A Long-Term Study of the Environment Within a Tunnel Incubator for Turkey Eggs

A 6-mo study of the temperatures within a tunnel incubator in a commercial turkey hatchery was conducted to determine the extent that the incubation environment varied with the type of egg incubated. The tunnel incubator moves air through the mass of eggs from the oldest to the youngest embryos, and air temperature was found to increase by approximately 1°F as it passed through the eggs. The temperature of the air entering the eggs was maintained at a constant temperature by the incubator, but the temperature of the air leaving the eggs showed considerable day-to-day variation. The main cause of temperature variation within the incubator was the setting of fresh eggs into and the transferring of d-25 eggs out of the incubator. However, the temperature was also found to vary with the predicted total embryo metabolic heat production within the incubator estimated from the age of the embryo, egg mass, and breeder flock fertility. The temperature of air within the egg mass was also measured and shown to correspond more closely to the temperature of the air where it exits the eggs rather than where it enters the eggs or the machine-operating temperature.     

Effects of coated hatching eggs obtained from old broiler breeders with chitosan on embryonic growth,hatching results and chick quality

The aim of this research was to determine the effects of coating broiler hatching eggs with chitosan on egg quality, embryonic growth, hatching results and chick quality. Eggs obtained from old broiler breeder, aged 59 weeks, were used. Eggs were divided into two groups (coated with chitosan and uncoated) groups. Each group was divided into three groups according to the storage period. Eggs were stored for periods of 1, 4 and 7 days at 15°C and 80% humidity. Then, they were incubated. Storage period of eggs up to 7 days did not affect the egg quality, egg weight loss, embryo growth, chick properties and hatchability of fertile eggs. However, embryo development, relative residual yolk sac weight and relative chick weight were affected by coating eggs with chitosan. Interaction was not found between storage lengths and coating of eggs with chitosan for all examined parameters. The results of the present study suggested that hatching eggs obtained from old broiler breeder flocks were immersed into chitosan solution once and quickly have negative effect on the embryo weight, yolk sac absorption and relative chick weight. It has been observed that covering the hatching eggs with chitosan is not suitable in this respect even if immersion takes place once and in a short time.     

Incidence and classification of early embryonic mortality in broiler breeder chickens

1. Unusually high early embryonic mortality (EEM) was observed in hatching eggs from broiler compared with white or brown table‐egg breeders in Atlantic Canada. Broiler breeder EEM in Atlantic Canada was twice the EEM in broiler breeders from other areas of North America.

2. Comparisons of holding temperatures (18 and 30°C) for 24 h after egg collection, in combination with a storage time of 0 or 7 d at 18°C prior to incubation, were made using the criteria: embryo development (stage), and size at 0, 3, 6 and 9 d incubation, EEM, late embryonic mortality (LEM) and hatchability (HAT).

3. Stage of development of embryos, at 0 d incubation, was highest for eggs held for 24 h at 30°C and stored for 7 d. Embryo stage, weight and length at 3, 6 and 9 d incubation were positively correlated.

4. Hatchability of fertile eggs was lowest (66.5%) for eggs held for 24 h at 30°C and stored for 7 d and highest (87.2%) for eggs held for 24 h at 18°C and stored for 0 d. Holding temperature and storage time significantly influenced EEM and LEM.

5. EEM classification differed for strain of breeder. In broiler breeders the majority of the EEM was at a relatively late stage of development (exhibiting an obvious blood ring with a visible embryo). In comparison, EEM from table egg breeders was distributed equally among three categories.     

Effect of pre-incubation storage conditions on hatchability,chick weight at hatch and hatching time in broiler breeders

1. Eggs were stored for two different times at varying temperatures. The effects on hatchability, chick weight at hatch and hatching time were examined in two broiler breeder lines from 33 to 58 weeks of age. 2. Short storage (1 to 3 d). Storage at 20 degrees C compared with 16.5 degrees C reduced hatchability of all eggs set. No effect was observed on hatchability of fertile eggs, hatching time or chick weight. 3. Long storage (9 to 11 d). Storage at 16.5 degrees C compared with 10 degrees C decreased both hatchability of fertile eggs and chick weight at hatch. Incidence of early embryonic death increased and incubation time decreased at 16.5 degrees C compared with 10 degrees C. 4. Chicks from morning eggs were heavier than those from afternoon eggs irrespective of storage conditions. 5. Hatchability (all eggs set and fertile eggs) and chick weight varied with hen age irrespective of storage conditions. During long storage, hatching time varied with hen age independently of breeder line, storage temperature or egg laying time. 6. Hatchability (all eggs set and fertile eggs) was higher in line A than in line B. Line B eggs hatched later and produced heavier chicks than line A eggs irrespective of storage time.     

Effects of egg weight on the egg quality,chick quality,and broiler performance at the later stages of production (week 60) in broiler breeders

The objective of the present study was to determine the effect of broiler breeder egg weight on egg quality, chick quality, and broiler performance using Hubbard Classic broiler breeder flock. Hatching eggs from a commercial broiler breeder flock (Hubbard classic strain) were obtained at the age of 60 wk and divided into 3 egg-weight categories, namely small, medium, and large. For this purpose, 930 eggs having weights 63.09 ± 0.21, 68.85 ± 0.23, and 74.81 ± 0.11g were divided into 3 egg categories labeled small, medium, and large respectively. We further divided these eggs into 2 categories, eggs for quality parameters and eggs for incubation and posthatch performance parameters. Eggs from the small egg category had greater proportion of the shell weight and more shell strength. Egg weight did not significantly affect the albumen and yolk weight percentage. Egg weight affected the shape index and specific gravity for which lower values were observed for large eggs. Egg weight positively affected the chick weight, chick yield, and chick length (P < 0.05) of both male and female chicks. Results of the body weight gain showed that effect of egg weight on the posthatch performance of chick diminishes with the age of broilers. Egg weight significantly affected the body weight gain of male and female chicks up to 3 wk of age. Egg weights did not significantly affect the feed intake and mortality of broiler. Different egg-weight categories significantly affected the feed conversion ratio of female chicks at wk 2 and 3 of age and did not affect the feed conversion of male and female chicks at the end of wk 5. In conclusion, egg weight positively affected the chick characteristics (e.g., chick weight, chick length) and did not affect the final live body weight, feed conversion ratio, feed intake, and mortality in broilers.     

Effects of ad libitum feeding on performance of different strains of broiler breeders

(1) Tolerance to ad libitum feeding was compared in three genotypes of broiler breeder hens: a standard broiler breeder fed ad libitum (SA) or restricted (SR), a slow growing 'label' broiler breeder (L) and an experimental dwarf heavy broiler breeder (E). Two similar experiments were conducted in two distinct research centres. (2) Feed intake and body weight were measured every 3 weeks from hatch to 40 to 49 weeks of age. Egg production and egg abnormalities were recorded. The number of yellow follicles in ovaries was counted at the age of 32 weeks. (3) Body weight was stabilised at 2.2, 3.7 and 5.4 kg after 24 weeks of age in L, E and SA hens, respectively. Growth of the SR hens was similar to that of L up to 20 weeks and stabilised at a similar level to that of E hens after 30 weeks of age. (4) Sexual maturity was delayed by 6 weeks in restricted breeders compared to ad libitum fed hens that started to lay at 20 weeks. SA hens had low egg production and a high proportion of defective eggs, which was largely compensated for by feed restriction. However, productivity of SR hens remained lower than that of L breeders. (5) Compared to the low viability and reproductive fitness observed with SA hens, the E dwarf broiler breeder tolerated ad libitum feeding and had better egg production, fewer egg abnormalities and yellow follicles per ovary and a higher egg production. However, laying rate was still lower than that of the SR and L groups. Energy conversion (kJ/g egg) from 32 to 40 weeks of age was much higher in the SA group than in the other three groups. 6. The feasibility of feeding a dwarf broiler breeder ad libitum calls for further research on implications of specific IGF and GH-receptor expression at the level of the ovary in dw chickens.     

Effects of Temperature on In Vitro Short‐Term Storage of Sterlet Sturgeon (Acipenser Ruthenus) Ova

Artificial propagation of sturgeons is becoming increasingly important for recovery efforts as well as for commercial production. Sterlet Acipenser ruthenus is a common Eurasian sturgeon with a small body size and one of the fastest reproductive cycles among the sturgeons. The practical question being addressed in this study was how long fertilization of ovulated eggs can be delayed without substantially reducing the hatching rate, and an ancillary question is under what' temperature conditions do eggs retain good quality. Broodstock were injected with homogenized carp pituitary extract (CPE); ovulated eggs from three females were allocated to various treatment groups for temperature storage (control, 7°C, 11°C, 15°C and 19°C) until fertilized. Storage times at the regulated temperatures prior to fertilization were for 2.5, 5.0, 7.5 and 10.0 h. After the selected storage times in ovarian fluid, eggs were fertilized and transferred to incubation cages and then they were counted. Three replicates were allocated to each storage period and temperature. Hatched larvae were counted at 7‐day post‐fertilization. We found that sterlet eggs do not need to be fertilized immediately after collection. Reasonably good quality was retained for several hours if temperature conditions are fairly cool and stable. Eggs retained good quality when stored at 7°C and 11°C for up to 10 h with 54.1 ± 2.9 to 69.9 ± 7.9% hatching success, but egg quality was significantly reduced after 5‐h storage at 19°C (p < 0.01) and 7.5‐h storage at 15°C (p < 0.05) compared to cooler temperatures. Uniform temperatures between 7°C and 11°C can be considered as appropriate for storage of eggs in ovarian fluid for up to 10 h. This information can have practical application to routine hatchery practice for acipenserids, as well as for certain research protocols.     

Histochemical and histological evaluations of the effects of high incubation temperature on embryonic development of thymus and bursa of Fabricius in broiler chickens

1.?The effects of experimentally induced heat-stress on the embryonic development of bursa of Fabricius and thymus of the chicken were investigated by means of histological and enzyme histochemical methods.

2.?In the experiments, 250 fertile eggs of the Ross 308 broiler strain were divided into two groups. The control eggs were maintained under optimal conditions (37?8°C and 65 ± 2% relative humidity, RH) during the whole incubation period. Heat stressed eggs were maintained under normal conditions (37?8°C and 65 ± 2% RH) until the 10th d of incubation and then exposed continuously (24 h per d) to high temperature (38?8°C and 65 ± 2% RH). Blood and tissue samples were taken from 10 animals of each group at d 13, 15, 18 and 21 of incubation and at d 2, 4 and 7 post-hatch. Tissue samples were processed for enzyme histochemical methods in addition to routine histological techniques.

3.?The results revealed that egg temperatures were higher than incubator air temperature. Long-term heat-stress (40?1–40?6°C egg temperature) retarded development of thymus and bursa of Fabricius. Peripheral blood ACP-ase and ANAE-positive lymphocyte levels of heat-stressed animals were lower than in the controls.

4.?These results give some morphological evidence for immunosuppression induced by high temperature exposure during the embryonic development. Temperature distribution and air circulation in incubator should be questioned in the case of lower broiler flock immunity.     

Modelling energy utilisation in broiler breeder hens

1. The objective of this study was to determine a metabolisable energy (ME) requirement model for broiler breeder hens. The influence of temperature on ME requirements for maintenance was determined in experiments conducted in three environmental rooms with temperatures kept constant at 13, 21 and 30 degrees C using a comparative slaughter technique. The energy requirements for weight gain were determined based upon body energy content and efficiency of energy utilisation for weight gain. The energy requirements for egg production were determined on the basis of egg energy content and efficiency of energy deposition in the eggs. 2. The following model was developed using these results: ME = kgW0.75(806.53-26.45T + 0.50T2) + 31.90G + 10.04EM, where kgW0.75 is body weight (kg) raised to the power 0.75, T is temperature ( degrees C), G is weight gain (g) and EM is egg mass (g). 3. A feeding trial was conducted using 400 Hubbard Hi-Yield broiler breeder hens and 40 Peterson males from 31 to 46 weeks of age in order to compare use of the model with a recommended feeding programme for this strain of bird. The application of the model in breeder hens provided good productive and reproductive performance and better results in feed and energy conversion than in hens fed according to strain recommendation. In conclusion, the model evaluated predicted an ME intake which matched breeder hens' requirements.     

Preincubation storage of turkey eggs: Impact on rate of early embryonic development

1. The effect of cooling and storage on preincubation development of turkey embryos was examined.

2. Fresh laid eggs were stored at 15°C for 3, 7, or 14 d (group 1) or held initially at room temperature (21°C) for 6 to 9 h and subsequently stored at 15°C for 3, 7, or 14 d (group 2).

3. Most embryos in eggs from both groups progressed developmentally to Stage‐8, just prior to onset of hypoblast formation. There were no significant differences in embryo development either within or between groups.

4. It is concluded that under the conditions of this study, egg cooling and storage augment development of the embryo, albeit only slightly.     

Moisture content and moisture quantity of sweated chicken eggs in 2 storage environments

There are instances where shell eggs may be moved from refrigeration into ambient temperature with high humidity, such as before wash and during transportation. Under these conditions, it is of concern that bacteria on wet eggs can grow and migrate through the shell pores into the egg. Objectives of this experiment were: 1) to compare 3 methods of quantifying condensate on eggs and 2) to quantify condensate on refrigerated shell eggs at 2 temperatures (22°C and 32°C). For objective 1, 270 fresh shell eggs (3 replications, 90 eggs per replication) were stored at 4°C, 60% relative humidity (RH), then placed at 22°C, 60% RH for 1 h. After this time, 30 pre-weighed eggs were randomly selected and weighed. Thirty eggs were thoroughly wiped with pre-weighed paper towels to collect condensate. Thirty eggs were evaluated with a pinless moisture meter for quantifying egg condensate, which was found to be an ineffective method. There was no difference in quantifying egg condensation by egg weight or weight of moisture absorbed on a paper towel (0.2% vs. 0.19% percentage gain mL condensation/egg surface area) (P > 0.05). For objective 2, 104 fresh eggs formed condensation at 2 temperatures (22°C and 32°C, 60% RH). Each egg weight was continuously recorded from the beginning of condensation formation to the point where the egg reached a constant weight. There was a difference found in the time it took for an egg to reach maximum condensation (11 min at 32°C, 17 min at 22°C), as well as completely dry (25 min at 32°C, 34 min at 22°C) between the 2 temperatures (P < 0.05).     

Presence and recovery of Ascaridia dissimilis ova on the external shell surface of turkey eggs.

Ascaridia dissimilis, a roundworm in turkeys, has been noted with increased frequency in commercial turkeys. Because infected turkeys can shed A. dissimilis ova in their feces, the potential exists for the external surface of turkey eggshells to be contaminated with A. dissimilis ova. The objectives of this study were to determine the presence of and recover A. dissimilis ova on the external surface of the turkey egg. In Experiment 1, turkey eggs were collected from naturally infected flocks, and eggs were processed by a sodium hydroxide procedure to recover any A. dissimilis ova on the external egg surface. In Experiment 2, the external surface of the turkey eggs was inoculated with 116 A. dissimilis ova/g feces, and eggshells were sampled every 3 days until 28 days of incubation to assess the recovery of A. dissimilis ova from the eggshell. In Experiment 1, of the 36 eggs examined from a flock naturally infected with A. dissimilis, one egg had an A. dissimilis ovum on its external eggshell surface. Experiment 2 demonstrated that A. dissimilis ova can be recovered from the external egg surface after a 28-day incubation period in the incubator. Ova recovery declined from an average of 62 A. dissimilis ova/turkey egg at day 2 of incubation to an average of 3 A. dissimilis ova/turkey egg at day 28 of incubation.     

The effect of palm oil and safflower oil in the feed of parent fattening hens on fertility, hatchability and growth of progeny]

The aim of two experiments with broiler breeder hens was to evaluate the effect of diets containing palm butter or safflower oil (25 g and 50 g/kg feed, resp.) on fertility, hatchability and growth of progeny. Especially the incorporation of oleic and linoleic acid in egg yolk reflected the dietary fatty acid source. Eggs were collected and stored in the incubator at a hen age of 31, 40, 50, and 60 weeks. Hatched chicks were reared over 5 weeks. The number of fertile eggs (Experiment 1 and 2, 75 and 88%, resp.) differed between the experiments (P < or = 0.05). Neither embryonic mortality nor hatchability (Experiment 1 and 2, 76 and 78%, resp.) were significantly affected by fatty acid composition of yolk. No clear maternal dietary effect was recorded on chicken weight at hatching (Experiment 1 and 2, 43.3 g and 43.7 g, resp.) and at 35 days of age (Experimental 1 and 2, 1676 g and 1764 g, resp.) The fatty acid composition in the analysed egg yolk sac of chicks showed a different fatty level but corresponded to fatty acid composition of breeding eggs before incubation. According to a decreased level of docosahexaenoic acid in egg yolk due to increased incorporation of linoleic acid, the content of this fatty acid was also diminished in phospholipids of the brain of chicken on days 1 and 5 after hatching.     

Feeding motivation on the incidence of floor eggs and extraneously calcified eggs laid by broiler breeder hens

1. Commercial broiler breeder hens lay many eggs on the floor rather than in nest boxes provided. A study was conducted to determine whether feeding feed-restricted broiler breeder hens during the sitting phase of nesting results in a higher incidence of floor eggs and/or retained eggs. 2. Sixty broiler breeder females (Ross 308) were randomly assigned to 6 deep litter pens containing 10 nest-boxes. At 35 weeks of age and for 9 weeks, feed was distributed to all pens at lights-on every second day (fed normally, FN). On alternate days (feeding delay, FD), feed was distributed when 2-3 hens/pen were sitting in a nest box. Behaviour was sampled at 41 weeks of age, for 26 d. Eggs and egg location data were collected daily, and eggs were scored for extra-cuticular calcium. 3. Of 81 instances in which the hen was sitting firmly in a nest box at the time of feeding, on 80 instances the hen left the nest-box to feed, and on one instance the hen laid her egg then exited to the feeder. Of these 80 instances, on 58 occasions the hen returned to a nest-box to lay her egg; on 12 the hen returned to the nest-box but laid no egg; on 7 the hen did not return to the nest box and laid no egg; and on three the hen laid her egg on the floor. 4. Mean floor egg percentage was 13·3 ± 3·2% on FN and 13·3 ± 4·7% on FD days; these did not differ significantly. 5. The mean extra-cuticular calcium score over all pens was 0·9 ± 0·06 on FN days and 1·2 ± 0·06 on FD days; these differed significantly. 6. In conclusion, feeding broiler breeder hens during nesting results in a conflict between feeding and nesting motivation and higher numbers of extraneously calcified eggs, but does not result in a significant increase in floor eggs even though nesting hens will leave the nest box for food.     

Influence of the dwarfing gene dw on egg production and viability under summer heat stress

1. Dwarf egg layer (Narmada XL) dwarf broiler (DB) and normal bodied sib (NB) hens were studied under cyclic summer hot and dry heat stress of 21.1 to 45.5 degrees C for a period of 50 d. The genotype effect for egg production was significant (P less than 0.01). 2. N-XL and DB genotypes laid 12.1% more eggs than NB. Egg production declined by 3.17, 1.27 and 3.25% for a rise in temperature (maximum) of 1 degree C for N-XL, DB and NB genotypes respectively. 3. Egg production in Narmada XL declined by 42% compared to 25% in the dwarf broilers. The regression coefficients differed significantly. 4. For polygenically identical DB and NB broiler breeder hens the heat stressor significantly reduced egg production 1.98% more in the NB genotype compared with DB with a 1 degree C rise in temperature. 5. Mortality was less in the N-XL as compared to DB, but NB hens showed 11.7% more mortality than dwarfs.     

Lack of effect of oviposition time and parental age on chick weight when egg weight remains constant

1. An experiment was conducted utilising 480 eggs from broiler breeder hens to determine the effect of oviposition and parental age on 1-d-old chick weight when egg weight remained constant. 2. Neither the age of the breeder flock nor the time of oviposition had a significant effect on egg weight loss during the 18 d of incubation. Nor was there any effect on chick weight: egg weight ratio and 1-d-old chick weight when chicks were removed and weighed at the same time. 3. Hatching time was significantly affected by time of oviposition and age of parents. Afternoon eggs or eggs from older hens tended to hatch earlier than morning eggs or eggs from younger ones.     

Correlations between breeder age, egg cholesterol content, blood cholesterol level and hatchability of broiler breeders

1. The research was carried out to investigate correlations between breeder age, egg cholesterol content, blood cholesterol level and hatchability of broiler breeders. 2. Egg cholesterol content increased with increased breeder age. The mean yolk cholesterol contents (mg per g yolk) were 10.47+/-0.28, 15.34+/-0.65 and 15.64+/-0.71 mg/g at 28, 45 and 65 weeks of age, respectively. 3. There were positive correlations between yolk weight and yolk cholesterol content (mg/g yolk) (r=01.941; P<0.01) and egg cholesterol content (mg/egg) (r=0.980; P<0.01). 4. Negative correlations were found between egg yolk cholesterol content and hatchability of fertile eggs (r=-0.345; P<0.05), fertility ratio (r=-0.609; P<0.01) and hatchability of total eggs (r=-0.574; P<0.01). 5. The mean blood cholesterol levels were 165.1+/-11.04, 166.5+/-11.97 and 179.5+/-11.33 mg/dl at 28, 45 and 65 weeks of age, respectively.     

爱拔益加肉鸡父母代后备期的生长性能分析

肉种鸡的后备期生长发育状况对其产蛋期有很大的影响,后备期的生长性能是否达标,是保证产蛋数量和质量的先决条件,也是提高种鸡场经济效益的关键环节。汇总并分析了实际生产中爱拔益加肉鸡父母代种鸡场的第一手资料,结合理想状态下的生产性能标准,通过直观的数据表和曲线图展示了后备期生长性能以周为单位的波动情况,进而对如何缩小实际值与理论值的差距,如何提升后备期生长性能,以及采用何种措施加强饲养管理工作做了深入分析,以期提高广大养殖户对肉种鸡后备期生产管理的重视程度,切实做好产蛋之前的准备工作,以获得更大的经济效益,为市场供应更多更优质的产品做出贡献。     

Risk Factors Associated with Salmonella Status of Broiler Flocks Delivered to Grow‐Out Farms

In a prospective field observational study in the southeastern USA, we sampled gastrointestinal (GI) tracts from chicks of 65 broiler flocks delivered to conventional grow‐out farms for rearing. The flocks were hatched at seven broiler hatcheries. The mean within‐flock prevalence of Salmonella‐positive samples was 6.5% and ranged from 0% to 86.7%. Of the 65 flocks studied, 25 (38.5%) had at least one Salmonella‐positive sample. Accounting for confounding variability among the hatcheries and broiler companies, we tested whether the probability of detecting Salmonella in GI tracts of the chicks delivered was associated with certain characteristics of parent breeder flocks; hatchery production volume; hatchery ventilation system; hatchery egg‐room conditions; egg incubation, candling, hatching, eggshell and bird separation, and bird‐processing procedures; management of hatchery‐to‐farm transportation; day of week of hatch; weather conditions during transportation; or season of the hatch. Two risk factor models were adopted. The first model indicated that a greater number of parent flocks, manual separation of eggshell and bird, and a greater amount of fluff and feces on tray liners used during hatchery‐to‐farm transportation at delivery were associated with increased probability of detecting Salmonella in chick GI tracts, whereas a greater number of birds in the delivery vehicle was associated with decreased probability. The second model indicated that broiler flocks hatched on Tuesdays versus either Mondays or Thursdays (with no hatches on Wednesdays, Fridays or week‐ends), increased average hatchability of the eggs from the parent flocks, and greater amounts of fluff and feces on the transport tray liners at delivery were all associated with increased probability of detecting Salmonella in chick GI tracts. The results of this study suggest potential management decisions to lessen Salmonella contamination of broilers supplied by commercial hatcheries and areas for further research.     

The Impact of Yeast Culture Residue on the Suppression of Dietary Aflatoxin on the Performance of Broiler Breeder Hens

A study was conducted to examine the effect of yeast culture residue (YCR) on the suppression of aflatoxicosis in broiler breeder hens. One hundred twenty, 35-wk-old, Cobb broiler breeder hens of the same cross were fed diets supplemented with aflatoxin (AF) (0 or 3 mg/kg) and YCR (0 or 2 lb/ton) singly and combined in a 2 × 2 factorial designed experiment. The birds were randomly assigned to pens with 3 replicates of 10 females and 1 male per treatment. Eggs laid by the hens were collected daily, stored at room temperature, and incubated every 7 d for 3 wk. Response variables analyzed were mean percentage of fertility, hatchability, hen-day egg production, egg weight, chick weight at hatch, and embryonic mortality over the 3-wk treatment period. At the end of 3-wk treatment, blood was collected from the hens and analyzed for total protein, globulin, and albumin. Aflatoxin did not negatively affect fertility. However, hen-day egg production (57.6%), percentage of hatchability (67.6%), embryonic mortality (24%), serum total protein, globulin, and albumin were significantly (P < 0.05) affected by AF. Hatch of fertile eggs from the AF-fed hens was significantly lower than the control (67.6 vs. 78.5%). The inclusion of YCR in the AF-treated diet raised the level of hatchability (74.9 vs. 67.6%), egg production (65.83 vs. 57.26%), and lowered embryonic mortality (16.8 vs. 24%). Serum globulin and albumin were lowered in the AF-fed hens but was partially restored with the addition of YCR. The data demonstrated that YCR may enhance the performance of broiler breeder hens that are provided feed contaminated with AF.