Distribution of Lectin‐Bindings in the Testis of the Lesser Mouse Deer,Tragulus javanicus

The distribution of lectin bindings in the testis of the smallest ruminant, lesser mouse deer (Tragulus javanicus), was studied using 12 biotinylated lectins specific for d ‐galactose (peanut agglutinin PNA, Ricinus communis agglutinin RCA I), N‐acetyl‐d ‐galactosamine (Dolichos biflorus agglutinin DBA, Vicia villosa agglutinin VVA, Soybean agglutinin SBA), N‐acetyl‐d ‐glucosamine and sialic acid (wheat germ agglutinin WGA, s‐WGA), d ‐mannose and d ‐glucose (Lens culinaris agglutinin LCA, Pisum sativum agglutinin PSA, Concanavalin A Con A), l ‐fucose (Ulex europaeus agglutinin UEA I), and oligosaccharide (Phaseolus vulgaris agglutinin PHA‐E) sugar residues. In Golgi‐, cap‐, and acrosome‐phase spermatids, lectin‐bindings were found in the acrosome (PNA, RCA I, VVA, SBA, WGA and s‐WGA), and in the cytoplasm (PNA, RCA I, VVA, SBA, WGA, LCA, PSA, Con A and PHA‐E). s‐WGA binding was confined to the spermatid acrosome, but other lectins were also observed in spermatocytes. In spermatogonia, VVA, WGA, Con A, and PHA‐E bindings were observed. Sertoli cells were intensely stained with DBA and Con A, and weakly with PHA‐E. In interstitial Leydig cells, RCA I, DBA, VVA, Con A, PSA, LCA, WGA and PHA‐E were positive. UEA I was negative in all cell types including spermatogenic cells. Unusual distribution of lectin‐bindings noted in the testis of lesser mouse deer included the limited distribution of s‐WGA only in the spermatid acrosome, the distribution of DBA in Sertoli cells, Leydig cells and lamina propria, and the absence of UEA I in all type cells. The present results were discussed in comparison with those of other animals and their possible functional implications.     

Glycomolecule Modifications in the Seminiferous Epithelial Cells and in the Acrosome of Post‐testicular Spermatozoa in the Alpaca

A lectin histochemical investigation of the seminiferous epithelium and acrosomes of spermatozoa present in the efferent ductules and epididymal regions was carried out in the alpaca. The histochemical characterization was performed using a battery of different lectins: Con‐A, UEA‐I, LTA, WGA, GSA‐IB4, SBA, PNA, ECA, DBA, MAL‐II and SNA. Sialidase digestion and deglycosilation pre‐treatments were also employed. The cytoplasm of the Sertoli cells contained N‐linked oligosaccharides with α‐d ‐Man/α‐d ‐Glc and GlcNAc and O‐linked glycans with α‐l ‐Fuc, β‐GalNAc, β‐d ‐Gal‐(1‐4)‐d ‐GlcNAc, α–Gal and Neu5Acα2,6α‐GalNAc moieties whereas β‐d ‐Gal‐(1‐3)‐d ‐GalNAc residues were included in both O‐ and N‐glycoproteins. Spermatogonia expressed α‐d ‐Man/α‐d ‐Glc residues included in N‐glycoproteins and α‐Fuc in O‐glycoproteins. Spermatocytes contained the N‐glycoproteins residues α‐d ‐Man/α‐d ‐Glc and GlcNAc and the O‐glycoproteins residues α‐l ‐Fuc, β‐d ‐Gal‐(1‐4)‐d ‐GlcNAc, α–Gal, β‐GalNAc, Neu5Acα2,6α‐GalNAc and Neu5Acα2,6β‐d ‐Gal‐(1‐3)‐d ‐GalNAc. The results of the present study show differences in the presence and distribution of lectin reactive sites throughout the acrosomal development in the alpaca. In particular, Fuc moieties were found only during the Golgi‐phase of spermatids, α‐Gal were found in the acrosome of Golgi‐ and cap‐phase spermatids, sialic‐acid/α‐GalNAc sequence was revealed during the cap‐phase and elongated spermatids, and α‐d ‐Man/α‐d ‐Glc and GlcNAc were detected only in the acrosomes of elongated spermatids. Finally, β‐GalNAc, β‐d ‐Gal‐(1‐3)‐d ‐GalNAc and β‐d ‐Gal‐(1‐4)‐d ‐GlcNAc were added to acrosomal glycoproteins in the early stages of spermatogenesis and remained unchanged during the later phases. Differences in the carbohydrate expression were also demonstrated on the sperm acrosomes during passage through the post‐testicular ducts.     

Histochemical Analysis of Glycoconjugates in the Skin of a Catfish (Arius Tenuispinis, Day)

A histochemical study using conventional carbohydrate histochemistry (periodic‐acid staining including diastase controls, alcian blue staining at pH 1 and 2.5) as well as using a battery of 14 fluorescein isothiocyanate (FITC)‐labelled lectins to identify glycoconjugates present in 10 different areas of the skin of a catfish (Arius tenuispinis) was carried out. The lectins used were: mannose‐binding lectins (Con A, LCA and PSA), galactose‐binding lectins (PNA, RCA), N‐acetylgalactosamine‐binding lectins (DBA, SBA, SJA and GSL I), N‐acetylglucosamine‐binding lectins (WGA and WGAs), fucose‐binding lectins (UEA) and lectins which bind to complex carbohydrate configurations (PHA E, PHA L). Conventional glycoconjugate staining (PAS staining, alcian blue at pH 1 and 2.5) showed that the mucous goblet cells contain a considerable amount of glycoconjugates in all locations of the skin, whereas the other unicellular gland type, the club cells, lacked these glycoconjugates. The glycoproteins found in goblet cells are neutral and therefore stain magenta when subjected to PAS staining. Alcian blue staining indicating acid glycoproteins was distinctly positive at pH 1, but gave only a comparable staining at pH 2.5. The mucus of the goblet cells therefore also contains acid glycoproteins rich in sulphate groups. Using FITC‐labelled lectins, the carbohydrate composition of the glycoproteins of goblet cells could be more fully characterized. A distinct staining of the mucus of goblet cells was found with the mannose‐binding lectins LCA and PSA; the galactosamine‐binding lectins DBA, SBA and GLS I; the glucosamine‐binding lectin WGA; and PHA E which stains glycoproteins with complex carbohydrate configurations. No reaction occurred with the fucose‐binding lectin UEA and the sialic acid‐specific lectin SNA. In addition, the galactose‐binding lectins PNA and RCA showed only a weak or completely negative staining of the mucus in the goblet cells. The specificity of the lectin staining could be proved by inhibiting binding of the lectins by competitive inhibition with the corresponding sugars. From these data, we can conclude that the mucus produced by the epidermal goblet cells of A. tenuispinis is rich in mannose, N‐acetylgalactosamine and N‐acetylglucosamine residues.     

Ion,Protein, Phospholipid and Energy Substrate Content of Oviduct Fluid During the Oestrous Cycle of Buffalo (Bubalus bubalis)

The aim of this research was to analyse the composition of oviduct fluid (ODF) in buffalo cows at different oestrous cycle phases to fulfil the requirements of buffalo embryos in vitro. ODF was collected by chronic cannulation from three cows that were synchronized by administering a synthetic prostaglandin. Based on hormonal profiles, the pre‐ovulatory, ovulatory, post‐ovulatory and luteal phases of the oestrous cycle were defined. The volume of ODF produced (ml/24 h) was influenced by the oestrous cycle, with values (mean ± SE) around ovulation (1.0 ± 0.2) greater (p < 0.05) than in both the luteal (0.4 ± 0.1) and the post‐ovulatory phases (0.5 ± 0.1), but not different from the intermediate values in the pre‐ovulatory phase (0.8 ± 0.2). Among cycle phases, no differences were found in sodium, potassium, calcium and magnesium concentrations (130.0 ± 1.1, 5.1 ± 0.3, 2.8 ± 0.1 and 0.59 ± 0.04 mmol/l respectively). Interestingly, the chloride secretion (μm /24 h) was higher (p < 0.05) at ovulation (150.2 ± 16.5) than during both the luteal (73.7 ± 22.0) and the post‐ovulatory phases (63.7 ± 11.2), with intermediate values in the pre‐ovulatory phase (113.4 ± 23.5). Glucose concentration (mmol/l) was higher (p = 0.056) in the pre‐ovulatory phase (0.06 ± 0.02) than in the luteal (0.02 ± 0.01) and post‐ovulatory (0.02 ± 0.01) phases but not different from values in the ovulatory phase (0.04 ± 0.02). Concentrations of pyruvate and lactate among oestrous cycle phases were similar (0.08 ± 0.01 and 1.0 ± 0.1 mmol/l respectively). The total quantity of phospholipids (μmol/24 h) was greater (p < 0.05) at ovulation (0.21 ± 0.02) compared with the luteal, pre‐ovulatory and post‐ovulatory phases of the cycle (0.09 ± 0.02, 0.13 ± 0.02 and 0.09 ± 0.01 respectively). No differences were found in either the protein concentration (1.8 ± 0.3 mg/ml) or the quantity of proteins secreted in 24 h (1.8 ± 0.4 mg) among oestrous cycle phases. In conclusion, this study provides the first characterization of buffalo ODF during the oestrous cycle, showing species‐specific differences that may be useful for developing suitable media for buffalo in vitro embryo production.     

Comparison of Different Treatments for Oestrous Induction in Seasonally Anovulatory Mares

The aim of this study was to evaluate the effects of different treatments for induction and synchronization of oestrus and ovulation in seasonally anovulatory mares. Fifteen mares formed the control group (C), while 26 mares were randomly assigned to three treatment groups. Group T1 (n = 11) were treated with oral altrenogest (0.044 mg/kg; Regumate^®) during 11 days. Group T2 (n = 7) was intravaginally treated with 1.38 g of progesterone (CIDR^®) for 11 days. In group T3 (n = 8), mares were also treated with CIDR^®, but only for 8 days. All mares received PGF2α 1 day after finishing the treatment. Sonographic evaluation of follicles, pre‐ovulatory follicle size and ovulation time was recorded. Progesterone and leptin levels were analysed. Results show that pre‐ovulatory follicles were developed after the treatment in 88.5% of mares. However, the pre‐ovulatory follicle growth was dispersal, and sometimes it was detected when treatment was not finished. While in mares treated with intravaginal device, the follicle was soon detected (1.5 ± 1.2 days and 2.3 ± 2.0 days in T2 and T3 groups, respectively), in T1 group, the pre‐ovulatory follicle was detected slightly later (3.9 ± 1.6 days). The interval from the end of treatment to ovulation did not show significant differences between groups (T1 = 13.1 ± 2.5 days; T2 = 11.0 ± 3.6 days; T3 = 13.8 ± 4.3 days). The pregnancy rate was 47.4%, similar to the rate observed in group C (46.7%; p > 0.05). Initial leptin concentrations were significantly higher in mares, which restart their ovarian activity after treatments, suggesting a role in the reproduction mechanisms in mares. It could be concluded that the used treatments may be effective for oestrous induction in mares during the late phase of the seasonally anovulatory period. Furthermore, they cannot synchronize oestrus, and then, it is necessary to know the reproductive status of mares when these treatments are used for oestrous synchronization.     

Clinical relevance of pre‐ovulatory follicular temperature in heat‐stressed lactating dairy cows

Temperature gradients in female reproductive tissues seem to influence the success of key processes such as ovulation and fertilization. The objective of this study was to investigate whether pre‐ovulatory follicles are cooler than neighbouring uterine tissue and deep rectal temperatures in lactating dairy cows under heat stress conditions. Temperatures within the pre‐ovulatory follicle, on the uterine adjacent surface and 20 cm deep within rectum, were measured using fine thermistor probes within 45 min after sunrise (dawn). Cows were selected from synchronized groups for fixed‐time insemination during the warm period of the year. Five cows under direct sun radiation and 11 cows in the shade were included in the study. None of the cows in the sun area ovulated within 24 hr, whereas 10 of the 11 cows in the sun area ovulated. Four of the 10 ovulating cows became pregnant. In the ovulating cows, follicular temperatures were 0.74 and 1.54°C significantly cooler than uterine surface and rectal temperatures, respectively, whereas temperatures in the uterine area were 0.80°C significantly cooler than rectal temperatures. No significant differences among temperatures were found in non‐ovulating cows. Follicular size was similar for ovulating and non‐ovulating cows. Environmental temperatures in the shade area were 6.4°C significantly lower than those in the sun area. Results of this study indicate that pre‐ovulatory follicles are cooler than neighbouring uterine tissue and deep rectal temperatures and those temperature gradients were not found in cows suffering ovulation failure.     

Lectin Histochemistry as a Tool to Identify Apoptotic Cells in the Seminiferous Epithelium of Syrian Hamster (Mesocricetus auratus) Subjected to Short Photoperiod

Lectins have been widely used to study the pattern of cellular glycoconjugates in numerous species. In the process of cellular apoptosis, it has been observed that changes occur in the membrane sugar sequences of these apoptotic cells. The aim of our work was to identify which lectins, out of an extensive battery of the same (PNA, SBA, HPA, LTA, Con‐A, UEA‐I, WGA, DBA, MAA, GNA, AAA, SNA), show affinity for germinal cells in apoptosis, at what stage of cell death they do so and in which germinal cell types they can be detected. For this, we studied testis sections during testicular regression in Syrian hamster (Mesocricetus auratus) subjected to short photoperiod. Several lectins showed an affinity for the glycoconjugate residues of germ cells in apoptosis: Gal β1,3‐GalNAcα1, α‐d ‐mannose, N‐acetylgalactosamine and l ‐fucose. Furthermore, lectin specificity was observed for some specific germinal cells and in certain stages of apoptosis. It was also observed that one of these lectins (PNA) showed affinity for Sertoli cells undergoing apoptosis. Therefore, we conclude that the use of lectin histochemistry could be a very useful tool for studying apoptosis in the seminiferous epithelium because of the specificity shown towards germinal cells in pathological or experimentally induced epithelial depletion models.     

A lectin histochemical study of the thoracic respiratory air sacs of the fowl

The lectin-binding characteristics of the epithelial lining of the thoracic air sacs of the chicken were determined. Con A, LCA and PSA bound to the apical membrane as well as to the cytoplasm distal to the nucleus of the surface epithelium, indicated the presence of a-linked mannose as well as N-acetylchitobiose-linked alpha-fucose residues in the glycoproteins. GSL I bound to the apical membrane and cytoplasm distal to the nucleus, but not to the cilia of the epithelium, where-as MPL, DBA and RCA120 bound to the apical membrane, cilia and cytoplasm, indicated the presence of a-linked N-acetylgalactosamine residues. However, neither SJA or SBA showed any binding, indicating the absence of beta anomers of galactosyl (beta1.3)N-acetylgalactosamine and beta-linked N-acetylgalactosamine residues. UEA I bound to the apical membrane and cilia, as well as to the cytoplasm of a few cells, indicated the presence of alpha-linked fucose residues. PNA bound to the apical membrane of some, but not all, surface epithelium cells, indicated the presence of galactosyl (beta1.3)N-acetylgalactosamine residues. WGA bound to the apical membrane and cilia, as well as to the cytoplasm of a few cells, indicated the presence of neuraminic acid residues.     

Expression of aquaporin 4 in the chicken ovary in relation to follicle development

In the mammalian ovary, aquaporins (AQPs) are thought to be involved in the regulation of fluid transport within the follicular wall and antrum formation. Data concerning the AQPs in the avian ovary is very limited. Therefore, the present study was designed to examine whether the AQP4 is present in the chicken ovary, and if so, what is its distribution in the ovarian compartment of the laying hen. Localization of AQP4 in the ovarian follicles at different stage of development was also investigated. After decapitation of hens the stroma with primordial follicles and white (1–4 mm), yellowish (4–8 mm), small yellow and the three largest yellow pre‐ovulatory follicles F3‐F1 (F3 < F2 < F1; 20–36 mm) were isolated from the ovary. The granulosa and theca layers were separated from the pre‐ovulatory follicles. The AQP4 mRNA and protein were detected in all examined ovarian compartments by the real‐time PCR and Western blot analyses, respectively. The relative expression of AQP4 was depended on follicular size and the layer of follicular wall. It was the lowest in the granulosa layer of pre‐ovulatory follicles and the highest in the ovarian stroma as well as white and yellowish follicles. Along with approaching of the largest follicle to ovulation the gradual decrease in AQP4 protein level in the granulosa layer was observed. Immunoreactivity for AQP4 was present in the granulosa and theca cells (theca interna ≥ theca externa > granulosa). The obtained results suggest that AQP4 may take part in the regulation of water transport required for follicle development in the chicken ovary.     

Modification by metyrapone of the “open period” for pre‐ovulatory LH release in the hen

1. A single injection into laying hens of 60 mg metyrapone 28 h after the final ovulation of a sequence induced increases in the plasma concentrations of LH and progesterone, followed by premature ovulation. Injection of metyrapone 8 h after ovulation, however, did not affect plasma concentrations of either LH or progesterone.

2. Injection of laying hens with 60 mg metyrapone on 5 successive days reduced the effectiveness of exogenous ACTH in increasing the plasma concentration of corticosterone and abolished the system of “ open “ and “ closed periods “ for pre‐ovulatory LH release. Thus, pre‐ovulatory LH surges and ovipositions occurred throughout the 24‐h day instead of being restricted to an 8 to 10‐h period of the day.

3. These observations suggest that changes in environmental stimuli such as light act via the adrenal gland in regulating the timing of the “ open period “ for the pre‐ovulatory release of LH in the hen.     

Does Clinical Treatment with Phenylbutazone and Meloxicam in the Pre‐ovulatory Period Influence the Ovulation Rate in Mares?

The presence of anovulatory haemorrhagic follicles during the oestrous cycle of mares causes financial impacts, slowing conception and increasing the number of services per pregnancy. Non‐steroidal anti‐inflammatory drugs (NSAIDs) such as meloxicam and phenylbutazone are used in the treatment of several disorders in mares, and these drugs can impair the formation of prostaglandins (PGs) and consequently interfere with reproductive activity. This study aimed to evaluate the effects of treatment with NSAIDs on the development of pre‐ovulatory follicles in mares. In total, 11 mares were studied over three consecutive oestrous cycles, and gynaecological and ultrasound examinations were performed every 12 h. When 32‐mm‐diameter follicles were detected, 1 mg of deslorelin was administered to induce ovulation. The first cycle was used as a control, and the mares received only a dose of deslorelin. In the subsequent cycles, in addition to receiving the same dose of deslorelin, each mare was treated with NSAIDs. In the second cycle, 4.4 mg/kg of phenylbutazone was administered, and in the third cycle, 0.6 mg/kg of meloxicam was administered once a day until ovulation or the beginning of follicular haemorrhage. All of the mares ovulated between 36 and 48 h after the induction in the control cycle. In the meloxicam cycle, 10 mares (92%) did not ovulate, while in the phenylbutazone cycle, nine mares (83%) did not ovulate. In both treatments, intrafollicular hyperechoic spots indicative of haemorrhagic follicles were observed on ultrasound. Thus, our results suggested that treatment with meloxicam and phenylbutazone at therapeutic doses induced intrafollicular haemorrhage and luteinization of anovulatory follicles.     

Efficiency of Oestrous Synchronization by GnRH,Prostaglandins and Socio‐Sexual Cues in the North African Maure Goats

This study aims to develop at different seasons, for local North African Maure goats, synchronizing protocols simultaneously to the standard ‘S’ protocol using progestagens in association with prostaglandins and gonadotropin. In late May, 40 goats were assigned to either the ‘S’ protocol or to a protocol where oestrus and ovulation were induced by the buck effect in single‐injection progesterone‐treated goats and provoking early luteolysis using prostaglandin 9 days after exposure to bucks ‘B’. During the 72 h after the treatments ended, 15 and 5 goats expressed oestrus in the ‘S’ and ‘B’ protocols (p < 0.01). Mean time to oestrus was shorter for ‘S’ than for ‘B’ goats. Ovulation rate averaged 2.1 ± 0.22 and 1.60 ± 0.35 for, respectively, ‘S’ and ‘B’ goats (p > 0.05). During mid‐September, 60 goats were assigned to either ‘S’ treatment, ‘PGF’ treatment where oestrus and ovulation were synchronized using two injections of prostaglandin 11 days apart or to ‘GnRH’ treatment where the goats had their oestrus and ovulation synchronized with a GnRH (day 0)–prostaglandin (day 6)–GnRH (day 9) sequence. More ‘S’ goats were detected in oestrus over the 96‐h period after the end of the treatments (88.8, 73.7 and 55% in ‘S’, ‘PGF’ and ‘GnRH’ treatments, respectively; p < 0.05). Mean ovulation rates were 2.3 ± 0.27, 1.33 ± 0.27 and 1.33 ± 0.27 for, respectively, ‘S’, ‘PGF’ and ‘GnRH’ goats (p < 0.001). Despite a similar ovulatory response to ‘S’ protocol, efficiency of prostaglandin and GnRH‐based treatments should be tested in mid‐breeding season.     

Effect of Deslorelin and/or Human Chorionic Gonadotropin on Inducing Ovulation in Mares During the Transition Period Versus Ovulatory Season

The objective of this study was to compare the rate of ovulation when deslorelin and/or human chorionic gonadotropin (hCG) was administered in mares in both the transition period and the ovulatory season. A total of 200 Paint Horses, Quarter Horses, and crossbred mares were used during the transition season (July to September) and the ovulatory season (October to February) of the southern hemisphere. The animals were divided into four groups. In the control group (n = 72), mares received 1 mL of saline; in deslorelin group (n = 171), 1.5 mg of deslorelin was administered by intramuscular (IM) injection; in hCG group (n = 57), 1,667 IU of hCG was administered IV; and in hCG + deslorelin group (n = 438), 1.5 mg of deslorelin (IM) and 1,667 IU of hCG (IV) were administered. The drugs were administered after follicles ≥35 mm in diameter were identified and grade III uterine edema was observed. At 48 hours after application, ultrasonography was performed to detect ovulation. During the transition period, the ovulation rates were 4.3% (control), 78.6% (deslorelin), 50% (hCG), and 73.3% (hCG + deslorelin). During ovulatory season, the ovulation rates were 16.4% (control), 68.8% (deslorelin), 60% (hCG), and 73% (hCG + deslorelin). There was no significant difference (P > .05) in the ovulation rate between the groups or the periods, except that the control group was lower than all others. Furthermore, both hCG and deslorelin are viable options for inducing ovulation during the transition period before ovulation season.     

Ovarian and Hormonal Responses to Follicular Phase Administration of Investigational Metastin/Kisspeptin Analog,TAK‐683, in Goats

This study evaluated the effects of follicular phase administration of TAK‐683, an investigational metastin/kisspeptin analog, on follicular growth, ovulation, luteal function and reproductive hormones in goats. After confirmation of ovulation by transrectal ultrasonography (Day 0), PGF_2α (2 mg/head of dinoprost) was administered intramuscularly on Day 10 to induce luteal regression. At 12 h after PGF_2α administration, intravenous administration of vehicle or 35 nmol (50 μg)/head of TAK‐683 was performed in control (n = 4) and treatment (n = 4) groups, respectively. Blood samples were collected at 6‐h intervals for 96 h and then daily until the detection of subsequent ovulation (second ovulation). After the second ovulation, ultrasound examinations and blood sampling were performed every other day or daily until the subsequent ovulation (third ovulation). Mean concentrations of LH and FSH in the treatment group were significantly higher 6 h after TAK‐683 treatment than those in the control group (12.0 ± 10.7 vs 1.0 ± 0.7 ng/ml for LH, 47.5 ± 28.2 vs 15.1 ± 3.4 ng/ml for FSH, p < 0.05), whereas mean concentrations of oestradiol in the treatment group decreased immediately after treatment (p < 0.05) as compared with the control group. Ovulation tended to be delayed (n = 2) or occurred early (n = 1) in the treatment group as compared with the control group. For the second ovulation, ovulatory follicles in the treatment group were significantly smaller in maximal diameter than in the control group (3.8 ± 0.5 vs 5.4 ± 0.2 mm, p < 0.05, n = 3). Administration of TAK‐683 in the follicular phase stimulates gonadotropin secretion and may have resulted in ovulation of premature follicles in goats.     

Short‐Term Undernutrition Affects Final Development of Ovulatory Follicles in Sheep Synchronized for Ovulation

The objective of this study was to determine, in sheep, the effect of a short‐term undernutrition on growth dynamics and competence of pre‐ovulatory follicles. Synchronization of sexual cycles and induction of ovulation were performed, with progestagens and gonadotrophins, in 14 adult female sheep. Morphological characteristics and developmental competence of ovarian follicles to achieve ovulation were determined by imaging techniques (ultrasonography and laparoscopy) and blood sampling. All the animals ovulated and mean ovulation rates were similar between groups (2.0 ± 0.6 corpora lutea in control ewes and 2.2 ± 0.8 in undernourished sheep). However, nutritional restriction, even during a short period, was related to the presence of large follicles in static growing phase which, despite reaching ovulation, persisted static during the induced follicular phase and evidenced functional alterations as there was no inhibition of the development of subordinate follicles. Thus, this study suggests the existence of deleterious effects from short‐term undernutrition on functionality of pre‐ovulatory follicles, which can compromise fertility.     

Evaluation of different hormonal treatments on oestral and ovarian responses in Moroccan Beni Arouss goats during anoestrus and breeding season

The efficacy of eight combinations of fluorogestone acetate (FGA, 20 or 40 mg as intravaginal device during 11 days), equine chorionic gonadotropin (eCG, 300 or 500 UI injected 48 hr before FGA removal) and prostaglandin F_2α (cloprostenol, 0 or 50 μg injected 48 hr before FGA removal) aiming at induction and synchronization of oestrus and ovulation was evaluated during the anoestrus season in spring and during the breeding season in autumn in adult Beni Arouss goats. Oestrous behaviour was recorded between 12 and 60 hr after FGA removal. Blood samplings allowing to assess onset of the pre‐ovulatory LH surge and increase of progesterone as sign of an active corpus luteum were performed, respectively, between 20 and 60 hr and 3, 5, 8 and 15 days after FGA removal. No season‐related differences (spring vs. autumn) were observed for oestrous response (95% vs. 93%), pre‐ovulatory LH surge (94% vs. 84%) and luteal response after 3–8 and 11–15 days post‐treatment (respectively 92% vs. 66% and 92% vs. 98%). The onset of oestrus (21 [13–53] vs. 32 [12–54] hr) and LH surge (26 [20–60] vs. 38 [22–60] hr) occurred significantly later in autumn. FGA (40 vs. 20 mg) in autumn significantly delayed the onset of oestrus (36 [16–54] vs. 23 [12–47] hr) and LH surge (44 [26–58] vs. 33 [22–60] hr). Significant treatment‐related differences were recorded for onset of LH surge (earliest for 20 mg FGA, 300 IU eCG, 50 μg PGF_2α) and onset of luteal phase (latest for 40 mg FGA, 300 IU eCG, 50 μg PGF_2α). In conclusion, the hormone combinations tested appeared equally effective in terms of oestrous and ovulation rates. Season has influenced significantly the onset of oestrus and LH surge, and the high dose regimen of FGA delayed the ovarian response in autumn.     

Vital Aspects of Fallopian Tube Physiology in Pigs

This essay reviews four topical aspects of Fallopian tube physiology that bear on either successful fertilization or early development of the zygote. An initial focus is on glycoprotein secretions of the duct that accumulate as a viscous mucus in the caudal isthmus. Because this is the site of the pre‐ovulatory sperm reservoir, an involvement of the secretions is considered in: preventing uterine and ampullary tubal fluids from entering the functional sperm reservoir; removing residual male secretions from the sperm surface; deflecting spermatozoa towards endosalpingeal organelles and reducing flagellar beat before ovulation. The subtle prompting of flagellar movement with impending ovulation is examined in terms of potential reactivation mechanisms, with overall control attributed to increasing secretion of progesterone. The site of full capacitation and the acrosome reaction in a fertilizing spermatozoon is then debated, with strong arguments pointing to completion of these processes in the specific fluids at the ampullary‐isthmic junction. Finally, the synthetic activity of cumulus cells released at ovulation as a paracrine tissue in the Fallopian tube is highlighted with reference to steroid hormones, peptides and cytokines. Not only does the suspension of granulosa‐derived cells influence the process of fertilization, but also it may amplify oocyte or embryonic signals to the endosalpinx and ipsilateral ovary.     

Induction of Ovulation of Ovulatory Size Non‐Ovulatory Follicles and Initiation of Ovarian Cyclicity in Summer Anoestrous Buffalo Heifers (Bubalus bubalis) Using Melatonin Implants

This study was conducted on summer anoestrous buffalo heifers to monitor the efficacy of melatonin for induction of ovulation and ovarian cyclicity. During pre‐treatment period of 24 days, the ovarian dynamics of five cycling and 10 summer anoestrous heifers was monitored on each alternate day using a transrectal ultrasound scanner. Thereafter, during treatment period, these 10 anoestrous heifers along with additional seven anoestrous heifers were randomly allocated into non‐implanted (n = 5) and implanted (n = 12, one melatonin implant/50 kg, 18 mg melatonin/implant) group. Non‐implanted heifers were monitored on each alternate day till the confirmation of second‐ovulation in implanted heifers. Pre‐treatment period revealed the presence of dominant follicles in anoestrous heifers which attained the diameter comparable with ovulatory follicles of cycling heifers but failed to ovulate and regressed. Between 6 and 36 days (15.3 ± 2.9 days) post‐treatment, all the implanted heifers (p < 0.05) exhibited ovulation of dominant follicles; however none of the non‐implanted heifers ovulated during the corresponding period. The first‐interovulatory period in implanted heifers ranged between 8 and 28 days (18.0 ± 1.8 days). The implanted heifers with short (≤16 days) interovulatory period had short‐lived corpus luteum (CL) that had smaller diameter and secreted less progesterone (p < 0.05). The diameter of CL was large (p < 0.05) and plasma progesterone was high (p < 0.05) following second‐ovulation compared with first‐ovulation in implanted heifers. In conclusion, using melatonin implants, ovulatory size nonovulatory follicles observed in summer anoestrous buffalo heifers can be successfully ovulated to initiate ovarian cyclicity.     

Follicular Dynamics and Oestrous Detection in Thai Postpartum Swamp Buffaloes (Bubalus bubalis)

This study characterized follicular activity and oestrous behaviour from 5 to 9 days post‐calving up to the 4th ovulation postpartum (pp) in 16 multiparous (range 2–7 parities) Thai swamp buffalo cows (Bubalus bubalis), aged 4–12 years and weighing from 432 to 676 kg. Ovarian follicular activity was examined by transrectal ultrasonography (TUS) every morning. Oestrous detection was performed twice daily by direct personal observation of behaviour and for presence of clear cervical mucus discharge and indirectly by video camera recording during 21 h/day. A follicular wave‐like pattern was present before the 1st ovulation leading to short oestrous cycles. Growth rates and maximum diameters of the ovulatory follicles did not differ between the 1st and 4th ovulations. However, growth rate for non‐ovulatory dominant follicles (DF) before the 1st ovulation was lower than for the ovulatory follicle (p < 0.05). In addition, the diameter of all ovulatory follicles (14.3 ± 0.46 mm, n = 39) was significantly larger (p < 0.01) than those of the preceding last but one non‐ovulatory DF (10.8 ± 0.20 mm, n = 5), but similar to the last preceding non‐ovulatory DF diameter (12.92 ± 0.96 mm, n = 14). Short oestrous cycles were most common between the 1st and 2nd ovulations (93.75%, 15/16 cows, 10.2 ± 0.38 days) decreasing in prevalence thereafter (50%, 3/6 buffaloes, 12.0 ± 1.53 days). Oestrous signs were relatively vague around the 1st ovulation pp to become more easily detectable thereafter. This study suggests that properly fed swamp buffaloes could be mated successfully within 2 months pp, at their 2nd spontaneous ovulation, provided oestrous detection is at least performed daily at 06:00–08:00 hour.     

Evaluation of a Neck Mounted 2‐Hourly Activity Meter System for Detecting Cows About to Ovulate in Two Paddock‐Based Australian Dairy Herds

Two studies were conducted to assess the performance of a commercially available neck‐mounted activity meter to detect cows about to ovulate in two paddock‐based Holstein‐Friesian dairy herds. The activity monitoring system recorded cow activity count in 2‐hourly periods. Study I investigated the ability of the system to detect cow ovulatory periods in dairy herds managed in two different Australian environments and breeding systems using five activity alert algorithms. Herd 1 consisted of approximately 130 milking cows calving year‐round in a sub‐tropical environment and kept in a single dry lot paddock. Herd 2 consisted of approximately 400 milking cows calving seasonally in a temperate climate and fed pasture by rotation through multiple grazing paddocks. Ovulatory periods and non‐ovulatory days were identified using milk progesterone monitoring alone or in combination with ovarian ultrasonography; using these ‘gold standards’ 141 and 135 ovulatory periods were identified in 64 and 135 cows in Herds 1 and 2 respectively. Sensitivity of the activity monitoring system for detecting cow ovulatory periods ranged from 79.4% to 94.1%, specificity from 90.0% to 98.2% and positive predictive value from 35.8% to 75.8%. Study II investigated the ability of the activity meter system to predict the timing of ovulations in paddock‐based pasture‐fed dairy cattle (Herd 2). The time of ovulation was estimated by repeat trans‐rectal ovarian ultrasonography at approximately 0, 12, 24 and 36 h after artificial insemination (AI). The mean times (±SD) from onset and end of increased activity to ovulation were 33.4 ± 12.4 and 17.3 ± 12.8 h respectively (n = 94). Fifty per cent of cows (n = 47) ovulated within the 8‐h period between 30 to 38 hs after the onset of increased activity, 76.6% (n = 72) within the 16 h between 24 to 40 h, 85.1% (n = 80) within the 24 h between 18 and 42 h and 90.4% (n = 85) within the 32 h from 19 to 51 h after the onset of increased activity. Results from these studies show that in paddock‐based dairy cows in two diverse management systems, this neck‐mounted activity meter system detects high proportions of cows that are about to ovulate and provides a useful indication of when ovulation is likely to occur. However, the specificities and positive predictive values using the algorithms assessed may be lower than desirable.