Effects of Supplementation of Rumen Protected Fats on Rumen Ecology and Digestibility of Nutrients in Sheep.

Rumen protected fats (RPF) are known to improve animal performance without affecting rumen metabolism in sheep. However, comparative effects of prilled fat, prilled fat with lecithin and calcium soap have not been fully studied. Hence this experiment was planned using 36 male Dorper sheep in a completely randomized design in four treatment groups. The diets included: Basal diet (70:30 concentrate to rice straw) with no added RPF as a control (CON), basal diet plus prilled fat (PF), basal diet plus prilled fat with lecithin (PFL) and basal diet plus calcium soap (CaS). The trial lasted 90 days following two weeks adaptation period. The body weights, average daily gain and gain to feed ratio were not affected by treatments. The intake and digestibilities of dry matter, organic matter, crude protein and neutral detergent fibre were not affected, while those for ether extract and crude fibre differed (p < 0.05). RPF had no effect on concentrations of ammonia nitrogen, total volatile fatty acids and total bacterial population. The concentrations of rumen total saturated fatty acids, unsaturated fatty acids, total n - 3, total n - 6, unsaturated fatty acids:saturated fatty acids and polyunsaturated fatty acids:saturated fatty acids differed (p < 0.05) among the treatments with RPF supplementation. Hence supplementation of different types of protected fats did not influence animal performance in Dorper sheep.

Effect of docosahexanoic acid on quality of frozen-thawed bull semen in BioXcell extender.

This study was conducted to investigate the effect of docosahexanoic acid (DHA) supplementation in BioXcell extender on the quality of frozen-thawed bull semen. Twenty-four ejaculates were collected from three bulls (eight from each bull). Ejaculates with motility ≥70% and normal morphology ≥80% were extended into BioXcell extender to which 0 (control), 3, 5, 10 or 15ngmL-1 DHA was added. The supplemented semen samples were incubated at 37°C for 15min for DHA uptake by spermatozoa. Later, samples were cooled for 2h at 5°C and packaged into 0.25-mL straws, frozen in liquid nitrogen for 24h and subsequently thawed for evaluation. Results are presented as percentages ± s.e.m. Supplementation with DHA at 3ngmL-1 significantly improved sperm functional parameters including sperm motility, normal morphology, viability, acrosome integrity and membrane integrity when compared with other supplemented groups and the control. Lipid peroxidation increased as the incorporation of DHA supplementation increased. In conclusion, 3ngmL-1 concentration of DHA resulted in superior quality of frozen-thawed bull spermatozoa and is suggested as the optimum level of DHA to be added into BioXcell extender.

Serum concentration of ketamine and antinociceptive effects of ketamine and ketamine-lidocaine infusions in conscious dogs.

BACKGROUND: Central sensitization is a potential severe consequence of invasive surgical procedures. It results in postoperative and potentially chronic pain enhancement. It results in postoperative pain enhancement; clinically manifested as hyperalgesia and allodynia. N-methyl-D-aspartate (NMDA) receptor plays a crucial role in the mechanism of central sensitisation. Ketamine is most commonly used NMDA-antagonist in human and veterinary practice. However, the antinociceptive serum concentration of ketamine is not yet properly established in dogs. Six dogs were used in a crossover design, with one week washout period. Treatments consisted of: 1) 0.5 mg/kg ketamine followed by continuous rate infusion (CRI) of 30 µg/kg/min; 2) 0.5 mg/kg ketamine followed by CRI of 30 µg/kg/min and lidocaine (2 mg/kg followed by CRI of 100 µg/kg/min); and 3) 0.5 mg/kg ketamine followed by CRI of 50 µg/kg/min. The infusion was administered up to 120 min. Nociceptive thresholds and ketamine serum concentrations were measured before drug administration, and at 5, 10, 20, 40, 60, 90, 120, 140 and 160 min after the start of infusion. RESULTS: Maximum concentration recorded was 435.34 ± 26.18 ng/mL, 582.34 ± 227.46 ng/mL and 733.77 ± 133.6 ng/mL for K30, KL30 and K50, respectively. The concentration at 120 min was 250.87 ± 39.87, 221.73 ± 91.03 and 343.67 ± 63.21 ng/mL at 120 min in K30, KL30 and K50, respectively. All the three infusion regimes maintained serum concentrations above 200 ng/mL. The thresholds returned towards baseline values within 20 min, after cessation of infusion. CONCLUSION: Serum concentration to produce mechanical antinociceptive effects in dogs is between 100 and 200 ng/mL. All the three infusion regimes in this study provided antinociceptive effects throughout the infusions. In this study, we found that the serum concentration of ketamine to produce mechanical antinociceptive effects in dogs is above 200 ng/mL. All three infusion regimes provided antinociceptive effects throughout the infusions without causing harmful effects. Further studies are recommended in a clinical setting.

Butylated hydroxytoluene can reduce oxidative stress and improve quality of frozen-thawed bull semen processed in lecithin and egg yolk based extenders.

The aims of this study were to evaluate the effects of anti-oxidant butylated hydroxytoluene (BHT), when added at different concentrations into lecithin-based Bioxcell(®) (BX) and two egg-yolk-based; Tris (TY) and citrate (CE) semen extenders, on post-thaw bull sperm quality and oxidative stress. A total of 30 ejaculates from three bulls were collected using an electro ejaculator. Ejaculates were extended with one of the BX, TY and CE extenders, which contained different concentrations (0.0 - control, 0.5, 1.0, 1.5, 2.0 and 3.0mM/ml) of BHT. The extended semen samples were chilled to 4 °C, and then frozen slowly to -196 °C in 0.25 ml straws before being stored in liquid nitrogen for 2 weeks. Results showed that supplementation of BHT improved (P<0.05) general motility, progressive motility, morphology, acrosome integrity, DNA integrity and malondialdehyde of sperm at 0.5mM/ml for BX and at 1-1.5mM/ml of BHT for TY and CE when compared with the control. However, greater concentrations of 2.0 and 3.0mM/ml of BHT had a detrimental (P<0.05) effect compared with the control with all extenders evaluated. In conclusion, BHT supplementation at lesser concentrations (0.5-1.5mM/ml) could improve frozen-thawed bull sperm quality by reducing oxidative stress produced during the freezing-thawing procedures in either lecithin or egg-yolk based extenders.

Electroencephalographic changes associated with antinociceptive actions of lidocaine, ketamine, meloxicam, and morphine administration in minimally anaesthetized dogs.

Effects of ketamine and lidocaine on electroencephalographic (EEG) changes were evaluated in minimally anaesthetized dogs, subjected to electric stimulus. Six dogs were subjected to six treatments in a crossover design with a washout period of one week. Dogs were subjected to intravenous boluses of lidocaine 2 mg/kg, ketamine 3 mg/kg, meloxicam 0.2 mg/kg, morphine 0.2 mg/kg and loading doses of lidocaine 2 mg/kg followed by continuous rate infusion (CRI) of 50 and 100 mcg/kg/min, and ketamine 3 mg/kg followed by CRI of 10 and 50 mcg/kg/min. Electroencephalogram was recorded during electrical stimulation prior to any drug treatment (before treatment) and during electrical stimulation following treatment with the drugs (after treatment) under anaesthesia. Anaesthesia was induced with propofol and maintained with halothane at a stable concentration between 0.85 and 0.95%. Pretreatment median frequency was evidently increased (P < 0.05) for all treatment groups. Lidocaine, ketamine, and morphine depressed the median frequency resulting from the posttreatment stimulation. The depression of median frequency suggested evident antinociceptive effects of these treatments in dogs. It is therefore concluded that lidocaine and ketamine can be used in the analgesic protocol for the postoperative pain management in dogs.

α-Linolenic acid supplementation in BioXcell® extender can improve the quality of post-cooling and frozen-thawed bovine sperm.

The present study was conducted to determine the effects of supplementing α-linolenic acid (ALA) into BioXcell(®) extender on post-cooling, post-thawed bovine spermatozoa and post thawed fatty acid composition. Twenty-four semen samples were collected from three bulls using an electro-ejaculator. Fresh semen samples were evaluated for general motility using computer assisted semen analyzer (CASA) whereas morphology and viability with eosin-nigrosin stain. Semen samples extended into BioXcell(®) were divided into five groups to which 0, 3, 5, 10 and 15 ng/ml of ALA were added, respectively. The treated samples were incubated at 37°C for 15 min for ALA uptake by sperm cells before being cooled for 2 h at 5°C. After evaluation, the cooled samples were packed into 0.25 ml straws and frozen in liquid nitrogen for 24 h before thawing and evaluation for semen quality. Evaluation of cooled and frozen-thawed semen showed that the percentages of all the sperm parameters improved with 5 ng/ml ALA supplement. ALA was higher in all treated groups than control groups than control group. In conclusion, 5 ng/ml ALA supplemented into BioXcell(®) extender improved the cooled and frozen-thawed quality of bull spermatozoa.