Evaluation of maize grain and polyunsaturated fatty acid (PUFA) as energy sources for breeding rams based on hormonal, sperm functional parameters and fertility

Metabolomics Analysis of Sodium Salicylate Improving the Preservation Quality of Ram Sperm

The aim of this study was to investigate the effects of sodium salicylate (SS) on the preservation and metabolic regulation of sheep sperm. Under 4 °C low-temperature conditions, SS (at 10 µM, 20 µM, 30 µM, and 50 µM) was added to the semen diluent to detect sperm motility, plasma membrane, and acrosome integrity. Based on the selected optimal concentration of SS (20 µM), the effects of 20 µM of SS on sperms' antioxidant capacity and mitochondrial membrane potential (MMP) were evaluated, and metabolomics analysis was conducted. The results showed that on the 20th day of low-temperature storage, the sperm motility of the 20 µM SS group was 62.80%, and the activities of catalase (CAT) and superoxide dismutase (SOD) were significantly higher than those of the control group (p < 0.01). The content of Ca2+, reactive oxygen species (ROS), and malondialdehyde (MDA) were significantly lower than those of the control group (p < 0.01), and the total antioxidant capacity (T-AOC) was significantly higher than that of the control group (p < 0.05); mitochondrial activity and the total cholesterol (TC) content were significantly higher than those in the control group (p < 0.01). An ultrastructural examination showed that in the SS group, the sperm plasma membrane and acrosome were intact, the fibrous sheath and axoneme morphology of the outer dense fibers were normal, and the mitochondria were arranged neatly. In the control group, there was significant swelling of the sperm plasma membrane, rupture of the acrosome, and vacuolization of mitochondria. Using metabolomics analysis, 20 of the most significant differential metabolic markers were screened, mainly involving 6 metabolic pathways, with the amino acid biosynthesis pathway being the most abundant. In summary, 20 µM of SS significantly improved the preservation quality of sheep sperm under low-temperature conditions of 4 °C.

Identification of hub genes and their expression profiling for predicting buffalo (Bubalus bubalis) semen quality and fertility

Sperm transcriptomics provide insights into subtle differences in sperm fertilization competence. For predicting the success of complex traits like male fertility, identification of hub genes involved in various sperm functions are essential. The bulls from the transcriptome profiled samples (n = 21), were grouped into good and poor progressive motility (PM), acrosome integrity (AI), functional membrane integrity (FMI) and fertility rate (FR) groups. The up-regulated genes identified in each group were 87, 470, 1715 and 36, respectively. Gene networks were constructed using up- and down-regulated genes from each group. The top clusters from the upregulated gene networks of the PM, AI, FMI and FR groups were involved in tyrosine kinase (FDR = 1.61E-11), apoptosis (FDR = 1.65E-8), translation (FDR = 2.2E-16) and ribosomal pathway (FDR = 1.98E-21), respectively. From the clusters, the hub genes were identified and validated in a fresh set of semen samples (n = 12) using RT-qPCR. Importantly, the genes (fold change) RPL36AL (14.99) in AI, EIF5A (54.32) in FMI, and RPLP0 (8.55) and RPS28 (13.42) in FR were significantly (p < 0.05) up-regulated. The study suggests that the expression levels of MAPK3 (PM), RPL36AL + RPS27A or RPL36AL + EXT2 (AI), RPL36AL or RPS27A (FMI) and RPS18 + RPS28 (FR) are potential markers for diagnosing the semen quality and fertility status of bulls which can be used for the breeding program.

X chromosome-linked genes in the mature sperm influence semen quality and fertility of breeding bulls

The role of sperm expressed X-linked genes on bull fertility has not been studied in detail. The objective of the present study was to assess the influence of X-linked genes on the sperm functional parameters and field fertility rate in the Holstein Friesian cattle (n = 12) and Murrah buffalo (n = 7) bulls. The enrichment analysis (cattle = 8; buffalo = 8) of the X-linked genes was carried out using retrospective RNA-seq data and mRNA expression levels of functionally relevant genes were validated using the RT-qPCR. The mRNA expression levels of these genes were functionally associated with sperm attributes and field fertility rate. The sperm transcriptome studies revealed that the total number of expressed genes and the transcript content of the X-linked genes in the mature sperm were very low in both species, and only 23.31% of these genes were commonly expressed between them. The transcript pool corresponding to the X-linked genes represents embryonic organ development (p = 0.03) and reproduction (p = 0.02) processes in cattle and buffalo sperm, respectively. The mRNA expression levels of X-linked genes, RPL10 and ZCCHC13 in cattle; AKAP4, TSPAN6, RPL10 and RPS4X in buffalo were significantly (p < 0.05) correlated with sperm kinematics. Importantly, the mRNA expression levels of the genes RPL10 (r = -0.68) and RPS4X (r = 0.81) had a significant correlation with the field fertility rate in cattle and buffalo, respectively. Multivariate regression models and receiver operating curve analysis suggest that the mRNA expression levels of X-linked genes may be useful in predicting bull fertility. The study indicates that sperm-expressed X-linked genes influence semen quality and field fertility rate in both cattle and buffalo.

High-sensitivity pattern discovery in large, paired multiomic datasets

MOTIVATION

Modern biological screens yield enormous numbers of measurements, and identifying and interpreting statistically significant associations among features are essential. In experiments featuring multiple high-dimensional datasets collected from the same set of samples, it is useful to identify groups of associated features between the datasets in a way that provides high statistical power and false discovery rate (FDR) control.

RESULTS

Here, we present a novel hierarchical framework, HAllA (Hierarchical All-against-All association testing), for structured association discovery between paired high-dimensional datasets. HAllA efficiently integrates hierarchical hypothesis testing with FDR correction to reveal significant linear and non-linear block-wise relationships among continuous and/or categorical data. We optimized and evaluated HAllA using heterogeneous synthetic datasets of known association structure, where HAllA outperformed all-against-all and other block-testing approaches across a range of common similarity measures. We then applied HAllA to a series of real-world multiomics datasets, revealing new associations between gene expression and host immune activity, the microbiome and host transcriptome, metabolomic profiling and human health phenotypes.

AVAILABILITY AND IMPLEMENTATION

An open-source implementation of HAllA is freely available at http://huttenhower.sph.harvard.edu/halla along with documentation, demo datasets and a user group.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Effect of Bovine Serum Albumin Supplementation in Tris-Soybean Lecithin-Based Extender on Quality of Chilled Ram Epididymal Spermatozoa

Objective: This study was designed to assess the effects of using tris-soybean lecithin (TSL)-based extender supplemented with bovine serum albumin (BSA) on the quality of ram epididymal spermatozoa during refrigerated storage. Method: Epididymal sperm were collected from 22 Zandi rams, diluted in TSL-based extender at different concentrations (0%, 2.5%, 5%, 7.5%, and 10%) of BSA, and stored for 5 days at 4°C. Sperm parameters including motility, viability, plasma membrane integrity, chromatin protamination, and malondialdehyde (MDA) content were evaluated at 0, 24, 72, and 120 hours of refrigeration. Results: The addition of 10% BSA to the extender significantly improved sperm viability at 24 and 120 hours of refrigerated liquid storage (p < 0.05). An enhancement in plasma membrane integrity was observed along with a decrease in MDA level by increasing the concentration of BSA from 0% to 10% (p > 0.05). Sperm motion characteristics were higher in the BSA-free group at 120 hours of preservation (p < 0.05). No statistical difference was found for nuclear protamination between experimental groups (p > 0.05). Conclusion: BSA supplementation in TSL-based extender can preserve the viability of epididymal ram spermatozoa during liquid storage at 4°C.

Orchestrating the expression levels of sperm mRNAs reveals CCDC174 as an important determinant of semen quality and bull fertility

Bulls with acceptable semen quality vary in actual field fertility and this can be elucidated by studying the expression levels of mRNAs in the sperm. The present study aimed at assessing the variations in the sperm gene expression levels of PRM1, CCDC174, RPL36A, TMCO2, SWI5 and OIT3 in bulls differing in fertility status. Frozen semen samples from Holstein-Friesian bulls were classified into high-fertile (n = 8, average field conception rate = 46.1 ± 0.51, p < 0.001) and sub-fertile (n = 7, average field conception rate = 39.4 ± 0.69) groups. In the post-thaw semen samples, sperm kinematics, structural and functional membrane integrities, mitochondrial membrane potential and chromatin distribution were analyzed. The sperm total RNA was subjected to gene expression studies by Real-Time PCR. Multivariate regression analysis was performed using gene expression levels and conception rates. The sperm functional attributes did not differ significantly between the groups. The relative mRNA levels (fold change) of CCDC174 (6.20), RPL36A (4.66), SWI5 (1.86) and OIT3 (1.53) were higher in high-fertile bulls. Further, the expression level of the CCDC174 gene was significantly (p = 0.02) up-regulated in high-fertile bulls. The fertility prediction multivariate model with genes, CCDC174, RPL36A, TMCO2 and OIT3 had the maximum coefficient of determination (R² = 0.68) with the field conception rate. This model had 93.3% bull fertility prediction accuracy with 100% sensitivity and 87.5% specificity. The study suggests that the expression level of CCDC174 can be used as a potential marker for assessing bull fertility.

Effect of feeding linseed diet on testis development, antioxidant capacity, and epididymal cauda sperm concentration in Chinese Hu lamb

Polyunsaturated fatty acids (PUFAs) are essential for mammalian testis development and sperm function. However, PUFAs that are contained in linseed oil are easily oxidized in the diet and biohydrogenated in the rumen. In this study, we investigated the effect of linseed as a source of PUFAs on the antioxidant capacity and testis development in Hu lamb. Seventy-five 3-month-old lambs were randomly assigned to three groups. Within each treatment group, 25 lambs were allocated to five pens (five lambs per pen). The lambs in the control group were fed a control diet without linseed for 42 days from D22 to D63. Group I (BS28) was fed a control diet from D22 to D35 and 8% linseed diet from D36 to D63. Group II (BS42) was fed an 8% linseed diet for 42 days from D22 to D63. After 63-day feeding trial, all lambs except the heaviest and lightest in each pen were humanely slaughtered and investigated. Results revealed that feeding linseed did not affect the body weight, scrotal circumference, and testis weight, whereas feeding linseed for 42 days increased the epididymis weight (37.85 ± 1.61 g vs. 32.09 ± 1.06 g, P < 0.05) compared with the control group. Feeding lambs with linseed for 42 days also significantly upregulated the expression of antioxidative (glutathione peroxidase 4 and copper-zinc superoxide dismutase), steroidogenesis (3β-hydroxysteroid dehydrogenase and steroid acute regulatory protein), and PUFA metabolism-related genes (fatty acid desaturase 2 and elongation of very long-chain fatty acid protein 2) and proliferating cell nuclear antigen mRNA (P < 0.05). It also increased the relative expression of mitochondrial DNA (P < 0.05), total antioxidant capacity (0.230 ± 0.019 mmol/mgprot vs. 0.175 ± 0.011 mmol/mgprot, P < 0.05), and superoxide dismutase (1661.467 ± 147.117 U/mgprot vs. 1158.891 ± 98.850 U/mgprot, P < 0.05) in testicular tissue but decreased the cholesterol concentration (0.331 ± 0.073 mmol/mgprot vs. 0.671 ± 0.092 mmol/mgprot, P < 0.05) compared with the control group. Therefore, feeding lambs with linseed for 42 days stimulated seminiferous tubule development and increased the number of Sertoli cells (20.71 ± 0.89 vs. 17.6 ± 0.73, P < 0.05), epididymal cauda lumina diameter (638.26 ± 22.32 μm vs. 444.41 ± 34.80 μm, P < 0.05), and the number of sperm in the epididymal cauda (68.91 ± 7.06 × 10⁸/g vs. 36.61 ± 7.50 × 10⁸/g). All these results suggested that feeding linseed in the early reproductive development stage of lambs upregulated the expression of antioxidative, steroidogenesis, and PUFA metabolism-related genes; increased the antioxidant capacity in lamb's testis; and contributed to testis development and spermatogenesis.

Sexual maturity and fertility-related measures in young Nellore bulls receiving long-term dietary supplementation with rumen-protected polyunsaturated fatty acids

The objective of this study was to evaluate the effects of long-term supplementation with rumen-protected fatty acids (FA) on growth and reproductive parameters of young Nellore bulls in a grazing regime. Forty-eight young bulls were distributed into two groups: FA (supplemented with rumen-protected polyunsaturated FA); and control (control fat-free supplement). The animals were supplemented from 14.3 to 24.6 months of age and growth and reproductive parameters were evaluated at 28-day intervals. The semen was cryopreserved in the last collection and fresh and post-thaw semen samples were evaluated. Feeding FA did not affect (P > 0.05) growth, reproductive parameters (scrotal circumference, sperm concentration per mL of ejaculate, percentage of sperm defects, sperm quality and fertility in vitro), or testicular ultrasonographic characteristics. However, thawed semen from bulls fed FA exhibited better quality (P < 0.05) than control semen for the following parameters evaluated by computer-assisted sperm analysis: average path velocity [μm/s: 90.48 vs. 79.66 post-thaw and 74.81 vs. 72.80 post-rapid thermoresistance test (TRT)], straight-line velocity (μm/s: 72.37 vs. 65.20 post-thaw and 64.96 vs. 63.25 post-TRT), and curvilinear velocity (μm/s: 148.44 vs. 131.31 post-thaw and 115.68 vs. 113.35 post-TRT). In addition, feeding FA increased peripheral concentrations of testosterone, leptin, total cholesterol and high-density lipoprotein. In conclusion, the increase in testosterone concentrations in bulls fed FA was not related to variations in growth parameters and sexual maturity. In addition, post-thawing sperm velocities were enhanced by diet, however, such increases were not related to better in vitro embryo production rates.

Pituitary Transcriptomic Study Reveals the Differential Regulation of lncRNAs and mRNAs Related to Prolificacy in Different FecB Genotyping Sheep

Long non-coding RNA (LncRNA) have been identified as important regulators in the hypothalamic-pituitary-ovarian axis associated with sheep prolificacy. However, their expression pattern and potential roles in the pituitary are yet unclear. To explore the potential mRNAs and lncRNAs that regulate the expression of the genes involved in sheep prolificacy, we used stranded specific RNA-seq to profile the pituitary transcriptome (lncRNA and mRNA) in high prolificacy (genotype FecB BB, litter size = 3; H) and low prolificacy sheep (genotype FecB B+; litter size = 1; L). Our results showed that 57 differentially expressed (DE) lncRNAs and 298 DE mRNAs were found in the pituitary between the two groups. The qRT-PCR results correlated well with the RNA-seq results. Moreover, functional annotation analysis showed that the target genes of the DE lncRNAs were significantly enriched in pituitary function, hormone-related pathways as well as response to stimulus and some other terms related to reproduction. Furthermore, a co-expression network of lncRNAs and target genes was constructed and reproduction related genes such as SMAD2, NMB and EFNB3 were included. Lastly, the interaction of candidate lncRNA MSTRG.259847.2 and its target gene SMAD2 were validated in vitro of sheep pituitary cells. These differential mRNA and lncRNA expression profiles provide a valuable resource for understanding the molecular mechanisms underlying Hu sheep prolificacy.

Plasma IGF-I, INSL3, testosterone, inhibin concentrations and scrotal circumferences surrounding puberty in Japanese Black beef bulls with normal and abnormal semen

The relationships between semen abnormalities and peripheral concentrations of testicular and metabolic hormones in beef bulls are unclear. Here we compared plasma insulin-like growth factor I (IGF-I), insulin-like peptide 3 (INSL3), testosterone, inhibin concentrations, and scrotal circumferences surrounding puberty in Japanese Black beef bulls (n = 66) with normal or abnormal semen. We collected blood samples and measured scrotal circumferences monthly from 4 to 24 months of age. Semen was collected weekly from 12 months until at least 18 months of age. Fresh semen was evaluated for semen volume, sperm motility, concentrations, and morphological defects. The normal fresh semen was frozen by a standard method and examined for post-thaw sperm motility and fertility. Bulls were classified as having either normal post-thaw semen (n = 45) or abnormal semen (n = 21, when at least one of the above test items was abnormal for 6 months). Abnormal semen was classified into abnormal fresh or low-fertility post-thaw which evaluated for rates of transferable embryos. The abnormal fresh was categorized as having sperm morphological defects, low motility, and morphological defects plus low motility. Scrotal circumferences were smaller for the abnormal-semen group vs. the normal-semen group at 20 and 24 months (p < 0.05). Plasma IGF-I, INSL3, and inhibin concentrations in the abnormal-semen group were lower than those of the normal-semen group (p < 0.05) surrounding puberty (4-6, 8, 18-22, and 24 months for IGF-I; 6, 9, 11-14, 17, and 20-21 months for INSL3; 5, 8-13, 16, 17, 19, and 20 months for inhibin). The plasma testosterone concentrations were lower in the abnormal-semen bulls vs. normal-semen bulls only at 22 months (p < 0.05). Analyses of the classified abnormal semen showed lower plasma INSL3 concentrations for morphological defects plus low motility in fresh semen (p < 0.05) and lower IGF-I and inhibin concentrations for low-fertility post-thaw semen (p < 0.05) compared to the normal semen. Our results suggest that reduced secretions of IGF-I, INSL3, and inhibin surrounding puberty may be associated with semen aberration in beef bulls. Notably, the combined sperm abnormality of morphological defects and low motility in fresh semen could involve lowered INSL3, whereas the low-fertility post-thaw semen might be related to decreases of IGF-I and/or inhibin. Pre-puberty blood IGF-I, INSL3 and inhibin concentrations could be used as indicators to predict aberrant semen in beef bulls.

Effect of Vitamin E and Polyunsaturated Fatty Acids on Cryopreserved Sperm Quality in Bos taurus Bulls Under Testicular Heat Stress

Taurine bulls are highly susceptible to heat stress, leading to increased oxidative stress (OS) and impaired sperm viability. Polyunsaturated fatty acids (PUFAs) supplementation can be an alternative to improve semen quality, which also results in more sperm susceptibility to lipid peroxidation. Moreover, this deleterious effect can be exacerbated in animals affected by heat stress. Vitamin E is a key antioxidant that counteracts lipid peroxidation of sperm membrane caused by OS. Thus, combining PUFAs with vitamin E may improve sperm quality. In this context, this study aimed to evaluate the effect of interaction between PUFAs and vitamin E on sperm quality in Bos taurus bulls under testicular heat stress. Sixteen taurine bulls under testicular heat stress were randomly assigned in four groups: Control, Vitamin E, PUFA, and PUFA + Vitamin E. All groups lasted for 60 days. Samples were cryopreserved/thawed and analyzed for motility variables (CASA), membrane and acrosome integrity, mitochondrial activity, susceptibility to oxidative stress, DNA integrity, and sperm-binding capacity. Results showed that vitamin E had a beneficial effect on some sperm characteristics, whereas PUFA supplementation had an adverse effect when the two treatments were evaluated separately. Finally, the association between PUFAs and vitamin E did not improve sperm quality.

Dietary n-6:n-3 ratio and Vitamin E improve motility characteristics in association with membrane properties of boar spermatozoa

This study was aimed to evaluate the effects of dietary n-6:n-3 ratio and Vitamin E on the membrane properties and motility characteristics of spermatozoa in boars. Forty Duroc boars were randomly distributed in a 2 × 2 factorial design with two n-6:n-3 ratios (14.4 and 6.6) and two Vitamin E levels (200 and 400 mg kg⁻¹). During 16 weeks of treatment, fresh semen was collected at weeks 0, 8, 12, and 16 for measurements of motility characteristics, contents of fatty acids, membrane properties (membrane fluidity and membrane integrity), and lipid peroxidation of the spermatozoa. The semen was diluted in Beltsville Thawing Solution (BTS) extender and stored at 17°C, and the sperm motility was assessed at 12, 36, 72, and 120 h of storage. The 6.6 n-6:n-3 dietary ratio increased the contents of n-3 polyunsaturated fatty acids (PUFAs) and docosahexaenoic acid (DHA) and improved the membrane integrity and membrane fluidity of the spermatozoa, resulting in notably increased total motility, sperm progressive motility, and velocity parameters of fresh semen. Feeding diet with Vitamin E (400 mg kg⁻¹) prevented sperm lipid peroxidation, and resulted in higher total motility and sperm progressive motility in fresh and liquid stored semen. In conclusion, the adjustment of n-6:n-3 ratio (6.6) and supply of Vitamin E (400 mg kg⁻¹) successfully improved sperm motility characteristics and thus may be beneficial to the fertility of boars, which might be due to the modification of the physical and functional properties of spermatozoa membrane in response to dietary supplementation.

Effects of supplemental conjugated linoleic acids (CLA) on fresh and post-thaw sperm quality of Holstein bulls

This study was designed to investigate the effects of feeding-protected conjugated linoleic acid (CLA) on the semen production and sperm freezability in Holstein bulls. Twelve bulls were randomly assigned to two groups (n = 6 per group). Bulls received the normal diet (control group) or the normal diet top-dressed with 50 g of CLA (treated group) for 10 weeks. The control group received 40 g/day calcium soap of fatty acid. Fresh and post-thaw semen quality was assessed on ejaculates collected at the 0, 4, 6, 8 and 10 week of supplementation. Semen evaluations including sperm concentration, motion characteristics (subjective and computer-assisted), viability (Eosin-Nigrosin), membrane integrity (hypo-osmotic swelling test) and abnormality were conducted. Semen volume, sperm concentration and total sperm output were not affected by dietary treatment (p > .05). The proportion of spermatozoa with abnormal morphology in fresh semen significantly increased (p < .05) in the CLA-fed group compared to control group. Also, in CLA-fed group, the proportion of post-thaw spermatozoa with abnormal morphology at week 10 of trial was significantly higher in CLA than control group (p < .05). Progressive motility tended to be increased in the CLA-fed group, although dietary supplementation did not affect other CASA parameters or viability in fresh and frozen-thawed sperm. In this study, CLA supplementation had little positive effect on fresh or post-thaw sperm quality of Holstein bulls.

Effect of dietary fish oil with or without vitamin E supplementation on fresh and cryopreserved ovine sperm

This study was carried out to determine whether dietary fish oil (FO) with or without vitamin E (VE) supplementation would have a beneficial effect on characteristics of fresh and cryopreserved ovine sperm. Sixteen rams were allotted to four groups and fed one of the four diets: control diet (CON; without FO and VE supplementation), VE diet supplying 200 IU VE/day.ram, FO diet containing 2.5% (dry matter basis) FO, and OVE diet containing FO and VE. Semen samples were collected at Weeks 7, 9 and 11 for evaluation of seminal quality. Frozen samples from Weeks 9 and 11 were subjected to computer-assisted semen analysis (CASA). Seminal volume, percentage of sperm with normal morphology and intact acrosome and seminal concentration of malondialdehyde were increased in FO rams (P < 0.05). In VE rams, semen volume and percentage of morphologically normal sperm were higher compared with CON rams; however, in OVE rams these attributes were not different from those in CON rams. Other traits in fresh semen were not affected by the diet. Fish oil alone negatively affected the sperm viability, but not motility, of the frozen–thawed semen; however, simultaneous supplementation with FO and VE resulted in increased percentage of morphologically normal sperm, motility, and viability. The percentages of CASA type A (showing rapid progressive motility) and type B (showing medium progressive motility) sperm were higher in OVE compared with other groups. Vitamin E supplementation decreased the beat-cross frequency values compared with other groups. Other CASA parameters were not affected by the diets. In conclusion, dietary FO and VE in the breeding season of ram, generally, do not cause significant changes in fresh sperm quality but, for cryopreservation of sperm, supplementation of the diet with an antioxidant such as VE may be beneficial when polyunsaturated fatty acids are added to the diet.

Effect of dietary fish oil supplementation on ram semen freeze ability and fertility using soybean lecithin- and egg yolk-based extenders

Ram semen cryopreservation is not efficient for artificial insemination in commercial herds. Beneficial effects of dietary fish oil have been evaluated for cryopreservation of ram semen in soybean lecithin (SL) and egg yolk (EY)-based extenders. A factorial study (two diets × two extenders) was used to analyze the effects of two diets supplemented with fish oil (n-3 fatty acid) or palm oil (saturated fatty acids; [SFAs]) to freeze ram semen in two extenders containing SL or EY. Motility characteristics, membrane integrity, abnormal morphology, mitochondria activity, acrosome integrity, apoptotic status, and fertilizing ability were assessed after freeze-thawing. Although diet had significant (P ≤ 0.05) effects on the quality parameters of frozen-thawed sperm, effects of extenders on these traits were not significant (P > 0.05). The higher significant (P ≤ 0.05) percentage of total motility and progressive motility were observed in n-3/SL (44.83 ± 1.56 and 28.33 ± 1.4) and n-3/EY (43.33 ± 1.56 and 28.50 ± 1.4) than SFA/SL (32.16 ± 1.56 and 14.00 ± 1.4) and SFA/EY (31.66 ± 1.56 and 12.66 ± 1.4) groups. Moreover, n-3/SL and n-3/EY produced the higher significant (P ≤ 0.05) percentage of membrane integrity of sperm (39.83 ± 1.4 and 37.33 ± 1.4) than SFA/SL and SFA/EY (29.83 ± 1.4 and 28.5 ± 1.4). For viability results, the higher significant percentage of live sperm was observed in n-3/SL and n-3/EY (43.16 ± 1.38 and 45.66 ± 1.38) than SFA/SL and SFA/EY (28.66 ± 1.38 and 27.5 ± 1.38). For fertility trials, n-3-based diets (n-3/SL and n-3/EY) improved significantly (P ≤ 0.05) pregnancy rate (44% and 46%), parturition rate (42% and 42%), and lambing rate (46% and 44%) compared with the SFA-based diets (SFA/SL and SFA/EY). No interaction effects have been found between diets and extenders (P > 0.05). It seems that dietary fish oil can improve the semen performance after freezing-thawing process and artificial insemination aside from type of extenders.

Role of amino acids as additives on sperm motility, plasma membrane integrity and lipid peroxidation levels at pre-freeze and post-thawed ram semen

The possibility of including amino acids for cryopreservation of ram semen to improve the quality of frozen semen was explored in this study in sheep model. 24 samples were collected in triplicate from 8 rams of 2-3 year old Bannur cross bred rams maintained at the Institute Experimental Livestock Unit. Semen was diluted in tris-egg yolk glycerol diluent and made into 7 aliquots as follows: aliquot 1 served as control, "l-alanine" was added at 100 and 135mM in the aliquots 2 and 3, "l-glutamine" was added at 20 and 25mM in the aliquots 4 and 5 and "l-proline" was added at 25 and 50mM in the aliquots 6 and 7, respectively. Diluted semen was filled in 0.25ml French straws and frozen in LN2. Inclusion of "l-proline" and "l-glutamine" in the diluent increased the percent live sperm (P<0.001), total motility (P<0.05) and maintained higher functional membrane and acrosomal integrity (P<0.001) by decreasing lipid peroxidation (P<0.001) compared to the control group. In contrast, "l-alanine" decreased the percentage of total motility, fast progressive spermatozoa and increased (P<0.01) the percentage of immotile spermatozoa. It can be concluded that 20mM "l-glutamine" and 25mM "l-proline" can be used as semen additive to freeze ram semen as they prevented cryoinjuries to sperm and improved the pre-freeze and post-thaw semen characteristics.

Relationship between seminal plasma tuberoinfundibular peptide of 39 residues and sperm functional attributes in buffalo (Bubalus bubalis)

The buffalo seminal plasma protein profile and its relationship with sperm quality have not been studied in detail. Thus, the aim of the present study was to profile buffalo seminal plasma proteins and to assess the relationship between differentially expressed proteins and sperm characteristics. Semen samples (n = 44) were collected from 11 Murrah buffalo bulls (four ejaculates from each animal) and seminal plasma protein profiling was performed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Matrix-assisted laser desorption ionisation time-of-flight analysis of one of the differentially expressed proteins, namely the 11-12 kDa protein, identified it as tuberoinfundibular peptide of 39 residues (TIP39). Western blot analysis confirmed the presence of TIP39, with TIP39 expression in seminal plasma varying among bulls. Based on TIP39 levels, bulls were classified into two groups, those with high and low protein. The percentages of spermatozoa positive for mitochondrial membrane potential test, chromatin distribution test, synthetic media sperm penetrability test and acrosomal integrity test were significantly (P < 0.05) high in the high protein group. The present study is the first to demonstrate the presence of TIP39 in buffalo seminal plasma and the positive effect of TIP39 on the functional parameters and fertilising ability of spermatozoa.