Broiler embryo bone development is influenced by incubator temperature,oxygen concentration and eggshell conductance at the plateau stage in oxygen consumption1

1. Four experiments were conducted to evaluate the effects of temperature (TEM) and oxygen (O₂) concentrations during the last 4 d of incubation on bone development. Fertile eggs from two strains were obtained that either exhibited Low or High eggshell conductance (G).

2. Four experimental cabinets provided either four TEM (36, 37, 38 or 39^°C) or four O₂ concentrations (17, 19, 21 or 23% O₂). Data were analysed as a 2 × 2 factorial design. In the fourth experiment, two temperatures (36 and 39^°C), two O₂ concentrations (17 and 23%) and the same Low and High G strains were evaluated in a 2 × 2 × 2 factorial design.

3. Body weights (BW) and residual yolks were obtained, both legs were dissected. Femur, tibia and shank weights, length and thickness were recorded. Relative asymmetry (RA) of each leg section was calculated.

4. The results indicated that elevated TEM during incubation increased RA between the two legs, mainly in the Low G strain. Chickens at the lowest O₂ concentrations had lighter and shorter tibias, lighter shanks, and increased RA of femur length compared to chickens in the 23% O₂. In the fourth experiment no interactions were observed between O₂ and TEM. High TEM depressed BW of Low G broilers, but no significant effect of treatments was observed on BW of High G broilers. Nevertheless, the high TEM or low O₂ independently caused reduced femur and tibia weights and length, shank length and thickness, and both low O₂ and high TEM together increased RA in shank weight.

5. These results suggest that late incubation conditions affect long bone development in broilers.     

Induction of functional defects in macrophages by a poult enteritis and mortality syndrome-associated turkey astrovirus.

The interaction of a poult enteritis and mortality syndrome (PEMS)-turkey astrovirus-Ohio State University (TAst-OSU) with the mononuclear phagocytic system cells, namely macrophages, was examined after in vitro and in vivo exposure. In vitro exposures were performed by incubating adherent turkey macrophages with various volumes of 10(6) 50% embryo infective dose (EID50)/ml TAst-OSU stock, whereas for in vivo challenge, poults were given a 200 microl inoculum of 10(6) EID50/ml TAst-OSU stock at 7 days of age. Results show that TAst-OSU in vitro exposure reduced macrophage viability relative to controls (P < 0.05) and decreased phagocytosis (P < 0.05) and intracytoplasmic killing of Escherichia coli (P < 0.05) after a 42-48-hr exposure. Poults challenged with TAst-OSU in vivo recruited almost 50% fewer Sephadex-elicited inflammatory cells in the abdominal cavity (P < 0.05) as compared with the sham controls. Similar to in vitro exposure, macrophages isolated from in vivo TAst-OSU-challenged poults exhibited reduced percentage of phagocytic macrophages (P < 0.05) as well as fewer intracytoplasmic E. coli per phagocytic macrophage (P < 0.05). TAst-OSU-challenged poults had a greater number of viable E. coli in their spleens (P < 0.05) after an intravenous E. coli challenge as compared with the non-TAst-OSU-challenged control poults. Macrophage-mediated cytokines and metabolites were also examined during this study. Both in vitro and in vivo TAst-OSU challenge resulted in reduced interleukin (IL)-1 and IL-6 activity. On the contrary, nitrite levels in macrophage culture supernatant fraction of TAst-OSU-challenged macrophages were significantly higher (P < or = 0.05). The findings of these studies indicated that TAst-OSU challenge induced defects in macrophage effector functions, implying that PEMS-turkey astrovirus can potentially impair the immune response of turkeys, thereby leading to enhanced susceptibility of turkeys to secondary, perhaps even fatal, bacterial infections.     

通过营养调控提高蛋壳质量

家禽的品种、疾病、饲养的环境温度、不同的生理阶段以及饲料中各种营养物质的含量都能影响蛋壳的质量。本文主要从营养调控的角度较为全面地介绍了改善与提高蛋壳质量的具体方法。     

影响蛋壳质量的原因及对策

众所周知,蛋壳质量差,色泽发白,则会降低鸡蛋的商品价值,对种鸡来讲,经济效益影响会更大.特别在每年冬夏季节,白壳蛋发生的现象尤为严重,养殖户采取了许多应对方法,但终因原因不明,收效甚微.现笔者结合工作实践,将临床上遇到的一些问题进行总结与分析,供读者参考.     

Utilisation of a sperm quality analyser to evaluate sperm quantity and quality of turkey breeders

1. A relatively new instrument known as a Sperm Quality Analyzer (SQA) offers a rapid assessment of sperm quality and quantity by providing a sperm quality index (SQI). The SQA measures a combination of the intensity of sperm activity and motile concentration by determining the number and amplitude of sperm movements per second in a capillary tube as detected through light beam interference. 2. Because the SQA has not been tested for its potential use in turkeys, the objective was to determine if the SQA could accurately respond to changes in turkey sperm concentration, viability, and motility in semen collected from turkey breeders. 3. The effect of varying concentrations of sperm on SQI values was evaluated by diluting replicate pools of semen from 4 different aged turkey breeder flocks with saline. Results from all 4 flocks showed that semen dilutions greater than 20-fold resulted in a linear decline in SQI values. 4. Additional in vitro analysis evaluated the effects of turkey sperm viability on the SQI under conditions of constant sperm concentration. Incubated, live sperm was mixed in various proportions with thawed, dead sperm to determine changes in viability. Increased proportions of dead sperm caused a decline in the SQI. 5. To assess sperm motility, turkey semen was incubated under either aerobic (motile) or anaerobic (immotile) conditions. Varied amounts of immotile and motile sperm samples were mixed. A linear increase in the SQI was observed as per cent motile sperm increased. 6. These results indicate that the SQA can respond to differences in turkey sperm concentration, viability, and motility using in vitro analyses.     

Compensation for seasonal changes in eggshell conductance and hatchability of goose eggs by dynamic control of egg water loss

1. The water loss for optimal hatchability of goose eggs was 12% of initial egg mass.

2. Mass specific eggshell water vapour conductance, G_sp, increased by approximately 50% over about 13 weeks during the winter breeding cycle. A similar increase occurred over 8 weeks during summer.

3. Constant setting of humidity in goose incubators and changes in mean G_sp may cause sub‐optimal egg water loss which increases late mortality.

4. Mean G_sp was measured for every batch from each flock. Humidity was changed accordingly in order to reach optimal water loss. A significant improvement of 6% in hatchability and of 8% in Class‐A goslings was noted during 14 successive weeks compared with the previous 11 weeks.

5. Dynamic humidity control for optimising water loss according to mean batch G_sp thus increases hatchability.     

通过营养调控提高蛋壳质量

蛋壳质量的好坏一直是影响禽蛋业经济效益的重要因素。影响蛋壳品质的因素很多 ,一般认为 ,家禽品种、疾病、饲养环境的温度、动物所处的生理阶段和饲料中各种营养物质的含量都能影响蛋壳质量。饲料中各种营养元素的含量和配比对禽类蛋壳质量的影响很大 ,主要影响因素是各种矿物质常量元素、微量元素和各种维生素的含量。下面将蛋壳的结构和通过营养提高蛋壳质量的方法作一综述。1　蛋壳结构蛋壳共有五层结构 ,从里到外依次是蛋壳内膜、蛋壳外膜、乳头状锥形层、海绵层和蛋壳层。蛋壳外膜是蛋壳形成的基础 ,蛋壳的海绵层决定蛋壳厚度和硬度 …     

Susceptibility of broiler chicks to infection by avian pneumovirus of turkey origin

In this paper we present the results of studies on the infectivity of an isolate of avian pneumovirus (APV) from turkeys to broiler chickens. Two-week-old broiler chicks free of antibodies to APV were exposed either by oculonasal or oral route with a cell cultured APV of turkey origin. Chickens from both APV-inoculated groups exhibited clinical signs that included coughing, sneezing, nasal discharge, and watery eyes during 2-8 days postinoculation. Tissue samples from birds in the APV-inoculated group were positive for APV by polymerase chain reaction (PCR) up to 9 days postinoculation. Samples of blood from both oculonasally and orally infected chickens were positive for APV. Intestinal samples from chickens infected with APV orally were positive for the presence of APV on PCR up to 9 days postinoculation. APV was reisolated from samples taken from chickens in both groups inoculated orally and oculonasally. Sera from birds exposed by the oculonasal or by the oral route showed the presence of APV-specific antibodies.     

Improving pork quality by feeding supranutritional concentrations of vitamin D3

Duroc-cross pigs (n = 25) were assigned to one of three experimental finishing diets containing 0 (control), 40,000 (40), or 80,000 (80) IU of supplemental vitamin D3/kg of feed (as-fed basis)to test the effects of vitamin D3 on pork quality traits. Experimental diets were fed for 44 or 51 d before slaughter, and days on feed were blocked in the experimental design. A trend existed for pigs receiving the highest concentration of vitamin D3 supplementation to have a lower (P = 0.08) ADG (0.77 kg/d) compared with pigs fed either the 40-diet (0.88 kg/d) or control (0.92 kg/d). Diet did not (P > 0.10) affect backfat thickness measured along the midline, 10th-rib fat depth, longissimus muscle area, muscle score, or hot carcass weights. Longissimus pH, measured at 0.5, 1, 2, 3, 4, and 24 h postmortem, was higher (P < 0.05) for pigs on the 80-diet than those fed the control diet. Longissimus muscle color, measured at 24 h postmortem, from pigs fed either the 40- or 80-diet were darker (lower L* values; P < 0.05) than those fed the control diet. Objective longissimus color scores were higher (P < 0.01), and firmness/wetness scores lower (P < 0.05), for pigs on the 80-diet as compared to those on the 40-diet or control diet. The diet had no (P > 0.10) effect on Warner-Bratzler shear force values; percentage of cook loss; or trained sensory panel evaluations for tenderness, juiciness, and flavor. Feeding the 80-diet increased (P < 0.05) plasma vitamin D3 and calcium after 2, 4, and 6 wk on feed compared with the control diet. Vitamin D3 and 25-hydroxy vitamin D3 concentrations in the longissimus muscle increased (P = 0.001) with increasing vitamin D3 levels in the diet; however, muscle calcium concentrations and fiber type were not (P > 0.30) affected by diet. These results indicate that feeding supranutritional levels of vitamin D3 for at least 44 d improves pork color and increases pH, but may retard growth if fed at 80,000 IU/kg of feed.     

The effect of the method of adding ethylene glycol to turkey ejaculate on the quality of cryopreserved sperm

Ethylene glycol at concentrations of 8 + 8, 4 + 12 or 0 + 16% was added to the ejaculate of the White Broad-Breasted turkey-stags by the method of (ejaculate : diluent) 1 : (1 + 1), 1 : (1 + 1/4 + 1/4 + 2/4) or 1 : (1 + 1/15 + 1/15 + 1/15 + 2/15 + + 4/15 + 6/15) at temperatures of 25, 15 or 5 degrees C. The dissolved ejaculate was equilibrated for 15 minutes, three minutes it was left to freeze in liquid nitrogen vapours and 24 hours it was stored at a temperature of -196 degrees C. Motility, percentage of live spermatozoa and percentage of morphologically normal spermatozoa were evaluated after sample thawing at 15 degrees C. The quality of cryo-preserved spermatozoa of stags was most effectively influenced by the addition of ethylene glycol to ejaculate at the concentration of 0 + 16% by the method of 1 : (1 + 1/15 + 1/15 + + 1/15 + 2/15 + 4/15 + 6/15) at the temperature of 25 degrees C.     

Improving growth performance and blood profile by feeding autolyzed yeast to improve pork carcass and meat quality

The 63 commercial pigs were divided into three groups consisting of seven replicates of three piglets each. The experimental diets were (1) control diet, (2) diet with autolyzed yeast (AY) 0.5%, and (3) diet with AY 1.0%. Compared to the control group, using AY 0.5% in the diet reduced average daily feed intake (ADFI) and improved feed conversion ratio (FCR) (p < 0.05). The blood urea nitrogen (BUN) and neutrophil/lymphocyte ratio (N/L) in blood decreased with the addition of AY 0.5% (p < 0.05). The pH at 6-h postmortem of meat in the 0.5% AY diet group was higher than for the control group (p < 0.05). Backfat thickness (p = 0.09) and P2-backfat thickness (p = 0.07) tended to decrease, while the fat free index (FFI; p = 0.07) tended to increase with 0.5% AY supplementation. The protein percentage (p = 0.07) and the a* value (redness) (p = 0.08) in the meat tended to increase, and the springiness increased with 0.5% AY supplementation (p < 0.05). An appropriate level of AY supplementation can impact positively on the physiological functions in swine with a consequent seems to improve in qualitative traits of the meat quality.     

Resistance of Pasteurella multocida A:3,4 to phagocytosis by turkey macrophages and heterophils

A virulent field isolate and 2 vaccine strains of Pasteurella multocida A:3,4 were compared for resistance to phagocytosis by turkey macrophages and heterophils, using in vitro assays. The least virulent vaccine strain (M-9) was phagocytosed to a greater degree than was the field isolate or the other vaccine strain (Clemson University). All 3 bacteria differed significantly from each other in the amount of capsular material present as measured by polycationic ferritin labeling and electron microscopy. Removal of the capsule with hyaluronidase resulted in a significant increase in phagocytosis of the field isolate.     

骨粉替代磷酸氢钙对蛋重和蛋壳品质的影响

骨粉营养成分十分丰富,与磷酸氢钙作为钙磷饲料添加剂相比,骨粉既可补充动物的钙磷又富含动物必需的其他成分,进而增强动物食欲且无副作用,对蛋重和蛋壳品质有很好的改善作用,是一种经济、实用且价廉的饲料添加剂。     

提高MSY质量是实现低成本养猪的重要技术路径

MSY质量包含商品猪的生长速率、饲料利用率、瘦肉率和屠宰率等生产指标.MSY质量与猪场利润密切相关,比如猪的生长速率越快,则维持消耗越少,自然,饲料成本支出就越低;饲料利用率越高,单位增重耗料越少;同时,饲料支出成本越低,瘦肉率达到品种标准,销售价格会更高,合成耗料就会更少;屠宰率越高,可卖部分就越多,最终收入就越高....     

Detection of antibody to turkey coronavirus by antibody-capture enzyme-linked immunosorbent assay utilizing infectious bronchitis virus antigen

An antibody-capture enzyme-linked immunosorbent assay (ELISA) for detection of antibody to turkey coronavirus (TCV) utilizing infectious bronchitis virus (IBV) antigen was developed. Anti-TCV hyperimmune turkey serum and normal turkey serum were used as positive or negative control serum for optimization of the ELISA system. Goat anti-turkey immunoglobulin G (light plus heavy chains) conjugated with horseradish peroxidase was used as detector antibody. The performance of the ELISA system was evaluated with 45 normal turkey sera and 325 turkey sera from the field and the cutoff point was determined. Serum samples of turkeys experimentally infected with TCV collected sequentially from 1 to 63 days postinfection were applied to the established antibody-capture ELISA using IBV antigens. The optimum conditions for differentiation between anti-TCV hyperimmune serum and normal turkey serum were serum dilution at 1:40 and conjugate dilution at 1:1600. Of the 325 sera from the field, 175 were positive for TCV by immunofluorescent antibody (IFA) assay. The sensitivity and specificity of the ELISA relative to IFA test were 93.1% and 96.7%, respectively, based on the results of serum samples from the field turkey flocks using the optimum cutoff point of 0.18 as determined by the logistic regression method. The ELISA values of all 45 normal turkey sera were completely separated from that of IFA-positive sera. The ELISA results of serum samples collected from turkeys experimentally infected with TCV were comparable to that of the IFA assay. Reactivity of anti-rotavirus, anti-reovirus, anti-adenovirus, or anti-enterovirus antibodies with the IBV antigens coated in the commercially available ELISA plates coated with IBV antigens could be utilized for detection of antibodies to TCV in antibody-capture ELISA.     

Use of a sperm quality analyser on semen of turkey breeders to monitor storage time effects and age-related changes during a reproductive cycle

1. A relatively new instrument known as a Sperm Quality Analyzer (SQA) offers a rapid assessment of sperm quality and quantity by providing a sperm quality index (SQI). The SQA measures the intensity of sperm activity and motile concentration by determining the number and amplitude of sperm movements per second in a capillary tube as detected through light beam interference. 2. The objectives of the current study were to determine if the SQA could accurately reflect changes in semen quality that occur with prolonged storage of semen and to determine the variation and change in SQI values among individual breeding male turkeys during their semen production cycle. 3. The effect of storage time on SQI values was evaluated by diluting semen with extender and placing the semen on an oscillating shaker at 4 degrees C for 8 h. The SQI values and sperm viability, expressed as % dead sperm, were recorded hourly. The SQI readings declined linearly with increased storage time while % dead sperm increased linearly with increased semen storage. 4. Semen from 220 individual males was analysed monthly for 9 months. Semen diluted 50-fold with saline had lower SQI values during pre- and post-peak phases of production (months 1, 7, 8, and 9 as compared with months 2 to 6 of semen production). The highest SQI values occurred during months 2 to 6. The largest variation in SQI values occurred during months 1 (CV = 26%) and 9 (CV = 31%) with a CV that averaged 16% for the remaining months. 5. Correlation analysis of SQI values for each bird averaged over 9 months with individual male SQIs for each month showed monthly correlation coefficients that ranged from 0.22 to 0.63. 6. These results indicate that the SQA accurately assessed the decline in sperm quality that occurs with prolonged storage of turkey semen and reflected age-related changes in semen quality and quantity that occurred during a semen production cycle of turkey breeders. In addition, the semen quality rank of some turkey breeders in a population changed with age.     

兰州荷斯坦牛导入一次西德公牛血液的改良效果

８０年代末９０年代初 ,为提高我场奶牛的生产性能和乳脂率 ,纠正奶牛乳房性状和斜尻的缺陷 ,引进了西德优良公牛精液改良牛群。几年来 ,根据对１ -３胎次泌乳牛的监测和资料分析结果表明 ,对改进奶牛体形外貌缺陷和提高乳脂率都有较明显的效果 ,牛群基本上达到遗传性稳定、产奶性能较好的奶牛群体。１对段家滩分场１３３头１ -３胎次泌乳牛乳房形状鉴定结果统计比较乳房形状较前有显著改进 ,浴盆形状者１０５头 ,占被鉴定牛只的７８ ９５ %;近似浴盆形状者１８头 ,占被鉴定牛只的１３ ５３ %;山羊型或漏斗形状者１０头 ,占被鉴定牛只的７ …     

Improving the fermentation quality of wheat straw silage stored at low temperature by psychrotrophic lactic acid bacteria

This study aimed to explore the feasible approaches to develop a silage production technique in regions with low temperatures. An effective low‐temperature silage technology system was constructed and two frigostable Lactobacillus (L.) strains isolated from alpine pastures were selected and proved to be available for wheat straw silage at 5°C. The strains QZ227 and QZ887 were both identified as L. plantarum according to the phenotype, 16S rRNA, and RecA gene analysis. QZ227, QZ887 and a commercial inoculant FG1 consisting of L. plantarum were effective for improving the fermentation quality of wheat straws silage at 5°C for 30 days as indicated by the higher content of lactic acid and for 60 days by lower pH values, while the control with sterile water instead conferred reduced benefits. Additionally, silages fermented at low temperature proved to be acceptable for feeding livestock after being placed in a simulated environmental temperature of 20°C for 14 days to detect its edibility during the early spring when the temperature begins to rise. Both QZ227 and QZ887 showed potential applications of silage making in frigid areas and were effective inoculants in a low‐temperature silage technology system.     

Improving the quality of rooster semen frozen in straws by screening the glycerol concentration and freezing rate

ABSTRACT

• 1. This study examined different glycerol concentrations (GC) and freezing rates to improve the quality of rooster spermatozoa frozen in straws, and to determine the effect of varying GC on post-thawed spermatozoa quality, as evaluated by fertility and hatchability.

• 2.The experiment included two tests. In test 1, rooster semen straws containing 2, 4, 6, 8 and 11% glycerol were put in a rack (nine tiers with a 1 cm interval between every two tiers, 1 to 9 cm above liquid nitrogen (LN) source), and gradually frozen. The semen straws located in different tiers experienced different temperatures and freezing rates. The straws were then thawed and live sperm numbers determined. In test 2, rooster semen straws containing 2, 4, 6, 8 and 11% glycerol were put on optimal tiers (identified in test 1) for freezing, and stored at ?196°C. Hens were inseminated with the frozen semen (post-thawed and glycerol removed, about 4.0 × 10⁸ sperm per hen), and eggs incubated.

• 3. The numbers of live sperm in the 11% glycerol group was higher than that in 2, 4 or 6% glycerol group (P < 0.05) for the semen straws on tiers 1 to 9, while that on tiers 1 to 5 was lower than that on tier 6 to 8 (P < 0.05). GC, freezing rate and the interaction between GC and freezing rate had a significant effect on live sperm numbers (P < 0.01). The highest fertility was in the 6% glycerol group and occurred on day 5 after insemination. The lowest fertility occurred in the 2% glycerol group on day 10 after insemination.

• 4. The optimal combination was 11% glycerol in straws located 6 cm above the LN surface (on tier 6). The 6% glycerol group achieved the highest fertility (77.6%), which surpassed that reported in recent years.

     

Improving sow efficiency by management to enhance opportunity for nutritional intake by neonatal piglets

Starvation, primarily during the first week postpartum, is the direct or indirect cause of at least one-half of preweaning mortalities in healthy herds. Causes of starvation originate from characteristics of the dam, of the litter and of individual piglets. A major cause of starvation is congenital weakness associated with birth weights less than 1000 g. Increasing energy during late gestation shows inconsistent effects on birth weight; some dietary component energy sources appear to improve stamina of newborn and(or) energy content of sow's milk with favorable effects on survival. Total or partial supplemental nutrient intake supplied by caretakers, automated feeding devices or transfer of piglets to foster dams are the primary means of providing enhanced nutrient intake opportunity. Nutrient intake from non-dam sources ranges from temporary tube-feeding, administered by caretakers to excessively small or weak pigs, to self-feeding by pigs from simple or sophisticated dispensers of sow milk substitutes. Transfer of piglets to foster dams as a nutrient intake source is most successful when characteristics such as size of dam, size of teats, stage of lactation and temperament are in harmony with characteristics affecting pigs' needs. If other dams are not available, sows 2 to 3 wk into lactation can serve as foster dams for large and strong newborn piglets after resident litters are removed. Planning for availability of appropriate foster dams, based on prior or projected prolificacy and other sow and litter traits, should be done at time of assembling each mating group. Research results show that, on a weight-to-weight basis, pigs requiring artificial or foster dam rearing perform similarly to other pigs and thus justify management to secure their survival.