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Simple Summary: Light is a very important parameter in poultry farming. It can influence production, meat quality and welfare. The increasingly popular energy-efficient light-emitting diode (LED) lighting has replaced other light sources in many farms. We aimed to investigate the effects of incandescent light (IL) and LED lighting on production, meat quality parameters and behavior. In the first five weeks, there was a significant difference in body weights between the groups. The feed conversion ratio was more favorable in all weeks in the LED group. Among the meat quality parameters, only the shear force values differed significantly between the groups. Broilers raised under LED lighting were more active, spent more time socializing and rested less. The results indicated that LED lighting positively impacts animal welfare and production efficiency. Many farms have been replacing traditional lighting sources with light-emitting diode (LED) bulbs because of technological modernization. We aimed to investigate the effects of incandescent lighting (IL) and LED lighting on Cobb 500 broiler chickens for six weeks. Production parameters (body weight, feed consumption, feed conversion ratio), calculated slaughter values (yield%, relative breast%, thigh%) and breast meat quality parameters (pH at 45 min and 24 h postmortem, color, drip loss, kitchen equipment losses, shear force, meat composition) were recorded. Non-stop recordings were used to analyze the behavior of the birds during several periods of rearing. The LED group was significantly better in the body weight parameter between week 1 and 5 and the feed conversion ratio between week 2 and 3. The most significant difference in behavior was observed in the middle of the rearing period. The chickens in the LED group spent more time eating, drinking and interacting, and rested less. There was no difference in the meat quality parameters; only shear force was significantly lower in the LED group (1781.9 g/s vs. 2098.8 g/s). According to our results, LED lighting can bring about positive changes in animal production efficiency, behavior and other important characteristics for meat consumers. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Animal Production & Processing Technology / JurnalIlmu Produksi dan Teknologi Hasil Peternakan is the property of IPB University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Many farms have been replacing traditional lighting sources with light-emitting diode (LED) bulbs because of technological modernization. We aimed to investigate the effects of incandescent lighting (IL) and LED lighting on Cobb 500 broiler chickens for six weeks. Production parameters (body weight, feed consumption, feed conversion ratio), calculated slaughter values (yield%, relative breast%, thigh%) and breast meat quality parameters (pH at 45 min and 24 h postmortem, color, drip loss, kitchen equipment losses, shear force, meat composition) were recorded. Non-stop recordings were used to analyze the behavior of the birds during several periods of rearing. The LED group was significantly better in the body weight parameter between week 1 and 5 and the feed conversion ratio between week 2 and 3. The most significant difference in behavior was observed in the middle of the rearing period. The chickens in the LED group spent more time eating, drinking and interacting, and rested less. There was no difference in the meat quality parameters; only shear force was significantly lower in the LED group (1781.9 g/s vs. 2098.8 g/s). According to our results, LED lighting can bring about positive changes in animal production efficiency, behavior and other important characteristics for meat consumers.

Copyright of Journal of Animal Production & Processing Technology / JurnalIlmu Produksi dan Teknologi Hasil Peternakan is the property of IPB University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Livestock & Animal Research is the property of Sebelas Maret University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Affective state can bias an animal's judgement. Animals in positive affective states can interpret ambiguous cues more positively ("optimistically") than animals in negative affective states. Thus, judgement bias tests can determine an animal's affective state through their responses to ambiguous cues. We tested the effects of environmental complexity and stocking density on affective states of broiler chickens through a multimodal judgement bias test. Broilers were trained to approach reinforced locations signaled by one color and not to approach unreinforced locations signaled by a different color. Trained birds were tested for latencies to approach three ambiguous cues of intermediate color and location. Broilers discriminated between cues, with shorter latencies to approach ambiguous cues closest to the reinforced cue than cues closest to the unreinforced cue, validating the use of the test in this context. Broilers housed in high-complexity pens approached ambiguous cues faster than birds in low-complexity pens–an optimistic judgement bias, suggesting the former were in a more positive affective state. Broilers from high-density pens tended to approach all cues faster than birds from low-density pens, possibly because resource competition in their home pen increased food motivation. Overall, our study suggests that environmental complexity improves broilers' affective states, implying animal welfare benefits of environmental enrichment. [ABSTRACT FROM AUTHOR]

Spot 14 gene plays important roles in chicken growth, it’s a small acidic protein that responds to thyroid hormone stimulation and therefore its play a role in growth. The purpose of the present study was to analyze association of the Spot 14 gene with feed intake and body weight in local chicken. DNA from blood samples was extracted to amplify the MC4R gene and purified by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP), and investigated its association with economic traits and statistical data were analyzed using SAS program. There was significantly affect (P<0.05) of the Spot 14 gene polymorphism on mean of the weekly live body weight and weekly feed intake in all weeks, the genotype BB recorder the highest mean followed by genotype AB and AA. [ABSTRACT FROM AUTHOR]

In the single-ossicle ear of chickens, the quasi-static displacement of the umbo shows great asymmetry; umbo displacements are much larger for negative than for positive pressure in the middle ear, which is opposite to the typical asymmetry observed in mammal ears. To better understand this behavior, a finite-element model was created of the static response of the chicken middle ear. The role of flexibility of the extracolumella in the model was investigated, and the potential effect of the outward orientation of the tympanic-membrane cone was studied by building two adapted models with a flat membrane and an inverted conical membrane. It is found that the extracolumella must be made of flexible material to explain the large inward displacements of the umbo, and that displacements of the footplate are much smaller due to bending of the flexible extracolumella. However, increasing extracolumellar stiffness mostly reduces umbo displacement rather than increasing footplate displacement. The results suggest that the inverted orientation of the membrane cone is responsible for the change in asymmetry of the umbo displacement curve. The asymmetry of the footplate displacement curve in the normal model is smaller, but increases towards positive middle-ear pressure in the case of a flat or inverted membrane geometry. • Quasi-static middle-ear behavior in chicken was studied by finite-element modeling. • The flexible extracolumella permits large inward eardrum displacements. • Flexibility of the extracolumella affects umbo motion rather than footplate motion. • Inverting the eardrum may lead to opposite asymmetry of avian umbo displacements. [ABSTRACT FROM AUTHOR]

The concept of a quasi-king space is introduced, which is a natural generalisation of a king space. In the realm of suborderable spaces, king spaces are precisely the compact spaces, so are the quasi-king spaces. In contrast, quasi-king spaces are more exible in handling coarser selection topologies. The main purpose of this paper is to show that a weakly orderable space is quasi-king if and only if all of its coarser selection topologies are compact. [ABSTRACT FROM AUTHOR]

Highlights • Conditioned Place Preference tests were used to study affective responses in hens. • Both air puff and water spray stimuli produced conditioned place aversions. • A robotic snake, and the sound of conspecific alarm calls, did not. • Negative affective responses can differ in their persistence and generalization. Abstract When measuring animals’ valenced behavioural responses to stimuli, the Conditioned Place Preference (CPP) test goes a step further than many approach-based and avoidance-based tests by establishing whether a learned preference for, or aversion to, the location in which the stimulus was encountered can be generated. We designed a novel, four-chambered CPP test to extend the capability of the usual CPP paradigm to provide information on four key features of animals’ affective responses: valence, scale, persistence and generalization. Using this test, we investigated the affective responses of domestic chickens ( Gallus gallus domesticus ) to four potentially aversive stimuli: 1. Puffs of air; 2. Sight of (robotic) snake; 3. Sprays of water; 4. Sound of conspecific alarm calls. We found conditioned avoidance of locations associated with the air puffs and water sprays (Friedman’s χ2 (3) = 13.323 p >.005; χ2 (3) = 14.235 p >.005), but not with the snake and alarm calls. The scale of the learned avoidance was similar for the air puff and water spray stimuli, but persistence and generalization differed. We conclude that the four chambered CPP test can have a valuable role to play in making multi-feature measurements of stimulus-generated affective responses, and we highlight the value of such measurements for improving our understanding of the structure of affect in chickens and other animals. [ABSTRACT FROM AUTHOR]

Fragmentation and degraded habitat conditions can result in increased competition for critical resources, altered mating systems, and can eventually result in population declines or extinction. We investigated the degree to which habitat degradation and habitat loss impacted the breeding ecology of Greater Prairie-Chickens at 3 study sites across relatively intact grasslands in Kansas, USA. Across all 3 study systems, we found similar rates of multiple mating by females at 14–20% of broods. In addition, we found evidence for facultative nest parasitism of conspecific females. Prairie-chicken females inhabiting more intact and less fragmented landscapes with a higher probability of survival did not engage in parasitic egg laying, whereas ∼17% of females inhabiting a more fragmented and isolated landscape engaged in parasitic egg laying. Parasitic egg layers tended to be older females that parasitized nests of yearling females. Parasitic egg layers only laid parasitically after an initial nesting attempt failed. Parasitic laying females all renested and hatched their own clutches. When counting parasitically laid eggs, parasitic egg-laying females laid significantly more eggs than nonparasitic egg layers and, as a result, had 25% greater fecundity. This case study across the relatively intact grasslands of Kansas highlights how land use and management can influence adaptive life history traits and population stability. Consequently, understanding these relationships will be essential to developing effective future conservation and management plans for prairie-grouse. [ABSTRACT FROM AUTHOR]

The objective was to determine the effect of black tuna meal (BTM) at different concentrations and time of addition, in chicken diets on production variables, quality, and concentration of fatty acids in eggs and sensory evaluation. A 3 x 4 factorial design was used. Increasing the concentration of BTM modified the production variables. The cholesterol level was higher with 3% of BTM, the total lipids were increased at the time, the highest level was the control and the lowest with 3%, the Decosahexaenoic acid (DHA) was greater than 3% of BTM, the alpha-linolenic acid (ALA) did not obtain differences, arachidonic acid (AA) and linoleic acid (LA) showed their lowest values with 2% of BTM. As for the sensory evaluation, color, smell, and taste were well accepted. Therefore, it is concluded that BTM can be used to enrich the nutritional values of the bird´s diet. [ABSTRACT FROM AUTHOR]

The present study was carried out to evaluate the effect of sequential feeding on egg production performance of Athulya (White Leghorn) layer chicken. At the end of 16th week of age, 75 birds were distributed in a completely randomized experimental design with three treatments each having five replicates of five birds each. T1 group (Control) was fed with complete layer diet, T2 group (sequential feeding) was fed with coarsely ground maize in the morning and balancer diet in the afternoon and the T3 group (loose mix) was given coarse maize combined with balancer diet. In all the treatments, feed was given in two distributions at 6.00 a.m. and 1.00 p.m. From the results, it could be observed that egg production in sequential feeding was similar to that of control but significantly (p<0.05) lower to that of loose mix. Lower egg production rate in sequential feeding could be due to a signifi cant reduction in total feed intake. [ABSTRACT FROM AUTHOR]

In this paper, we propose an automatic convolutional neural network (CNN)-based method to recognize the chicken behavior within a poultry farm using a Kinect sensor. It resolves the hardships in flock behavior image classification by leveraging a data-driven mechanism and exploiting non-manually extracted multi-scale image features which combine both the local and global characteristics of the image. To our best knowledge, this is probably the first attempt of deep learning strategy in the field of domestic animal behavior recognition. To testify the performance of our proposed method, we conducted experiments between state-of-the-art methods and our method. Experimental results witness that our proposed approach outperforms the state-of-the-art methods both in effectiveness and efficiency. Our proposed CNN architecture for recognizing flock behavior of chickens produces an extremely impressive accuracy of 99.17%. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the effect of probiotic on comfort and body care behaviors of broilers reared at two different densities. Two hundred and forty chicks were subdivided into four groups, two groups were reared under low stocking density (LSD); 10 bird/m2 and another 2 groups were reared under high stocking density (HSD); 15 bird/m2. In each density, one group was supplemented with probiotic in the drinking water and the other was not supplemented. Normal behavior of birds was recorded throughout the growing cycle twice a week, using video camera (Sony, Japan). Then after, comfort (standing, lying and sleeping), body care (preening, dust bathing, wing/leg stretching and head scratching) and aggressive behaviors of birds were analyzed. HSD reduced comfort behavior compared to low density without probiotic group. Standing frequency was significantly increased at the 6th week of the growing cycle. In addition, interrupted lying bouts frequency was increased and the non-interrupted lying bouts (frequency and duration) were decreased significantly. Moreover, preening frequency was decreased. However, aggressive behavior was not observed in all groups. Probiotic supplementation didn't alter comfort, aggressive and body care behaviors of broilers at both densities in comparison to low density without probiotic group. However, birds stocked at high stocking density and supplemented with probiotic showed no alterations in all behavioral patterns compared to HSD group without probiotic supplementation. Data suggested that the used probiotic in this study was unable to improve comfort and body care behaviors of broilers reared at low stocking density and failed to alleviate impacts of high density stress on these behaviors. [ABSTRACT FROM AUTHOR]

The use of feed additives to improve feed conversion while increasing growth is the goal of any broiler nutrition program. Therefore, it is important to evaluate potential feed additives not only for increased performance, but also for any negative attributes. A study was conducted to evaluate the effects of feeding phosphatidic acid (PA) to broiler chickens. Two experiments were conducted using exercise in conjunction with PA (Experiment 1(E1)) and administering PA at different inclusion rates in the diet (Experiment 2 (E2)); LowPA (5 mg/bird/day), MidPA (10 mg/bird/day), HighPA (15 mg/bird/day), and control (CON). All birds were weighed bi-weekly during the experiments to obtain average pen weights and feed conversion ratios (FCRs). At the end of the experiments, eight birds per pen were processed to evaluate carcass traits and breast yield. In E1, exercise did not affect growth, feed conversion or processing traits (p > 0.05). However, PA supplementation did increase growth, carcass and breast weight, and carcass and breast yields (p < 0.05). In E2, differences (p < 0.05) in live bird weights between the control birds (1.65 kg) and all PA treatments (pooled mean: 1.73 kg) began at 28 days; however, only the LowPA carried that effect (p = 0.05) through to the conclusion of the trial (3.55 vs. 3.81 kg). Overall, LowPA (1.64) and MidPA (1.69) had lower (p < 0.05) FCRs than the CON treatment (1.74). Increased growth observed in live bird weights in the LowPA translated to increased (p < 0.05) overall carcass weights (2.78 vs. 2.99 kg) and specifically breast filet weights (0.69 vs. 0.76 kg). Yields did not differ (p > 0.05), but with the increased weight feeding LowPA resulted in more total breast meat. Phosphatidic acid did not affect (p > 0.05) woody breast or white striping. In conclusion, dietary PA improved FCR, increased live bird weights, and increased breast fillet weight without increased incidence of white striping. These results indicate that feeding PA may increase production efficiency in broilers. [ABSTRACT FROM AUTHOR]

Little is known about the effect of accessing an outdoor range on chicken welfare.We tracked individual ranging behavior of 538 mixed-sex Ross 308 chickens on a commercial farm across 4 flocks in winter and summer. Before range access, at 17 to 19 d of age, and post-range access, at 30 to 33 and 42 to 46 d of age in winter and summer flocks respectively, welfare indicators were measured on chickens (pre-range: winter N = 292; summer N = 280; post-range: winter N = 131; summer N = 140), including weight, gait score, dermatitis and plumage condition. Post-ranging autopsies were performed (winter: N = 170; summer: N = 60) to assess breast burn, leg health, and ascites. Fewer chickens accessed the range in winter flocks (32.5%) than summer flocks (82.1%). Few relationships between welfare and ranging were identified in winter, likely due to minimal ranging and the earlier age of post-ranging data collection compared to summer flocks. In summer flocks prior to range access, chickens that accessed the range weighed 4.9% less (P = 0.03) than chickens that did not access the range. Pre-ranging weight, gait score, and overall plumage cover predicted the amount of range use by ranging chickens in summer flocks (P < 0.01), but it explained less than 5% of the variation, suggesting other factors are associated with ranging behavior. In summer flocks post-range access, ranging chickens weighed 12.8% less than non-ranging chickens (P < 0.001). More range visits were associated with lower weight (P < 0.01), improved gait scores (P = 0.02), greater breast plumage cover (P = 0.02), lower ascites index (P = 0.01), and less pericardial fluid (P = 0.04). More time spent on the range was associated with lower weight (P < 0.01) and better gait scores (P < 0.01). These results suggest that accessing an outdoor range in summer is partly related to changes in broiler chicken welfare. Further investigations are required to determine causation. [ABSTRACT FROM AUTHOR]

The reliable assessment and management of avian pain is important in the context of animal welfare. Overtly expressed signs of pain vary substantially between and within species, strains and individuals, limiting the use of behaviour in pain studies. Similarly, physiological indices of pain can also vary and may be confounded by influence from non-painful stimuli. In mammals, changes in the frequency spectrum of the electroencephalogram (EEG) recorded under light anaesthesia (the minimal anaesthesia model; MAM) have been shown to reliably indicate cerebral responses to noxious stimuli in a range of species. The aim of the current study was to determine whether the MAM can be applied to the study of nociception in birds. Ten chickens were lightly anaesthetised with halothane and their EEG recorded using surface electrodes during the application of supramaximal mechanical, thermal and electrical noxious stimuli. Spectral analysis revealed no EEG responses to any of these stimuli. Given that birds possess the neural apparatus to detect and process pain, and that the applied noxious stimuli elicit behavioural signs of pain in conscious chickens, this lack of response probably relates to methodological limitations. Anatomical differences between the avian and mammalian brains, along with a paucity of knowledge regarding specific sites of pain processing in the avian brain, could mean that EEG recorded from the head surface is insensitive to changes in neural activity in the pain processing regions of the avian brain. Future investigations should examine alternative electrode placement sites, based on avian homologues of the mammalian brain regions involved in pain processing. [ABSTRACT FROM AUTHOR]

The use of electroencephalograms (EEG) to study the avian brain relative to behavior was conducted as early as the 1960's. EEG readings, combined with visual cues, provide the ability to elucidate and correlate behaviors to neurological and physiological changes in a chicken. The use of EEG recordings in animal models require access to the brain to implant electrodes. Having the ability to observe EEG activity on sensible birds without surgical implantation could broaden the research in this area and give further insight related to the hen's state of awareness. The development, construction, and implementation of a minimally invasive EEG electrode placement method is described. After implementation, test animals were exposed to extreme environmental stressors as part of a concurrent depopulation methods study and EEG placement withstood the condition changes and corresponding animal physical activity. Sixteen white commercial laying hens had three monopolar 32-gauge needle electrodes inserted subcutaneously and secured to their head and body. Electrodes were attached to a pre-amplifier which transferred EEG signals to a laptop based recording system. Once the electrodes were in place, the hens were placed in individual treatment/ observation chamber then various environmental stressors were applied. Verification that the observed brainwave activity was neural and not muscular was done using a photic stimulation validation test. Behavior observations were recorded to correlate sensible and insensible brainwave activity. The validation test and behavior observations demonstrated the method was successful in measuring EEG in sensible laying hens. The use of a non-surgical method for recording EEG will broaden research capabilities and enhance the understanding of a hen's response its environment, eliminate the need for invasive surgical procedures, and minimizes the confounding components of anesthesia, brain surgery, and recovery. With further refinements, the method could open new avenues in avian behavioral and physiological research. [ABSTRACT FROM AUTHOR]

The objective of this study was to explore the effects of free-range (FR), part-time freerange (PTFR), and cage system (CS) on behavioral repertoire in Lakha (LK), Mushki (MS), Peshawari (PW), and Sindhi (SN) varieties of Aseel chicken during the growing phase (9 to 18 wk of age). In total, 144 Aseel pullets were allotted to 12 treatment groups in a 3 x 4 (rearing system x Aseel variety) factorial arrangement, according to a randomized complete block design (RCBD). Each treatment group was replicated 3 times with 4 birds in each replicate (12 birds per treatment group). The pullets were randomly marked weekly for identification, and their behavior was observed through the focal animal sampling method. Time spent on different behavioral activities was recorded and converted to a percentage. The data were analyzed using 2-way ANOVA under a factorial arrangement using SAS 9.1, and the behavioral parameters were evaluated. The results indicated greater (P < 0.05) sitting, standing, drinking, preening, and aggressiveness in CS; walking, running, and jumping in PTFR; and foraging and dustbathing in both FR and PTFR, whereas feather pecking was found to be reduced in FR compared with PTFR and CS. Among varieties, PW showed the least feeding/foraging and feather pecking behavior, and greater standing, running, and jumping behavior (P < 0.05). However, SN spent less time in walking and preening, and more time in sitting, drinking, and aggressiveness. Dustbathing was found to be similar in all Aseel varieties (P = 0.135). In conclusion, the PTFR system could be suggested as a substitute for conventional housing systems because it better accommodates normal behavior in Aseel pullets. [ABSTRACT FROM AUTHOR]

Individuals often differ in behavior in a consistent way, that is, they show variation in personality. Understanding the processes explaining the emergence and maintenance of this variation is a current major topic in the field of animal behavioral research. Recent theoretical models predict that differences in various "states" can generate individual variation in behavior. Previous studies have mainly focused on endogenous states like metabolic rate or energy reserves, but theory also suggests that states based on social interactions could play important roles in shaping personality. We have earlier demonstrated short-term status-dependent variation in behavior in the domestic fowl (Gallus gallus domesticus), but whether such behavioral variation remains also after a longer period of time, is unknown. Therefore, we examine the influence of social status on variation in behavior, using experimental manipulation of social status in pairs of male domestic fowl. We scored males in 3 personality assays (novel arena test, novel object test, and aggression test) before and after 3 weeks in pairs as either dominant or subordinate. We observed individual consistency of behavior despite alteration of social status. We further found no support for social status acting as a state that generates variation in personality over the used time interval: social status had no significant effect on the change in behavioral responses between repeated personality tests. Our results suggest that personality is more important than current social situation for describing individual behavior in stable groups. [ABSTRACT FROM AUTHOR]

Copyright of Avian Diseases is the property of American Association of Avian Pathologists, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The world's most numerous bird, the domestic chicken, and their wild ancestor, the red junglefowl, have long been used asmodel species for animal behaviour research. Recently, this research has advanced our understanding of the social behaviour, personality, and cognition of fowl, and demonstrated their sophisticated behaviour and cognitive skills. Here, we overview some of this research, starting with describing research investigating the well-developed senses of fowl, before presenting how socially and cognitively complex they can be. The realisation that domestic chickens, our most abundant production animal, are behaviourally and cognitively sophisticated should encourage an increase in general appraise and fascination towards them. In turn, this should inspire increased use of them as both research and hobby animals, as well as improvements in their unfortunately often poor welfare. [ABSTRACT FROM AUTHOR]

Automated tracking of the location of individual chickens is becoming more common in behavioural research. This technology has several advantages including gathering large amounts of data and monitoring of individual animals as opposed to flocks. To ensure the quality of the research the transmitters or tags attached to the bird as part of the automated positioning system should not have any effect on bird behaviour, welfare and production. Tag-related effects may lead to unreliable results which cannot be extrapolated to untagged birds. Therefore, we tested the effects of wearing a backpack containing a tag as part of an ultra-wideband system for automated position monitoring. The chickens’ behaviour, leg health, cleanliness and body weight gain were studied. Sixty slow-growing broiler chickens (Sasso XL451) were housed in groups of 10 birds. Per pen, five birds were fitted with a 36-g tag (TAG) in a backpack from day 35–70 and the other five were identified using colour markings (CON). Behavioural observations from video recordings of TAG and CON chickens were performed twice daily (15-min periods) every other day. Birds were weighed on day 35 and 70, and on day 70 foot pad and hock dermatitis, gait, and cleanliness were scored. TAG birds walked less than CON birds in week 6, but this difference was absent from week 7 onwards. CON birds pecked more at TAG birds than other TAG birds did in week 6, probably due to the novelty of the tags, whereas the TAG birds could investigate their own tag instead of pecking at other birds’ tags. No significant differences were observed for scores for foot pad and hock dermatitis, gait and cleanliness scores or weight gain between TAG and CON birds. These results indicate that the backpacks with tags had only minor, non-persistent effects on slow-growing broiler chickens’ behaviour. The effects of colour-marking on behaviours observed in this study are likely to be small. The results indicate that the tags can be used for further studies in which these behaviours, welfare measures and production parameters play an important role. [ABSTRACT FROM AUTHOR]

It has been reported that a functional fat-taste receptor, GPR120, is present in chicken oral tissues, and that chickens can detect fat taste in a behavioral test. However, although triglycerides need to be digested to free fatty acids to be recognized by fat-taste receptors such as GPR120, it remains unknown whether lipase activities exist in chicken oral tissues. To examine this question, we first cloned another fat-taste receptor candidate gene, CD36 , from the chicken palate. Then, using RT-PCR, we determined that GPR120 and CD36 were broadly expressed in chicken oral and gastrointestinal tissues. Also by RT-PCR, we confirmed that several lipase genes were expressed in both oral and gastrointestinal tissues. Finally, we analyzed the lipase activities of oral tissues by using a fluorogenic triglyceride analog as a lipase substrate. We found there are functional lipases in oral tissues as well as in the stomach and pancreas. These results suggested that chickens have a basic fat-taste reception system that incorporates a triglycerides/oral-lipases/free fatty acids/GPR120 axis and CD36 axis. [ABSTRACT FROM AUTHOR]

(1) To evaluate the cognitive ability of male and female Vanaraja birds, three hundred and sixty 1-d-old sexed chickens were reared under similar conditions in three treatment groups with 4 replicates in each group: 120 females in Treatment 1, 120 males in Treatment 2 and both males and females (60 + 60) as a mixed group in Treatment 3. (2) To assess learning ability, the birds were trained in T- and Y-mazes and tested at 3-week intervals in 4 test schedules (21, 42, 63 and 84 d). The birds were put into tonic immobility (TI) in each test schedule. (3) In each maze test, the latency to find the feed was regarded as a successful completion of the task. In the TI-test, the time taken to stabilise on a plane surface after swinging in the hanging cradle for 20–25 s was recorded. (4) The results indicated that male birds appeared to be cognitively superior to females in terms of learning and cognitive evolution in all the mazes, but by d 84, the females performed as well as the males. With increasing age, spatial memory gathering and processing improved. In the TI-test, the effect of sex or grouping system had no significant effect on the performance of birds at the various ages. [ABSTRACT FROM AUTHOR]

Prohormone convertase 1/3 is a serine endoprotease belonging to the subtilisin-like proprotein convertase family that is encoded by the proprotein convertase subtilisin/kexin type 1 (PCSK1) gene, and its major function is the processing and bioactivation of the proproteins of many kinds of neuroendocrine hormones, including insulin, cholecystokinin, and adrenocorticotropic hormone. The results of our previous genomewide association study indicated that the PCSK1 gene might be an important candidate gene for fatness traits in chickens. The objectives of this study were to investigate the tissue expression profiles of PCSK1 gene and to identify functional variants associated with fatness and growth traits in the chicken. The results indicated that PCSK1 mRNA was widely expressed in various tissues, especially neuroendocrine and intestinal tissues. Of these 2 tissue types, PCSK1 mRNA expression in lean males was significantly higher than in fat males. A SNP in the 3' untranslated region of PCSK1 (c.*900G > A) was identified. Association analysis in the Arbor Acres commercial broiler population and Northeast Agricultural University broiler lines divergently selected for abdominal fat content (NEAUHLF) population showed that the SNP c.*900G > A was associated with abdominal fat weight, abdominal fat percentage, BW, metatarsus length, and metatarsal circumference. In the 5th to 19th generation (G5 to G19) of NEAUHLF, the allele frequency of c.*900G > A changed along with selection for abdominal fat content. At G19, allele G of c.*900G > A was predominate in the lean line, whereas allele A was predominate in the fat line. Functional analysis demonstrated that allele A of c.*900G > A reduced mRNA stability and consequently downregulated gene expression. These results suggested that c.*900G > A was a functional SNP for fatness and growth traits in the chicken. The results of this study provide basic molecular information for the role of PCSK1 gene in avian growth and development, especially obesity. [ABSTRACT FROM AUTHOR]

Real-time quantitative PCR is an exceptionally sensitive method that can detect even very small differences in gene expression and, as such, it is essential to use suitable reference genes. Domestic chickens are used in a wide range of studies including neurobiology, behavior, ecology and disease transmission. In recent avian gene expression experiments, 18S (18S ribosomal RNA), beta actin (ACTB) and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) have frequently been used; however, there is not enough evidence that these reference genes are suitable for all types of experiments. There is considerable evidence for lateralization in numerous learning tasks and for differences in the functional contribution of the two brain hemispheres. Therefore, the purpose of this study was to identify a set of reference genes for chick brain region called an intermediate medial mesopallium (IMM), which is connected with memory formation in the chick brain, whilst also taking into consideration the differences between the left and right hemispheres. This study evaluated the expression stability of eleven candidate housekeeping genes in the IMM region of the 1-day old chick brain. In our experimental system, the most reliable results were given by the NormFinder algorithm. The results show for the first time that ACTB, commonly used as an avian reference gene, is not suitable for investigation of gene expression in the chick brain and that brain lateralization exact selection of different reference gens for each hemisphere. For memory process investigations using tasks in one-day old chicks the most effective reference genes for the left hemisphere were HMBS and SDHA, and for the right hemisphere the most effective was RPL19. [ABSTRACT FROM AUTHOR]

It is well documented that vasoactive intestinal peptide (VIP) is an avian prolactin-releasing factor, regulating the reproductive cycle, that initiates and maintains incubation behavior in avian species. Native Thai chicken has strong maternal behaviors. Thus, it is an excellent animal model to study this phenomenon. Changes in the numbers of VIP neurons within the nucleus inferioris hypothalami (IH) and nucleus infundibuli hypothalami (IN) are associated with maternal behaviors in the native Thai chicken. The objective of this study was to elucidate the role of VIP during the transition from egg incubation to rearing behavior in this species. The distributions of VIPimmunoreactive (-ir) neurons and fibers within the nucleus septalis lateralis (SL), nucleus anterior medialis hypothalami (AM), regio lateralis hypothalami (LHy), nucleus commissurae pallii (nCPa), nucleus ventromedialis hypothalami (VMN), and IH-IN were compared between incubating (INC) hens and replaced-egg-withchicks (REC) hens, in which eggs were replaced by 3-day-old chicks after 6, 10, and 14 d of incubation period for 3 days. Using an immunohistochemistry technique, the results revealed that VIP-ir neurons and fibers were found within the SL, AM, LHy, nCPa, VMN, and IH-IN, with the greatest expression observed in the IH-IN in both groups. The number of VIP-ir neurons in the IH-IN was markedly decreased (P < 0.05) in the REC hens when compared with those of the INC hens at 3 different time points (at d 9, 13, and 17). However, changes in the number of VIP-ir neurons between the INC and REC hens were not observed within other hypothalamic areas tested. These findings indicate that the presence of eggs and chicks affects the VIPergic system, and VIP neurons in the IH-IN might play a role in the transition from incubating to rearing behavior in the native Thai chicken. [ABSTRACT FROM AUTHOR]

Metformin is a biguanide drug that is widely used in the treatment of diabetes. Epidemiological studies have indicated that metformin exhibits anti-cancer activity. However, the molecular mechanisms underlying this activity currently remain unclear. We hypothesized that metformin is cytotoxic in a tumor-specific environment such as glucose deprivation and/or low oxygen (O2) tension. We herein demonstrated that metformin was highly cytotoxic under glucose-depleted, but not hypoxic (2% O2) conditions. In order to elucidate the underlying mechanisms of this selective cytotoxicity, we treated exposed DNA repair-deficient chicken DT40 cells with metformin under glucose-depleted conditions and measured cellular sensitivity. Under glucose-depleted conditions, metformin specifically killed fancc and fancl cells that were deficient in FANCC and FANCL proteins, respectively, which are involved in DNA interstrand cross-link repair. An analysis of chromosomal aberrations in mitotic chromosome spreads revealed that a clinically relevant concentration of metformin induced DNA double-strand breaks (DSBs) in fancc and fancl cells under glucose-depleted conditions. In summary, metformin induced DNA damage under glucose-depleted conditions and selectively killed cells. This metformin-mediated selective toxicity may suppress the growth of malignant tumors that are intrinsically deprived of glucose. [ABSTRACT FROM AUTHOR]

The best performer hilly chickens in consideration of light and heat were assessed under rural conditions. Based on the survey, the chickens and farm household were selected. The chickens were provided supplementations of concentrate feed (50g/chicken/day). The selected chickens were divided into 3 groups (heat stress, light and control) for the study of their egg production potential. Heat was generated in the chicken's shelter by keeping a black shaded light (Lantern) for 2 to 3 h more after sunset. A lighting device (Lantern) was kept in the chicken's shelter for 2 to 3 h more after sunset for increasing the duration of day light. Temperature and humidity index was calculated from the recorded temperature and humidity. The individual chicken's egg production, egg weight and mature live weight were studied for different types of hilly and non-descriptive desi chickens. It was observed that hilly chickens produced more eggs than desi. The hen house egg production percentage (19.95%) and yearly egg production (90 no/year/chicken) of desi white was significantly higher than spotted hilly (17.29% and 83.4 no egg, respectively) but reddish brown hilly type produced more number (100.80 no/year/chicken) of eggs than all types. The egg weight varied from 41.27 g to 43.85 g. Mature live weight were significantly different between hilly and desi (1438.70 g vs 1309.27 g). Among the 3 treatments, the lighting group hilly chickens produced 7.71 and 5.60 more eggs than control and heat stress group, respectively. One hour lighting length increased egg production by 4 to 5.8%. [ABSTRACT FROM AUTHOR]

The neural serotonin (5-HT)/serotonin transporter (5-HTT) system is involved in the regulation of physiological processes and emotional states. In humans, the short (S) allele in the 5-HTT gene-linked polymorphic region, which decreases 5-HTT expression, has been shown to be associated with behavioral changes including an increased level of anxiety. Also in birds a polymorphism in the 5-HTT gene is described, a deletion (D) has been found to have functional consequences on growth and locomotion. Furthermore, the D-allele leads to an increased 5-HTT expression compared to the wild type (W), a feature which is linked to lower levels of fear in mammalian species. Thus, we aimed here to test whether the polymorphism in the chicken 5-HTT gene also leads to respective alternations of fear-related behaviors. We tested 268 hens of three genotypes (W/W, W/D, D/D) in two behavioral paradigms (open field, light–dark test) to assess fear-related behavior. Both tests revealed that hens possessing the D-allele showed lower levels of fear than those having the W-allele. These similar outcomes in fear-related behaviors in an avian and a mammalian species are associated with an increased 5-HTT expression. In the human 5-HTT gene, the long (L) allele is linked to such increased expression, whereas in chickens it is the D-allele. Thus, increased 5-HTT expression causing decreased fear may be a general mechanism in vertebrates. [ABSTRACT FROM AUTHOR]

Transportation of newly hatched chicks from the hatchery to the farm is inevitable, especially for parent stock and grandsire parent stock chicks. However, the possible effects of transport stress in the newly hatched chicks are poorly understood. The aim of this study was to determine the adaptive responses to transport stress by activing the nuclear factor-erythroid 2-related factor 2 (Nrf2)-induced antioxidant defense. One hundred twenty newly hatched chicks were divided into 3 groups (control group, transport group, and simulation transport group) for 2, 4, and 8 h of real or simulated transportation. Transport stress could cause oxidative stress in the cerebrum of newly hatched chicks by increasing lipid peroxidation and production of free radicals and decreasing the activities of antioxidant enzymes and the glutathione:oxidized glutathione ratio. Transport stress activated the Nrf2 signaling pathway and triggered the transcription of antioxidant parameters. However, transport stress-induced cerebrum oxidative stress was not mitigated by activating the Nrf2 antioxidant defense response in newly hatched chicks. [ABSTRACT FROM AUTHOR]

The purpose of this experiment was to investigate the behaviour of fast- and slow growing chickens, when the birds had access to the outdoors. Fifty of both 1-day-old male chicks of a laying hybrid ISA BROWN (IB) and broilers ROSS 308 (RS) were kept in two pens in the same building. In each group ten birds were marked with a colored spray. From three weeks of age the birds had access to the outdoors. From the age of one to seven weeks old, one day a week the marked birds were observed from 8:00 to 18:00 every ten minutes and the activity was noted. At 49 and 90 days old twenty birds were slaughtered and the strength of bones was measured. The behaviour was expressed as percentage of the time spent in activity. The average time that the birds spent eating during the 7 week period was almost the same in IB and RS. On average, IB birds spent significantly higher (P<0.05) an amount of time moving around, but until the fifth week of age there was no significant difference between these genotypes. In IB, movement was the more frequent activity. The resting sitting down was the most frequent activity in RS and since three weeks of age they spent significantly more (P<0.05) time with this activity than IB. On average, the IB birds spent significantly more (P<0.05) time scratching than did the RS. No aggression or pecking was observed in the IB males during the whole test period. The strength of the femur was significantly higher in RS in comparison with IB in both ages (49d - P<0.001, 90d - P<0.05). Although the rules for organic farming dictate that the chickens have to have enough outdoor area to move around in, the fast growing broilers do not use it. [ABSTRACT FROM AUTHOR]

Background: Growth traits can be used as indicators of adaptation to sub-optimal conditions. The current study aimed at identifying quantitative trait loci (QTL) that control performance under variable temperature conditions in chickens. Methods: An F2 population was produced by crossing the Taiwan Country chicken L2 line (selected for body weight, comb area, and egg production) with an experimental line of Rhode Island Red layer R- (selected for low residual feed consumption). A total of 844 animals were genotyped with the 60 K Illumina single nucleotide polymorphism (SNP) chip. Whole-genome interval linkage mapping and a genome-wide association study (GWAS) were performed for body weight at 0, 4, 8, 12, and 16 weeks of age, shank length at 8 weeks of age, size of comb area at 16 weeks of age, and antibody response to sheep red blood cells at 11 weeks of age (7 and 14 days after primary immunization). Relevant genes were identified based on functional annotation of candidate genes and potentially relevant SNPs were detected by comparing whole-genome sequences of several birds between the parental lines. Results: Whole-genome QTL analysis revealed 47 QTL and 714 effects associated with 178 SNPs were identified by GWAS with 5% Bonferroni genome-wide significance. Little overlap was observed between the QTL and GWAS results, with only two chromosomal regions detected by both approaches, i.e. one on GGA24 (GGA for Gallus gallus chromosome) for BW04 and one on GGAZ for six growth-related traits. Based on whole-genome sequence, differences between the parental lines based on several birds were screened in the genome-wide QTL regions and in a region detected by both methods, resulting in the identification of 106 putative candidate genes with a total of 15,443 SNPs, of which 41 were missense and 1698 were not described in the dbSNP archive. Conclusions: The QTL detected in this study for growth and morphological traits likely influence adaptation of chickens to sub-tropical climate. Using whole-genome sequence data, we identified candidate SNPs for further confirmation of QTL in the F2 design. A strong QTL effect found on GGAZ underlines the importance of sex-linked inheritance for growth traits in chickens. [ABSTRACT FROM AUTHOR]

Domestic chickens are members of an order, Aves, which has been the focus of a revolution in our understanding of neuroanatomical, cognitive, and social complexity. At least some birds are now known to be on par with many mammals in terms of their level of intelligence, emotional sophistication, and social interaction. Yet, views of chickens have largely remained unrevised by this new evidence. In this paper, I examine the peer-reviewed scientific data on the leading edge of cognition, emotions, personality, and sociality in chickens, exploring such areas as self-awareness, cognitive bias, social learning and self-control, and comparing their abilities in these areas with other birds and other vertebrates, particularly mammals. My overall conclusion is that chickens are just as cognitively, emotionally and socially complex as most other birds and mammals in many areas, and that there is a need for further noninvasive comparative behavioral research with chickens as well as a re-framing of current views about their intelligence. [ABSTRACT FROM AUTHOR]

To investigate the neural basis of socio-economic behaviors in birds, we examined the effects of bilateral electrolytic lesions of arcopallium (Arco, the major descending pallial area of the avian telencephalon) and the surrounding nuclei in domestic chicks. We tested foraging effort (running distance) in an I-shaped maze with two food patches that delivered food in a biased manner according to a variable interval schedule. Normally, chicks run back and forth between the patches, and the patch use time matches the respective food delivery rate. In the paired phase, even without actual interference of food, chicks showed social facilitation of running effort compared with the single phase. Chicks with lesions in the Arco and lateral Arco showed significant reductions in social facilitation. The lesion effects of the lateral Arco were particularly selective, as it was not accompanied by changes in running distance in the single phase. Lesions of the nidopallium and nucleus taeniae of the amygdala produced no changes in foraging behavior. On the other hand, the Arco lesion did not impair social facilitation of operant peck latency. In accordance with this, anterograde tracing revealed characteristic projections from the lateral Arco to the extended amygdala, hippocampus, and septum, as well as wide areas of limbic nuclei in the hypothalamus and medial areas of the striatum including the nucleus accumbens. Pathways from the lateral Arco could enable chicks to overcome the extra effort investment of social foraging, suggesting functional and anatomical analogies to the anterior cingulate cortex and basolateral amygdala in mammals. [ABSTRACT FROM AUTHOR]

The genetic relationships between behavior and digestive efficiency were studied in 860 chickens from a cross between two lines divergently selected on digestive efficiency. At 2 weeks of age each chick was video-recorded in the home pen to characterize general activity and feeding behavior. Tonic immobility and open-field tests were also carried out individually to evaluate emotional reactivity (i.e. the propensity to express fear responses). Digestive efficiency was measured at 3 weeks. Genetic parameters of behavior traits were estimated. Birds were genotyped on 3379 SNP markers to detect QTLs. Heritabilities of behavioral traits were low, apart from tonic immobility (0.17-0.18) and maximum meal length (0.14). The genetic correlations indicated that the most efficient birds fed more frequently and were less fearful. We detected 14 QTL (9 for feeding behavior, 3 for tonic immobility, 2 for frequency of lying). Nine of them co-localized with QTL for efficiency, anatomy of the digestive tract, feed intake or microbiota composition. Four genes involved in fear reactions were identified in the QTL for tonic immobility on GGA1. [ABSTRACT FROM AUTHOR]

The anticipatory behaviour of animals has been credited with enabling scientists to more closely infer what an animal wants. From a welfare perspective, this knowledge could improve how we care for animals under our management, as information about how animals prioritise rewarding items may guide how we allocate resources effectively. Our goal was to determine if behaviour in anticipation of different types of reward was differentially expressed. We investigated whether certain behaviours were characteristic of anticipation of both food and non-food rewards, and whether signals indicating rewards led to increased activity levels. Twelve laying hens experienced a Pavlovian conditioning paradigm using sound cues to signal the availability of two different food rewards (mealworms, normal food), one non-food reward (a container of mixed soil and sand substrate suitable for foraging and dustbathing (Dusty substrate)) and a sound-neutral event, which was signalled by a sound, but no reward was given. A muted-neutral treatment (no reward and no sound cue) controlled for any specific behaviour as a result of the sound cues. Behavioural responses and the number of transitions between behaviours were measured during a 15 s anticipatory period, before birds accessed rewards in an adjoining compartment by pushing through a door. These responses and latency to access the rewards were analysed using linear and generalised linear mixed models. Differences in pushing and pecking at the door (frequency: Dusty substrate 4.87 a , Mealworm 3.18 b , Normal Food 2.23 b , Sound Neutral 0.30 c , Muted Neutral 0.03 d , χ 2 (4) = 228.99, p < 0.001), standing (not walking) (duration (s): Sound Neutral 9.92 c , Muted Neutral 7.49 bc , Normal Food 7.39 bc , Mealworm 7.05 b , Dusty substrate 3.06 a , χ 2 (4) = 36.28, p < 0.001), reflected the perceived value of the rewards, with birds appearing to be more motivated to access the Dusty substrate compared with the food rewards. Rewarded sound cues elicited increased transitions between behaviours, compared with neutral events (Dusty substrate 10.16 a , Mealworm 10.13 a , Normal Food 9.22 ab , Sound Neutral 7.89 bc , Muted Neutral 6.43 c , χ 2 (4) = 72.05, p < 0.001). The sound-neutral treatment induced increased head movements, previously associated with anticipation of rewards (duration (s): Sound Neutral 1.58 b , Muted Neutral 0.58 ab , Normal Food 0.48 a , Mealworm 0.27 a , Dusty substrate 0.00 a , χ 2 (4) = 25.56, p < 0.001). Latency to access rewards conveyed the relative value of rewards (Dusty substrate 7.30 a , Mealworm 10.06 ab , Normal Food 16.53 b , χ 2 (2) = 10.88, p = 0.004). Our experiment indicates that, under certain conditions, hens increase their activity levels (behavioural responses and transitions) in anticipation of rewards. Importantly, we demonstrate that this response is not food specific, but rather a general response to both food and non-food rewards. This outcome extends our knowledge of reward-related anticipatory behaviour, and of how hens rank rewards of contrasting incentive value, which may have implications for the methods and environments applied to improve the welfare of laying hens in managed systems. [ABSTRACT FROM AUTHOR]

Recently, it was found that the avian central vasotocin receptor (V1aR) is associated with the regulation of food intake. To identify V1aR-containing brain structures regulating food intake, a selective V1aR antagonist SR-49059 that induced food intake was administrated intracerebroventricularly in male chickens followed by detection of brain structures using FOS immunoreactivity. Particularly, the hypothalamic core region of the paraventricular nucleus, lateral hypothalamic area, dorsomedial hypothalamic nucleus, a subnucleus of the central extended amygdalar complex [dorsolateral bed nucleus of the stria terminalis], medial septal nucleus and caudal brainstem [nucleus of the solitary tract] showed significantly increased FOS-ir cells. On the other hand, the supraoptic nucleus of the preoptic area and the nucleus of the hippocampal commissure of the septum showed suppressed FOS immunoreactivity in the V1aR antagonist treatment group. Further investigation revealed that neuronal activity of arginine vasotocin (AVT-ir) magnocellular neurons in the supraoptic nucleus, preoptic periventricular nucleus, paraventricular nucleus and ventral periventricular hypothalamic nucleus and most likely corticotropin releasing hormone (CRH-ir) neurons in the nucleus of the hippocampal commissure were reduced following the antagonist treatment. Dual immunofluorescence labeling results showed that perikarya of AVT-ir magnocellular neurons in the preoptic area and hypothalamus were colabeled with V1aR. Within the nucleus of the hippocampal commissure, CRH-ir neurons were shown in close contact with V1aR-ir glial cells. Results of the present study suggest that the V1aR plays a role in the regulation of food intake by modulating neurons that synthesize and release anorectic neuropeptides in the avian brain. [ABSTRACT FROM AUTHOR]

The serotonergic system has been shown to be implicated in the regulation of mood and feeding behavior. Previous studies have identified a polymorphism in the 5;-flanking region of the serotonin transporter (5-HTT) gene of Lohmann Brown (LB) laying hens. The deleted variant D was found to be associated with increased body weight. The objective of this study was to address whether the increased body weight may be due to an increased feed intake. After hatching, hens were kept under ad libitum feeding conditions, and their body weight and feed intake were weekly determined. From 5 weeks of age, the body weight of hens with the D/D and W/D genotypes was significantly greater than that of W/W carrying hens. Interestingly, we found that the feed intake of D/D carrying hens, relative to body weight, was transiently increased only between 4 and 7 weeks of age (p < 0.05), leading to a higher growth rate (p < 0.05), compared with that of W/W carrying hens. These results suggest that the presence of variant D may be correlated with a transiently increased appetite of D/D carrying hens. [ABSTRACT FROM AUTHOR]

In this study pure Aflatoxin B1 (AFB1) was given to broiler birds at the rate of 50, 100, 200, 400 and 800μg/kg feed for 28 days. Birds of experimental groups intoxicated with 50, 100 and 200µ/kg feed did not show any clinical and behavior alteration. Birds of experimental groups intoxicated with 400 and 800µg/kg showed depression, ruffled feathers and had decreased feed intake, increased water consumption with soft to watery feces. Birds fed 800µg/kg AFB1 for 28 days also exhibited nervous signs (torticollis). Mortality occurred in all treatment groups with the exception of those given 50 and 100µg/kg AFB1 for 28 days. Clinical signs and mortality percentages score increased with the increase in AFB1 levels. Dose related significantly decreased in relative organs weight were recorded in all groups with the exception of birds given 50 and 100µg/kg AFB1 for 28 days. Significantly increased scores of gross lesions were recorded with increasing dietary levels of AFB1. The present study concluded that, AFB1 at level of 50µg/kg feed did not show any behavioral, gross and pathological effect on broilers when fed continuously for 28 day. In other groups pathological changes were seen in dose related manner. Severe changes were seen in higher dose levels. [ABSTRACT FROM AUTHOR]

This study compared behavioural time budgets, presence of comfort behaviours and social behaviours in two different broiler genotypes (the fast-growing Ross 308 (R) and the slower-growing Rowan Ranger (RR)) fed organic diets with high (17.0% crude protein (CP)) or low (14.5% CP) protein content during a 10-week rearing period. 429-day-old chicks (218 R and 211 RR, respectively) were included in the study and behaviour was recorded at 2, 6 and 9 weeks of age. The results showed no effect of diet treatments but that R broilers were less active and sat, ate and drank more frequently than RR broilers, which stood and perched more frequently. However, both hybrids showed decreasing activity and foraging behaviour with increasing age, while time spent eating and sleeping was approximately similar over the entire rearing period. [ABSTRACT FROM PUBLISHER]

Xinyang green-shell laying hens (n = 720), 32 wk of age were allocated to 5 dietary treatments groups, each of which included 6 replicates of 24 hens. The control group was given a basal corn-peanut-soybean meal diet containing 0.47% L-threonine (L-Thr). L-Thr levels of the experimental groups were 0.57, 0.67, 0.77, and 0.87%, respectively. The trial lasted 10 wk. Serum concentrations of total superoxide dismutases (T-SOD) and superoxide dismutases (SOD) were maximized at 0.67% L-Thr group. The 0.57% L-Thr group had the highest serumtotal antioxidative capacity (T-AOC),while the 0.67%L-Thr group had the lowest serum malondialdehyde (MDA) concentration. Hens fed 0.67%L-Thr of the diet resulted in the highest SOD and T-AOC levels in the liver. The activity of amylase and lipase in the jejunum was maximized at 0.77% L-Thr level. Hens fed 0.77% L-Thr in the diet resulted in the highest IgM and IgG levels in the jejunum. In conclusion, we suggest that a L-Thr level above 0.67% may have had an antioxidant capacity and positive effect on digestive enzyme activities and antibody production in the jejunum of Xinyang green-shell laying hens. [ABSTRACT FROM AUTHOR]