Play is a self-motivated seemingly non-functional behavior mainly observed in young animals. Moreover, play behaviors can be divided into three categories; social play, object play and locomotor play. The type of activity the category contains varies, as play behaviors vary between species. Play behavior is seen as an indicator of positive emotions in animals, therefore play could be an indicator of welfare. However, the relationship between play and welfare requires further studies. In this study, information was compiled from various articles about play and its relation to welfare. Above all, the study focuses on welfare and play in chickens, as studies on chickens are most lacking. Play provides several benefits regarding motor training, social cohesion and cognitive training. Livestock such as calves, piglets and lambs have all been observed playing. No play has been confirmed in chickens which is mainly due to lack of research. However, play has been observed in other bird species, including birds within the order Galliformes. Amount and type of play varies depending on the environment, which suggests that animal welfare has a great significance for play. If no play occurs, one could conclude that welfare needs to be improved. Lack of play observed in chickens could be due to poor welfare or lack of research. After all, presence of play in other bird species increases the probability that chickens also play. Results indicate that play could be used as an indicator for welfare.

No description available.

The tegmentum vasculosum of the duckling consists of a highly folded epithelium which extends over the dorsal and lateral walls of the cochlear duct, separating the scala media from the scala vestibuli. This epithelium consists of two distinct cell types, dark cells and light cells, and is well vascularized. The surface of the epithelium is formed by a mosaic of alternating dark and light cells. The goblet-shaped dark cells have an electron-dense, organelle-rich cytoplasm, and are expanded basally by extensive basolateral plasma membrane infoldings, within which are numerous mitochondria. Dark cells are isolated from each other and from the capillaries within the epithelium by intervening light cells. In contrast, columnar light cells exhibit an electron-lucent, organelle-poor cytoplasm and may extend from the underlying capillaries to the endolymphatic surface. Light cells contain abundant, coated endocytic vesicles on their apical surfaces and are bound, apically, to other light cells or to dark cells by tight junctions and desmosomes. Laterally, light cells are linked to each other either by complex, fluid-filled membrane interdigitations or by extensive gap junctions. Plasma membrane interdigitations and obvious, fluid-filled intercellular spaces characterize the lateral borders between light and dark cells. Vascular corrosion casting reveals the three-dimensional anatomy of the cochlear vasculature. A continuous arteriolar loop fed by anterior and posterior cochlear arterioles encircles the cochlear duct. The rich capillary beds of the tegmentum vasculosum are supplied by arching arterioles arising from this loop. These capillaries are the continuous type and are situated primarily within the core of the epithelium or along its border with the scala vestibuli. The structure and blood supply of the tegmentum vasculosum are characteristic of an epithelium involved in active transport.

1,25-dihydroxyvitamin D3 [1,25(0H)2D3] has been shown to promote phosphate transport rapidly in the perfused duodenal loop, relative to controls, reaching treated/av basal at T = 40 min = 1.82 ± 0.42 and 1.11 ± 0.21, respectively. By using isolated chick enterocytes, studies were undertaken to determine whether 1,25(0H)2D3 has a direct effect on isolated intestinal cells that is manifested by either enhanced uptake or extrusion of phosphate. In time course studies, with 4- to 8-wk-old chicks, 32P uptake in enterocytes at 10 min after addition of test substance was 0%, 130%, 151%, and 123% of controls for 10 pM, 50 pM, 130 pM, and 300 pM 1,25(0H)2D3, respectively. The metabolite 24,25- dihydroxyvitamin D3 [24,25(0H)2D3] exerted an inhibitory effect on phosphate uptake by 1,25(0H)2D3 at a concentration of 130 pM. This result was in agreement with perfusion studies and supports the physiological relevance of isolated cell studies. For signal transduction studies, isolated enterocytes were incubated with 20 µM forskolin (an activator of protein kinase A), 100 nM phorbol ester (an activator of protein kinase C), or 2 µM BAY K 8644 (a calcium channel activator). Enhanced 32P levels relative to controls were found for phorbol ester (126% of controls at T = 7 min, P < 0.05) and BAY K 8644 (150% of controls at T = 7 min, P < 0.05) but not for forskolin, suggesting involvement of protein kinase C and calcium channel signal transduction pathways in uptake. These results paralleled those observed for the perfused duodenal loop. For aging studies, white leghorn roosters were raised for 7, 14, and 28 wk prior to experiments. These studies showed a 1,25(0H)2D3-mediated increase in 32P uptake in isolated cells at 7 wk, but not at 14 or 28 wk. Further analysis of isolated basal lateral membrane (BLM) on SDS-PAGE followed by Western analysis with a well characterized antibody (Ab099) showed a decreased expression of the putative membrane receptor for 1,25(0H)2D3 with increasing age, paralleling the results obtained for 32P uptake in isolated intestinal cell studies. Analyses of 1,25(0H)2D3 effect on protein kinase C activity likewise revealed hormone-mediated stimulation in cells from 7-wk- old chicks, with decreasing responsiveness at a later age. The combined results indicate a physiologically important role for 1,25(0H)2D3 membrane-initiated phosphate uptake in enterocytes of young, rapidly growing animals. Furthermore, these studies validate the use of isolated intestinal cells for further studies on ribozyme-mediated ablation of the 1,25(0H)2D3 membrane receptor function.

No description available.

24 pairs of newly-hatched Leghorn chicks were randomly divided into 3 groups. Ss in one group followed a moving object for 30 min on Day 1 of life; Ss in another group followed for 30 min on Day 2; Ss in the remaining group followed for 15 min on Day 1 and 15 min on Day 2. One S in each pair followed by his own effort, while the other S rode behind the object in a transparent box. On Day 4, Ss were tested for the duration of following of the object. No important differences among groups were observed. On Day 6, Ss were tested for ability to discriminate between the original and a novel object, and for following the original. Active Ss scored significantly higher than passive Ss on all Day 6 tests; Ss trained on Day 2 scored significantly higher on the following than Ss trained on Day 1. The results suggest that the ‘law of effort’ may apply more to discrimination than to recognition of the imprinting object.

No description available.

No description available.

Chickens in the poultry industry are reared under intensive conditions where they are often exposed to opportunistic pathogens. Escherichia coli strain O78 is responsible for about half of the cases of avian colisepticemia. Potential therapeutic treatments have been proposed to inhibit the hydrolases that controls the endogenous levels of the endocannabinoid, 2-arachidonoylglycerol (2-AG). 2-AG is the full agonist at the CB2 receptors of the endocannabinoid system expressed among leukocytes and it plays a role in mediating the activation of phagocytic macrophages. It is speculated that elevating 2- AG levels could increase macrophage cytokines and promote the recruitment of immune cells at the infected tissues. The purpose of this study was to investigate the immunomodulating effect of the 2-AG hydrolase inhibitor, JZL184 in chickens. The treatments could potentially up-regulate the innate immune responses in chickens during an E. coli infection by conveying a message from the endocannabinoid system to the immune system.

Campylobacteriosis is a leading foodborne illness worldwide, primarily caused by Campylobacter jejuni (C. jejuni) which is associated with poultry consumption. The emergence of antibiotic resistance has emphasized the need for alternative strategies to control C. jejuni colonization in poultry. To assess the prevalence of C. jejuni in poultry, 270 cloacal swab samples were collected from broilers raised under No-Antibiotics Ever system. Among these samples, 16.3% were identified as C. jejuni positive. Notably, these isolates exhibited a diverse range of virulence factors and antimicrobial resistance genes, with 61.36% of isolates showing hyper-motile and 20.45% demonstrating multidrug resistance. Following isolation, whole genome sequencing was conducted on four selected strains using a hybrid sequencing approach. Subsequently, the complete genomes of these C. jejuni strains were analyzed to identify vaccine candidates using reverse vaccinology. Three conserved potential vaccine candidates were identified as suitable targets for vaccine development, namely phospholipase A (PldA), TonB dependent transporter (ChuA), and cytolethal distending toxin (CdtB). Furthermore, the gene expression of these candidates was examined in four C. jejuni strains during host-pathogen interactions using avian macrophage cell line HD11. Significant upregulation of all three candidate genes were observed in the four tested C. jejuni strains during interaction with host cells, indicating their crucial role in C. jejuni infection. Additionally, the expression of immune genes was evaluated in avian macrophage cells to understand the immune responses during C. jejuni infection. The infection resulted in the upregulation of toll-like receptor genes (TLR-4), pro-inflammatory genes (IL-1β, IFN-γ, IL-6, IL-8L1), anti-inflammatory gene (IL-10), and iNOS2 gene expression. The observed immune response demonstrates the potential of C. jejuni to induce host immunity for protection. In conclusion, our study identifies three conserved potential vaccine candidates and provides insights into the immune responses induced by C. jejuni infection in avian macrophage cells. These findings are crucial for the development of an effective vaccine against C. jejuni, aiming to reduce C. jejuni transmission through poultry consumption and the risk of human infection.