The experimental production of big liver and spleen disease in broiler breeder hens

SUMMARY Big liver and spleen disease (BLS) was reproduced experimentally by intravenous (IV) and oral (PO) administration of BLS inocula to susceptible broiler breeder hens 34 to 36 weeks of age. Serological and pathological signs of BLS similar to those seen in the natural disease occurred in inoculated and in-contact birds. Splenomegaly was the earliest and often the only necropsy finding, with hepatomegaly and kidney enlargement occurring in some birds later in the course of the disease. After IV administration, serum antigen was detected between 2 and 4 weeks, and antibody between 3 and 5 weeks. After PO administration, antigen was detected between 2 and 4 weeks, and antibody between 3 and 6 weeks. Antibody persisted in all birds to the end of the experiment (6 weeks), and horizontal transmission probably occurred since in-contact birds developed BLS. Liver probably contained the highest concentration of BLS agent because it had the highest infectivity.     

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.     

Rupture of gastrocnemius tendon in broiler breeder hens

Lameness and mortality of 0.55% to 1.00% per week occurred in 32-to-33-wk-old broiler breeder hens in a complex involving eight houses. Males were not affected. Laboratory evaluation of 19 birds, over 2 wk, revealed complete rupture or partial tear, primarily of the gastrocnemius tendon; the fibularis longus, fibularis brevis, and flexor muscles and their tendons were injured in a few birds. Rupture of the gastrocnemius tendon has been observed in broiler breeder chickens older than 12 wk of age and it is characterized by lameness secondary to unilateral or bilateral rupture of the tendon. The cause of this condition has been primarily attributed to reovirus infection but rupture by other causes can also occur. In this case, there was no evidence of synovitis or reovirus infection in the birds. The cause of the ruptures was attributed to aggressive males when the ratio of males to females was increased from seven or eight males per 100 females at 22-23 wk to nine or 10 per 100 at 31 wk of age.     

泄殖腔炎——肉种鸡生产中的新问题

泄殖腔在鸟类的生理机能上起着重要的作用。机能失常可能导致严重病变:泄殖腔炎,并主要发生在种鸡群中的产蛋母鸡。此类产蛋母鸡要得到完全的治癒非常困难,防止肥胖或许是预防泄殖腔炎的最好措施。     

疑有禽白血病病毒混合感染的肉种鸡大肝大脾病

山东某父母代肉种鸡开产后死淘率突然升高,死亡鸡肝脏、脾脏、腺胃等内脏器官肿大,高峰期周产蛋率仅为72%,明显低于同场区未发病鸡群的83%,更显著低于其标准产蛋率（87%）。利用RT-PCR技术对肿大的脏器分别进行分子病原学诊断,禽网状内皮增生症病毒、戊型肝炎病毒和马立克氏病毒等PCR检测结果阴性,而ALV pol基因检测阳性,经测序与GenBank 已发表的ALV E 亚群毒株的核苷酸同源性高达97.5%-99.5%。血清学检测证实, ALV-AB亚群在发病前阳性率为8.3%,而发病后的抗体阳性率则攀升为70%。鸡群发病后的种蛋蛋清p27抗原检测ALV阳性率为5.3%。综上所述,鸡群可能混合感染ALV。     

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.     

Teratogenic activity of Arasan fed to broiler breeder hens.

Tetramethylthiuramdisulfide (TMTD), the active ingredient in Arasan, fed to broiler breeder hens at 10, 20, or 40 ppm depressed egg production, reduced hatchability, and resulted in soft-shelled eggs. The progeny of these hens had anomalies manifested by bilaternal medial deviation of the toes, exophthalmia, and shortened femurs. Broiler breeder hens that consumed a ration containing 80 ppm of TMTD produced only soft-shelled eggs.     

产蛋期肉种鸡脂肪肝综合征的诊治

某场饲养的9500套肉种鸡在产蛋上高峰期间,其中一栋鸡舍鸡只发病并死亡,经检测诊断为鸡脂肪肝综合征。现将诊治情况介绍如下：     

Myopathy of the deep pectoral muscle in broiler breeder hens.

Myopathy of the pectoralis profundus and ambiens muscles was found in chickens from 5 flocks of broiler breeder hens. Histological lesions in the muscles varied from steatosis to loss of striations, fragmentation of fibers, and mineral deposition. A clinical response followed oral medication with vitamin E and selenium although analysis showed that selenium and vitamin E levels in the feed were normal. The possible relation between myopathy and Cassia seed in the feed is discussed.     

The response of broiler breeder hens to dietary lysine and methionine.

1. Broiler breeder hens were used in an experiment lasting 10 weeks (29 to 38 weeks of age) to measure the responses to dietary lysine and methionine, the main objective being to determine whether the coefficients of response to these amino acids were the same for broiler breeders and for laying pullets. 2. The hens were offered 150 g/d of one of 20 dietary treatments, 10 being lysine-limiting and 10 being methionine-limiting. The diets were mixed by diluting one of two concentrate (summit) mixes with a protein-free dilution mixture. The lysine-limiting summit diet was designed to supply approximately 1300 mg lysine/bird d, while the other supplied 520 mg methionine/bird d, when fed at 150 g/bird d. 3. Birds on the 5 lowest concentrations of both lysine and methionine did not consume the allotted amount of food, the amount decreasing, in a curvilinear fashion, to approximately 105 g/bird d. 4. The minimum egg weight recorded was 0.8 of the maximum, whereas the rate of lay of birds fed on the diets with the lowest amino acid concentrations was 0.2 of the maximum. 5. Using the Reading Model, the coefficients of response were calculated to be (for lysine) 16.88 E and 11.2 W, and for methionine, 7.03 E and 1.52 W, where E = egg output, g/bird d, and W = body mass, kg/bird. An average, individual, broiler breeder of 3 kg, producing 45 g of egg output per day, would need 793 mg of lysine and 321 mg of methionine daily. This intake of methionine is similar to that estimated by means of coefficients used for laying pullets, but the lysine requirement would be underestimated by 0.18 if the coefficients for laying pullets were used. 6. The coefficients for maintenance for both lysine and methionine, determined in this experiment, are considerably lower than values published previously, whilst the coefficients for egg output are, in both cases, higher. The resultant flock response curves therefore differed significantly from those in which the coefficients of response for for laying pullets were used.(ABSTRACT TRUNCATED AT 400 WORDS)     

Effect of density and season on stress and behaviour in broiler breeder hens

1. We examined the effect of density (5, 7, 9 and 11 birds/m2) and season (summerand winter; different hens each season) on stress and behaviour in two flocks of 64 broiler breeder females divided among 8 pens. 2. The hens, approximately the same age and body mass in each season, were maintained on hard-packed ground, without litter, in an open-sided chicken house and were offered the same amount of food each season. 3. Mean house max/min temperatures varied between 18 and 33 degrees C in summer and 7 and 17 degrees C in winter. Mean relative humidity in summer varied between 68% at 08:00 h and 42% at 14:00 h and in winter was 64% at 08:00 h and 47% at 14:00 h. 4. No difference was found in heterophil:lymphocyte ratios among densities and between seasons; however, basophil numbers were higher in winter than in summer indicating prolonged stress in winter. 5. Stereotyped pecking increased with an increase in density and was higher in winter than in summer. Pecking on the ground was higher in winter, but was not affected by density. 6. In summer the hens spent more time lying and eating than in winter, whereas in winter the hens spent more time walking, preening and drinking than in summer. They spent the same amount of time standing in both seasons. None of these behaviours was density dependent. 7. We conclude that season had more of an effect than density on stress and behaviour in broiler breeder hens under the conditions of our study.     

Prevention of foot lesions in broiler breeder hens kept in individual cages

Individually-caged broiler breeder hens were fed allowances of 1.88, 1.61, 1.32 or 1.13 MJ apparent metabolisable energy (AME) per bird d at four different protein intakes (27, 23, 19.5 or 16.5 g crude protein per bird d) from 21 to 60 weeks of age. A system of foot scoring was used to assess the extent and severity of foot damage. Damage increased as energy intake increased but protein intake had little effect on foot condition. Cushion floors or perches introduced into the cages at 27 weeks of age reduced the deterioration in foot condition observed on all dietary treatments during lay. Egg output was not affected by foot condition although severe foot damage was observed in several cases.     

Relationship between fertility duration and in vivo sperm storage in broiler breeder hens

1. Seventy Hubbard hens, 75 weeks of age, were divided into groups containing equal numbers of hens on the basis of duration of fertility. Average fertile periods were 14.5 d (long, L) and 6.9 d (short, S). Each hen was artificially inseminated (AI) on three consecutive days with an average of 1.61 X 10(9)/0.05 ml spermatozoa per insemination. Seven hens from each group were killed 1, 3, 6, 9, and 13 d after insemination. 2. Three longitudinal sections of uterovaginal junction were evaluated microscopically for spermatozoal storage capacity by assigning each sperm host gland (SHG) to one of 5 categories: unscorable, empty, one to 5 spermatozoa, 6 to 20 spermatozoa and greater than 20 spermatozoa. 3. The only significant difference in sperm storage at any time between the L and S duration groups occurred at day 1 after AI, when L duration hens possessed significantly more glands with more than 20 spermatozoa. 4. One day after AI the proportion of SHG containing sperm were 28.8% (L group) and 18.6% (S group). There was a significant decrease in the number of glands containing 1 to 5, 6 to 20 and greater than 20 spermatozoa between days 1 to 3 in both groups. 5. Numbers of glands in all categories containing sperm decreased throughout the 13-d period. The L duration group possessed 18.5% more glands with 1 to 5, 6 to 20 and greater than 20 spermatozoa than the S duration group. 6. There were no significant differences between groups in the proportion of unscorable or empty glands throughout, which ranged from 35.9 to 56.8% and 36.3 to 47.1%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Recovery of Campylobacter from segments of the reproductive tract of broiler breeder hens

Three groups of >60-wk-old broiler breeder hens were assessed for the presence of Campylobacter within segments of the reproductive tract. In the first group, after stunned, the hens were bled, scalded, and defeathered, the reproductive tracts were aseptically excised from 18 hens, six from each of three adjacent floor pens that were feces positivefor Campylobacter. The reproductive tract segments (infundibulum, magnum-isthmus, shell gland, vagina, and cloaca) were pooled by pen. In the second group, 10 individual hens were sampled from the pens; the reproductive tract was divided into the following segments: magnum, isthmus, shell gland, vagina, and cloaca. For the third group, hens were obtained from two commercial farms that had been determined to be feces positive for Campylobacter, and the reproductive tract was divided into five segments, as described for the second group. Segments of the reproductive tract were placed into sterile plastic bags and suspended 1:3 (w/v) in Bolton enrichment broth, and serial dilutions were plated (0.1 ml) onto Campy-Cefex agar. The agar places were incubated at 42 C for 24 hr in a microaerobic atmosphere. In group 1, the pooled reproductive tract segments for hens from pen A were Campylobacter positive for the shell gland, vagina, and cloaca; hens from pen B were positive for the cloaca only; and hens from pen C were positive for the magnum-isthmus and doaca. In the second group, 9 of 10 cloaca samples were Campylobacter positive. Commercial hens in group 3 had campylobacter-positive cloaca samples (12/12), vagina (10/12), shell gland (7/12), isthmus (2/12), and magnum (4/12). Campylobacter colonization of the reproductive tract of the hen could enable vertical transmission of Campylobacter from the hen to the chick.     

The role of retinal and extra-retinal photostimulation in reproductive activity in broiler breeder hens

Photostimulation of retinal photoreceptors, which are sensitive to green light, appears to inhibit reproductive activity in birds, whereas photostimulation of extra-retinal photoreceptors, which are sensitive to red light, accelerates it. The objective of this study was to determine the effect of either retinal or extra-retinal photostimulation on reproductive activities of broiler breeder hens. At 23 wk of age, Cobb hens (N = 135) were divided into 9 rooms with individual cages (n = 15). At 24 wk of age, 3 rooms were photostimulated (14L:10D) with white light (Control, n = 45). Six rooms had 2 parallel lighting systems, red (660 nm) and green (560 nm), which were both on during 6 out of 14 h of the light period. Then, in 3 of these rooms, the green light was turned off and hens were exposed to a total of 14 h of red light (Red, n = 45), and in the other 3, the red light was turned off and green lighting continued for a total of 14 h (Green, n = 45). The Green group had reduced egg production; reduced plasma concentrations of ovarian steroids; reduced luteinizing hormone (LH)-β, vasoactive intestinal peptide (VIP), and prolactin mRNA expression; and greater retinal green opsin mRNA expression (P ≤ 0.05). The Red group had greater egg production; greater gonadotropin-releasing hormone-I (GnRH-I) and red opsin gene expression in the hypothalamus; and lesser green opsin gene expression in the retina (P ≤ 0.05). We suggest that selective photostimulation of extra-retinal photostimulation as opposed to retinal photostimulation is a key factor in the determination of successful reproduction of broiler breeder hens.     

夏季日粮营养水平对肉用种母鸡生产繁殖性能的影响及相关性研究

本文研究了夏季日粮营养水平对肉用种母鸡生产繁殖性能的影响及与高温月份、产蛋周龄的相关关系。结果,高营养水平日粮极显著地增加了种母鸡的死淘率和体增重(P<0.01),显著降低了入舍母鸡产蛋数、入舍母鸡产蛋率(P<0.05),显著增加了每枚蛋的耗料量和每枚种蛋的耗料量。种母鸡的死淘率7月和8月最高,且呈显著相关;入舍母鸡产蛋数、入舍母鸡产蛋率、种蛋数随产蛋周龄增加而逐渐下降,种蛋率、枚蛋耗料量、枚种蛋耗料量和枚蛋重随产蛋周龄增加而逐渐增加,与气温无显著相关;结果表明,对照日粮的营养水平是适合的,在此基础上调整增加日粮的营养水平,并不能提高肉种母鸡的生产繁殖性能。气温高和高营养水平日粮是肉用种母鸡死淘率高的主要原因,高营养水平日粮是体重过速增加的主要因素。