Evaluation of in ovo feeding of low or high mixtures of cysteine and lysine on performance, intestinal morphology and physiological responses of thermal-challenged broiler embryos.

The objective of this study was to evaluate the effect of in ovo feeding cysteine, lysine or their combinations on the perinatal and post-hatch physiological responses of broiler embryos exposed to heat stress during incubation. A total of two thousand fertile eggs of broiler breeders (Ross 308) flock (at 38 weeks of age) were used for this study. In the first 10 days, the eggs were incubated using the conventional protocol of relative humidity and temperature of 55% and 37.8°C respectively. From day ten onward, the temperature was increased to 39.6°C for 6 h per day. On day 17.5, 1,500 eggs with the evidence of living embryos were randomly selected and assigned to 6 treatments having five replicates of 50 eggs each. The treatments were: un-injected eggs (UI), eggs injected with only 0.5 ml distilled water (DW), 3.5 mg/egg cysteine (CY), 2mg/egg lysine (LY), 3.4 mg cysteine+2 mg lysine (CLH) and 1.7 mg cysteine+1 mg lysine (CLL). On day 21, the hatchability, anatomical characteristics, chick quality and the antioxidant status of the chicks were evaluated. During the post-hatch phase, data were collected on the haematology, biochemical parameters, growth performance and intestinal morphology of the birds. The results revealed that the hatchability of CY chicks was higher (p < 0.05) than in the other treatments, while the lowest values were recorded in CLH. The hatching muscle of the chicks of CLL was similar to those of CY but higher (p < 0.05) than the others. The MDA of DW and UI chickens was similar and higher than birds in the other treatment groups. The serum SOD of CLL birds was comparable to that of CY but higher than the values recorded in the other treatments. The final weights of CLL chickens were similar to those of LY but significantly higher (p < 0.05) than those of the other treatments. The duodenal villus heights of the birds of CLL were higher than those of the other treatment groups, whereas the villus height of the birds of CLH was higher than those of UI, DW and CY. Overall, in ovo feeding of cysteine alone improved the hatchability of thermally-challenged broiler embryos. In contrast, a low-dose mixture of cysteine plus lysine improved the post-hatch growth performance.

Evaluation of light colour manipulation on physiological response and growth performance of broiler chickens.

Artificial illumination, including light quality, is crucial in modern broiler management. The aim of this study was to examine the effect of a switch in light colour on the performance of broiler chickens in tropical environments. A total of 280 1-day-old Arbor acre male chicks were used for this study and were weighed and assigned to different light environments viz. white (WH), green (GR), blue (BL), GR switched to BL at 14 days (GB), BL switched to GR at 14 days (BG), BL switched to GR at 28 days (BGG) and GR switched to BL at 28 days (GBB) having four replicates of ten birds each. Body weight, weight gain, feed intake and feed conversion ratio were recorded weekly. Blood samples were collected from 2 birds per replicate weekly for the determination of plasma triiodothyronine (T3), haematology and serum biochemical parameters. The experiment was laid out in a completely randomised design. Results showed that the final body weights of the birds in GBB and GB were comparable but higher than those of the other treatment groups. Feed intake of the chickens in WH was similar to that of BG but higher than those of the other treatment groups, while FCR of the birds in WH was higher (P < 0.05) than the other treatment groups. Plasma T3 of the birds in GR was comparable to that of birds in BL but significantly higher than those of the birds in WH and a similar trend was also observed at weeks 1 and 2. Heterophil/lymphocyte ratio (H/L) of the birds in WH was significantly higher than those of BL and GR whose values were similar to those in GB and BG. Heterophil/lymphocytes of the birds in WH was higher than those of BG, GR, BGG, GB and GBB but similar to those of BL. The breast muscle of the birds in GBB and GB was similar to those of BGG and GR and significantly higher than those of WH, BL and BG. Based on the results obtained in this study, it was concluded that the use of green light up to 28 days in combination with blue light stimulated the growth of broiler chickens and manipulation of light colours can be used to improve the welfare and performance of chickens.

Increasing ketamine dose enhances the anaesthetic properties of ketamine-xylazine-midazolam combinations in growing pigs.

The influence of increasing the dosage of ketamine on anaesthesia induced by a combination of ketamine, xylazine and midazolam in pigs was determined by assessing the onset of action (OAN), duration of analgesia (DAN), anaesthesia time (ANT), and recovery time (RCT) in 10 growing pigs (Mean weight: 18.2 +/- 1.65 kg) receiving either 10 mg/kg intramuscular (i.m.) injection of 10% ketamine, 2 mg/kg i.m. injection of 2% xylazine and 0.25 mg/kg i.m. injection of 0.1% midazolam (K10XM) or 20 mg/kg i.m. injection of ketamine and 2 mg/kg i.m. injection of xylazine and 0.25 mg/kg i.m. injection of 0.1% midazolam (K20XM). In addition, the heart rates (HR), respiratory rates (RR) and rectal temperatures (RT) were determined immediately after drug administration and at 10 minute intervals over a period of 60 minutes. Analgesia was assessed by the response of the pigs to artery forceps applied at the interdigital space. Recovery was determined as pigs' ability to stand without ataxia. Data were expressed as mean +/- SEM while anaesthetic indices were compared using Student's t-tests. A P value of 0.05 was accepted as significant in all cases. In this study, both the OAN and RCT were significantly (P < 0.05) shorter in K10XM (1.4 +/- 0.2 min; 7.8 +/- 2.2 min) than in K20XM (2.2 +/- 0.2; 18.6 +/- 1.4 min) respectively. Similarly, the duration of anaesthesia was significantly (P < 0.05) shorter in K10XM (55.4 +/- 8.4 min) than in K20XM (92.0 +/- 13.6 min). The pigs that received K20XM combination had analgesia of duration of 41.4 +/- 12.6 min while those that received K10XM combination had no analgesia. However, the HR, RR, and RT were not significantly (P > 0.05) different between K10XM and K20XM. It was therefore concluded that the lower dose ketamine combination is better for the induction of anaesthesia, while the higher dose ketamine combination is preferable for surgery of short duration in pigs.

Epitopes of immunoreactive myelin basic protein in human cerebrospinal fluid.

To define in more detail the features of the immunoreactive myelin basic protein (MBP) present in cerebrospinal fluid (CSF) of humans following acute injury to central nervous system myelin, the epitopes of MBP recognized by three different antisera, each capable of detecting immunoreactive MBP in CSF, were examined. All three antisera reacted well with human MBP and human MBP peptide 45-89. Only in radioimmunoassays in which the MBP peptide 45-89 served as the radioligand could clearly elevated values of immunoreactive MBP be measured in CSF specimens from 5 patients with multiple sclerosis during or immediately after an exacerbation. The two antisera that reacted well with MBP peptide 80-89 resulted in higher levels of immunoreactive MBP measured in CSF. An epitope present in human MBP peptide 80-89 but sharing a conformation with both MBP and MBP peptide 45-89 is present in CSF following acute central nervous system myelin damage in multiple sclerosis.