Freezing equine semen: the effect of combinations of semen extenders and glycerol on post-thaw motility

Objective   We evaluated combinations of two commercial semen extenders and three concentrations of glycerol to determine the combination that yielded the highest post-thaw sperm motility.
Design   A randomised 2 × 3 block design was used.
Procedure   Semen was collected from four stallions (6 collections per stallion). The sample was diluted with either a dried skim-milk glucose extender (EZ Mixin Original Formula) or a chemically defined, milk-free diluent (INRA 96), and each was used in combination with 2%, 3% or 4% glycerol in standard commercial freezing medium. Sperm motility was assessed by microscopy in fresh and post-thaw semen.
Results   There was a significant difference between the two extenders in the motility of spermatozoa after cryopreservation (48.9% for INRA 96; 38.6% for EZ Mixin OF; P < 0.0001). Glycerol at 4% in freezing medium yielded the highest post-thaw motility, significantly better than 2% ( P < 0.05). Three of four stallions had significantly higher post-thaw motility using INRA 96 relative to EZ Mixin OF ( P < 0.01), and two of four stallions had significantly higher post-thaw motility using 4% glycerol ( P < 0.05). The combination of INRA 96 and 4% glycerol in freezing medium gave the highest average post-thaw motility of 51.5%.
Conclusion   In this study, INRA 96 combined with 4% glycerol yielded an average recovery of progressively motile sperm consistently above the 35% target.     

Reproductive Performance of Gilts with Similar Age but with Different Growth Rate at the Onset of Puberty Stimulation

The aim of this study was to evaluate the reproductive performance of gilts that had a similar age but different weights at the onset of puberty stimulation by boar exposure at 144 days. Gilts were divided into two groups according to their lifetime growth rate from birth to approximately 144 days of age. Mean growth rates at this moment were 577 and 724 g/day for group 1 (G1; n = 58) and group 2 (G2; n = 58), respectively. After selection, gilts were weighed at approximately 155, 165 and 175 days of age, on the insemination day and at slaughter. Gilts were inseminated, on average, at 193 days of age and were slaughtered 32 days after insemination, when the number of corpora lutea and embryos were recorded. Higher growth rate gilts (G2) reached puberty earlier (155.3 vs 164.1 days; p < 0.01). More gilts of G2 group attained puberty by 190 days of age (p = 0.004) than G1 gilts (95%; 55/58 vs 76%; 44/58). The anoestrous rate, until 60 days after the onset of boar exposure was higher (p < 0.01) in G1 (19.0%; 11/58) than in G2 (3.4%; 2/58) group. However, there were no differences in the pregnancy rate (90.7 vs 94.5), ovulation rate (15.9 vs 16.5), total embryos (12.9 vs 11.7), viable embryos (12.0 vs 11.1) and embryo survival (73.7% vs 68.5%), between G1 gilts and G2 gilts, respectively (p > 0.05). High growth rate gilts attain puberty earlier and have a lower anoestrous rate than low growth rate gilts.     

Selection of rhizobacteria able to produce metabolites active against Meloidogyne exigua

This work aimed to select potentially useful rhizobacteria for the control of Meloidogyne exigua, a widely disseminated root-knot nematode found in Brazilian coffee fields. Initially, crude metabolites produced in liquid medium by 69 isolated rhizobacteria strains (previously obtained from several plants collected in the south of Minas Gerais State, Brazil) were tested in vitro for lethality towards M. exigua second stage juveniles (J₂). Substances produced by strains of Bacillus cereus, B. megaterium, B. pumilus, B. thuringiensis, Enterobacter asburiae, E. cloacae and Paenibacillus macerans caused high mortality in J₂. Subsequently, the ten most active crude metabolites were selected and assessed for nematicidal activity in a biotest with M. exigua-inoculated coffee plants. Although strains of B. cereus, B. pumilus and P. macerans caused a significant reduction in the number of root galls and/or nematode eggs per plant 90 days after treatment, the best results were obtained with the application of B. megaterium strain 54-06.     

Subcutaneous granuloma caused by Mycobacterium avium complex infection in a cat

A localised subcutaneous swelling developed on the nasal bridge of a cat receiving chemotherapy for alimentary tract lymphosarcoma. Cytological and histological examination of representative samples of the lesion demonstrated pyogranulomatous inflammation and abundant acid-fast bacilli. A Mycobacterium sp was cultured from tissue excised from the lesion. Extensive testing at three reference laboratories indicated the strain was a member of the Mycobacterium avium complex. The infection was treated successfully by cytoreductive surgery and a 6 weeks course of orally administered clofazimine.     

Growth periodicity in trees of Coffea arabica L. in relation to nitrogen supply and nitrate reductase activity

Vegetative growth of branches and leaf area gain in field-grown Arabica coffee trees in Viçosa, southeastern Brazil, exhibited active and quiescent phases. Nitrogen supplementation during the cool season did not prevent growth decline, nor did it alter the overall pattern of the tree growth; however, it enabled the plants to grow faster following the quiescent growth phase. Growth was related poorly to both nitrate content and nitrate reductase activity in leaves. In roots, N-fertilization in addition to accounting for greater content of nitrate, amino acids and ammonium was also associated with the maintenance of the nitrate reductase activity, but nitrate reduction was apparently nil in leaves during most of the cool season.     

Use of Spray-Dried Blood Meal as an Alternative Protein Source in Pirarucu (Arapaima gigas) Diets

We evaluated the effects of various dietary blood meal levels on the growth performance and body composition of pirarucu (Araipama gigas) juveniles. Fish (8.5 ± 0.4 g) were stocked into 24 tanks and fed for 60 days with eight isoproteic diets, having 0% to 21% incorporation of blood meal. Fish increased weight by six to 15 times from their initial weight. The highest body weights (117–135 g), growth rates (4%–5% BW/day), and protein retentions (19%–20%) were observed in fish fed 0% to 6% blood meal. Feed intake increased from 2.9% to 4.4% BW/day with increasing blood meal level. Feed conversion ratio (FCR: 1.0–1.1) did not vary among groups fed 0% to 6% blood meal (P < 0.001). However, when fish were fed more than 6% blood meal, FCR (1.3–1.7) and protein retention (11.1–13.7) deteriorated sharply. Lipid (7.7–11.7%) and energy (18.7–21.2 kJ/g) content increased with increasing blood meal levels up to 9%.