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.     

Characterization of the anthracnose resistance gene present in Ouro Negro (Honduras 35) common bean cultivar

Ouro Negro (Honduras 35) is a highly productive Mesoamerican black seeded bean cultivar that possesses a major dominant gene conferring resistance to anthracnose (causal organism Colletotrichum lindemuthianum). In this work the anthracnose resistance gene present in Ouro Negro was characterized by studying allelic relationships to the following previously characterized anthracnose resistance genes (cultivars): Co-1 (MDRK), Co-1 ² (Kaboon), Co-1 ³ (Perry Marrow), Co-2 (Cornell 49-242), Co-3 (Mexico 222), Co-4 (TO), Co-4 ² (SEL 1308), Co-5 (SEL1360), Co-6 (AB 136), and the resistance genes present in PI 207262 and Widusa. In addition, we determined the resistance spectrum of Ouro Negro in relation to 19 pathotypes of C. lindemuthianum. The allelism tests confirmed that the dominant anthracnose resistance gene present in Ouro Negro is positioned at a locus distinct from those with which it was compared. We propose that this new gene be named Co-10. The inoculation of Ouro Negro with the 19 pathotypes of C. lindemuthianum demonstrated that Co-10 confers resistance to pathotypes 23, 64, 67, 73, 81, 83, 87, 89, 95, 102, 117, 119, 343, 453, 1033, 1545 and 1600. The identification of Co-10 is an important contribution to bean breeding programs that are in constant need of new sources of resistance to anthracnose. This revised version was published online in July 2006 with corrections to the Cover Date.     

Nicotinic acetylcholine receptor chimeras of rat α7 and Drosophila SAD reveal species-specific agonist binding regions

Species-specific agonist binding regions of nicotinic acetylcholine receptors (nAChR) were examined. Imidacloprid and physostigmine (Phy) selectively activated insect nAChR composed of Drosophila second alpha-like subunit (SAD) and chick β2, in contrast to rat α7 nAChR. The Phy-activated currents were α-bungarotoxin (α-BGT) sensitive, suggesting activation at the agonist binding loop C. Several SAD-α7 chimeras were constructed, by switching agonist binding regions, and expressed in oocytes. Though none of the chimeras was activated by a range of nicotinic agonists, [¹²⁵I]α-BGT binding revealed homomeric assembly of all chimeric cDNAs. Phy differentially displaced [¹²⁵I]α-BGT from the nAChR chimeras, suggesting that the β subunit is not involved in Phy binding, and that Phy targets the insect agonist binding loop C.     

Reference Values on Serum Biochemical Parameters of Brazilian Donkey (Equus asinus) Breed

Seventeen serum biochemical variables were determined in 40 donkeys of the Brazilian breed (34 females and 6 males) aged from 3 to 19 years. Mean ± standard deviation (SD) (minimum–maximum) values, obtained by automated analysis, were as follows: glucose, 58.35 ± 10.40 (44.00–90.00) mg/dL; cholesterol, 88.41 ± 9.86 (73.58–124.26) mg/dL; serum protein, 6.82 ± 0.40 (6.00–7.52) g/dL; albumin, 3.13 ± 0.21 (2.65–3.69) g/dL; creatinine, 1.80 ± 0.14 (1.51–2.19) mg/dL; urea, 24.25 ± 5.37 (14.12–34.39) mg/dL; lactate, 20.10 ± 4.58 (12.99–33.47) mg/dL; aspartate aminotransferase (AST), 295.81 ± 62.79 (173.71–466.07) IU/L; creatine kinase (CK), 158.00 ± 76.94 (51.69–440.33) IU/L; γ-glutamil-transferase (GGT), 45.82 ± 13.34 (26.17–86.38) IU/L; lactate dehydrogenase (LDH), 576.02 ± 156.32 (213.53–1162.81) IU/L; alkaline phosphatase (AP), 345.36 ± 65.90 (227.25–490.16) IU/L; calcium (Ca), 8.54 ± 0.18 (8.19–8.90) mg/dL; phosphorus (P), 2.76 ± 0.38 (1.99–3.97) mg/dL; chloride (Cl), 106.05 ± 3.20 (99.00–112.00) mEq/L; sodium (Na), 121.50 ± 4.14 (116.00–132.00) mEq/L; and potassium (K), 3.70 ± 0.42 (2.80–4.40) mEq/L. Comparisons of biochemical ranges obtained for the Brazilian donkey breed with reference ranges for other donkey breeds suggested that most values were similar. Biochemical values determined in the present study serve as reference ranges for donkey populations and can be used for health control and diagnosis of diseases.     

Diet change from a system combining total mixed ration and pasture to confinement system (total mixed ration) on milk production and composition,blood biochemistry and behavior of dairy cows

This study aimed to determine if a diet change from a mixed system to a confinement system affects the milk production and composition, behavior and blood biochemistry of dairy cows. Cows were assigned randomly to one of the two treatments: cows fed with TMR (total‐mixed‐ration) (confined) throughout the period group fed TMR (GTMR, n = 15) and cows that changed their diet from pasture plus TMR to exclusive TMR at 70 ± 14 DIM (GCHD, n = 15). GTMR cows produced more milk and greater lactose and protein yield before the change of diet than GCHD cows (p ≤ .01), but these differences disappeared after the change. GCHD cows decreased the frequency of rumination and lying from before to after the change (p ≤ .03), but in GTMR cows no changes were observed. After diet change, GCHD cows had lower frequency of rumination and lying than GTMR cows (p ≤ .02). Before the change, GCHD cows had greater NEFA (non esterified fatty acids) concentrations than GTMR cows (p = .002). Abrupt change from a mixed system to a confined system was favorable on blood biochemical and milk variables of dairy cows. However, in relation to behavior, the cows expressed difficulties to adapt quickly to the abrupt change of system.     

Polymorphism,coupling interval and prematurity index in dogs with degenerative mitral valve disease and ventricular arrhythmias

Ventricular arrhythmias (VA) are a recognized concern in dogs with degenerative mitral valve disease (DMVD). The coupling interval (CI) and the prematurity index (PI) have been shown to accurately differentiate between benign and malignant VA in people, where ventricular arrhythmias are known to be associated with an increased risk of development of signs of heart failure or sudden death. In this study, we characterized ventricular arrhythmias in dogs with symptomatic and asymptomatic DMVD. Seventy dogs with naturally-occurring DMVD and ventricular arrhythmias were retrospectively studied. A cross-sectional investigation including dogs with either symptomatic (stages C/D; n?=?41) or asymptomatic (stages B1/B2; n?=?29) DMVD was performed. Electrocardiographic tracings were reviewed to calculate both the CI and PI. In eight dogs these indices were compared with those obtained from both a Holter recording and a standard ECG tracing and no statistical differences were found (CI, p?=?0.97; PI, p?=?0.17). Even though CI and PI were determined in all animals enrolled in the study, VPC characteristics were only compared between symptomatic and asymptomatic dogs when a 24-h Holter recording was available (n?=?49). The PI was different (p?=?0.01) between symptomatic (0.65?±?0.17) and asymptomatic (0.56?±?0.18) dogs, but CI was considered similar (p?=?0.91). Also, the symptomatic dogs had more polymorphic VPC (p?=?0.002) and supraventricular arrhythmias (p?=?0.0002) than the asymptomatic animals. Polymorphism, and repeating patterns of ventricular premature complexes, were characteristics frequently present in overtly symptomatic animals affected by mitral endocardiosis.