Determining of heat balance design criteria for laying hen houses under continental climate conditions

This study focuses on the heat balance status of laying hen houses in regions with continental climate. The material consists of 45 laying hen houses from 27 commercial farms selected from the survey area where continental climate prevails. These laying hen houses differ from each other with respect to capacity, planning system and materials used in construction. First observations were conducted on the size and dimensions of laying hen houses as well as construction materials used, insulation, heat loss factors, ventilation capacity, ground space per hen and total size of laying hen house in order to assess the sufficiency of heat balance. Then, seven laying hen house models were developed. These models were developed by considering the present situation in operating laying hen houses, relevant literature, features of continental climate and suggestions made by firms manufacturing laying hen house construction materials in Turkey. These models give heat conduction coefficients that will prevent moisture concentration and ensure heat balance under continental climate conditions and suggest different sets of materials that can be used on walls and roofs. At the end of the study, under the condition of no moisture on surface of structural components and in areas where the indoor and outdoor temperatures are 25.3 °C and 20.2 °C, respectively, maximum total heat conduction coefficients are calculated to be between 1.38 and 1.73 Kcal/m² °C h. According to the features of area and housing, for providing heat balance, total heat conduction coefficients requirements are calculated to be between 0.62 and 2.08 Kcal/m² °C h for walls, 0.33 and 1.62 Kcal/m² °C h for roofs. In research area, minimum ventilation capacities are determined as 0.72 m³/h hen for carbon dioxide balance and, according to outdoor temperature, as 0.83–1.20 m³/h hen for water vapor balance. Heat loss factors are calculated to be between 0.10 and 0.15 Kcal/°C h hen. We believe that these suggestions will greatly facilitate the work of project engineers in the design of laying hen houses in regions and areas with continental climate.     

Dose-response feeding study of short chain chlorinated paraffins (SCCPs) in laying hens: effects on laying performance and tissue distribution, accumulation and elimination kinetics

Technical short chain chlorinated paraffins (C10-C13 with 60% chlorine) were fed to 93 laying hens from 24 to 32 weeks of age in increasing concentrations of up to 100 mg/kg feed. No significant influence on health, relative organ weights or performance (laying intensity, egg weight, feed consumption) was noted. The chlorinated paraffin content of the tissues was linearly related to the concentration of short chain paraffins of the feed. The highest concentrations were found in abdominal fat, egg yolk and fatty tissues. Breast muscle, egg albumen and bile fluid contained minimal or no residues. Less than 1% of the chlorinated paraffins ingested were incorporated into the body (without head, feet, gut and feathers), whereas about 1.5% were eliminated with the egg yolk and 30% were excreted with urine and faeces. A six-week kinetic depuration study revealed a biphasic elimination with half-lifes of 4-40 min (liver, kidneys, legs, fat, blood) for the initial rapid phase, and 15-30 days (blood, fat, liver, yolk, kidneys, legs) for the terminal slow phase.     

腐植酸对蛋鸡的生产性及质量的影响

把添加了腐植酸的商品饲料,投放到蛋鸡的产蛋后期到末期,观察了腐植酸对蛋鸡生产性的影响,结果如下：（1）单饲试验区的产蛋率会随着饲养时间的推移而增加,而且有抑制高龄蛋鸡产蛋率下降的作用,同时饲料的消费量有增加的趋势。但是,并没有影响到鸡蛋的质量。（2）在控制鸡粪臭气的试验中,腐植酸含量添加比例越高,经过时间越长,氨气的浓度就会越低,特别是在24 h以后,具有明显控制氨气产生的效果,同时它对硫化氢与甲硫醇的生成也有抑制作用。     

八珍乌鸡的生产工艺

本文简述了八珍乌骨鸡的生产工艺和配方     

Investigation of the peptides with calcium chelating capacity in hydrolysate derived from spent hen meat

Calcium peptide chelates are developed as efficient supplements for preventing calcium deficiency. Spent hen meat (SHM) contains a high percentage of proteins but is generally wasted due to the disadvantages such as hard texture. We chose the underutilized SHM to produce peptides to bind calcium by proteolysis and aimed to investigate chelation between calcium and peptides in hydrolysate for a sustainable purpose. The optimized proteolysis conditions calculated from the result of response surface methodology for two-step hydrolysis were 0.30% (w_enzyme/w_meat) for papain with a hydrolysis time of 3.5 h and 0.18% (w_enzyme/w_meat) for flavourzyme with a hydrolysis time of 2.8 h. The enzymatic hydrolysate (EH) showed a binding capacity of 63.8 ± 1.8 mg calcium/g protein. Ethanol separation for EH improved the capacity up to a higher value of 68.6 ± 0.6 mg calcium/g protein with a high association constant of 420 M⁻¹ (25°C) indicating high stability. The separated fraction with a higher amount of Glu, Asp, Lys, and Arg had higher calcium-binding capacity, which was related to the number of ─COOH and ─NH₂ groups in peptide side chains according to the result from amino acid analysis and Fourier transform infrared spectroscopy. Two-step enzymatic hydrolysis and ethanol separation were an efficient combination to produce peptide mixtures derived from SHM with high calcium-binding capacity. The high percentage of hydrophilic amino acids in the separated fraction was concluded to increase calcium-binding capacity. This work provides foundations for increasing spent hen utilization and developing calcium peptide chelates based on underutilized meat.     

Isolation of Lysozyme from Hen Egg Albumen by Alcohol-Insoluble Cross-Linked Pea Pod Solid Ion-Exchange Chromatography

ABSTRACT: Albumen from hen eggs was diluted 3-fold with 0.05 M NaCl solution at pH 4.0 and was further treated with 30% ethanol for 8 h. The supernatant (77900 U/mg protein) thus obtained was further diluted (2.5-fold) with distilled water and its pH value was adjusted to 8.0 before being subjected to alcohol-insoluble cross-linked pea pod solid (AICLPPS) ion-exchange chromatography for lysozyme isolation. Results showed that AI-CLPPS ion-exchange chromatography increased the purification to 68-fold with a 72% lysozyme recovery from the starting albumen.     

Dietary High‐Oleic Acid Soybean Oil Dose Dependently Attenuates Egg Yolk Content of n‐3 Polyunsaturated Fatty Acids in Laying Hens Fed Supplemental Flaxseed Oil

Chickens can hepatically synthesize eicosapentaenoic acid (20:5 n‐3) and docosahexaenoic acid (22:6 n‐3) from α‐linolenic acid (ALA; 18:3 n‐3); however, the process is inefficient and competitively inhibited by dietary linoleic acid (LNA; 18:2 n‐6). In the present study, the influence of dietary high‐oleic acid (OLA; 18:1 n‐9) soybean oil (HOSO) on egg and tissue deposition of ALA and n‐3 polyunsaturated fatty acids (PUFA) synthesized from dietary ALA was investigated in laying hens fed a reduced‐LNA base diet supplemented with high‐ALA flaxseed oil (FLAX). We hypothesized that reducing the dietary level of LNA would promote greater hepatic conversion of ALA to very long‐chain (VLC; >20C) n‐3 PUFA, while supplemental dietary HOSO would simultaneously further enrich eggs with OLA without influencing egg n‐3 PUFA contents. Nine 51‐week‐old hens each were fed 0, 10, 20, or 40 g HOSO/kg diet for 12 weeks. Within each group, supplemental dietary FLAX was increased every 3 weeks from 0 to 10 to 20 to 40 g/kg diet. Compared to controls, dietary FLAX maximally enriched the total n‐3 and VLC n‐3 PUFA contents in egg yolk by 9.4‐fold and 2.2‐fold, respectively, while feeding hens 40 g HOSO/kg diet maximally attenuated the yolk deposition of ALA, VLC n‐3 PUFA, and total n‐3 PUFA by 37, 15, and 32%, respectively. These results suggest that dietary OLA is not neutral with regard to the overall process by which dietary ALA is absorbed, metabolized, and deposited into egg yolk, either intact or in the form of longer‐chain/more unsaturated n‐3 PUFA derivatives.     

A sulfadimidine model to evaluate pharmacokinetics and residues at various concentrations in laying hen

Low level intake of drugs from the ingestion of contaminated feed may lead to residue problems in food animals. Sulfadimidine (SDD) was used as a model to determine the residue risk at various doses in laying hens. The drug was administered as a single intravenous injection (100 mg kg^-1 body weight, BW), as a single oral dose (100, 30, 10, 3, 1 mg kg^-1 BW) and via medicated feed for 7 consecutive days (30, 10, 3 mg kg^-1 BW). Drug levels were determined with HPLC-UV for plasma, yolk and albumen. Pharmacokinetic values, which were calculated using a first-order one-compartment model, residue levels and transfer rates into the eggs were found to be dose-dependent. Even low doses of 3 and 1 mg kg^-1 BW resulted in measurable residues in yolk and albumen 1 day after a single oral administration. After ingestion of medicated feed at 3 mg kg^-1 BW, mean drug levels at 0.14 ± 0.01 µg g^-1 were found in albumen and at 0.09 ± 0.01 µg ml^-1 in plasma. Generally, the residue levels in albumen and plasma were higher than in yolk. These findings demonstrate a residue risk for the consumer even after low level intake of drugs.