Chick Production Research Articles

Application of air energy heat pump in brood production of closed yellow-feathered chicken house

The aim of the study was to compere the effects of using air energy heat pump, flue heating and water heating as brood heating system on brood production of yellow-feathered broilers. In the experiment, three heating methods were used to heat chicks, and the parameters such as heating time, temperature uniformity, concentration of poisonous and harmful gases in the house, chick weight gain, mortality rate and production benefit were compered and analyzed. The results showed as follows: 1. There was no significant difference in NH3 and H2S concentration among the three groups (P > 0.05). The CO2 concentration in the flue group was significantly higher than that in the other two groups (P < 0.01), and there was no significant difference in CO2 concentration between the other two groups (P >0.05). 2. The body weight of chickens in the flue group at 30 days of age was the lowest, which was significantly different from that in the other two groups (P < 0.01); The air energy heat pump group had significant difference with coal fired boiler group (P < 0.05), the uniformity and survival rate of flue group were the lowest, and the air energy heat pump group had the best; 3. The temperature rise of honeycomb flue was the slowest, the temperature distribution uniformity was the worst, and the cost was the highest; The heating rate of coal-fired boiler was faster than that of flue, and the temperature distribution uniformity was better, and the cost was lower. The heating rate of air energy heat pump was the fastest, and the temperature distribution uniformity was better, and the operating cost was the lowest. 4. The air energy heat pump group has higher investment in the early stage, better use effect, better production performance of brood, long service life and lower brood cost.

Effects of Fish Populations on Pacific Loon (<i>Gavia pacifica</i>) and Yellow-billed Loon (<i>G. adamsii</i>) Lake Occupancy and Chick Production in Northern Alaska


 Predator populations are vulnerable to changes in prey distribution or availability. With warming temperatures, lake ecosystems in the Arctic are predicted to change in terms of hydrologic flow, water levels, and connectivity with other lakes. We surveyed lakes in northern Alaska to understand how shifts in the distribution or availability of fish may affect the occupancy and breeding success of Pacific (Gavia pacifica) and Yellow-billed Loons (G. adamsii). We then modeled the influence of the presence and abundance of five fish species and the physical characteristics of lakes (e.g., hydrologic connectivity) on loon lake occupancy and chick production. The presence of Alaska blackfish (Dallia pectoralis) had a positive influence on Pacific Loon occupancy and chick production, which suggests that small-bodied fish species provide important prey for loon chicks. No characteristics of fish species abundance affected Yellow-billed Loon lake occupancy. Instead, Yellow-billed Loon occupancy was influenced by the physical characteristics of lakes that contribute to persistent fish populations, such as the size of the lake and the proportion of the lake that remained unfrozen over winter. Neither of these variables, however, influenced chick production. The probability of an unoccupied territory becoming occupied in a subsequent year by Yellow-billed Loons was low, and no loon chicks were successfully raised in territories that were previously unoccupied. In contrast, unoccupied territories had a much higher probability of becoming occupied by Pacific Loons, which suggests that Yellow-billed Loons have strict habitat requirements and suitable breeding lakes may be limited. Territories that were occupied had high probabilities of remaining occupied for both loon species.

Single fluff-spray application of mother hen uropygial secretion analogue positively influences bursa of Fabricius development and the heterophil-to-lymphocyte ratio in ROSS 308 chicks

Stress is an important cause of illness and mortality in chick production. Stressors such as manipulation, absence of maternal care, transport, and housing can lead to welfare issues, immunodepression, and decreased productivity. The mother hen uropygial secretion analogue (MHUSA), a synthetic analog of a maternal semiochemical secretion, has been proven to protect chicks and broilers against stress, significantly reducing the heterophil-to-lymphocyte ratio. The aim of the present study was to test the effects of the MHUSA on chicks' stress when single-sprayed on their fluff at the age of 1 d. Two-hundred eighty ROSS 308 chicks were included in the study. At day 1, each chick received a spray of 200 μL of a 2% MHUSA aqueous solution (140 chicks) or the same amount of the excipient (control group, 140 chicks), and then chicks were housed in 2 separate rooms. To assess the persistence of the MHUSA after this single application, fluff was sampled from 10 chicks every day for 7 d and at day 13 and 19, weighed, placed in dichloromethane, and analyzed by gas chromatography. Blood smears and the bursa of Fabricius were collected every 3 d from 10 chicks of each group for 36 d to assess the heterophil-to-lymphocyte ratio and the bursa weight–to–BW ratio, respectively. Gas chromatography analysis showed that the MHUSA was present on chick fluff until day 5. The statistical analysis revealed that the heterophil-to-lymphocyte ratio was lower in the MHUSA group at day 4, 7, and 9 (P < 0.0001 for day 4 and 7; P = 0.0377 for day 9). The bursa weight–to–BW ratio was significantly higher in the MHUSA group than in the control group from day 4 until day 29. These results confirm the beneficial effects of the MHUSA on chicks' adaptation to the new environment and on bursa of Fabricius development, suggesting its potential role in improving chicks' immune response.

Meat quality, skin damage and reproductive performance of ostriches exposed to extensive human presence and interactions at an early age.

The effect human presence and interactions performed after hatch to 3months of age has on ostrich meat quality, skin damage and reproductive performance at a later age was investigated in 416-day-old ostrich chicks. The chicks were allocated to one of the three treatments, which varied with regard to exposure to human presence and care for 3months post-hatch: HP1-extensive human presence with physical contact (touch, stroking), gentle human voice and visual contact; HP2-extensive human presence with gentle human voice and visual contact without physical contact; S-standard control treatment, where human presence and visual contact were limited to routine management, feed and water supply only. Carcass attributes (carcass weight, dressing percentage and drumstick weight), meat quality traits (pH, colour and tenderness) and skin traits (skin size, skin grading and number of lesions) were evaluated on twenty-four 1-year-old South African Black (SAB) ostriches. Reproductive performance (egg production, average egg weight, number of clutches, clutch size, chick production, average chick weight, fertility and hatchability percentage) were recorded for the first three breeding seasons of 23 SAB pair-bred females from this study. No differences in carcass attributes, meat quality, skin traits and reproductive performance were found between treatments (P > 0.05). It was evident that exposure of day-old ostriches to extensive human presence and interaction as chicks did not influence carcass attributes, meat quality or skin traits at slaughter age, but more importantly, it did not compromise their reproductive performance.

Effects of Fish By-product Meal Inclusion in Broiler Feeds on Growth Performance

Background: The presence of inadequate and inconsistent feeds to the chicken resulted in lower performance of chick production in Ethiopia. Broilers are meat type chickens with fast income generation and depend on high quality feed. Feed costs alone currently account for over 65-70% of poultry production in third world countries, there has been recent interest in determining the feeding value of different locally available alternative feeding resources. As fish is generally appreciated as one of the healthiest and cheapest source of protein and it is available in Gambella water bodies, this research is intended to investigate the effects of fish by-product inclusion in broiler feeds on growth performance. Two hundred and forty (240) day old broiler chicks (Cobb 500) were reared and assigned to four treatments for 42 days. Treatment one was the control without fish by-product meal, treatment 2 contained 2% fish by-product meal, treatment 3 contained 3% fish by-product meal and treatment 4 contained 5% fish by-product meal. Each treatment was replicated 3 times with 20 birds per replicate in a completely randomized design. Parameters measured for the experiment were the initial body weight, final weight, daily feed intake while weight gain and feed conversion ratio (FCR) were calculated. Data were analyzed using General linear model procedure of statistical analysis software (SAS) version 9.2.&#x0D; Results: This study indicated that the average daily feed intake of broiler significantly increased (P&lt;0.05) in 3 and 5% fish by-product meal level to the diets during 11-20 days of age. At the age of 32 – 42 days the average body weight and daily feed intake at the age of 21-32 days were significantly (P&lt;0.05) increased in 3 and 5% fish by-product meal level compared to control and 2% fishmeal diet.&#x0D; Conclusion: This study revealed that inclusion of fish by-product meal in the diet improved the performance of broiler. To utilize and exploit the potential of fish by-product meal as broiler feed in Gambella region, farmers should get training on preparation and utilization of fish by product.

To Hide or Not to Hide: Nesting Habitat Dynamics in a Threatened Gull

Lesser Black-backed Gulls (Larus fuscus fuscus) were studied over 10 breeding seasons (2005-2014) to assess factors influencing nesting distribution among 7 subcolonies with two distinct habitats (open-rocky or vegetated) in an archipelago on the Norwegian Coast. The study was divided into an early (2005-2008) and late period (2009-2014), depending on a predatory event in 2008, where one subcolony suffered a complete reproductive failure. In the early period, three open-rocky subcolonies in the periphery appeared to contain birds of higher quality (assessed by stability in number of pairs among years, reproductive timing, clutch size, and chick production) compared to a large vegetated subcolony. In the late period, the proportion of the population nesting in the large vegetated subcolony increased, as did the quality of individuals, a result of birds from the depredated subcolony settling there. In subcolonies not subject to complete reproductive failure, philopatry to natal subcolonies was high among juveniles (∼80%), and the rate of among-year change between subcolonies by adult breeders was as low as 0-3%, although the rate of change increased up to ∼15% following years of poor reproductive success. However, there was no evidence that either habitat consistently offered better nest protection and reproductive success than the other.

Research Note: Molecular and pathologic characterization of avian adenovirus isolated from the oviducts of laying hens in eastern Japan

Cases of poor egg production were investigated in 2 layer farms from Ibaraki Prefecture in eastern Japan. To identify any microbial agents that may have caused the problem, necropsy, bacterial isolation, histopathology, and virus detection were performed. Members of the avian adenoviruses was detected by PCR in oviduct samples from both farms; chicken anemia virus coinfection was also confirmed in one of the farms. Avian adenovirus was isolated from the oviducts of the affected chickens on each farm. Inoculation into chick embryos showed tropism for the chorio-allantoic membrane. Stunting and hemorrhaging was observed in all infected embryos, as well as death in a few. Inoculation of 1-day-old specific pathogen-free chicks, and 400-day-old commercial hens, did not result in any significant findings. The isolated viruses were analyzed by sequencing of the hexon gene and were confirmed as fowl adenovirus type-c serotype-4 (FAdV-4). The 2 virus strains were found to be 99.29% similar to each other. One of the strains, Japan/Ibaraki/Y-H6/2016, was 99.15% similar to the KR5 strain. The other, Japan/Ibaraki/M-HB2/2016, was 99.57% similar to the KR5 strain. Fiber-2 gene analysis confirmed the identity as FAdV-4 that is closely related to nonpathogenic strains. Although nonpathogenic to chicks and laying hens, this infection can possibly cause economic damage. Perhaps the bigger concern is the effect on infected breeder operations. Because the virus is fatal to 9.09% of infected embryos, this could translate to a considerable loss in chick production owing to embryonic death. This is the first report of detection and isolation of FAdV-4 from the chicken oviduct; however, further studies are needed to elucidate its impact on both layer and breeder flocks. Indeed, FAdV-4 has negative effects on the avian reproductive tract as well.

THE EFFECT OF DIETARY LEVELS OF CALCIUM, PHOSPHORUS AND CHOLECALCIFEROL ON PERFORMANCE, CARCASS AND TIBIA CHARACTERISTICS OF BROILER CHICKS

A study was conducted to determine the effect of increasing dietary cholecalciferol in deficient calcium and phosphorus broiler diets on productive performance, carcass characteristics and some tibia measurements. A total of 270 one day old Hubbard chicks were weighed and randomly allocated into a completely randomized design (five treatments, six replicate groups, nine chicks in each group). The experimental diets were as follows: (T1) control diet, was formulated according to the manual guide of Hubbard broiler chicks. (T2 to T5) tested diets were containing half of the calcium and available phosphorus requirements with extra levels of cholecalciferol 5000 (T2), 6000 (T3), 7000, (T4) and 8000 (T5) international units. The main results obtained can be summarized as follows: At 6 weeks of age, body weight and gain of birds fed either control or deficient calcium and phosphorus diets with 7000 (T4) and 8000 (T5) I.U. of cholecalciferol were significant heavier than those with 5000 (T2) or 6000 (T3) and consume less feed and gave better feed conversion ratio. The highest production efficiency factors were recorded for the control and T5 groups. Carcass characteristics (dressing % and ready to cook %) were significantly higher in birds fed control or those fed T4 and T5 diets compared with that fed T2 and T3 diets. Tibia breaking strength, tibia length and width of birds fed control or T5 diets were higher than other treatments with significant differences. It could be concluded that using the half requirements of calcium and available phosphorus in broiler diets supplemented with 8000 IU/kg cholecalciferol would have a positive effect on the cost of production of broiler chicks, without any adverse effect on productive performance, carcass and tibia characteristics.

The appropriate time to improve day-old chick production and post-hatch growth through Moringa oleifera leaf extract inoculation into the hatching egg

The appropriate time to improve day-old chick production and post-hatch growth through Moringa oleifera leaf extract inoculation into the hatching egg

Effect of maternal environment on yolk immunoreactive corticosterone and its influence on adrenocortical and behavioral activity in chicks of Greater Rhea (Rhea americana)

Maternal corticosterone in avian eggs may modify offspring phenotype in order to increase survival in poor environments. In the Greater Rhea (Rhea americana), we previously found that yolk immunoreactive corticosterone is influenced by the quality of the maternal environment: eggs laid by females of the intensive rearing system (IRS), living in poor captive conditions, had higher yolk immunoreactive corticosterone than those produced by females of the semi-extensive rearing system (SRS), living in better conditions. Here, we evaluate if these different hormone levels are associated with the production of different phenotypes. We collected eggs from the IRS and SRS for hormonal quantification and artificial incubation. Then, half of the chicks selected from each environment were exposed to a capture and restraint protocol, and the rest remained undisturbed and were used as controls. In the IRS, we found that higher yolk immunoreactive corticosterone was associated with the production of chicks that had reduced hatchability, lower hatchling mass and higher baseline fecal glucocorticoid metabolites (FGM) than those produced by SRS females. Moreover, after capture and restraint, IRS chicks did not modify their FGM nor their behaviors compared to their controls, while SRS chicks increased their FGM and spent more time ambulating and less time pecking, compared to their controls. These results indicate that yolk immunoreactive corticosterone could modify offspring phenotype. Although future studies are needed to elucidate their implications for fitness, our results suggest that yolk corticosterone could be mediating an adaptive maternal effect that allows individuals to better cope with poor conditions.

Equitable Chick Survival in Three Species of the Non-Migratory Shorebird Despite Species-Specific Sexual Dimorphism of the Young.

Simple SummaryWe aimed to determine whether seasonal brood sex-ratio, sex-biased chick survival, and sex specific dimorphism at hatching or during growth occurs among three species of resident Australian shorebird. Our results describe no sex-bias in chick production, survival or growth rates between sexes for any of the three species studied. Sex-biases in populations can have important implications for species’ social biology, population demography and mating systems. It has recently been suggested that in some shorebirds, sex-specific bias in survival of precocial young may occur. This may be driven by variation in the brood sex-ratio and/or the sexual size dimorphism of young birds, which may influence predator escape capacity. Understanding the survival of young birds remains a significant knowledge gap for many taxa, especially when young birds are mobile and cryptic. Our aims were to estimate the sex-ratio variation in three species of Australian resident shorebird, specifically to determine: (1) whether seasonal brood sex-ratio variation at hatching is occurring, (2) the extent of any sex-biased chick survival, (3) if sex specific dimorphism at hatching or during growth occurs; and, (4) whether escape capacity differs between the sexes. We radio-tracked 50 Masked Lapwing Vanellus miles, 42 Red-capped Plover Charadrius ruficapillus and 27 Hooded Plover Thinornis cucullatus chicks from individual broods, examined the likelihood of hatchlings being male or female based on the hatching date within the breeding season, and compared size at hatching, growth and mortality of chicks of different sexes. There was no sex-bias with the hatching date across the breeding season, nor were there differences in survival or growth rates between sexes for any of the three species studied. In one species, male hatchlings had longer tarsi than females, but this did not result in differential escape propensity or improved survival. In conclusion, the hatching date, survival and growth of chicks from three species of resident shorebird was not influenced by their sex.

The influence of chick production on territory retention in Arctic-breeding Pacific and Yellow-billed loons

Abstract Adult birds may use the production of offspring as a measure of habitat quality when prospecting for territories, increasing competition for productive territories. We evaluated the impact of breeding success on territory retention of Pacific (Gavia pacifica) and Yellow-billed (G. adamsii) loons in the National Petroleum Reserve-Alaska on the Arctic Coastal Plain of northern Alaska using mark–resight data and multi-state modeling. We also used behavioral observations of brood-rearing adult loons to quantify the frequency of visits by prospecting loons. We hypothesized that increased competition for productive territories would result in a decrease in territory retention rates. Territory retention rates the year following successful breeding attempts were only slightly lower (0.90) than after failed breeding attempts (0.93), and few territories were consistently successful across years. Overall territory retention rates were high (0.92) and similar for both species, suggesting that adults were able to defend their territories successfully. Males had higher territory retention rates than females, but we found no influence of mass (a possible proxy for fighting ability) on territory retention. These observations, coupled with the high frequency of visits by prospecting loons, provide additional evidence that site familiarity may provide advantages to territory holders. Quantifying territory retention behaviors may also inform land management decisions for oil and gas development in areas where loons are present. High territory retention rates, frequency of visits by prospectors, and limited habitat where new territories can be established suggest that breeding habitat in northern Alaska is saturated and may be limiting Yellow-billed Loon populations. In contrast, Pacific Loons attempting to acquire a territory may be able to form new territories on smaller, unoccupied lakes.

Diversionary feeding and nestling diet of Hen Harriers Circus cyaneus

ABSTRACTCapsule: Diversionary feeding reduced Hen Harrier Circus cyaneus nestlings’ natural food intake by half. Red Grouse Lagopus lagopus scotica chicks constituted 0–4% of all nestling food items. Annually, this reduced annual grouse chick production by 0–6%.Aim: To quantify proportions of diversionary and natural food (including grouse) delivered to Hen Harrier nestlings in relation to brood size, male status and natural prey abundance.Methods: We recorded diversionary food provisioned to 25 Hen Harrier broods (2008–15) and studied the diet of 15 broods using observations from hides, nest cameras and regurgitated pellet analysis. Variation in nestling diet was analysed using compositional analysis.Results: Hen Harriers took 76% of diversionary food provided. Depending on assessment method, average nestling diet was 44–53% diversionary food, 39–55% natural prey (including 24–45% passerines, 4–15% small mammals, 0–4% grouse chicks) and 0–9% unknown items. The amount of diversionary food consumed was not influenced by male status, brood size or natural prey abundance. The number of Red Grouse chicks delivered annually was 34–100% lower than expected under unfed conditions, however, the confidence intervals associated with these estimates were large.Conclusion: Diversionary food influenced Hen Harrier nestling diet and reduced the number of Red Grouse chicks taken relative to modelled predictions. It may help reduce conflict between Hen Harrier conservation and Red Grouse shooting, but only if overall grouse productivity is thereby maintained or increased.

Hormonal levels of estradiol, testosterone, and progesterone at entry into lay of year 1980 vs. 2000 broiler breeder females under fast and slow release from feed restriction.

In the mid-1960s egg production, fertility, and hatchability of broiler breeder females dropped precipitously. Due to disrupted follicle hierarchies and development of the erratic oviposition and defective eggs (EODES) syndrome. EODES was controlled by restricting feed. In the 1990s, another set of problems arose at entry of broiler breeders into lay and characterized by high mortality followed by lower peak lay and reduction in egg and chick production. These problems are induced by even slight over-feeding, and hence we termed it the "Over Feeding Complex" (OFC). We have speculated that OFC is a quasi-EODES condition, induced by the intense selection for increased breast proportion. To test this, we compared, under fast (FF) and slow (SF) release from feed restriction, body composition and reproductive performance of a broiler breeder from year 1980 (B1980) and kept without selection for performance traits since then, to a line hatched in 2000 (B2000). During the first 16 d of lay, feeding treatment had little effect on egg mass or Laying % for the B1980 birds, while for the B2000 birds, SF treatment resulted in significantly greater egg mass and Laying % compared to FF, showing that the OFC indeed manifested in this experiment. However, contrary to hypothesis, follicle hierarchies were normal for both lines under both feeding treatments. To gain further insight into the OFC syndrome, we here report levels of estradiol, testosterone, and progesterone for these line and treatment groups in the time period leading up to and into lay. A significant line × feeding treatment interaction effect was found for estradiol and testosterone, to a lesser extent for progesterone. For all 3 hormones, for B1980 levels 2 to 3 wk post entry into lay were similar and intermediate under FF and SF, but differed significantly for B2000, being much greater under SF than under FF. Thus, the hormonal effects were parallel and may explain the egg mass and Laying % effects of FF and SF in the 2 genetic types.

Nest use dynamics of an undisturbed population of bald eagles.

Management or conservation targets based on demographic rates should be evaluated within the context of expected population dynamics of the species of interest. Wild populations can experience stable, cyclical, or complex dynamics, therefore undisturbed populations can provide background needed to evaluate programmatic success. Many raptor species have recovered from large declines caused by environmental contaminants, making them strong candidates for ongoing efforts to understand population dynamics and ecosystem processes in response to human‐caused stressors. Dynamic multistate occupancy models are a useful tool for analyzing species dynamics because they leverage the autocorrelation inherent in long‐term monitoring datasets to obtain useful information about the dynamic properties of population or reproductive states. We analyzed a 23‐year bald eagle monitoring dataset in a dynamic multistate occupancy modeling framework to assess long‐term nest occupancy and reproduction in Lake Clark National Park and Preserve, Alaska. We also used a hierarchical generalized linear model to understand changes in nest productivity in relation to environmental factors. Nests were most likely to remain in the same nesting state between years. Most notably, successful nests were likely to remain in use (either occupied or successful) and had a very low probability of transitioning to an unoccupied state in the following year. There was no apparent trend in the proportion of nests used by eagles through time, and the probability that nests transitioned into or out of the successful state was not influenced by temperature or salmon availability. Productivity was constant over the course of the study, although warm April minimum temperatures were associated with increased chick production. Overall our results demonstrate the expected nesting dynamics of a healthy bald eagle population that is largely free of human disturbance and can be used as a baseline for the expected dynamics for recovering bald eagle populations in the contiguous 48 states.

Effects of dietary protein level and age at photo stimulation on reproduction traits of broiler breeders and progeny performance.

A study with a 2 × 2 factorial arrangement was conducted to determine the effects of 2 dietary crude protein levels, high (CPh) or low (CPl), supplemented with free amino acids (AA), and 2 ages at photo stimulation (PS)-early (21wk; PSe) or late (23wk; PSl)-on reproduction traits of broiler breeders and progeny performance. Diets were isocaloric, and calculated CP content of the CPl diets was 15g/kg lower than the CPh diets during all phases. A total of 480 female and 64 male Ross 308 breeders of 20wk of age were used. Total egg production was similar between CPl and CPh birds during phase 1 and 2 but was reduced by 2.8 eggs for CPl birds during phase 3. For the overall laying period, CPl birds tended (P = 0.075) to produce 4.7 fewer total eggs. Hatchability of set eggs was similar between CPl and CPh birds during phases 1 and 2 but tended (P = 0.064) to be lower for CPl birds in phase 3. PSe birds showed an advanced age at sexual maturity and age at peak production of 4.6 and 5.3 d, respectively, resulting in 2.5 more total eggs during phase 1. During phase 1, PSe birds showed an almost 5% increased fertility. Chick production in phase 1 was higher for PSe birds resulting in a tendency (P = 0.071) to higher overall chick production of almost 8 chicks. Progeny from early PS breeders showed an overall significant lower feed conversion ratio (FCR). It was concluded that egg and chick production during phases 1 and 2 were not affected by dietary CP level, but egg and chick production was reduced for CPl birds during phase 3. On the other hand, PSe birds showed an increased number of chicks. It is possible to decrease CP level of breeder diets with comparable reproduction from 22 to 46wk; however, this is questionable for phase 3. For maximal chick production, early PS is recommended.

Compare the chick length and weights of the Ross broiler breeder in different ages and farms

reeder flock age affects the quality and quantity of eggs and chicks. The purpose of this study was to investigate the effect of breeder flock age on egg (quality and quantity) and weight and height of hatched chicks. In recent study 271 fertilizable eggs were selected randomly from 3 farms of broiler breeder. Broiler breeder eggs were used when they were 30 (young), 36 (peak), 43 (after peak), 53 (old), 60 (very old) and 82 (molt) weeks. Collected eggs after hatching were stored during 3 to 4 hours at ambient temperature. Quantitative traits such as weight of chick and chick height were considered. The effect of ages and farms on the chick weight and chick height were significant (P < 0.001). The chick weight increased until 53 weeks then decreased. The chick height increased with age increment. According to limitation of researches about studying the effect of age of broiler breeder flock on the chick production, it is needed to carry out a research to eliminate unknown points. Since the majority of poultry have no sufficient information about the quality of chick and the best age of broiler breeder for buying chicks it could be answered to many questions using the results of this research.

Parental sex effect of parthenogenesis on progeny production and performance of Chinese Painted Quail (Coturnix chinensis)

Embryonic development of an unfertilized egg, parthenogenesis, is known to occur in Chinese Painted quail. However, selection for parthenogenesis in both the dam and sire leads to a reduction in hatchability following mating. Therefore, the objective of this study was to determine if selection for parthenogenesis in the dam, sire, or both also impact their progeny performance. There were 2 lines of birds used in this trial: 1 line selected for parthenogenesis and 1 line not selected for parthenogenesis (control) yielding breeding pairs as follows: control dams + control sires (CC), control dams + parthenogenetic sires (CP), parthenogenetic dams + control sires (PC), and parthenogenetic dams + parthenogenetic sires (PP). For all progeny, a dam line main effect revealed that the parthenogenetic line dams had heavier offspring hatch weight and 4 wk body weight as well as higher 1st wk chick mortality versus control line dams. However, control line dams had the highest 4th wk chick mortality versus parthenogenetic line dams. In female virgin progeny, a dam by sire interaction revealed that PP, PC, and CP had the heaviest 1st egg in the clutch position versus CC. Also, eggs from PP had the highest number of eggs and the most female progeny exhibiting parthenogenesis versus CC. There was a linear increase in egg weight as clutch position increased for progeny from PP and CC yet a linear decline for CP. In conclusion, it appears that both the dam and sire selected for parthenogenesis impact progeny performance as parthenogenetic dams and sires additively contribute to the degree of parthenogenesis exhibited by virgin female progeny. Moreover, because parthenogenesis is known to exist in the modern poultry industry, even the accidental selection of the parthenogenetic trait in either males or females could have a negative impact on overall chick production and performance.

Evaluating hydrolyzed yeast in the diet of broiler breeder hens

One of the greatest challenges for nutritionists is ensuring that breeder hens consume the quantity of nutrients necessary to ensure proper development while also ensuring the production of good quality chicks. However, new studies must investigate how nutrition can positively affect the performance of these poultry. The present study aimed to evaluate hydrolyzed yeast supplementation in the diet of Cobb 500 broiler breeder hens, starting from 25 wk of age, and to evaluate the performance of the hens and their progeny. Broiler breeder hens fed hydrolyzed yeast supplement exhibited better performance compared with the control group. The results of the progeny demonstrated improved performance in chicks from the breeder hens fed the hydrolyzed yeast supplement. However, no improvement was observed in breast or leg yields; only carcass yield improved in these broilers. The results demonstrate that supplementation with hydrolyzed yeast in the diet of broiler breeder hens improves the performance of hens and their progeny.

A CFD approach to assess the effects of different opening combinations in poultry houses

ABSTRACT The aim of this study was to use computational fluids dynamics (CFD) to evaluate hygiene and comfort conditions in function of temperature level and ammonia (NH3) concentration during the night in commercial poultry houses used in Brazil and countries with tropical and subtropical climates. Four models with different curtain heights and different air inlet and outlet positions were used, adopting the open building typology without thermal insulation. The validated CFD model did not present statistical differences from the experimental data, making it possible to use this model to predict the behavior in the four proposed cases. This model can be used to improve the internal conditions of the poultry facilities during the night and could be an important tool to reduce energy consumption and generate better conditions for animal production of chicks over 21 days old.