Effect of olive-derived antioxidants (3,4-dihydroxyphenylethanol and 3,4 dihydroxyphenylglycol) on sperm motility and fertility in liquid ram sperm stored at 15°C or 5°C.

The aim of the present study was to evaluate the effect of the addition of two olive oil-derived antioxidants, hydroxytyrosol (3,4-dihydroxyphenylethanol, HT) and 3,4-dihydroxyphenylglycol (DHPG), on ovine semen during liquid storage at 5°C and 15°C. Semen was collected, pooled, diluted and then divided into aliquots supplemented with different concentrations (5 µg/ml, 10 µg/ml, 50 µg/ml and 100 µg/ml) of HT, DHPG and a mixture (MIX) of both antioxidants. Sperm motility characteristics were assessed in the different samples at 0, 6, 24, 48, 72 and 96 hr after cooling, and a fertility trial was also conducted. The results showed that the antioxidant addition did not significantly improve total and progressive motility in ovine cooled sperm maintained at 15° or 5°C. However, in samples stored at 5°C, LIN (48, 72, 96 hr), STR (0 hr) and WOB (0, 48, 72, 96 hr) values significantly decreased in comparison with control treatment when high antioxidant concentrations were added (MIX100 or HT100). When samples were maintained at 15°C, MIX50 showed significantly higher VCL values than the control treatment after 6 hr cooling, and MIX100 showed significantly lower VCL values at 96 hr after cooling. According to the artificial insemination trial, no significant differences were observed when antioxidants were added. In conclusion, the use of HT and DHPG showed small impact in sperm motility and fertility was not affected (nor detrimentally nor positively) when insemination was carried out using antioxidant-supplemented liquid sperm.

Welfare Quality® for dairy cows: towards a sensor-based assessment.

This Research Reflection addresses the possibilities for Welfare Quality® to evolve from an assessment method based on data gathered on punctual visits to the farm to an assessment method based on sensor data. This approach could provide continuous and objective data, while being less costly and time consuming. Precision Livestock Farming (PLF) technologies enabling the monitorisation of Welfare Quality® measures are reviewed and discussed. For those measures that cannot be assessed by current technologies, some options to be developed are proposed. Picturing future dairy farms, the need for multipurpose and non-invasive PLF technologies is stated, in order to avoid an excessive artificialisation of the production system. Social concerns regarding digitalisation are also discussed.

Vitrification induces critical subcellular damages in ram spermatozoa.

The aim of the present study was to analyse morphological variations in ovine spermatozoa subjected to different cryopreservation protocols using high resolution imaging techniques. Ejaculates were pooled and diluted in Tris-based extender. Aliquots containing 300 × 106 spz/ml were prepared and evaluated a) after the semen collection and pooling, b) after conventional freezing, c) after vitrification of samples maintained at room temperature (22 °C) prior to vitrification, and d) after vitrification of samples maintained at 5 °C prior to vitrification. Sperm motility, acrosome integrity, DNA fragmentation and morphology were assessed. Subcellular sperm changes were assessed and described by light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The maintenance of spermatozoa at 5 °C prior to vitrification and the use of 0.4 M sucrose pointed out lower dimensions of area, length and width than fresh, frozen and sperm maintained at 22 °C prior to vitrification. It was observed that the head width and length are significantly higher (P < 0.0001) in fresh spermatozoa than in the vitrified sperm samples. It could be hypothesized that greater intracellular fluid loss during vitrification could prevent damages in the spermatozoon throughout the reduced ice crystals formation, but mainly by the reduction of extracellular ice crystals due to the physical properties modification obtained when high concentrations of sugars are added. This is the first ultramicroscopic study carried out in ovine vitrified spermatozoa, which confirms the functional sperm alterations previously detected.

Assessment of on-farm welfare for dairy cattle in southern Spain and its effects on reproductive parameters.

In this Research Communication we analyse the animal welfare status of dairy farms located in southern Spain and test the hypothesis that monitoring of wellbeing could increase the profitability of dairy herds by improving indices of reproduction. Twenty dairy farms were visited and a total of 1650 cows were assessed using the Welfare Quality® (WQ) protocol to determine their welfare status. These farms were selected as representatives of the main types of dairy farms found in the south of Spain. No farms attained a welfare status of 'excellent', but all obtained an adequate score for most parameters. Feeding assessment showed relatively low variability among farms, whereas housing and health assessments exhibited high variability. Significant correlations were found between a number of welfare parameter pairings: between percentage of collisions and time needed to lie down; between cleanliness of water points and cleanliness of various animal parts; between farms with access to an outdoor loafing area and an inadequate body condition score and with animal cleanliness; between the frequency of animals lying partly or completely outside of the lying area and the percentage of integument alterations and finally between the presence of respiratory problems and farm hygiene parameters. Furthermore, significant correlations between welfare parameters, reproductive indices and milk production were found. The percentage of cows exhibiting an inadequate body condition score and farms where cows took longer to lie down were correlated with the calving-first insemination interval. Animals showing a higher incidence of coughing and hampered respiration presented lower heat detection rates and milk production and finally farms with dirtier animals had lower milk production. This study is the first step towards including welfare in the recording of routine data in dairy cattle farms in southern Spain.

Effect of three commercial extenders on sperm motility and fertility in liquid ram semen stored at 15 °C or 5 °C.

The effect of different extenders on sperm motility and fertility was evaluated during liquid storage of ram semen at 5 °C and 15 °C. The semen was collected, pooled and diluted in three commercial extenders: Inra 96® (INRA) based on skimmed milk, Biladyl® A fraction (BIL) based on egg yolk, and Ovixcell® (OVIX) based on soybean lecithin. Then, sperm motility was evaluated at 0, 6, 24, 48, 72 and 96 h. In order to evaluate fertility, samples stored at 15 °C were used after dilution in INRA and OVIX. Results showed that progressive motility was significantly higher up to 72 h of storage in sperm samples maintained at 5 °C in comparison with 15 °C, similarly for each tested diluent. When samples were stored at 5 °C in OVIX, kinematic parameters such as velocity (except curvilinear velocity, VCL), trajectory [linearity (LIN), straightness (STR), wobble (WOB)], amplitude of lateral head displacement (ALH) and beat/cross frequency (BCF) were higher than in INRA and BIL. No significant differences in pregnancy rate were detected between INRA (62.6%) and OVIX (58.9%). In conclusion, liquid storage at 5 °C with OVIX extender is an interesting option since non-animal components are used, and this extender offers similar in vitro and in vivo efficacy as other extenders containing animal components.

Cytological and bacteriological sampling from filters used for embryo recovery to evaluate the uterine status of donor mares.

While testing for uterine bacterial infection is usually performed prior to artificial insemination (AI), samples taken during or after embryo flushing are generally not assessed either in subfertile and old mares or in fertile mares, even though knowledge of the status of the uterine environment in which the embryo is to develop would help to predict the outcome of embryo transfer programmes. The presence of bacteria and inflammatory cells in the liquid retained in the filter after uterine flushing in donors was determined at the moment of embryo recovery. Primarily, a group of mares (n = 8) displaying evident clinical signs of endometritis was selected to evaluate the cytological and bacteriological findings in filters after uterine flushing and in uterine cotton swabs. Two uterine samples (for cytological and bacterial evaluation) were taken with cotton swabs and, subsequently, the uterus was flushed and the efflux was also subjected to bacteriological and cytological analysis. Later, a group of donors (n = 20) was also involved to evaluate the presence of bacteria and polymorphonuclear leukocytes (PMN). After embryo flushing and collection, the efflux retained in the filter was evaluated by cytology and bacteriology. A sterile cotton swab was then scrubbed on the filter mesh, and a bacterial culture was performed. The embryo recovery rate was 30% (n = 6); Escherichia coli was isolated in one efflux sample collected from embryo-productive flushings, while the other five samples were negative by culture. Bacterial growth (not considered as contamination) was observed in a total of three samples, although no inflammatory cells were detected. Bacteria were isolated in endometrial samples collected after embryo flushing in donor mares, although inflammatory cells were never present in the uterus of mares from which embryos were recovered. In the absence of clinical signs, cytological and/or bacteriological samplings are not very useful for estimating the success of embryo recovery in donor mares, but evaluation of the filter and efflux after uterine flushing in donors may provide valuable information regarding uterine status at embryo collection.

Oestrus synchronisation in postpartum dairy cows using repetitive prostaglandin doses: Comparison between D-cloprostenol and dinoprost.

This trial evaluated the reproductive performance in an early routine oestrus induction programme using two different PGF2α preparations in dairy cattle. D-cloprostenol sodium (n = 192; Group A) or dinoprost (n = 187; Group B) was administered between days 35 and 42 post partum. Also, a group of non-treated cows (n = 135; Group C) was included as control. Pedometers were used to detect oestrus, and also secondary oestrous signs and vaginal mucus quality were assessed prior to artificial insemination (AI). When oestrus was not detected for 14 days after PGF2α administration, the treatment was repeated, up to a maximum of three times. There were no differences between the study groups in oestrus detection (A = 73.48%, B = 73.01%, C = 79.26%; P = 0.428), good mucus quality (A = 96.45%, B = 91.30%, C = 93.45%; P = 0.203) and the presence of mounting lesions (A = 98.58, B = 94.93%, C = 98.13; P = 0.414). First-service pregnancy rates were 19.78%, 15.64% and 32.03% in Groups A, B and C, respectively (P = 0.003). There were no inter-group differences for the interval from parturition to first AI. However, a significantly shorter interval from parturition to conception (92.17 days, 99.45 days, 118.93 days; P = 0.002) and significantly less services per conception (2.12, 2.18, 2.66; P = 0.003) were observed in Groups A and B in comparison with Group C. The use of PGF2α resulted in better fertility in a repetitive, routine postpartum programme, although no differences between Dcloprostenol and dinoprost were detected.

Current Insights in the Repeat Breeder Cow Syndrome.

Cows can have difficulties becoming pregnant, and in certain cases, these reproductive failures do not have an evident cause. Furthermore, when these failures are repeated three or more times with estrous cycles of normal duration and in the absence of evident clinical signs, it is considered repeat breeder cow (RBC) syndrome. A substantive incidence of RBC syndrome has been reported all over the world, which severely affects the farm economy. This paper reviews those studies particularly focused on RBC syndrome from 2000 to 2023 but also includes consolidated information until this date. Hormonal imbalances, undetectable oviductal or uterine defects, or poor oocyte or embryo quality have been reported as causes of RBC syndrome, while subclinical endometritis has been considered a relevant causal agent. However, it is unresolved why this condition is recurrent in certain animals, despite the implementation of corrective management actions or treatments. Recent studies evaluate the putative role of certain genes, factors, hormones, or proteins in the pathogenesis of RBC syndrome. Numerous risk factors contribute to the appearance of this syndrome, and some of them could be mitigated to partially prevent this infertility, while others cannot be changed. Due to the complexity of this syndrome, it is important to increase knowledge about the mechanisms involved, develop new diagnostic tools to differentiate causal agents, and implement new treatments to restore fertility. There is consensus about the huge repercussions of this syndrome on farm profitability, but further studies are now needed to describe its economic impact.

Colostrum Quality Assessment in Dairy Goats: Use of an On-Farm Optical Refractometer.

Failure of passive immunity transfer is one of the main causes of increased susceptibility to infectious agents in newborn kids. To ensure successful transfer of passive immunity, kids need to be fed high-quality colostrum, containing an adequate concentration of IgG. This work evaluated the quality of colostrum obtained in the first 3 days postpartum from Malagueña dairy goats. The IgG concentration in colostrum was measured using an ELISA as a reference method, and it was estimated by optical refractometer. Colostrum composition in terms of fat and protein was also determined. The mean concentration of IgG was 36.6 ± 2.3 mg/mL, 22.4 ± 1.5 mg/mL and 8.4 ± 1.0 mg/mL on days 1, 2 and 3 after parturition, respectively. Brix values obtained using the optical refractometer were 23.2%, 18.6% and 14.1% for days 1, 2 and 3, respectively. In this population, 89% of goats produced high-quality colostrum with IgG concentrations of >20 mg/mL on the day of parturition, but this percentage declined dramatically over the following 2 days. The quality of the fresh colostrum estimated with the optical refractometer was positively correlated with those obtained using ELISA (r = 0.607, p = 0.001). This study highlights the importance of feeding first-day colostrum to newborn kids and demonstrates that the optical Brix refractometer is suitable for the on-farm estimation of IgG content in colostrum.

Targeted Glutamate Supply Boosts Insulin Concentrations, Ovarian Activity, and Ovulation Rate in Yearling Goats during the Anestrous Season.

The neuroendocrine regulation of the seasonal reproductive axis requires the integration of internal and external signals to ensure synchronized physiological and behavioral responses. Seasonal reproductive changes contribute to intermittent production, which poses challenges for optimizing goat product yields. Consequently, a significant objective in seasonal reproduction research is to attain continuous reproduction and enhance profitability in goat farming. Glutamate plays a crucial role as a modulator in several reproductive and metabolic processes. Hence, the aim of this study was to evaluate the potential impact of exogenous glutamate administration on serum insulin concentration and ovarian function during the out-of-season period in yearling goats. During the anestrous season, animals were randomly located in individual pens to form two experimental groups: (1) glutamate (n = 10, live weight (LW) = 29.1 ± 1.02 kg, body condition score (BCS) = 3.4 ± 0.2 units) and (2) control (n = 10; LW = 29.2 ± 1.07 kg, BCS = 3.5 ± 0.2), with no differences (p < 0.05) regarding LW and BCS. Then, goats were estrus-synchronized, and blood sampling was carried out for insulin quantification. Ovaries were ultrasonographically scanned to assess ovulation rate (OR), number of antral follicles (AFs), and total ovarian activity (TOA = OR + AF). The research outcomes support our working hypothesis. Certainly, our study confirms that those yearling goats treated with exogenous glutamate displayed the largest (p < 0.05) insulin concentrations across time as well as an augmented (p < 0.05) out-of-season ovarian activity.

Ultra-Rapid Freezing Using Droplets Immersed into Liquid Nitrogen in Bull Sperm: Evaluation of Two Cryoprotective Disaccharides and Two Warming Temperatures.

The present study analyzes the effects of different disaccharide concentrations and two thawing temperatures on the characteristics of ultrarapid frozen (URF) bovine sperm, compared with conventional slow-frozen (CF) sperm. For URF sperm, samples were diluted in media comprising 2% bovine serum albumin (BSA) and various nonpermeable cryoprotectants. Five groups were compared: control (without cryoprotectant), sucrose 0.15 M, sucrose 0.3 M, trehalose 0.15 M, and trehalose 0.3 M. In addition, the influence of warming temperatures, 37°C and 65°C, was analyzed. The aspect of different diluents (by drops) immersed in liquid nitrogen was also evaluated. Sperm quality was assessed by measuring motility, viability, acrosome status, and membrane lipid peroxidation (LPO). Moreover, the cryoresistance rate (CR) was determined. The drops immersed in liquid nitrogen showed that crystallization occurred, but not vitrification. CF sperm exhibited significantly higher scores for total motility (TM) and progressive motility (PM), viability, and acrosome integrity, in contrast with URF samples. Cryoprotectants for URF sperm showed a significant (p ≤ 0.05) influence on the TM and PM, viability, acrosome integrity, and CR, but not on LPO. Sperm viability was reduced after ultrarapid freezing, and the control samples were observed to have significantly lower values than those treated with disaccharides. Samples supplemented with 0.3 M sucrose exhibited higher LPO when they were thawed at 37°C. In short, a limited number of spermatozoa were able to maintain their motility and other functional attributes after ultrarapid freezing, but disaccharides showed a moderate protective effect. Samples with trehalose and sucrose at 0.15 and 0.3 M, respectively, showed higher sperm quality than samples containing only BSA. In sum, the function of spermatozoa was moderately maintained when disaccharides were used for ultrarapid freezing, although motility was significantly reduced. In addition, thawing temperatures did not modify the sperm values, suggesting that the easier procedure, that is, 37°C for 30 seconds, can be used.

Periovulatory Hormonal Profiles after Estrus Induction and Conception Rate by Fixed-Time AI in Payoya Goats during the Anestrous Season.

Sexual activity in domestic goats is positively influenced by reducing the photoperiod. Various protocols have therefore been developed in goats for the induction and synchronization of estrus during those months in which their sexual activity is reduced. The present observational study evaluates the periovulatory hormonal profile in Payoya goats (n = 24), during a non-favorable photoperiod (i.e., spring), being treated for estrus induction. The treatment comprised the vaginal insertion of sponges impregnated with progestogen (fluorogestone acetate, FGA), together with cloprostenol and equine chorionic gonadotrophin (eCG), 48 h before the end of the treatment. When the treatment ended, the plasma concentrations of the LH, FSH, progesterone and estradiol were determined. The goats were inseminated 46 h after the sponge withdrawal, and a pregnancy diagnosis was carried out 40-45 days after the insemination. Various parameters were monitored, such as the peaks of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and estradiol, and their respective intervals, in reference to the time of the sponge withdrawal. The conception rate was 62.5%, and the kidding rate was 50%. The results record the hormonal release pattern after the estrus synchronization treatment based on the FGA, and the differences between the pregnant and non-pregnant goats. The findings suggest that the LH peak produced after the estrus synchronization treatment, both in terms of the amplitude and the time of increment, is involved in the reproductive failure detected.

Goats as Valuable Animal Model to Test the Targeted Glutamate Supplementation upon Antral Follicle Number, Ovulation Rate, and LH-Pulsatility.

The potential effect of intravenous administration of glutamate on the ovarian activity and the LH secretion pattern, considering the anestrous yearling goat as an animal model, were assessed. In late April, yearling goats (n = 20) were randomly assigned to either (1) Glutamate supplemented (GLUT; n = 10, Live Weight (LW) = 29.6 ± 1.02 kg, Body Condition (BCS) = 3.4 ± 0.2 units; i.v. supplemented with 7 mg GLUT kg−1 LW) or (2) Non-supplemented (CONT; n = 10; LW = 29.2 ± 1.07 kg, BCS = 3.5 ± 0.2 units; i.v. saline). The oats were estrus-synchronized; blood sampling (6 h × 15 min) was carried out for LH quantification. Response variables included pulsatility (PULSE), time to first pulse (TTFP), amplitude (AMPL), nadir (NAD), and area under the curve (AUC) of LH. Ovaries were ultra-sonographically scanned to assess ovulation rate (OR), number of antral follicles (AF), and total ovarian activity (TOA = OR + AF). LH-PULSE was quantified with the Munro algorithm; significant treatment x time interactions were evaluated across time. The variables LW and BCS did not differ (p > 0.05) between the experimental groups. Nevertheless, OR (1.77 vs. 0.87 ± 0.20 units), TOA (4.11 vs. 1.87 ± 0.47 units) and LH-PULSE (5.0 vs. 2.2 pulses 6 h-1) favored (p < 0.05) to the GLUT group. Our results reveal that targeted glutamate supplementation, the main central nervous system neurotransmitter, arose as an interesting strategy to enhance the hypothalamic−hypophyseal−ovarian response considering the anestrous-yearling goat as an animal model, with thought-provoking while promising translational applications.

Bayesian Analysis of the Effects of Olive Oil-Derived Antioxidants on Cryopreserved Buck Sperm Parameters.

The present study evaluates the effect of olive oil-derived antioxidants, hydroxytyrosol (HT) and 3,4-dihydroxyphenylglycol (DHPG), on cryopreserved caprine sperm using Bayesian inference of ANOVA. For this proposal, sperm was collected, pooled and diluted in freezing media supplemented with different concentrations of HT, DHPG and the mixture (MIX) of both antioxidants. Sperm motility, viability, acrosome integrity, mitochondrial status, and lipid peroxidation (LPO) were assessed in fresh and frozen-thawed sperm samples. The results provided evidence that HT at low concentrations improves sperm motility and viability, and reduces the LPO. Contrastingly, DHPG and MIX exert a positive effect by reducing LPO values as concentration increases. Additionally, mitochondrial potential was reduced when samples were supplemented with HT at low concentrations and mixture of both antioxidants. Conclusively, the addition of olive oil-derived antioxidants (HT at 10 µg/mL and DHPG at 30 µg/mL) implements a protective effect in cryopreserved buck sperm. Bayesian analysis alternatives offer new possibilities to determine the repercussion of antioxidants on sperm, both quantitatively and qualitatively.

Effect of Social Rank upon Estrus Induction and Some Reproductive Outcomes in Anestrus Goats Treated With Progesterone + eCG.

We evaluated the possible role of the social rank [R] (i.e., low-LSR, middle-MSR, or high-HSR) in anestrus goats exposed to a P4 + eCG [D] (i.e., 100 or 350 IU) estrus induction protocol (EIP). Adult, multiparous (two to three lactations), multiracial, dairy-type goats (Alpine-Saanen-Nubian x Criollo goats (n = 70; 25°51' North) managed under stall-fed conditions were all ultrasound evaluated to confirm anestrus status while the R was determined 30 d prior to the EIP. The variables of estrus induction (EI, %), estrus latency (LAT, h), estrus duration (DUR, h), ovulation (OVU, %), ovulation rate (OR, n), corpus luteum size (CLS, cm), pregnancy (PREG, %), kidding (KIDD, %), and litter size (LS, n) as affected by R, D, and the R × D interaction, were evaluated. While OVU and CLS favored (p < 0.05) HSR (96% and + 1.04 ± 0.07 cm), an increased (p < 0.05) LS occurred in D350 vs. D100 (2.06 ± 0.2 vs. 1.36 ± 0.2); neither R nor D affected (p > 0.05; 38.5%) KIDD. However, EI, LAT, DUR, OR, and PREG were affected by the R × D interaction. The HSR group had the largest (p < 0.05) EI % and DUR h, irrespective of D. The shortest (p < 0.05) LAT occurred in D350, irrespective of R. While the largest (p < 0.05) OR occurred in HSR and MSR within D350, the HSR + D350 group had the largest PREG (p < 0.05). These research outcomes are central to defining out-of-season reproductive strategies designed to attenuate seasonal reproduction in goats.

Does Size Matters? Relationships among Social Dominance and Some Morphometric Traits upon Out-of-Season Reproductive Outcomes in Anestrus Dairy Goats Treated with P4 + eCG.

The possible role of the social rank (R) (i.e., low-LSR, middle-MSR, or high-HSR) in anestrus goats exposed to a P4 + eCG (D) (i.e., 100 or 350 IU) estrus induction protocol (EIP) was evaluated. Goats (Alpine-Saanen-Nubian × Criollo; n = 70; 25° North) managed under stall-fed conditions were all ultrasound evaluated to confirm anestrous status, while the social rank was determined 30 d prior to the EIP. The response variables included estrus induction (EI, %), duration of estrus (DUR, h), ovulation rate (OR, n), live weight (LW, kg), thoracic perimeter (TP, cm), thoracic diameter (TD, cm), body length (BL, cm), height at withers (HW, cm), beard length (BEA, cm), compactness index (COM, cm), and anamorphosis index (ANA, cm), as affected by R, D, and the R × D interaction were evaluated, while the correlation coefficients among reproductive and morphometric variables were quantified. An R × D interaction (p < 0.05) affected the response variables EI, DUR, and OR. While the largest (p < 0.05) EI% occurred in the HSR goats, irrespective of eCG (i.e., 100 or 350 IU), both the shortest estrus duration (DUR, h) and the lowest ovulation rate (OR, n) occurred in the LSR + D100 combination, with no differences among HSR and MSR either with D100 or D350. Regarding the LW and morphometric response variables, (i.e., LW, TP, TD, BL, HW, BEA, COM, and ANA) all of them favored either the HSR and MSR groups, with the lowest phenotypic values occurring in the LSR-goats. The EI% was observed to be positively correlated (p < 0.05) with DUR (0.71), LW (0.28), TP (0.31), TD (0.34), BL (0.33), HW (0.35), COM (0.23), and ANA (0.23). While DUR was correlated (p < 0.05) with TP (0.26) and ANA (0.24), OR demonstrated no-correlation (p > 0.05) with any response variable, either reproductive or morphometric. As expected, LW had high correlation coefficients (p < 0.01) with TP (0.86), TD (0.88), BL (0.82), HW (0.75), BEA (0.51), COM (0.97), and ANA (0.75). In general, the morphometric variables as a whole demonstrated important correlation coefficients among them (p < 0.01), ranging from 0.38 up to 0.84. To estimate the importance of the morphometric differences between social rank upon estrus induction, a principal component (PC) analysis was performed based on the correlation matrix derived from the corporal measurements. The PC1 and PC2 explained 70.3% and 17.6% of the morphometric variation, respectively. The PC1 was a measure of the goat size (i.e., small, medium, large) and its association with estrus occurrence was evaluated using a logistic regression model; the bigger the goat, the increased probability of being in estrus, by up to five times compared to small goats. Our results confirm that the higher social ranked, larger goats amalgamated some fundamental factors to be successful: aggressiveness, primacy to food access, augmented live weight, and corporal size; all of these were able to modulate out-of-season reproductive success in crossbred dairy goats subjected to an estrus induction protocol and managed under stall-fed conditions in Northern Mexico.

Precision Betacarotene Supplementation Enhanced Ovarian Function and the LH Release Pattern in Yearling Crossbred Anestrous Goats.

The possible out-of-season effect of beta-carotene supplementation on ovulation rate (OR), antral follicles (AFN), and total ovarian activity (TOA = OR + AFN) as related to the LH release pattern in yearling anestrous goats was evaluated. In late April, Alpine-Saanen-Nubian x Criollo goats (n = 22, 26 N) were randomly allotted to: (1) Beta-carotene (BETA; n = 10, orally supplemented with 50 mg/goat/d; 36.4 ± 1.07 kg live weight (LW), 3.5 ± 0.20 units, body condition score (BCS) or (2) Non-supplemented (CONT; n = 12, 35.2 ± 1.07 kg LW, 3.4 ± 0.2 units BCS). Upon estrus synchronization, an intensive blood sampling (6 h × 15 min) was accomplished in May for LH quantifications; response variables included (pulsatility-PULSE, time to first pulse-TTFP, amplitude-AMPL, nadir-NAD and area under the curve-AUC). Thereafter, an ultrasonography scanning was completed to assess OR and AFN. The Munro algorithm was used to quantify LH pulsatility; if significant effects of time, treatment or interaction were identified, data were compared across time. Neither LW nor BCS (p > 0.05) or even the LH (p > 0.05); PULSE (4.1 ± 0.9 pulses/6 h), NAD (0.47 ± 0.13 ng) and AUC (51.7 ± 18.6 units) differed between treatments. Nonetheless, OR (1.57 vs. 0.87 ± 0.18 units) and TOA (3.44 vs. 1.87 ± 0.45 units) escorted by a reduced TTFP (33 vs. 126 ± 31.9 min) and an increased AMPL (0.55 vs. 0.24 ± 0.9 ng), favored to the BETA supplemented group (p < 0.05), possibly through a GnRH-LH enhanced pathway and(or) a direct effect at ovarian level. Results are relevant to speed-up the out-of-season reproductive outcomes in goats while may embrace translational applications.

Fertility after insemination with frozen-thawed sperm using N-methylacetamide extender on the Combatiente Español avian breed.

The aim of this study was to evaluate the in vitro and in vivo quality of frozen-thawed sperm obtained from the Combatiente Español avian breed, with sperm having previously been diluted in N-methylacetamide (NMA). Experimental groups were established: fresh control semen (C); semen diluted without cryoprotectant (T1); semen diluted with extender containing NMA (T2); frozen-thawed sperm (with NMA) containing 500 × 106 spermatozoa (T3); frozen-thawed sperm (with NMA) containing 250 × 106 spermatozoa (T4). In the different groups, sperm motility and viability were assessed using a computer-assisted semen analyzer and flow cytometer, respectively. To evaluate the fertilizing capacity of the sperm, the percentage of fertile eggs was determined. The fertility rate after insemination with frozen-thawed semen was poor, and the concentration of the inseminating dose did not affect fertility rate (9.4 ±â€¯2.7% and 7.0 ±â€¯2.3%, respectively). The results indicate insemination using diluted semen without CPA leads to a reduced fertility, and the addition of 9% NMA to the extender has a greater negative effect on this in vivo variable. Furthermore, inclusion of NMA in the freezing-thawing processes reduced capacity of sperm for fertilization. Sperm viability was reduced during the freezing process, and the dilution in NMA extender affected both sperm viability and motility. The results indicate rooster fertility is negatively affected by sperm dilution, NMA addition and the frozen-thawed effects. Frozen-thawed sperm from Combatiente Español roosters maintained fertilizing capacity for no more than 6 days after insemination, whereas for fresh sperm this capacity was maintained for 14 days.

Frozen dog spermatozoa are negatively affected during storage at -80, -21 and -8 ºC.

Cryopreservation in liquid nitrogen (LN2) allows for semen to be stored for long periods of time while there is sustaining of sperm viability. In this study, there was assessment of effects induced by different storage temperatures on cryopreserved dog spermatozoa. After cryopreservation at -196 °C, sperm samples were transferred to storage conditions of -80, 21 or -8 °C. Sperm motility, morphology, viability, acrosome integrity, mitochondrial membrane potential and DNA fragmentation were determined in samples stored at -196 °C (evaluation time =0 h), and then after 12 h and 1, 4, 7 and 15 d of storage at 80, -21 and -8 °C. In samples stored at -80 °C, sperm morphology, viability, acrosome integrity, mitochondrial membrane potential and DNA fragmentation did not differ at successive evaluation times. Progressive motility was less (P < 0.05) after 12 h and total motility after 4 d of storage at -80 ºC as compared with that of the 0 h sample. With storage at the other temperatures (-21 and -8 ºC), there was a reduction of mean values for sperm total and progressive motility, viability and mitochondrial membrane potential after 12 h of storage at these temperatures. Results, therefore, indicate the use of ultra-freezers at -80 ºC to store frozen dog semen allows for maintenance of sperm characteristics for at least 15 d but motility is sustained for only 1 d. Neither of the -21 or -8 ºC storage temperatures were effective for storing of frozen dog sperm and retaining viability.