Effect of zearalenone on female White Leghorn chickens

Acute toxic effects of purified zearalenone were studied in growing female White Leghorn chickens. In the first experiment, zearalenone in gelatin capsules was administered to 10 chickens (zearalenone-treated chickens [ZC]) in a single oral dose of 15.0 g/kg. Another 10 control chickens (CC) received empty gelatin capsules. All chickens survived the 10-day experiment and did not show any noticeable gross or histopathological lesions. There were no differences between CC and ZC in weight gain, oviduct, comb and liver weights, hematological parameters, and serum cholesterol. ZC had significantly less (P less than 0.05) serum calcium but significantly greater (P less than 0.01) serum phosphorus than CC. In the second experiment, zearalenone was administered orally or intramuscularly (pectoral muscle) at levels of 0, 50, 200, 400, and 800 mg/kg for 7 consecutive days. The oviduct weight increased with increasing toxin levels in both orally (OZC) and intramuscularly (IZC) administered groups: there were more pronounced effects in the IZC. The liver weight increased and comb weight decreased in IZC. The relative estrogenic biopotency of zearalenone in IZC, using estradiol dipropionate as a standard, was 1.37%. The results of this experiment demonstrate that chickens are highly tolerant to zearalenone and that the estrogenic effects of the toxin are greater when it is administered in multiple doses than in a single dose and in IZC than in OZC.     

Fearfulness in red junglefowl and domesticated White Leghorn chickens

It may be hypothesised that reduced fearfulness has been a major target of selection during domestication. We tested 20 domesticated White Leghorn (WL) chickens and their ancestors, red junglefowl (RJF), in four different fear tests (Open Field, Novel Object, Aerial Predator, and Fear for Humans). The tests were designed to measure reactions to different types of potentially fearful stimuli. The correlations between durations of the same four variables from each of the tests (Stand/sit alert, Locomotion, Fly/jump, and Vocalisation) were analysed with principal components analysis (PCA). In the PCA, 33.5% of the variation in responses was explained by a single factor, interpreted as a general fear factor. Higher scores on this were related to stronger fear reactions. Red junglefowl scored significantly higher than White Leghorns on this factor, and also had a longer latency to feed in the Fear of Humans-test, used as an independent measure of fear in the same tests. The results suggest that selection for low fearfulness has been an important element of domestication.     

Effect of zearalenone on female White Leghorn chickens.

Acute toxic effects of purified zearalenone were studied in growing female White Leghorn chickens. In the first experiment, zearalenone in gelatin capsules was administered to 10 chickens (zearalenone-treated chickens [ZC]) in a single oral dose of 15.0 g/kg. Another 10 control chickens (CC) received empty gelatin capsules. All chickens survived the 10-day experiment and did not show any noticeable gross or histopathological lesions. There were no differences between CC and ZC in weight gain, oviduct, comb and liver weights, hematological parameters, and serum cholesterol. ZC had significantly less (P less than 0.05) serum calcium but significantly greater (P less than 0.01) serum phosphorus than CC. In the second experiment, zearalenone was administered orally or intramuscularly (pectoral muscle) at levels of 0, 50, 200, 400, and 800 mg/kg for 7 consecutive days. The oviduct weight increased with increasing toxin levels in both orally (OZC) and intramuscularly (IZC) administered groups: there were more pronounced effects in the IZC. The liver weight increased and comb weight decreased in IZC. The relative estrogenic biopotency of zearalenone in IZC, using estradiol dipropionate as a standard, was 1.37%. The results of this experiment demonstrate that chickens are highly tolerant to zearalenone and that the estrogenic effects of the toxin are greater when it is administered in multiple doses than in a single dose and in IZC than in OZC.     

Exoerythrocytic development of Plasmodium gallinaceum in the White Leghorn chicken

Plasmodium gallinaceum typically causes sub-clinical disease with low mortality in its primary host, the Indian jungle fowl Gallus sonnerati. Domestic chickens of European origin, however, are highly susceptible to this avian malaria parasite. Here we describe the development of P. gallinaceum in young White Leghorn chicks with emphasis on the primary exoerythrocytic phase of the infection. Using various regimens for infection, we found that P. gallinaceum induced a transient primary exoerythrocytic infection followed by a fulminant lethal erythrocytic phase. Prerequisite for the appearance of secondary exoerythrocytic stages was the development of a certain level of parasitaemia. Once established, secondary exoerythrocytic stages could be propagated from bird to bird for several generations without causing fatalities. Infected brains contained large secondary exoerythrocytic stages in capillary endothelia, while in the liver primary and secondary erythrocytic stages developed primarily in Kupffer cells and remained smaller. At later stages, livers exhibited focal hepatocyte necrosis, Kupffer cell hyperplasia, stellate cell proliferation, inflammatory cell infiltration and granuloma formation. Because P. gallinaceum selectively infected Kupffer cells in the liver and caused a histopathology strikingly similar to mammalian species, this avian Plasmodium species represents an evolutionarily closely related model for studies on the hepatic phase of mammalian malaria.     

Detection of sequence polymorphisms in red junglefowl and White Leghorn ESTs

Over 16,000 high quality expressed sequence tags (ESTs) from red junglefowl (RJ) and White Leghorn (WL) brain and testis cDNA libraries were generated. Here, we have used this resource for detection of single nucleotide polymorphisms (SNPs), and also completed full-length sequencing of 46 pairs of clones, representing the same gene from both the RJ and WL libraries. From the main set of ESTs, which were assembled using Phrap, 746 putative SNPs were identified, of which 76% were transitions and 24% were transversions. A subset of SNPs was evaluated by sequence analysis of five RJ and five WL birds. Nine of 12 SNPs were verified in this limited sample, suggesting that a majority of the putative polymorphisms documented in this study represent real SNPs. During full-length sequencing of the 46 RJ/WL clones 100 SNPs were identified, which translated to a frequency of 1.90 SNPs/1000 bp. The number of transitions and transversions were 77% and 23%, respectively, and the proportion of non-synonymous vs. synonymous SNPs was 20% and 80%, respectively. Four large insertions/deletions were identified between the RJ and WL full-length sequences, and they appear to represent different splice variants.     

Domestication and stress effects on contrafreeloading and spatial learning performance in red jungle fowl (Gallus gallus) and White Leghorn layers

White Leghorn layers (WL) show modified foraging strategies, compared to their ancestor, the red jungle fowl (RJF). Birds selected for high production may invest more resources into production traits and less in other biological processes. This may affect the capacity to adapt to new or variable environments.Thirty birds of each of RJF and WL were raised in a stressful environment (unpredictable light:dark schedule) and 30 control animals of each breed in similar pens, but on a 12:12 h light:dark schedule. We studied the differences between breed and treatment with respect to contrafreeloading (CFL), spatial learning ability and the birds’ behaviour in a T-maze.WL showed less CFL, were less cautious in the test arena and showed an impaired spatial learning ability compared with RJF in both test situations. Stress impaired spatial learning in both breeds, but stressed RJF showed a more active response to the test situation than non-stressed RJF, by starting to eat faster, while stressed WL prolonged their time to start eating compared to non-stressed WL.Our results may reflect different adaptive strategies, where RJF appear better adapted to an unpredictable environment.     

Origins of peripheral and brainstem auditory responses in the White Leghorn chick

1. Peripheral and central auditory projections were sectioned and far-field recordings measured to determine neural generators of the waveform in the White Leghorn chick. 2. The mesencephalicus lateralis p. dorsalis and more rostral structures do not contribute to the waveform. 3. Activity of N.VIII is reflected in peaks P1A and P2A; N2A appears to be central in origin but may be in part from the central stump of N.VIII. 4. The crossed dorsal cochlear tract but not the trapezoid body is necessary for P3A and P4A; it is therefore functionally homologous to mammalian trapezoid fibres. 5. P1A, P2A, N2A, P2B are not dependent on crossing fibres.     

Effects of male presence on agonistic behavior and productivity of White Leghorn hens

We studied the ways in which the presence of a male affects hens' agonistic activity, egg production and body weight. Three experiments were designed involving 18, 16 and 48 flocks with 9–16 females and 0–4 males per flock. Effects of genetic stocks, time elapsed after flock assembly, developmental age, and laying-house environment (cage as opposed to floor) were also examined using factorial experimental designs.Females emitted fewer peck-avoidances and threat-avoidances when one or more males were present; the frequencies decreased with additional males. Pullets in crowded colony cages displayed fewer threats than those in floor-pen flocks, and adolescent pullets displayed more of both kinds of agonistic acts than sexually mature females. Body weight gains and egg weights appeared to be reduced when a male was present within the flock for 30 weeks.     

Neuro-histochemical study of the tongue of Gallus domesticus (White Leghorn)

An investigation was undertaken to study the neuro-histochemistry of tonue of Gallus domesticus (white Leghorn) by cholinesterase technique under maintained pH of 5.2, temperature 40 degrees C and incubation period 20 h, and Ungewitter's silver impregnation method. Fungiform (8--16 in number), filiform (5--16 in number), circumvallate and foliate (numerous) were recorded profusely innervated in the various regions of the tongue. Neuro-muscular spindles related either with the non-myelinated, myelinated nerve fibres or with the ganglia via pre- or postganglionic nerve fibre showed cholinesterase (AChE) positive activity in the form of dark brown patches. Neural network over the glands, formed the basket envelope likestructures. Glands showed positive cholinesterase (AChE) reaction on the periphery. Dot-like nerve endings were connected with the neural terminal network in the foliate papillae region and motor end plate like endings on blood vessel, were occasionally recorded. Parasympathetic ganglia of various shape and sizes, arranged in chain-like fashion were observed in the connective tissue space between the fungiform and circumvallate papillae and foliate papillae region. The pre- and postganglionic fibres of these ganglia were related with the anteriorly and posteriorly located papillae via the neural terminal network. Cholinesterase (AChE) activity was marked either in the centre, of the fungiform or on the periphery of the filiform, circumvallate and foliate papillae.     

Aluminium and the phosphorus requirements ofPinus radiata

Summary WhenPinus radiata plants are grown in solutions containing adequate phosphorus for maximum growth and varying amounts of aluminium, phosphorus uptake in roots and tops is positively related to aluminium uptake. The amounts of both phosphorus and aluminium taken up by the plants bear a direct relationship to the aluminium content of the solution. The increased uptake of phosphorus is not accompanied by any increase in the rate of growth.     

Frequency of headshaking in White Leghorn chickens in response to hormonal and environmental changes

Frequency of headshaking in chickens from two selected lines (HA and LA) known to differ in this trait was observed at various ages, during hormonal fluctuations and in different environmental surroundings. Neither hormonal changes concomitant with the initial onset of lay nor ingestion of corticosterone (which stopped egg production in 240-day-old pullets) altered headshaking frequency. When pullets reared in flocks on litter were moved at 77 days of age to individual battery cages, headshaking frequency was dramatically increased in one flock but did not change in another flock. Moving 252-day-old birds from individual cages to floor pens decreased headshaking frequency in males but not in females; returning the birds to cages did not significantly alter levels of headshaking. In older birds (252 days of age), headshaking frequency in all birds in line HA and in males of line LA were considerably greater than in LA females.     

Sulphur and phosphorus requirements of Curvularia pallescens Boed

The effect of different sulphur and phosphorus compounds on the growth and sporulation ofCurvularia pallescens Boed. has been studied. Nine different sulphur sources were tried but among them only magnesium sulphate yielded the best dry weight of the fungus. Zinc sulphate, sodium sulphate, sodium thiosulphate, potassium sulphate and calcium sulphate supported good growth. Poor growth was recorded on sodium bisulphite, ammonium sulphate, sodium sulphide and control. Sporulation was excellent on magnesium sulphate. It was good on zinc sulphate, sodium sulphate and potassium sulphate. On sodium thiosulphate, calcium sulphate, sodium bisulphite and control it was fair. Sodium sulphide and ammonium sulphate had inhibitory effect as sporulation was poor and nil on these two compounds respectively.Six phosphorus compounds were studied. Tripotassium phosphate gave best growth and excellent sporulation. Good growth and excellent sporulation was recorded on monobasic potassium phosphate and magnesium phosphate. Growth and sporulation were good on dibasic potassium phosphate and sodium dihydrogen phosphate. Ammonium phosphate was poorly utilized.     

Chromosomal clustering of five defined endogenous retrovirus loci in White Leghorn chickens.

By using in situ hybridization, we localized three endogenous chicken retrovirus loci associated with the gs- chf- phenotype to distinct regions on chromosome 1. These three loci, ev4, ev5, and ev8, along with the two other known gs- chf--associated loci in White Leghorn chickens, ev1 and ev13, appear to be evenly distributed along chromosome 1, occurring approximately every 1.8 X 10(7) base pairs. The presence of all five loci on chromosome 1 represents a highly nonrandom distribution and all but eliminates a mechanism of independent random integration events for the generation of these loci.