither blood metabolites differed among groups nor a treatment x time interaction occurred. Peri-breeding protein enriched Opuntia cladodes supplementation of anestrous goats exposed to active males increased (p < 0.01) reproductive outcomes during the non-breeding season.

Fifty years of reproductive biology in Australia: highlights from the 50th Annual Meeting of the Society for Reproductive Biology (SRB)

The 2018 edition of the Society for Reproductive Biology's (SRB) Annual Meeting was a celebration of 50 years of Australian research into reproductive biology. The past 50 years has seen many important contributions to this field, and these advances have led to changes in practice and policy, improvements in the efficiency of animal reproduction and improved health outcomes. This conference review delivers a dedicated summary of the symposia, discussing emerging concepts, raising new questions and proposing directions forward. Notably, the symposia discussed in this review emphasised the impact that reproductive research can have on quality of life and the health trajectories of individuals. The breadth of the research discussed encompasses the central regulation of fertility and cyclicity, life course health and how the environment of gametes and embryos can affect subsequent generations, significant advances in our understanding of placental biology and pregnancy disorders and the implications of assisted reproductive technologies on population health. The importance of a reliable food supply and protection of endangered species is also discussed. The research covered at SRB's 2018 meeting not only recognised the important contributions of its members over the past 50 years, but also highlighted key findings and avenues for innovation moving forward that will enable the SRB to continue making significant contributions for the next 50 years.

Identification and analysis of microRNAs-mRNAs pairs associated with nutritional status in seasonal sheep

Given the important role of nutritional status for reproductive performance, we aimed to explore the potential microRNA (miRNA)-mRNA pairs and their regulatory roles associated with nutritional status in seasonal reproducing sheep. Individual ewes were treated with and without 0.3 kg/day concentrates, and the body condition score, estrus rate, and related miRNAs and target genes were compared. A total of 261 differentially expressed miRNAs were identified, including 148 hypothalamus-expressed miRNAs and 113 ovary-expressed miRNAs, and 349 target genes were predicted to be associated with nutritional status and seasonal reproduction in sheep. Ultimately, the miR-200b-GNAQ pair was screened and validated as differentially expressed, and a dual luciferase reporter assay showed that miR-200b could bind to the 3'-untranslated region of GNAQ to mediate the hypothalamic-pituitary-ovarian axis. Thus, miR-200b and its target gene GNAQ likely represent an important negative feedback loop, providing a link between nutritional status and seasonal reproduction in sheep toward enhancing reproductive performance and productivity.

A survey of the meat goat industry in Queensland and New South Wales. 2. Herd management, reproductive performance and animal health

An interview-based questionnaire survey was conducted on 31 goat properties in New South Wales and Queensland in 2013. This study has gathered information on goat herd management, reproductive performance and animal health, and has identified constraints that may limit goat productivity. Producers from high-rainfall regions reported having full blood Boer goats for stud breeding. In contrast, producers from pastoral regions had rangeland goats and Boer-cross goats. Overall, 87% of the producers identified a natural breeding season in goats and 61% separated kids from their mothers at weaning. The weaning age varied between 3.0 and 6.0 months. A total of 52% of producers castrated male kids. Only 10% of producers used ultrasound to conduct pregnancy diagnosis on their goats. The reported pregnancy rate was 60% for the pastoral regions and 94% for the high-rainfall regions. The average prolificacy was 1.4 kids/doe and the kidding interval was 12 months. Overall, 68% of producers fed their goat herd with supplements, with the exception that most producers from western New South Wales and south-western Queensland did not use supplements. Producers considered gastrointestinal parasites (61%) and body lice (48%) as the main diseases associated with their goat herds, although only 52% mentioned drenching the animals with anthelmintics. In general, properties in the pastoral regions showed low pregnancy and kidding rates, early age at first mating, high mortality rates, poor performance of Boer bucks and lower weights and weight gain compared with properties in the high-rainfall regions. The survey has highlighted areas that require further study to validate the observations of producers, for instance, factors that may be limiting the fertility of Boer goats in rangeland environments, the incidence of diseases, the use of Kidplan and management activities to improve goat productivity.

Macronutrient balance, reproductive function, and lifespan in aging mice

In invertebrates, reproductive output and lifespan are profoundly impacted by dietary macronutrient balance, with these traits achieving their maxima on different diet compositions, giving the appearance of a resource-based tradeoff between reproduction and longevity. For the first time in a mammal, to our knowledge, we evaluate the effects of dietary protein (P), carbohydrate (C), fat (F), and energy (E) on lifespan and reproductive function in aging male and female mice. We show that, as in invertebrates, the balance of macronutrients has marked and largely opposing effects on reproductive and longevity outcomes. Mice were provided ad libitum access to one of 25 diets differing in P, C, F, and E content, with reproductive outcomes assessed at 15 months. An optimal balance of macronutrients exists for reproductive function, which, for most measures, differs from the diets that optimize lifespan, and this response differs with sex. Maximal longevity was achieved on diets containing a P:C ratio of 1:13 in males and 1:11 for females. Diets that optimized testes mass and epididymal sperm counts (indicators of gamete production) contained a higher P:C ratio (1:1) than those that maximized lifespan. In females, uterine mass (an indicator of estrogenic activity) was also greatest on high P:C diets (1:1) whereas ovarian follicle number was greatest on P:C 3:1 associated with high-F intakes. By contrast, estrous cycling was more likely in mice on lower P:C (1:8), and the number of corpora lutea, indicative of recent ovulations, was greatest on P:C similar to those supporting greatest longevity (1:11).

Respostas bioquímicas de ovelhas submetidas a<italic>flushing</italic> de curto prazo em região subtropical

<p>Influências exercidas pela nutrição sobre produção animal dão-se por variações no peso e condição corporal, afetando a homeostase, em dietas com altos níveis de energia ou proteínas, cujas modificações causam rápida e imediata alteração em vários agentes metabólicos humorais. Com objetivo de avaliar a influência de cinco diferentes dietas de curto prazo sobre ganho de peso e perfil bioquímico (colesterol total e frações HDL/LDL, triglicerídeos, glicose, ureia, creatinina, proteínas totais, albumina), 70 ovelhas mestiças Santa Inês, aleatoriamente distribuídas em cinco grupos, foram submetidas às dietas, durante sete dias (1- milho, farelo de soja, gordura protegida, silagem de milho; 2 - milho, farelo de soja, silagem de milho; 3 - gordura protegida, silagem de milho; 4 - silagem de milho; 5 - feno de Tifton). Nos dias 0 e 8 (anterior à instituição das dietas e seguinte ao término) pesou-se as ovelhas e colheu-se sangue, visando quantificação do perfil bioquímico. Os dados foram analisados com delineamento experimental de 5x2 por ANOVA de duas vias de medidas repetitivas e pós-teste de Tukey. Não se observaram variações no peso corporal entre grupos de dieta, mas evidenciaram-se diferenças no ganho de peso (g/7 dias) entre grupos (G4 = 1,82±0,23 g <italic>versus</italic> G1 = 0,21±0,43 g). Colesterol total e LDL-colesterol variaram entre grupos, tendo o G1 apresentado maiores valores. Os demais componentes bioquímicos não tiveram diferenças significativas. Ovelhas submetidas a programa de <italic>flushing</italic>de curto prazo, responderam com ganho de peso, associado a aumentos em seus níveis de colesterol total e reduções na ureia sérica.</p>

Male reproductive success is correlated with testosterone in the eastern black rhinoceros (Diceros bicornis michaeli)

Among natural populations of polygynous species, males often vary in their lifetime reproductive success. However, in managed populations of endangered species, either in situ or as part of captive breeding programmes, it is important to understand why differences in reproductive success occur. The European captive population of the critically endangered eastern black rhinoceros is currently under-performing relative to their wild counterparts, with low reproductive output and high reproductive skew limiting growth and genetic diversity. To investigate why over 40% of captive males fail to breed, faecal samples were collected weekly from 23 males at 12 institutions across Europe for 4-32 months. Testosterone metabolite concentration was compared between proven and non-proven males and a number of intrinsic and extrinsic factors that could influence reproductive success were also investigated. Males that sired within the last 3½ years had significantly higher androgen concentrations than non-proven males, and average testosterone was positively correlated with the number of offspring sired per year spent in the reproductive age class. Proven and non-proven males did not differ in their body condition, or in average faecal glucocorticoid concentration. Differences in individual temperament were associated with adrenal activity, but did not correlate with reproductive category. Highest testosterone concentrations were observed in proven males that were housed with females during oestrus, and lowest concentrations in non-proven females not housed with females at all during the study period. Further work is necessary to determine whether proven males had higher testosterone due to underlying differences associated with quality, or whether external stimuli such as access to females could influence testosterone concentration and increase a male's chances of becoming a successful breeder.

The effect of periconceptional undernutrition of sheep on the cognitive/emotional response and oocyte quality of offspring at 30 days of age

Maternal periconceptional undernutrition is associated with altered development and increased risks of adverse outcomes in the offspring. This circumstance is normal in flocks under extensive farming systems, which depend on natural forage resources. The aim of this study was to determine the effect of periconceptional undernutrition in sheep on behavioral and reproductive aspects of the offspring. Eighty ewes were synchronized in estrus and allocated to two groups (n=40) to be fed diets that provided 1.5 (C) or 0.5 (L) times the requirements for maintenance. Ewes were mated and 7 days later fed the control diet until lambing. One month after lambing, 32 lambs were exposed to tests to determine their cognitive and emotional responses. Six ewe lambs were euthanized and in vitro maturation and fertilization procedures were performed. L ewes presented a significant reduction in prolificacy and fecundity (P<0.05) in comparison with C ewes. Mean LW at lambing of L lambs was significantly higher than C lambs (C: 3.80 ± 0.11; L: 4.24 ± 0.15 kg, P<0.05). Lambs born from C ewes spent more time walking than L lambs (P<0.05) in the isolation test, revealing a decrease in the locomotor activity of lambs born from undernourished ewes around conception. Ewe lambs from the undernourished ewes presented a total population of oocytes 2.3 times higher than ovaries from control ewe lambs (60.0 ± 7.8 v. 140.0 ± 18.5 oocytes; P<0.05). In conclusion, periconceptional undernutrition is able to produce an increment in the body weight and the oocyte population, and an alteration of the locomotor activity of the offspring.

Efeito do flushing sobre o desempenho reprodutivo de ovelhas Morada Nova e Santa Inês submetidas à inseminação artificial em tempo fixo

O objetivo do estudo foi analisar o efeito do flushing, do protocolo hormonal para sincronização de estro e da IATF sobre o desempenho reprodutivo de ovelhas Morada Nova (MN) e Santa Inês (SI). Foram utilizadas 27 ovelhas SI e 24 ovelhas MN suplementadas com concentrado (1% do peso vivo, em média) durante 75 dias de estação reprodutiva. Após 30 dias de suplementação, as ovelhas foram sincronizadas com protocolo hormonal (PH) à base de progestágeno, eCG e cloprostenol. A observação de estro foi realizada após 12, 24, 36 e 48 horas do término do PH, com o auxílio de dois rufiões, e a IATF foi realizada aproximadamente 55 horas após o final do PH. Do 20º ao 45º dia após o início do PH, realizou-se o repasse com um reproduto Dorper. O diagnóstico de prenhez foi realizado 70 dias após a IATF. Foi analisado o peso, escore da condição corporal (ECC), taxa de apresentação de estro, taxa de prenhez e prolificidade, testando-se os efeitos da raça, semana de suplementação (SS) e classe de ECC. O peso e ECC das ovelhas variaram em função da SS. Foi observada taxa de estro de 88,2%, sendo que 43,2% das ovelhas apresentaram estro até 24 horas do final do PH. A taxa de prenhez por IATF foi de 31,4% e a de prenhez após repasse foi de 50,0%, sendo que a classe de ECC interferiu nas taxas de prenhez. Obteve-se maior porcentagem de partos múltiplos de ovelhas prenhes por IATF do que por monta natural no repasse. Conclui-se que o flushing resultou em ganho de peso e aumento do ECC, o que garantiu a padronização do rebanho para a estação reprodutiva e, consequentemente, melhorou o desempenho reprodutivo. O PH utilizado aumentou a prolificidade e adiantou o início do estro; porém, não foi eficiente na sincronização de ovelhas deslanadas.

Glucogenic supply increases oocyte developmental competence in sheep

The present study aimed to determine the influence of a glucogenic supply on oocyte developmental competence. Oestrous cycles were synchronised in 22 Sarda ewes by the insertion (Day 0) of one intravaginal progestagen-impregnated sponge that was removed after 6 days. After removal, the ewes were randomly allocated into two experimental groups (treated and control ewes) and, from Day 7 to Day 11, treated ewes received oral administration of a glucogenic mixture, whereas control animals received water. Follicular development was stimulated by FSH administration from Days 8 to 10. Glucose metabolism was assessed from Days 7 to 11, whilst follicle and corpus luteum growth dynamics and functionality were evaluated between Days 6 and 11. At Day 11 ovaries were collected and processed for in vitro embryo production. Glucogenic treatment increased both the plasma levels of glucose, progesterone, oestradiol and the number of 2-3-mm follicles (P < 0.05). Higher fertilisation and blastocyst rates (P < 0.05) were obtained after IVM of oocytes recovered from treated ewes compared with control ones. In conclusion, glucogenic treatment modifies follicle and corpus luteum functionality and improves oocyte quality, as evaluated by in vitro developmental kinetics and blastocyst output.

Nutritional influences on folliculogenesis

Folliculogenesis is an intricate process that involves the proliferation and differentiation of both somatic and germ cells. This process depends on complex interactions between systemic factors such as both pituitary gonadotrophins and metabolic hormones and/or local factors produced by the ovarian somatic and germ cells, such as the IGF system and TGF-β superfamily members. In domestic ruminants, follicular development begins during foetal life with formation of primordial follicles from the association of germ cells and pre-granulosa cells. After follicular formation, folliculogenesis begins with a primordial follicle progressing into more developed stages (i.e. primary, secondary, pre-antral and antral) in a continuous, progressive process to either ovulation or, as in most cases, to atresia. Even early stages of follicular formation and subsequent development are influenced by both internal (e.g. genotype) and/or external environmental (e.g. nutrition and season) factors. Among these external factors, nutrition is one of the most important affecting reproductive function, and this is the focus of this review, because other reviews in this issue discuss other environmental factors. A number of studies have now shown that nutrition can have both positive and negative effects on follicular growth, oestrous activity, oocyte quality, blastocyst development and pregnancy outcome. Therefore, understanding the intricate processes involved during folliculogenesis and the ways in which factors, such as nutrition, affect them is leading to new opportunities to improve pregnancy rates by influencing follicle development and oocyte quality. This review will focus on follicular development from foetal to adult stages and the influences that nutrition has during some of these developmental stages.

Effect of multiple stresses on growth and adaptive capability of Malpura ewes under semi-arid tropical environment

A study was conducted to assess the effect of multiple stresses (thermal, nutritional, and walking stress) on the adaptive capability of Malpura ewes in terms of changes in physiological mechanisms and blood biochemical changes. The study was conducted for a period of 35 days covering two estrous cycles during summer season (April-May). The ewes were randomly allocated into two groups of 12 animals each, viz., GI (n = 12; control) and GII (n = 12; multiple stresses). GI ewes were maintained in the shed while GII ewes were subjected to multiple stresses. GI ewes were maintained in shed while GII ewes were subjected to heat stress by exposing them to 32-44 °C (average 42 °C) and RH of 12-26 % for 6 h from 10:00 to 16:00 h in natural environment. GI ewes were provided with ad libitum feeding while GII ewes were provided with restricted feed (30 % of intake of GI ewes) to induce nutritional stress. Further, GII ewes were subjected to walking stress by forcing them to walk 14 km in two spans between 9:00 and 10:30 h and 15:00 and 16:30 h. Blood collection was done at weekly intervals. Multiple stresses significantly (P < 0.01) affected body weight, respiration rate, pulse rate, rectal temperature, sweating rate, tri-iodo-thyronine, thyroxine, cortisol, hemoglobin, packed cell volume, glucose, and total protein. The findings from this experiment provide useful information to understand the ideal nutrient requirement for these animals to adapt to such stresses in the semi-arid tropical environment without compromising production.

The interaction between photoperiod and nutrition and its effects on seasonal rhythms of reproduction in the ewe

In sheep, the seasonal patterns of reproductive activity are driven primarily by the annual photoperiodic cycle, but can also respond to other environmental factors, such as nutrition, yet little is known about the mechanisms underlying this interaction. This study was designed to define the interaction between photoperiodic and nutritional cues on seasonal patterns of ovarian activity, and to determine if there is a central interaction between these cues. Groups of Ile-de-France ewes were maintained in two nutritional states (restricted and well fed) under a simulated annual photoperiod of 8-16 h of light per day over two breeding seasons. At the end of the first breeding season, half of the animals of each group were ovariectomized (OVX) and fitted subcutaneously with estradiol implants. Low nutritional status shortened the season of ovarian activity, determined from the pattern of progesterone concentrations, by modifying the timing of seasonal transitions between periods of ovarian activity and anestrus. The same results were observed for the seasonal rhythm of neuroendocrine activity, assessed in the OVX ewes, from the pattern of luteinizing hormone concentrations. These results were then confirmed for neuroendocrine activity induced by a photoperiodic treatment. We conclude that nutrition centrally modulates the interpretation of photoperiod to affect seasonal reproductive transitions. The mechanisms of this interaction are discussed in the paper.

Effect of multiple stresses (thermal, nutritional, and walking stress) on the reproductive performance of malpura ewes

A study was conducted to assess the effect of multiple stresses (thermal, nutritional, and walking stress) on the reproductive performance of Malpura ewes. The study was conducted for a period of 35 days covering two estrous cycles during summer season (April-May). The ewes were randomly allocated into two groups of twelve animals each namely, GI (n=12; Control), and GII (n=1 2; Multiple stresses). GI ewes were maintained in the shed, while GII ewes were subjected to multiple stresses (thermal, nutritional, and walking stress). The estrus % differed significantly (P< 0.05) between the groups. Estrus duration also showed similar trend to that of estrus %. Both conception and lambing rate also differed significantly (P< 0.05) between the control and multiple-stress group. In addition plasma estradiol and progesterone also showed significant difference between the groups. The study proved the detrimental effects of multiple-stresses on various reproductive parameters studied. Hence it is very pertinent to conclude that when two or more than two stressors occur simultaneously, the total impact may be severe on reproductive functions of the animals.

Food intake and social habits in male patients and its relationship to intracytoplasmic sperm injection outcomes

OBJECTIVE

To investigate the influence of the male partner's lifestyle, including eating and social habits, on semen quality and intracytoplasmic sperm injection (ICSI) success.

DESIGN

Observational study.

SETTING

Private fertility clinic.

PATIENT(S)

Two hundred fifty male patients undergoing ICSI cycles.

INTERVENTION(S)

We recorded dietary and social habits using a food frequency questionnaire adapted to meet specific study objectives. Evaluation of semen parameters and ICSI outcomes were performed.

MAIN OUTCOME MEASURE(S)

Frequency of intake of food items and social habits were registered on a scale with five categories ranging from no consumption to repeated daily consumption.

RESULT(S)

The sperm concentration was negatively influenced by body mass index (BMI) and alcohol consumption and was positively influenced by cereal consumption and the number of meals per day. The sperm motility was also negatively influenced by BMI, alcohol consumption, and smoking habit, whereas it was positively influenced by the consumption of fruits and cereals. The consumption of alcohol had a negative influence on the fertilization rate. The consumption of red meat as well as being on a weight loss diet had a negative impact on the implantation rate. In addition, the consumption of red meat and being on a weight loss diet had an effect on the pregnancy chance.

CONCLUSION(S)

Couples seeking assisted reproduction treatments must be advised about the drastic effect of both the male and female lifestyle on treatment success.

Progesterona plasmática de ovelhas submetidas ao efeito-macho e mantidas sob diferentes condições nutricionais

Dosou-se a concentração plasmática de progesterona (P4) em ovelhas Santa Inês (SI), Suffolk (SU) e Romney Marsh (RM) em anestro sazonal e submetidas ao efeito-macho, as quais receberam ou não suplementação alimentar. Machos vasectomizados foram introduzidos no grupo de fêmeas após um período prévio de isolamento de 60 dias, e amostras de sangue foram colhidas antes e após a introdução dos machos. Houve efeito (P<0,01) de período, raça, interação período x raça e interação suplementação x período x raça sobre a concentração de P4. Nas ovelhas SI ocorreu aumento (P<0,01) da concentração de P4 após a introdução do macho, indicando que houve aumento na atividade cíclica reprodutiva desse grupo. A suplementação, neste caso, potencializou este aumento. Nas ovelhas SU e RM não ocorreram modificações na concentração de P4 (P>0,01) após a introdução dos machos, nem houve efeito de suplementação. O efeito-macho foi eficaz em induzir a atividade reprodutiva durante o anestro sazonal em ovelhas SI, mas não em ovelhas SU e RM, e a associação dessa prática com a suplementação alimentar é recomendada para ovelhas da raça nativa SI.

The cactus effect: an alternative to the lupin effect for increasing ovulation rate in sheep reared in semi-arid regions?

The present study evaluated the effects of supplementation with cactus cladodes on follicular dynamics and ovulatory response of sheep reared in semi-arid areas. A total of 76 ewes were distributed into two equal groups supplemented with either concentrated feed or cactus cladodes. After 30 days of supplementation, no differences were found between feeding regimens on the final live weight (LW; 41.5 ± 0.6 and 42.1 ± 0.7 kg in the Concentrate and Cactus groups respectively) and body condition score (BCS; 1.8 ± 0.3 and 1.8 ± 0.4 for Concentrate and Cactus group respectively). Moreover, no differences were found between the initial and the final values of both LW and BCS; thus, there were no effects of supplementation on any of both parameters. Analysis of follicular population showed that, during the follicular phase induced by ram effect, the number of follicles reaching ovulatory size increased in both groups. However, the number was always higher in Cactus ewes and, at oestrus, Cactus ewes had 1.6 ± 0.2 and Concentrate sheep had 1.2 ± 0.2 large follicles (p < 0.05). Thereafter, ovulation rate was affected by duration of supplementation; being higher in sheep fed with cactus for 6-10 days (1.7 ± 0.1) than in ewes supplied with cactus for more than 11 days (1.3 ± 0.1; p < 0.05), in sheep fed with concentrate for 6-10 days (1.2 ± 0.1; p < 0.01) and even than in individuals subjected to classical flushing with concentrate (1.3 ± 0.1; p < 0.05).

Effect of concentrate supplementation on performance, ovarian response, and some biochemical profile of Malpura ewes

Effect of feed flushing on ovulation rate was investigated during the autumn seasons on 24 adult Malpura ewes (BW 34.8 ± 0.58 kg and age 4-7 years) equally divided into two groups. Ewes in G1 (group 1) were grazed 8-10 h daily on Cenchrus ciliaris pasture interspersed with seasonal shrub. In addition to grazing, concentrate was provided at 1.5% of BW to the animals in G2 (group 2) for a period of 35 days. Estrus was synchronized by a double injection schedule of PGF(2α) at 0 and 10 days of the experiment and detected by parading aproned rams at 6 h intervals. Blood samples were collected at weekly interval during the estrous cycle. A rumen fermentation study was conducted on day 23 of the experiment at 0 and 4 h post-concentrate feeding. Ovarian responses in terms of number of corpora lutea and large follicles was examined on all the ewes by laparoscopy after 3 to 6 days of each estrus and were found to be similar in both the groups. Hemoglobin and packed cell volume, total protein, albumin, and globulin were similar among the groups. Concentration of plasma glucose (12 and 22 days) was higher (P < 0.05) in G2 vis-à-vis control. Plasma urea was higher (P < 0.01) in the control than G2. Rumen liquor pH, concentration of total N, TCA-ppt N, NH(3)-N, and TVFA were significantly higher (P < 0.01) in G2 than the control. Thus, it can be concluded that concentrate supplementation in ewes prior to mating (flushing) did not enhance ovulation response during the autumn season.

Environmental factors and interval from the introduction of rams to estrus in postpartum Saint Croix sheep

The objective of this study was to determine whether season and total rainfall during the breeding season, sheep parity, and/or litter size affect the interval from the introduction of rams to estrus (IRE) in hair Saint Croix sheep in northeastern Mexico. An analysis was made of 874 services performed during 9 years, introducing the rams into the sheep flock after an isolation period of 60 days during the postpartum period. Estrus was recorded twice daily during 35 days. Year and season influenced significantly on the interval between ram introduction and estrus length (P < 0.01). Winter IRE length (7.9 ± 0.1 days) was shorter than in the other three seasons (11.1 ± 0.2, 11.1 ± 0.1, and 16.2 ± 0.2 days in summer, autumn, and spring, respectively) (P < 0.01). An interaction was observed between rainfall and season, then by rainfall between 0 and 100 mm, IRE was shorter (P < 0.05) in winter (6.8 ± 0.3 days), and by rainfall between 100 and 199 mm, IRE was shorter (P < 0.05) in autumn (10.2 ± 0.5 days); however, when rainfall was beyond 200 mm, IRE length was shorter (P < 0.01) in summer (4.8 ± 0.5 days) than in autumn (14.5 ± 0.3 days). The IRE length was also longer in first lambing ewes (P < 0.05) and was not affected by litter size. In the present study, several factors, including the breeding season, rainfall and parity, directly influenced the interval between the male introduction and the onset of estrus by Saint Croix hair sheep.

Adaptive capability as indicated by endocrine and biochemical responses of Malpura ewes subjected to combined stresses (thermal and nutritional) in a semi-arid tropical environment

A study was conducted to assess the effect of combined stresses (thermal and nutritional) on endocrine and biochemical responses in Malpura ewes. Twenty eight adult Malpura ewes (average body weight 33.56 kg) were used in the present study. The ewes were divided into four groups viz., GI (n = 7; control), GII (n = 7; thermal stress), GIII (n = 7; nutritional stress) and GIV (n = 7; combined stress). The animals were stall fed with a diet consisting of 60% roughage and 40% concentrate. GI and GII ewes were provided with ad libitum feeding while GIII and GIV ewes were provided with restricted feed (30% intake of GI ewes) to induce nutritional stress. GII and GIV ewes were kept in climatic chamber at 40°C and 55% RH for 6 h a day between 1000 hours and 1600 hours to induce thermal stress. The study was conducted for a period of two estrus cycles. The parameters studied were Hb, PCV, glucose, total protein, total cholesterol, ACP, ALP, cortisol, T(4), T(3), and insulin. Combined stress significantly (P < 0.05) affected all parameters studied. Furthermore, the results revealed that, compared to thermal stress, nutritional stress had a less significant effect on the parameters studied. However, when both these stresses were coupled, they had a severe impact on all the parameters studied in these ewes. It can be concluded from this study that two stressors occurring simultaneously may impact severely on the biological functions necessary to maintain homeostasis in sheep.

Effect of thermal stress, restricted feeding and combined stresses (thermal stress and restricted feeding) on growth and plasma reproductive hormone levels of Malpura ewes under semi-arid tropical environment

A study was conducted to assess the effect of thermal, nutritional and combined stresses (thermal and nutritional) on the growth, oestradiol and progesterone levels during oestrus cycles in Malpura ewes. Twenty-eight adult Malpura ewes were used in the present study. The ewes were randomly allocated into four groups, viz., GI (n=7; control), GII (n=7; thermal stress), GIII (n=7; restricted feeding) and GIV (n=7; combined stress). The animals were stall fed with a diet consisting of 60% roughage and 40% concentrate. GI and GII ewes were provided with ad libitum feeding while GIII and GIV ewes were provided with restricted feed (30% intake of GI and GII ewes) to induce nutritional insufficiency. GII and GIV ewes were kept in climatic chamber at 40°C and 55% RH for 6 h a day between 10:00 and 16:00 hours to induce thermal stress for a period of two oestrous cycles. Parameters studied were body weight, oestrus incidences, plasma oestradiol 17-β, plasma progesterone, conception rate, gestation period, lambing rate, and birth weight of lambs. The results indicate that combined stress significantly (p<0.05) reduced body weight, oestrus duration, birth weight of lambs, and oestradiol 17-β whereas significantly (p < 0.05) increased oestrus cycle length and progesterone. Furthermore, the results reveal that on comparative basis, ewes were able to better adapt in terms of growth and reproduction to restricted feeding than thermal stress. However, when restricted feeding was coupled with thermal stress it had significant (p<0.05) influence on body weight, average daily gain, oestradiol 17-β and progesterone concentrations. This showed that combined stress were more detrimental for these reproductive hormones in Malpura ewes under a hot semi-arid environment.