Bovine Oocyte Quality in Relation to Ultrastructural Characteristics of Zona Pellucida,Polyspermic Penetration and Developmental Competence

In the present study, the effect of bovine oocyte quality related to ultrastructural characteristics of zona pellucida (ZP), polyspermic penetration and embryo developmental competence was evaluated. Cumulus–oocyte complexes were punctioned from 453 ovaries, classified as 1, 2, 3 and 4 according to their morphological aspect, matured for 24 h and then divided into two groups. In group A, oocytes were fixed in 2.5% glutaraldehyde and 0.1 m sodium cacodylate and examined under a scanning electron microscope. Photomicrographs were taken and ZP’s pores were evaluated in squares of 6.4‐μm width. In group B, oocytes were fertilized in vitro. After 48 h, non‐cleaved oocytes were fixed for polyspermy evaluation. On days 7, 9 and 10, embryos were classified as developed (blastocysts and hatched blastocysts). Results showed that quality 1 oocytes revealed a ZP pore diameter of 0.50 ± 0.07 μm, which was smaller than the observed on oocytes of quality 2 (0.83 ± 0.10 μm), quality 3 (1.02 ± 0.22 μm) and quality 4 (1.38 ± 0.59 μm) (p ≤ 0.05). For In Vitro Fertilization (IVF), results showed that embryos originating from oocytes classed as 3 and 4 had lower cleavage rate (68.4% and 43.8%) than those belonging to class 1 and 2 (79.5% and 69.3%) (p ≤ 0.05). None oocyte classified as 3 and 4 developed to hatch blastocysts, while for oocytes belonging to quality 1 and 2, these values were, respectively, 15.2% and 12.5%. Concerning polyspermy, oocytes class 1 and 2 had lower polyspermic penetration than those belonging to class 3 and 4 (respectively 4.1%, 4.5%, 11.1% and 9.8%, for class 1, 2, 3 and 4). In conclusion, the present study demonstrated that oocytes with low qualities result in lower developmental competence and with high percentage of polyspermy after IVF, which can be the result of the ZP structure such as the number and the pore’s diameter.     

Supplementation of L‐glycine and L‐glutamate to Japanese quails from 01 to 36 days of age using the ideal protein concept

Experiment I: T_1‐1 = basal diet with 25% crude protein (CP) + limiting amino acids (LA); T_1‐2 = 20% CP + LA; T_1‐3 = 20% CP + LA + L‐glycine; T_1‐4 = 20% CP + LA + L‐glutamate; T_1‐5 = 20% CP + LA + L‐glycine + L‐glutamate. Experiment II: T_2‐1 = basal diet with 22% CP + LA; T_2‐2 = 20% CP + LA; T_2‐3 = 17.6% CP + LA + L‐glycine; T_2‐4 = 17.6% CP + LA + L‐glutamate; T_2‐5 = 17.6% CP + LA + L‐glycine + L‐glutamate. The reduction of dietary protein based on the concept of ideal protein decreases nitrogen excretion in quails when L‐glycine is added to the diets. Quails fed diets supplemented with L‐glutamate as the non‐specific nitrogen source equivalent to the nitrogen level of the control diet had increased nitrogen excretion. However, quails had reduced nitrogen excretion in both experiments when L‐glycine was added to diets with L‐glutamate. Carcass fat was increased by reducing dietary protein, but fat deposition was reduced by adding L‐glutamate and L‐glycine, or both. The dietary addition of L‐glutamate and L‐glycine in quails based on the ideal protein concept is not necessary (Exp. I). Although the total nitrogen, electrolytic balance and glycine level were adjusted in diets, quails had decreased performance. Therefore, other hypotheses besides protein reduction need to be studied (Exp. II). Protein reduction with supplementation of only limiting essential amino acids does not affect quail performance. Dietary addition of L‐glycine reduces nitrogen excretion.     

A novel strategy for resynchronization of ovulation in Nelore cows using injectable progesterone (P4) and P4 releasing devices to perform two timed inseminations within 22 days

We aimed to evaluate the reproductive performance of Nelore lactating cows submitted to a resynchronization 12 days after timed artificial insemination (TAI) with or without a long‐acting progesterone (P4‐LA) treatment. Nelore cows were submitted to a P4/oestradiol‐based TAI protocol (D0 = insemination). On D12, cows in the control group (n = 184) received a new P4 intravaginal device (0.96 g), whereas cows in the P4‐LA group (n = 192) received the P4 device and 75 mg P4‐LA. Cows identified as non‐pregnant (n = 120) by regression of corpus luteum using colour Doppler ultrasonography on D20 had the P4 device removed and received 500ug of sodium cloprostenol, 1 mg of oestradiol cypionate and 300 IU of eCG and were re‐inseminated on D22. There was no difference (p > 0.10) in the pregnancy rate at D20, D30 and D60 after first TAI between the control (69%, 59.7% and 57%, respectively) and P4‐LA (67%, 55.7%, and 55.2%, respectively) groups. Pregnancy losses were similar between both groups (p > 0.1). For cows submitted to the second TAI, the pre‐ovulatory follicle size did not differ (p > 0.1), but the oestrous detection and pregnancy rates were greater (p < 0.05) in the P4‐LA group (92.2% [59/64] and 60.9% [39/64], respectively) than in controls (75% [42/56] and 44.6% [25/56]). The cumulative pregnancy rate after two TAIs did not differ (p > 0.1) between control (73.3% [135/184]) and P4‐LA (76% [146/192]) groups. The use of P4‐LA at 12 days after TAI potentially increases the pregnancy rates for a new early resynchronization strategy associated with the Doppler imaging for pregnancy diagnosis and results in an alternative to perform two TAIs in 22 days in beef cows.     

Contrasting effects of heat shock during in vitro maturation on development of in vitro‐fertilized and parthenogenetic bovine embryos

This study investigated the influence of heat shock during in vitro maturation on embryo development following in vitro fertilization (IVF) or parthenogenesis (Part). Immature bovine cumulus–oocyte complexes were exposed to heat shock (41.0°C) during the first 12 hr of in vitro maturation (IVM), followed by 12 hr at 38.5°C. Control group consisted of in vitro maturation for 24 hr at 38.5°C. Oocytes were in vitro‐fertilized or activated with ionomycin and cultured in vitro for 192 hr post‐in vitro insemination or parthenogenetic activation (hpia). There was an interaction (p < .01) between temperature of IVM and method of oocyte activation (IVF or Part) for cleavage at 48 hpia. Heat shock had a negative impact (p < .01) on cleavage of IVF embryos, whereas no (p > .05) effect was found in the Part embryos. Embryo development towards blastocyst stage at 168 and 192 hpia decreased in both IVF and Part embryos derived from heat‐shocked oocytes. Heat shock increased (p < .05) the apoptotic index in Part blastocysts, but no effect (p > .05) was found in IVF counterparts. Heat shock also down‐regulated the expression of AQP3 (p < .01) and up‐regulated the expression of HSP70.1 (p < .01) in Part blastocysts, whereas it down‐regulated the expression of ATP1A1 (p < .05) in IVF blastocysts. In conclusion, the effects of heat shock during IVM on early embryo cleavage and blastocyst apoptosis are influenced by the method of oocyte activation and expression of some genes can be disturbed in embryos derived from heat‐shocked oocytes.     

Behavioral and physiological evaluation of sows raised in outdoors systems in the Brazilian semiarid region

Tropical Animal Health and Production - The objective of this study was to evaluate the biochemical, behavioral, and physiological parameters in pregnant sows of native and improved crossbreeds...     

Intranasal Osteosarcoma in a Dog—A Case Report

Osteosarcoma is the most commonly reported bone tumor in dogs, typically affecting the axial and appendicular skeleton. Involvement of the paranasal sinuses and the nasal cavity is extremely rare. This report describes a 6-year-old, female, cross-breed dog presented with signs of 90 days duration and diagnosed with a mass located in the right nasal cavity. Radiography, rhinoscopy, and computed tomography findings suggested the presence of an intranasal tumor. Osteosarcoma in the nasal cavity was diagnosed based on histopathological examination and clinical and imaging findings. Survival time was 12 months from diagnosis.     

Comparison Between a γ-IFN Assay and Intradermal Tuberculin Test for the Diagnosis of Bovine Tuberculosis in Field Trials in Brazil

Bovine tuberculosis is a major problem in Brazil. The intradermal tuberculin test is the standard test for detection of bovine tuberculosis in Brazil but can lack both sensitivity and specificity. The purpose of this study was to compare a bovine γ-IFN assay with the tuberculin test under field conditions in Brazil. A total of 1632 animals from 13 dairy farms were tested using the single cervical tuberculin test (SCTT). Among those animals, about 15% of each herd, 220 in total, represented a high-risk group and were selected to be tested using the γ-IFN test. Of the 1632 animals tested, 207 presented significant reactions representing 12.7% of the cattle studied. In the selected group the number of animals positive by the γ-IFN assay was 126/220 (57.3%) and the total number of reactive cows on SCTT was 106/220 (48.2%). The real number of infected cattle, following standards, was 120/220 (54.5%). From these results the relative sensitivity rate of γ-IFN test was 100% including the false-positive results and 88.3% for the SCTT — a significant (P < 0.01) difference in favour of the γ-IFN test of 11.7%. The γ-IFN assay also identified some positive animals 60–120 days earlier than the SCTT. In conclusion, we believe that the γ-IFN assay can be used alone or in combination with the SCTT, as a valuable tool for the control of bovine tuberculosis in the Brazilian national herd.     

Sperm cryopreservation of tiete tetra Brycon insignis (Characiformes): effects of cryoprotectants,extenders, thawing temperatures and activating agents on motility features

The aim of this study was to test the effects of cryoprotectants [dimethyl sulphoxide (DMSO) and methylglycol], extenders (0.9% NaCl, 5% glucose, Beltsville Thawing Solution^? and Merck III^?), thawing temperatures (30 and 60 °C) and activating agents (0.29% NaCl and 1% NaHCO₃) on the cryopreservation process of tiete tetra Brycon insignis sperm. Sperm was loaded in 0.5 mL straws, frozen in nitrogen vapour at ?170 °C and stored in liquid nitrogen. Post‐thaw sperm quality was evaluated in terms of subjective motility rate, quality motility score (0=no movement; 5=rapidly swimming spermatozoa), duration of motility and vitality (eosin–nigrosin staining). Post‐thaw sperm motility rate was greater in methylglycol (76–88%), compared with DMSO (23–59%). In general, the highest quality motility scores were observed when sperm was thawed at 30 °C and triggered in 1% NaHCO₃ (3.5–4.3). Duration of motility was longer when triggered in 1% NaHCO₃ (95–120 s) compared with 0.29% NaCl (69–107 s). Sperm vitality was not affected by any of the parameters tested and varied from 51% to 69% intact sperm. Brycon insignis sperm frozen in methylglycol combined with any of the extenders tested and using the methods described above yields motility above 57% and that should last long enough to fertilize oocytes.     

Effects of biofloc technology on reproduction and ovarian recrudescence in Nile tilapia

The objectives of this study were to evaluate the reproductive cycle, morphological changes of ovary and mobilization of energy reserves in Nile tilapia reared with biofloc technology (BFT). In general, the growth and reproductive performance were highly similar between BFT and Control system (clear water). Difference between the systems was found in the hepatosomatic index (using mixed‐effects models), which suggested that BFT can alter the energy mobilization in the post‐spawning period. The absolute and relative fecundity, fertilization rate, number of larvae produced per female, gonadosomatic index, proportion of oogenesis cells, number of post‐ovulatory and atretic follicles were similar between the two systems. We also did not detect a reduction in the reproductive cycle length in Nile tilapia reared in BFT. Because there was no evidence of the negative effects of BFT on Nile tilapia reproduction, we concluded that BFT might be used for breeder stocking of this species.