Spectral Doppler ultrasound in selecting an equine embryo receiver

The aim of this study was to evaluate whether the RI and PI values would help in choosing the best embryo recipient, and observe whether CL vascularization would influence P4 production. During the breeding season 2018/2019, the study was conducted using 35 mares, which is used for reference to collect data for the project on the day of embryo transfer. The utilized mares were divided into five groups followed by the day after ovulation, with D0 being the day of ovulation. Therefore, the five groups are as follows: D4—mares that were on the 4th post-ovulation day; D5—mares that were on the 5th post-ovulation day; and doing so successively for D6, D7 and D8. On the day of embryo transfer, the CL of the mares that selected as recipients was evaluated by B-mode and power flow mode ultrasonography and the right and left dorsal branches of the uterine arteries by spectral Doppler ultrasonography. Blood samples were taken on the day of the embryo transfer for a dosage of P4 concentration by radioimmunoassay. No statistical difference was found between the variables when the mares were separated into pregnant and non-pregnant mares, or when they were separated by age groups. When the groups of mares were compared by the day of embryo transfer, the statistical difference was found between the groups D5 × D6 (p = .0053) and D6 × D8 (p = .0036) in RI variable. In PI variable, the statistical difference was found between the groups D4 × D8 (p = .049), D5 × D6 (p = .0446) and D6 × D8 (p = .0024). We conclude that the mares with RI measurement of uterine arteries near 1.0 are correlated to mares with high CL vascularization and elevated P4 concentration.     

Ovum pick-up and in vitro maturation in spotted paca (Cuniculus paca—Linnaeus, 1766)

We tested FSHp, eCG and FSHp + eCG to establish ovum pick-up (OPU) and in vitro maturation method in spotted paca. Eight healthy adult females were subjected to each of four treatments to stimulate ovarian follicular growth. All females were subjected to a hormonal protocol using a single dose of 45 mg of injectable progesterone and single intramuscular injection of 0.075 mg d-cloprostenol on day 6. Ovarian stimulation was carried out as follows: in Group TFE (FSHp and eCG), animals were treated with a single dose of 80 mg of FSHp and 200 IU of eCG intramuscularly on day 6 after the application of progesterone; in Group TF (FSHp), they were treated with a single dose of 80 mg of FSHp intramuscularly on day 6 after application of progesterone; in Group treatment eCG, they were treated with 200 IU of eCG intramuscularly on day 6 after application of progesterone; and in Group TC (saline solution), 1 ml of saline solution was administered to control does. The OPU was performed between 22 and 26 hr after gonadotropin treatments. All recovered oocytes were placed into maturation media and incubated for 24 hr. There were no differences among the mean number of observed follicles, aspirated follicles and oocytes recovered per treatment. Oocyte maturation rates did not differ among groups, except, TF and treatment eCG oocytes had greater maturation rates than TC oocytes. In this study, gonadotropin administration failed to superovulate treated does and increase oocyte retrieval efficiency. Despite the feasibility of the procedure, further studies are needed to develop and refine hormonal protocols for oocyte recovery and in vitro maturation in this species.     

Use of two cloprostenol administrations 11.5 days apart efficiently synchronizes oestrus in photostimulated multiparous dairy goats in the non-breeding season

This study assessed the efficiency of synchronous oestrous induction by light programme followed by two doses of cloprostenol in acyclic Saanen goats of different parity orders. Primiparous (n = 22) and multiparous (n = 33) goats were subjected to 16 hr of light and 8 hr of darkness for 60 days (D0-D60), starting 10 days after the winter solstice. All goats received 120 µg cloprostenol doses on D130 (morning) and D141.5 (afternoon) (11.5 days apart). Oestrus behaviour, ovarian follicular dynamics and serum progesterone (P4) analyses were recorded from D0 to D174 at different intervals. Animals in oestrus after D141.5 were randomly assigned into two groups: assisted natural mating (NM) or artificial insemination (AI; 10–24 hr after oestrus onset with frozen-thawed semen). From D57 to D120, 89.0% of goats presented large follicles (5–8 mm) and P4 concentrations were subluteal from D0 to D120. More multiparous compared to primiparous goats (54.5%, 18/33 vs. 18.2%, 4/22) exhibited oestrus after both injections. More primiparous compared to multiparous goats (54.5%, 12/22 vs. 12.1%, 4/33) did not exhibit oestrus after any injection. A total of 35 goats (64%) were in oestrus after the second prostaglandin injection and were subjected to NM or AI. The conception rate was similar among primiparous (70.0%, 7/10) and multiparous (68.0%, 17/25) goats but the pregnancy rate differed, being 31.8% (7/22) and 51.5% (17/33), respectively. No interaction was found between parity order and P4 concentrations in does that became pregnant or not. Thus, the association between light programme (60 days, starting at the beginning of winter) and two cloprostenol administrations 11.5 days apart (starting 70 days after the end of the light treatment) resulted in sufficient synchronous oestrous response in multiparous acyclic Saanen goats to reach satisfactory fertility levels after both NM and AI.     

Weak connectivity and population cohesiveness in rudderfish Kyphosus sandwicensis (Teleostei: Kyphosidae) inhabiting remote oceanic islands

1. Population connectivity has a fundamental role in metapopulation dynamics, with important implications in conservation. Easter Island (EI) and Salas y Gómez Island (SG) in the Pacific Ocean are ideal for the study of population connectivity because they are separated by 415 km and isolated from other islands in the Pacific Ocean by >2,000 km.
2. Considering that dispersal processes could play a critical role in the persistence of its populations, the connectivity pattern of the rudderfish Kyphosus sandwicensis was evaluated between EI and SG using both a population genetics and a biophysical modelling approach.
3. The variability in the control region of the mitochondrial DNA did not show a significant phylogeographical pattern, and the variability in 16 microsatellite loci suggested that individuals of K. sandwicensis located at EI and SG belong to the same genetic population. However, historical migration showed that 0.2% of the recruits at EI come from SG and that 0.15% at SG come from EI per year.
4. Using simulated larval release during September and a larval development of 30 days in the plankton, biophysical modelling did not detect migration between the islands. Furthermore, self-recruitment shows interannual variation ranging from 5 to 10% of the total released larvae.
5. Whereas the genetic data showed a lack of population genetic structure but low connectivity of K. sandwicensis between EI and SG, the biophysical modelling showed null movement of particles between the islands. Stochastic movement of larvae or adults could explain the pattern observed, with rafting as an example. These low-frequency and stochastic movements may be important in maintaining the cohesiveness between EI and SG.

     

Inclusion of β-1,3/1,6-glucan in the ornamental fish,Jewel tetra (Hyphessobrycon eques), and its effects on growth,blood glucose,and intestinal histology

The effects of β-1,3/1,6-glucan on Hyphessobrycon eques were assessed after 42 days of feeding diets containing 0 (control group given commercial feed), 0.5, 1, or 2 g β-glucan/kg diet. In total, 180 fish, with an initial weight of 0.43?±?0.03 g, were used. There were 15 fish in each of twelve 42-L aquariums, and there were 3 aquariums of fish for each dietary treatment. The fish were fed until apparent satiety. Performance parameters (final weight, total length, standard length, feed intake, survival rate, weight gain, feed conversion, specific growth rate, and condition factor) and plasma glucose concentration were measured. Histological analysis of the proximal portion of the intestine (width and height of the villi, depth of the crypts, height of the enterocytes, thickness of the muscle layer, and number of goblet cells) was performed. Different levels of the additive did not influence fish performance (for example, final weight: control: 0.63 g, 0.5: 0.60, 1: 0.58, and 2: 0.61). Likewise, there was no influence on the plasma glucose concentration (control: 81.80 mg/dL, 0.5: 75.33, 1: 85.00, and 2: 81.00) and intestinal morphometry of the animals. However, the results showed that 2.0 g/kg of β-1,3/1,6-glucan provided a greater abundance of goblet cells secreting acidic and neutral mucus present in the epithelium (periodic acid-Schiff: 66.67 cells, Alcian blue pH 1.0: 72,67 cells, and Alcian blue pH 2.5: 95.00 cells), showing significant differences when compared to animals in the control group, which may represent better protection of the intestinal epithelium of H. eques.

     

Effect of the interaction between body weight and temperature on growth and maximum daily food intake in sharpsnout sea bream (<Emphasis Type="Italic">Diplodus puntazzo</Emphasis>)

In experimental culture conditions in tanks, the effect of weight (W: 11–452 g) and temperature (T: 14–29°C) on the growth rate (SGR, % bw day⁻¹) and maximum daily food intake (SFR, % bw day⁻¹) in sharpsnout sea bream (Diplodus puntazzo) was studied. The possible combined effect of both independent variables (W and T) was also analyzed by multiple regression analysis, fitting the data to the equation Ln Y = Ln a + b Ln W + cT + dT ² + eT Ln W. Both SGR and SFR, and therefore feed efficiency (FE = SGR/SFR), were significantly influenced by the interaction between temperature and weight and may be expressed by means of the following equations: Ln SGR = −6.1705 + 0.5809T − 0.0087T ² − 0.0249T Ln W ( R_\textadj² R_{\text{adj}}^{2}  = 0.949; ANOVA P < 0.0001); Ln SFR = −4.8257 + 0.4425T − 0.0063T ² − 0.0163T Ln W ( R_\textadj² R_{\text{adj}}^{2}  = 0.964; ANOVA P < 0.0001).The results suggest that the optimum temperature for SGR and FE (T _SGRopt and T _FEopt), and the temperature at which the maximum SFR (T _SFRmax) is reached, decreases with body weight, in accordance with the equations: T _SGRopt = 33.297 − 1.435 Ln W; T _FEopt = 29.332 − 1.890 Ln W; and T _SFRmax = 34.941 − 1.304 Ln W, respectively. In this way, T _SGRopt is 28.4, 26.7, and 24.7°C; T _SFRmax is 30.5, 28.9, and 27.1°C and T _FEopt is 22.9, 20.6, and 18°C for 30, 100 and 400 g body weight, respectively.     

Climatic variability and other site factor influences on natural regeneration of <Emphasis Type="Italic">Pinus pinaster</Emphasis> Ait. in Mediterranean forests

Background  

How environmental factors affect forest regeneration is relevant for systems that depend partially or fully on natural regeneration.     

Multinomial logit estimation of a diameter growth matrix model of two Mediterranean pine species in Spain

• Introduction   

Understanding diameter growth of the Mediterranean pine species is fundamental for evaluating and making appropriate strategic decisions in forest management. A matrix diameter growth model for two Mediterranean pine forest ecosystems in Spain has been developed.     

Effects of shrub and canopy cover on the relative growth rate of <Emphasis Type="Italic">Pinus pinaster</Emphasis> Ait. seedlings of different sizes

• Introduction   

Shrubs are recognized as important tree regeneration niches. In this study, we experimentally analysed the effects of shrub presence, canopy cover (closed cover and open cover-gaps), and seedling size on Pinus pinaster growth.