Testicular shape,scrotal skin thickness and testicular artery blood flow changes in bulls of different ages

The aim of this study was to compare the biometric testicular characteristics, skin thickness and haemodynamics of the testicular artery of 12- and 24-month-old bulls using Doppler ultrasonography, the study was conducted using 48 indicus-taurus animals. The scrotal circumference (SC) and biometry characteristics of the bulls were measured to calculate the testicular volume. Doppler ultrasonography was used to obtain the haemodynamic values of the testicular artery. The skin thickness and volume were lower (p<.01) in the younger bulls (12 months:4.68 ± 0.68 mm; 168.76 ± 47.96 cm³) versus 24 months (5.05 ± 0.89; 499.73 ± 129.24 cm³) animals (p<.01). During diastole, mean velocity was lower in the 12 months (7.98 ± 3.83) than in the 24 months (11.37 ± 4.15) animals (p <.05). The 12-month-old animals had higher pulsatility and resistivity indices (0.49 ± 0.02; 0.51 ± 0.20) compared to the 24-month-old animals (0.32 ± 0.16; 0.40 ± 0.15) (p < .05). The final testicular end velocity was lower in animals with long/moderate-shaped (L/M) (7.31 ± 2.91) than in those moderate/oval-shaped (M/O) (11.48 ± 3.88) testicles (p < .05). Animals with L/M testes presented higher pulsatility values and resistivity indices (0.51 ± 0.05; 0.55 ± 0.04) compared to animals with M/O shape (0.29 ± 0.20; 0.36 ± 0.15). We showed that the blood flow of the supra testicular artery between the two evaluated ages differed, and that 24-month-old bulls presented better thermoregulation capacity. Animals with a long/moderate testicular format presented a greater vascular resistance, which was imposed on the blood flow due to the anatomical differences in the testicular artery, resulting in lower velocity, and indicating better heat dissipation in this format.     

Is sperm cryopreservation in absence of permeable cryoprotectants suitable for subfertile donkeys?

Sperm from fertile donkeys have been successfully frozen in absence of permeable cryoprotectants. The aim of this study was to determine whether this cryopreservation method is suitable for subfertile donkeys in comparison to conventional sperm freezing with glycerol. Ejaculates were collected from four Andalusian Donkeys: three fertile and one subfertile. Semen was frozen with an extender containing glycerol (GLY), or adding instead sucrose 0.25 molar and 1% bovine serum albumin (SUC) as non‐permeable cryoprotectants. After thawing, samples were assessed for total (TM, %) and progressive (PM, %) sperm motility by CASA, plasma membrane integrity (PMI, %) by epifluorescence microscopy and DNA integrity (DFI, %) by SCSA. Results (mean ± SD) were compared between extenders in fertile and subfertile donkeys using the Student's t test. No differences between GLY and SUC treatments were found in the fertile group for the sperm parameters assessed. In subfertile donkey ejaculates, GLY resulted in significantly higher values than SUC for TM (25.5 ± 3.1 vs. 19.6 ± 1.9) and PM (13.3 ± 5.1 vs. 4.0 ± 1.2), respectively. In conclusion, considering all the sperm parameters assessed, sperm freezing in absence of permeable cryoprotectants may not be still an option for cryopreservation of subfertile donkey sperm.     

Feed and water deprivation has a negative but transient effect on the rumen kinetics of Bos indicus steers

The effects on rumen kinetics after feed and water had been deprived for 72 hr were studied using four fistulated Bos indicus steers. The animals were assigned in a 2 × 4 crossover design with two treatments: feed and water ad libitum (control) and no feed and water for 72 hr (deprived) with four steers per treatment over two time periods. Feed and water deprivation caused decreases in the numbers of cellulolytic bacteria (1.4 vs. 0.4 cfu × 10⁶/ml; p = .001), live (23.7 vs. 0.8 × 10⁹/ml; p = .001), dead (12.7 vs. 0.5 × 10⁹/ml; p = .001) and total bacterial counts (36.4 vs. 1.4 × 10⁹/ml; p = .001) at day 0, compared with the control treatment. However, the deprived group had greater numbers of cellulolytic bacteria (2.7 vs. 50.1 cfu × 10⁶/ml; p = .001), live (18.3 vs. 42.2 × 10⁹/ml; p = .001), dead (6. 5 vs. 19.1 × 10⁹/ml; p = .001) and total bacterial counts (24.8 vs. 61.3 × 10⁹/ml; p = .001) from rumen fluid on day 4, compared with the control treatment. The numbers of protozoa in rumen fluid from the deprived group were less than (551.2 vs. 2.4 × 10³/ml; p = .001) the control group on day 0. However, the deprived treatment had fewer protozoa in rumen fluid than the control treatment on day 4 (p = .001) and day 9 (p = .001). Volatile fatty acids and in vitro gas production as functional measurements of rumen fluid followed the same trend as the bacterial and protozoa populations. These results indicate that feed and water deprivation would have a negative but transient effect on the rumen kinetics of Bos indicus steers.     

Effects of dietary fish oil and alpha-tocopherol supplementation on selected blood parameters and fatty acid profiles in mares and their foals

The effects of fish oil (40 ml/day) supplementation, with or without synthetic all-rac-alpha-tocopherol-acetate (2,500 IU/day), during the last 65 days before expected parturition were investigated in 15 adult mares (553 ± 24 kg BW) and their foals. Mares were assigned to one of three diets: control (n = 5), control plus fish oil and alpha-tocopherol (n = 4; FO + AT) or control with just fish oil (n = 6; FO). Blood samples were obtained from the mares before a 15-day dietary adaptation period (T1) and from mares and foals the first (T2) and fifth (T3) days post-partum. Colostrum was collected at T2 and milk at T3. Routine haematological, biochemical and alpha-tocopherol analyses were undertaken on all blood samples. Fatty acid concentrations were determined in the foal serum and alpha-tocopherol concentrations measured in the milk and colostrum. Diet had no effect on haematology or biochemistry in the mares. Alpha-tocopherol concentrations were significantly higher at T2 & T3 in the FO + AT mares. Foal WBCs were higher in FO (11.33 ± 2.59 × 10⁹/l), comparing to FO + AT and control groups (9.18 ± 1.24 × 10⁹/l and 7.26 ± 1.03 × 10⁹/l, respectively), at T3 (p < .05). There was no significant effect of the fish oil supplementation on the foal's serum fatty acid profile. In the FO + AT group, both colostrum and milk alpha-tocopherol concentrations (2.56 ± 0.36 and 1.36 ± 0.22 µg/ml, respectively) were higher compared than those of the FO group (1.33 ± 0.39 and 0.72 ± 0.31 µg/ml, respectively; p < .05). Additional 2,500 IU/day of synthetic alpha-tocopherol in the last 65 days of pregnancy increased alpha-tocopherol concentrations in colostrum and milk and the foal's serum. 40 ml/day fish oil, however, did not significantly increase serum eicosapentaenoic acid and docosahexaenoic acid concentrations in the foals.     

Does a Boar's Season of Birth Determine Semen Parameters and Reproductive Performance?

This article studies the effect of a boar's birth season and breed on semen parameters and its further reproductive performance. Research material consisted of 72 boars from three breeds (24 Polish Large White PLW, 24 Polish Landrace PL, 24 Duroc × Pietrain D×P). During the whole period of the study, selected semen parameters were analysed: semen volume, spermatozoa concentration, total number of spermatozoa, total number of motile spermatozoa, number of insemination doses and also reproductive indicators: farrowing rate, total born litter size, total number of piglets born live and still, and average piglet weight. Boars born in the winter and summer months demonstrated the highest spermatozoa concentrations (383.25 and 392.37 × 10⁶/ml), total number of spermatozoa (91.75 and 93.21 × 10⁹), total number of motile spermatozoa (76.10 and 77.99 × 10⁹) and number of insemination doses (24.53 and 24.89; p ≤0.01). Statistically lower values for these parameters were observed for boars born in the spring and especially in autumn (p ≤0.01). The significant impact of birth season on farrowing rate (p ≤ 0.05) and average piglet weight (p ≤ 0.05) was confirmed for PLW boars. For the PL breed, only the total number of piglets born live was proven to be significantly affected (p ≤ 0.05). No impact of birth season was shown on semen quality or reproductive performance for D×P boars. In our study, we showed that the birth season of a boar had a more impact on the level of semen parameters, and less on the reproductive performance indicators. The results indicated that both the quality of semen and reproductive performance varied in terms of the study factors, as well as between individual breeds of boars involved in the experiment.     

Examination of jackass (Equus asinus) accessory sex glands by B-mode ultrasound and of testicular artery blood flow by colour pulsed-wave Doppler ultrasound: Correlations with semen production

The accessory sex glands play a major role in the production of seminal plasma, and testicular artery blood flow seems to strongly influence testicular function. However, very little ultrasound imaging of these organs has been undertaken in donkeys. The present work reports the results of such examinations in five jackasses along the year. The accessory glands were inspected by B-mode ultrasound while the testicular artery blood flow was assessed by colour pulsed-wave Doppler ultrasound. The testicular artery was examined at pampiniform plexus (PPT), supratesticular area (ST) and capsular artery (CA). Values were recorded for the total arterial blood flow (TABF), peak systolic velocity (PSV), end-diastolic velocity (EDV), resistive index (RI), pulsatility index (PI) and time average maximum velocity (TAMV). Semen was obtained and assessed for sperm concentration, viability, abnormalities and motility using a CASA system. The bulbourethral glands, prostate and ductus deferens ampullae were relatively larger than in the stallion. Bulbourethral glands and ampullae sizes were inversely correlated with sperm motility. An reduction in blood flow between the level the PPP and the CA was observed, helping to reduce testis temperature and oxygen pressure. Blood flow at the CA showed the strongest correlation with semen production. PI and RI were positively correlated with the CASA motility variable STR (p = .02, p = .06) and sperm viability (p = .01), while sperm concentration (p = .05) correlated inversely with PSV, EDV, TAMV and TABF. EDV also correlated negatively with the CASA variables VSL, LIN, STR and VAP (p ≤ .05). PI and RI were also negatively correlated with testis length (p = .0093, p = −.0438).     

Effect of weaning method on body weight,testicular growth,sexual behavior,age of puberty,and testosterone concentration of Beetal bucks

The current study evaluates the effects of early (8th week) and late (16th week of age) weaning of male goat kids on their body growth, testicular growth, sexual behavior, plasma testosterone concentration, and pubertal age. Early (n = 6) and late (n = 7) weaned Beetal bucks were weekly monitored from 18th to 38th week for their body weight, scrotal circumference, testicular volume, testicular echogenicity (via ultrasonography), sexual activities, and plasma testosterone concentration. In comparison to early-weaned, late-weaned bucks showed a marked increase (p < .05) in body weight (11.4 ± 0.8 vs. 13.7 ± 0.6kg), testicular volume (44.1 ± 7.2 vs. 79.8 ± 18.7cm³), scrotal circumference (10.7 ± 0.6 vs. 12.8 ± 0.7cm), and testicular echogenicity (28.3 ± 2.7 vs. 38.3 ± 2.1) from 18th, 28th, 21st, and 24th week onward, respectively. Sexual activities started earlier in late- than early-weaned bucks (22nd vs. 25th week, respectively). Moreover, the sexual behavior index was better (p < .05) after the 34th week in late than early-weaned bucks. The plasma concentration of testosterone (at 39 weeks of age) was relatively more and the onset of puberty was 2–3 weeks earlier (p < .05) in late than early-weaned bucks. In conclusion, age-based early weaning of male kids impairs their testicular growth, sexual behavior, and age at puberty compared to conventional weaning.     

Effect of housing system on reproductive behaviour and on some endocrinological and seminal parameters of donkey stallions

Reproductive management of male donkeys employed for artificial breeding has been poorly studied. The aim of this study was to evaluate the effect of housing system, with the animals grouped together in a paddock or kept in individual boxes, on sexual behaviour, cortisol and testosterone concentration and seminal characteristics of adult male donkeys. The study included four Amiata donkey jacks (stallions) from which ejaculates, saliva and blood were collected during two distinct 3 weeks periods, one in the group and one in the box housing system. Time needed for semen collection was shorter when donkeys were kept in paddocks compared to when they were kept in single boxes (14:57 ± 07:27 and 20:52 ± 09:31 min, p < .05). Native semen characteristics were not influenced by housing system, while cooled preservation in an Equitainer^® showed that sperm motility parameters were significantly higher during the paddock period compared to the box period. Salivary cortisol was influenced by housing system, both before and 60 min after ejaculation, being statistically higher when donkeys were housed in paddocks. On the contrary, overall and basal testosterone concentrations were significantly higher when animals were kept in boxes. In conclusion, in the present study, good quality semen could be successfully collected from donkeys irrespective of the housing system despite some differences in hormone concentrations.     

Changes in testicular size,echotexture, and arterial blood flow associated with the attainment of puberty in Dorper rams raised in a subtropical climate

There is a paucity of information on the relationships of testicular morphology, echotextural attributes, and blood flow dynamics with pubertal development of rams raised in a subtropical climate. Forty‐five Dorper rams (24 rams aged 8–11 months and 21 rams aged 12–24 months) were examined using a portable ultrasound scanner connected to a 7.5‐MHz transducer. Computer‐assisted analyses of testicular ultrasonograms utilized commercially available Image ProPlus^® analytical software. Spectral Doppler scans of testicular arteries were performed immediately after scrotal (B‐mode) ultrasonography to determine peak systolic velocity (PSV), end‐diastolic velocity (EDV), resistive index (RI = [PSV?EDV]/PSV), and pulsatility index (PI = [SPV–EDV]/mean velocity) of the blood vessels. The length of the testes (9.7 ± 0.3 compared with 9.0 ± 0.2 cm) and scrotal circumference (33.3 ± 0.5 compared with 31.8 ± 0.4 cm) were greater (p < 0.05) but testicular depth (4.5 ± 0.1  compared with 4.9 ± 0.08 cm) was less (p < 0.05) in sexually mature compared with peripubertal rams. [Corrections added on 9 Jan 2019 after initial online publication: The testicular size values in the sentence were corrected.] There were no differences (p > 0.05) between the two age groups of Dorper rams in blood flow indices of testicular arteries. Mean numerical pixel values (100.5 ± 4.1 compared with 89.2 ± 4.8) and pixel heterogeneity (25.6 ± 0.6 compared with 23.6 ± 0.5) of testicular parenchyma were greater (p < 0.05) in peripubertal than in postpubertal rams. Semen volume was negatively correlated with PI of testicular arteries (r = ?0.57, p = 0.04). In summary, the attainment of sexual maturity in the rams of the present study was associated with significant changes in testicular length and depth, scrotal circumference, and parenchymal echogenicity/hetrogeneity but not in testicular volume and blood perfusion rates. Testicular artery PI can be used to predict the volume of ejaculate in rams.     

Impact of intramammary tilmicosin infusion as a dry cow therapy

Three hundred subclinically infected quarters of 259 Holstein cows infected with gram‐positive bacteria were selected via quota sampling based on the California Mastitis Test (CMT) result and were divided randomly and equally into treatment and test groups. Quarters of test group (n = 150 in 128 cows) were treated with an intramammary infusion of tilmicosin, and quarters of the control group (n = 150 in 131 cows) were treated with cloxacillin as a traditional intramammary infusion of dry cow (DC) ointment. Cows with more than one infected quarter were randomly assigned to the same group, and adjacent quarters were treated the same. The milk samples of all quarters were obtained, and bacterial cultures and somatic cell count (SCC) were tested before dry cow therapy (DCT) (50 ± 15 days before parturition), and finally on day 2 of the next lactation. Results have shown that total bacteriological cure rates on day 2 of the next lactation were 45% and 78%, (p = .01), new infection rates were 43.3% and 56.6%, and SCC was (6.732 × 10⁵ ± 3.124 × 10⁵) and (5.025 × 10⁵ ± 2.935 × 10⁵), (p > .05) in test and control groups, respectively. Tilmicosin had less effect on reducing IMI due to Corynebacterium bovis, and had no effect on Streptococcus agalactiae, but had a potent effect against Staphylococcus aureus. It was concluded that tilmicosin alone should not be infused as an alternative to conventional dry cow therapy. However, it had a significant effect against S. aureus, and the potential of tilmicosin to treat S. aureus IMI should be confirmed in further studies.     

Cryopreservation of Nili‐Ravi buffalo (Bubalus bubalis) semen in AndroMed® extender; in vitro and in vivo evaluation

The study was designed to evaluate AndroMed^® for the freezability and fertility of Nili‐Ravi buffalo semen. Semen was collected from four adult Nili‐Ravi buffalo (Bubalus bubalis) bulls for 3 weeks (replicate). Semen ejaculates from each buffalo bull were divided into three aliquots. One aliquot was used for evaluation of motility, plasma membrane integrity, livability, viability, DNA integrity and normal apical ridge. Remaining two aliquots were diluted (37°C; 50 × 10⁶ spermatozoa/ml) in tris‐citric egg yolk or AndroMed^® extender and cryopreserved in 0.5 ml French straws. After thawing, per cent post‐thaw motility (47.9 ± 0.8, 49.2 ± 1.7), plasma membrane integrity (44.4 ± 1.2, 46.8 ± 1.8) and normal apical ridge (81.4 ± 0.3, 83.2 ± 0.3) were recorded similar (p > .05) in tris‐citric egg yolk and AndroMed^® extender. Higher (p < .05) percentage of sperm livability (70.5 ± 1.4 and 64.4 ± 1.0), viability (67.5 ± 1.5 and 61.5 ± 0.6) and DNA integrity (97.0 ± 0.3 and 93.4 ± 0.21) were recorded in AndroMed^® compared to tris‐citric egg yolk post‐thaw. Values for all the aforementioned spermatozoal quality parameters were observed lower (p < .05) in frozen‐thawed compared to fresh semen irrespective of the experimental extenders. Fertility rates of buffalo semen did not differ (p > .05) either cryopreserved in tris‐citric egg yolk or AndroMed^® extender (45.5% vs. 49%). It is concluded that AndroMed^® is capable in protecting the buffalo bull sperm during freeze‐thawing process and can be adopted safely for routine use replacing the tris‐citric egg yolk extender in artificial insemination programme.     

Influence of Bacillus subtilis GCB‐13‐001 on growth performance,nutrient digestibility,blood characteristics,faecal microbiota and faecal score in weanling pigs

The present study investigated the influence of Bacillus subtilis GCB‐13‐001 on growth performance, nutrient digestibility, blood characteristics, faecal microbiota and faecal score in weanling pigs. A total of 120 weaning pigs [(Landrace × Yorkshire) × Duroc; 7.73 ± 0.75 kg (28 days of age)] were randomly allotted into three treatments according to their initial body weight (BW) and gender in a 6‐week experiment. There were 8 replication pens in each treatment, with five pigs/pen. Dietary treatment groups were as follows: (a) basal diet (CON), (b) CON + 0.1% Bacillus subtilis GCB‐13‐001 1 × 10⁸ CFU/kg (T1) and (c) CON + 0.1% Bacillus subtilis GCB‐13‐001 1 × 10⁹ CFU/kg (T2). Days 1 to 7, the BW and ADG with T2 treatment were higher (p < .05) than CON treatment, as well as F:G showed trends in linear reduction (p < .1). Days 8 to 21, the BW and ADG were improved (p < .05) in pigs offered T1 and T2 diets compared with CON diet. Days 22 to 42, BW and ADG were higher (p < .05) in pigs fed T2 diet than CON and T1 diets, and the pigs fed T1 diet had higher BW than CON treatment. Overall, the ADG with the T2 treatment was higher (p < .05) than that with the T1 and CON treatments, and pigs offered T1 treatment had higher (p < .05) ADG than CON treatment. Moreover, F:G ratio were significantly decreased (p < .05) by T2 treatment compared with CON treatment. The faecal Lactobacillus counts were improved, and E. coli counts were reduced (p < .05) in pigs fed T2 diet compared with CON at the end of the experiment. In conclusion, supplementation of 0.1% Bacillus subtilis GCB‐13‐001 1 × 10⁹ CFU/kg has shown a beneficial effect in improving BW, increase ADG, decrease F:G ratio.     

Potential effect of the microbial fermented feed utilization on physicochemical traits,antioxidant enzyme and trace mineral analysis in rabbit meat

The study investigated the potential effect of the microbial fermented feed utilization on physicochemical traits, antioxidant enzyme and trace mineral analysis in rabbit meat. A total of 72 six-week-old male rabbits were weighed and randomly divided into four groups (1) (SRKC) control; (2) (SRKP) Lactobacillus plantarum 1 × 10⁶ cfu/g fresh weight (FW); (3) (SRKG) Pediococcus acidilactici 1 × 10⁶cfu/g FW and (4) (SRKPG) P. acidilactici + L. plantarum 1 × 10⁶ cfu/g FW. Performance characteristic, weekly body weight, was positively (p < .05) enhanced, while daily feed intake (DFI) and feed convention ratio (FCR) were not influenced in treatments group as compared to untreated. The water, protein, water holding capacity (WHC) and dry matter (DM) concentration were positively (p < .05) influenced, while ash, pH, lightness, redness and yellowness were not influenced in treated group as compared to untreated. The concentration of glutathione peroxidase (Gpx), superoxide dismutase (SOD) and aspartate aminotransferase (AST) was positively (p < .05) influenced in treatments group as compared to control. Regarding trace minerals, copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn) were positively (p > .05) reduced in treated group as compared to untreated. It is concluded that the addition of lactic acid bacteria (L. plantarum and P. acidilactici) in Hybrid pennisetum silage had a constructive influence on rabbit health performance and meat biochemistry.     

Evaluation of a portable device for assessment of motility in stallion semen

In horse breeding, quality assessment of semen before insemination is often requested. Non‐laboratory‐based techniques for objective analysis of sperm motility are thus of interest. The aim of this study was evaluating a portable device for semen analysis (Ongo sperm test) and its comparison with computer‐assisted semen analysis (CASA). Semen was collected from 10 stallions, diluted to 100, 50 and 25 × 10⁶ sperm/ml and analysed for total (TM) and progressive motility (PM). The final sperm concentration influenced total motility analysed by Ongo (p < 0.05) which was higher at 100 × 10⁶ sperm/ml when compared to 25 × 10⁶ sperm/ml (p < 0.05) but not when compared to 50 × 10⁶ sperm/ml (n.s.). Sperm concentration did not influence total motility when assessed by SpermVision (n.s.). Agreement between methods was evaluated by correlation analysis and Bland–Altman plot. Intra‐assay variation of Ongo was 5.2% ± 3.0 for TM and 6.9% ± 3.4 for PM. Correlation between Ongo and CASA was r = 0.79, 0.88 and 0.83 for 100, 50 and 25 × 10⁶ sperm/ml for TM, and r = 0.87, 0.89 and 0.87 for PM, respectively (all p < 0.001). At the 100 and 25 mio/ml dilutions, the difference between the two systems deviated significantly from 0, while no such bias existed at the 50 mio/ml dilution (TM Ongo 85.0%, CASA 82.3%; PM Ongo 64.1%, CASA 66.1%). The 95% confidence interval was 19.9%, 18.9% and 19.2% ± mean for TM and 20.7%, 17.4% and 20.3% ± mean for 100, 50 and 25 × 10⁶ sperm/ml, respectively. In conclusion, Ongo sperm test sperm motility data were strongly correlated with data obtained by CASA. In addition, at a concentration of 50 × 10⁶ sperm/ml values measured with both systems were close to identical. At this concentration, which is recommended in equine AI, Ongo and CASA can be used interchangeably.     

In vitro effects of lipopolysaccharides on bovine uterine contractility

Metritis is an important disorder in dairy cows during the early postpartum period. Myometrial contractility is a prerequisite for uterine involution; however, very scanty literature is available about the effect of metritis on this process and endocrine responsiveness. This study was aimed to evaluate the effect of inflammation on uterine contractility in vitro, and the inflammation was induced by incubating myometrial strips with lipopolysaccharides (LPS). Myometrial samples were collected from 17 healthy Holstein Friesian cows during caesarean section. Eight longitudinal strips from each cow were incubated in organ baths with LPS concentrations of 0 (LPS₀), 0.1 (LPS_0.1), 1 (LPS₁) and 10 µg/ml (LPS₁₀). Spontaneous contractility and contractility induced by increasing concentrations of oxytocin (10^–10 – 10^–7 mol/L) were recorded during nine 30-min intervals (T1 to T9). The minimum amplitude (minA), maximum amplitude (maxA), mean amplitude (meanA) and area under the curve (AUC) were calculated for each time interval. LPS had an effect (p ≤ .05) on maxA, meanA and AUC. In T1, myometrial strips incubated with LPS_0.1 and LPS₁ had higher (p ≤ .05) maxA, meanA and AUC than the strips incubated with LPS₀. In T9 without oxytocin, LPS₀ led to higher (p ≤ .05) maxA, meanA and AUC than LPS_0.1 and LPS₁. In T8 and T9 with oxytocin, LPS₁ had lower (p ≤ .05) maxA, meanA and AUC than the other LPS concentrations. Interestingly, the results show that LPS has a transient positive effect on myometrial contractility in vitro and that this effect is dependent on LPS concentration and duration of incubation.     

Correlation of testicular artery Doppler velocimetry with kinetics and morphologic characteristics of epididymal sperm in dogs

Sperm quality can be affected by a reduction in testicular blood flow, which can be measured by Doppler ultrasonography. The aim of this study was to correlate the Doppler velocimetry of the testicular artery with kinetics of the epididymal spermatozoa in dogs. Twenty-two dogs (44 testicles) were evaluated by Doppler ultrasonography in five regions of the testicular artery before orchiectomy. Spermatozoa were recovered by the epididymal tail compression technique and analysed for kinetics on a computer-assisted semen analysis (CASA system). Morphology (modified Karras) and sperm membrane integrity were analysed by eosin–nigrosine staining. Data were analysed by Pearson's correlation test (p < .01). The mean total motility was 69.0% ± 17.7, progressive motility was 43.7% ± 14.7, average path velocity (VAP) was 127.0 µm/s ± 20.7, curvilinear velocity (VCL) was 221.0 µm/s ± 31.1, and sperm velocity index (SVI) was 389.9 ± 56.1. There were positive correlations between the peak systolic velocity (PSV) in the proximal supratesticular region with the SVI (r = .529), VCL (r = .555) and VAP (r = .473), and a negative correlation with the percentage of slow spermatozoa (r = −.463). The results suggest that the testicular artery blood flow velocity can positively affect the speed of spermatozoa movement. For the first time, we have correlated sperm kinetics with the Doppler evaluation of the testicular artery in dogs.     

Use of Non‐invasive Methods for Evaluating the Testicular Biometry in Collared Peccaries (Pecari tajacu Linnaeus, 1758)

The aim of this study was to compare the accuracy of two methods used to estimate testicular volume in the collared peccary. Calliper and ultrasonographic measurements of testicular dimensions (length, width and height) of both testes were taken on five adult collared peccaries. The testicular volume was calculated by Lambert's empiric formula: length (L) × width (W) × height (H) × 0.71, the formula of an ellipsoid L × W × H × 0.52, and Hansen's formula: L × W² × 0.52. The calculated volumes were then compared with the actual ones, which were estimated by water displacement. The mean of true testicular volume was 22.65 ± 1.52 ml. Lambert's formula estimated testicular volume more accurately when ultrasound measurements were taken. However, when the calliper was the methodology used, the results were closest to the true volume, especially when Ellipsoid formula and Hansen's formula were applied, and underestimated the true volumes by 1.53 ± 1.75 ml and 1.53 ± 1.65 ml, respectively. This specific application of technologies in wild animals has the potential to revolutionize the selection process for the collared peccary entering artificial insemination or natural breeding programmes.     

Melatonin improves testicular haemodynamics,echotexture and testosterone production in Ossimi rams during the breeding season

The objective was to determine effects of a single parenteral dose of melatonin on testicular blood flow indices, testicular echogenicity and plasma testosterone concentrations in rams during the physiological breeding season. We hypothesized that melatonin enhances testicular blood flow, echogenicity and plasma testosterone concentrations during the breeding season in rams. During the breeding season, 12 sexually mature Ossimi rams were randomly allocated to either a melatonin group (n = 8) that received 18 mg of melatonin in 1 ml of corn oil (injected SC) or a control group (n = 4) that received 1 ml corn oil only. Blood collection and ultrasonographic assessment of the testes and supratesticular arteries were conducted immediately before treatment (W0) and once weekly for 6 weeks after melatonin injection (W1-W6). Mean plasma testosterone concentrations were greater (p < .05; at least 1 ng/ml) in the melatonin-treated group compared to the control group from W4 to W6 after treatment. A decrease (p < .05) in both resistive index (RI) and pulsatility index (PI) began 1 week after melatonin injection (W1) and persisted until the end of the experiment, with mean RI and PI values in the melatonin group lower (p < .05) than those in the control group on W3 and W4. Furthermore, plasma testosterone concentrations in melatonin-treated rams were inversely correlated to both RI and PI (r = −.7 and −.6, respectively, p < .01). Testicular echogenicity decreased (p < .05) 1 week after melatonin injection (W1) and remained lower (p < .05) in the melatonin-treated group compared to the control group until the end of the study (W6). In conclusion, melatonin administration significantly altered testicular blood flow and echogenicity and increased plasma testosterone concentrations in Ossimi rams during the breeding season.     

Luteal vascularity and embryo dynamics in mares during early gestation: Effect of age and endometrial degeneration

The present study characterized the luteal status and the dynamic of the conceptus during the first 20 days of gestation in mares with different ages and degrees of endometrial degeneration. Total area of the corpus luteum (CL), luteal vascularity, CL area with blood signals, progesterone concentrations (P4), embryonic vesicle diameter, number of embryonic location changes, embryonic fixation position and uterine contractility were evaluated. In Experiment 1, mares ≤6 years of age (Young group, 5.6 ± 0.2 years, n = 7 mares) and mares ≥15 years of age (Old group, 17.2 ± 0.9 years, n = 6 mares) were used to investigate the effect of age. In Experiment 2, the luteal and embryonic parameters were compared between mares with minimal (Mild group, endometrial category I, n = 9 mares) and severe (Severe group, endometrial category III, n = 7 mares) endometrial degeneration. The Old and Severe groups had greater (p ≤ 0.04) total CL area and reduced luteal vascularity (p ≤ 0.04) than the Young and Mild groups, respectively. However, P4 levels and CL area with blood signals were similar (p ≥ 0.8) between the groups. A negative effect of age (p < 0.01), but not of endometrial degeneration (p = 0.6), was found for the embryonic vesicle diameter. The conceptus mobility was high (p > 0.1) until day 14 of gestation in the Severe group, while a reduced number of changes of the embryo location was detected earlier (p < 0.05) in the Old group. In conclusion, the newly formed CL of aged mares and mares with severe endometrial degeneration suffered a structural remodelling to safeguard the local blood supply and the continuous P4 output during early gestation. Moreover, an earlier reduction of the embryonic mobility and a delayed development of the conceptus were associated with advanced age, regardless of the degree of endometrial degeneration.     

Semen parameters and testicular dimensions in small breed dogs below ten‐kilogram bodyweight

Because of few available data on semen parameters in small breed dogs, the study aimed to analyse semen and measure testes of dogs ≤10.0 kg bodyweight. Semen was collected from 41 fertile stud dogs, which were divided based on bodyweight: group 1 ≤ 5.0 kg and group 2 between 5.1 and 10.0 kg. Median values for ejaculate volume (group 1: 1.2 ml; group 2: 2.2 ml), total sperm output (group 1: 110.7 × 10⁶; group 2: 215.1 × 10⁶) and testicular volume (group 1: left testicle 2.8 ml, right testicle 2.7 ml; group 2: left testicle 5.5 ml, right testicle 5.0 ml) were lower in group 1 compared to dogs of group 2 (p = .001; p = .001; both testes: p < .001). There was no difference in sperm concentration (p = .985). Based on these results, introduction of an additional weight group to the commonly used reference values is recommended, since values for ejaculate volume, total sperm output and testicular dimensions for dogs ≤5.0 kg bodyweight differed significantly from values of dogs with a bodyweight from 5.1 to 10.0 kg.