Metal enrichment processes

There are many processes that can transport gas from the galaxies to their environment and enrich the environment in this way with metals. These metal enrichment processes have a large influence on the evolution of both the galaxies and their environment. Various processes can contribute to the gas transfer: ram-pressure stripping, galactic winds, AGN outflows, galaxy-galaxy interactions and others. We review their observational evidence, corresponding simulations, their efficiencies, and their time scales as far as they are known to date. It seems that all processes can contribute to the enrichment. There is not a single process that always dominates the enrichment, because the efficiencies of the processes vary strongly with galaxy and environmental properties.Comment: 18 pages, 8 figures, accepted for publication in Space Science Reviews, special issue "Clusters of galaxies: beyond the thermal view", Editor J.S. Kaastra, Chapter 17; work done by an international team at the International Space Science Institute (ISSI), Bern, organised by J.S. Kaastra, A.M. Bykov, S. Schindler & J.A.M. Bleeke

The Nigerian local chicken hormonal functional status as influenced by age and sex factors

A study was conducted to investigate the effect of age and sex on the hormonal status of the Nigerian Local Chicken raised in the Teaching and Research Farm of the Rivers State University Nkpolu-Oroworukwo, Port Harcourt. A total of forty (40) heterogeneous population of the Nigerian Local Chickens were used in a Completely Randomized Block Design (CRBD). Blood samples were collected from 10 males and 10 females from two different age groups (21 and 72 weeks). Hormonal assay was conducted to ascertain the values of some growth and reproductive hormones. These includes; thyroxin (T4), Triiodothyroxine (T3), Thyroid stimulating hormone (TSH). Prolactin (PRL), testosterone (TET), estrogen (E), luteinizing hormone (LH), follicle stimulating hormone (FSH) and progesterone (PROG). PRL, FSH, PROG and TET were significantly (p<0.05) affected by age while others were not significant (p<0.05). Prolactin had higher value for birds under the ages of 21 weeks than 72 weeks of age with a  corresponding value of 28.35ng/mL and 8.64ng/mL respectively. Sex effect on hormones showed that, all hormones studied were significant except Tri-iodothyronine (T3). Testosterone as observed in this study was also influenced by age. Male birds unlike their female counterparts at 72 weeks of  age recorded higher means value of 4.14 ± 0.52 than those of 21 weeks of age (1.11 ± 0.07). Therefore, the study was able to demonstrate the influence of age and sex on the status of hormones in the Nigerian Local Chicken. Keywords: Local chicken, age, sex, growth hormones, reproductive hormone

Performance of broiler chickens administered graded levels of bitter kola (Garcinia kola, Heckel) as feed additive

A study of 28 days (4 weeks) was carried out at the Poultry Section of Rivers State University, Nkpolu-Oroworukwo, Port-Harcourt Rivers State- Nigeria, to determine the effect of bitter kola (Garcinia kola, Heckel) powder as a growth promoter in broiler chicken diets. One hundred and forty-four (144) unsexed one day-old Anak strain broiler chicks were subjected to various concentrated levels of bitter kola at T1 (control), T2 (5g/kg feed), T3 (10g/kg feed), T4 (15g/kg feed), respectively using a Completely Randomized Design (CRD), with 36 4 birds/treatment and 12 birds/replicate. The parameters evaluated were weight gain, feed intake, feed conversion ratio and cost production. Data collected were subjected to Analysis of Variance (ANOVA). Results obtained indicated significant effect (P<0.05) in all the growth parameters evaluated. The mean total feed intake was  12.00kg, 11.85kg, 12.50kg and 11.55kg respectively for T1 , T2 , T3 and T4 . Mean total weight gain was highest in T4 (2.91kg) 1 2 3 4 4 and least in T 1(2.57kg). On feed conversion ratio, T recorded the best with 3.97. It was 1 4 therefore advocated that bitter kola should be included in broiler diets as  a feed additive to improve broiler chicken performance. Keywords: Bitter kola, Broiler chicken, feed intake, Weight gain, Production cos

Auto-sexing potential and growth performance in Rhode Island, Nigerian local chickens and their reciprocal crosses

This study was conducted to determine auto-sexing potential in Rhode Island, Nigerian local chicken and their reciprocal crosses. A total of 241 eggs  were set in the incubator to deter ine the fertility, hatchability, % Hatch, % dead in shell, % dead in cell and % deformed chicks in the four  genotypes (Rhode Island Red (RIR) x Rhode Island White (RIW), Rhode Island Red (RIR) x Rhode Island White (RIW), Nigerian Local Red (NLR) x  Rhode Island White (RIW) and Nigerian Local Red (NLR) x Nigerian Local White (NLW). Only 94 eggs were hatched. RIRXRIW crossbred chicks had the highest percentage fertility of 88.89% followed by RIRxRIW (86.27%), NLRXRIW (77.36%) and NLRxNLW (72.31%), respectively. RIRxNLW had the highest percentage hatchability of 65.19%, followed by RIRxRIW (51.56%), NLRxNLW (51.06%) and NLRxRIW (24.39%). It was observed in thehatch-out analysis that the cross between NLRxRIW had the highest percentage of dead in shell (29.27%) followed by RIRxRIW (17.19%), NLRxNLW (17.02%) and RIRxNLW (11.36%), respectively. The highest percentage of dead in cell was recorded in NLRxRIW crossbred (43.33%), followed by NLRxNLW (31.92%), RIRxRIW (28.13%) and RIRxNLW (15.91%). The observed deformed chicks were highest in NLRxNLW (20.85%) followed by RIRxNLW (10.34%), RIRxRIW (6.06%) and NLRxNLW (0%), respectively. Also observed was the occurrence of bangers with NLRxRIW, having the  highest occurrence of bangers (9.08%) and with NLRxNLW having no occurrence of bangers. The records of weekly body weight were taken on the 94 chicks and chi square analysis was used to test colour inheritance of chicks. Significant (P<0.05) difference was observed among genotypes in body weight of chicks at hatch and from weeks 1 to 8 weeks of age. The observed changes on body weight from 0 to 8th week of age of chicks showed significant difference across the four different genetic crossed groups (P<0.05) and weight at the 8th week showed that the cross between RIRxRIW (216.93g) had better in growth as compared to the cross between NLRxRIW (202.75g) and NLRxNLW (193.17g) which were statistically  similar (P>0.05) and RIRxNLW (179.75g) crossbred chicks which had the lowest bodyweight at 8 weeks of age. The chi square (X2) analysis revealed that both RIRxRIW and NLRxRIW crossbred chicks were autosexed. The study concluded that selection for plumage colour showed great potential in determining the probability of chicks being autosexed. Also, pure bred of RIRXRIW and reciprocal cross of NLRXRIW showed great potential of  producing autosexed chicks, while results on the direct crosses of NLRXNLW and RIRXNLW suggest that the pattern of inheritance of plumage colour is not simple. The study recommends further investigation to further ascertain the mode of plumage colour inheritance in the Nigerian Local Chickens. Keywords: Auto-sexing, plumage, growth performanc