Effect of chicken meat replacement by spent laying hen meat on physicochemical properties and sensorial characteristics of fresh sausage

1. Sausages were used to assess the effects of chicken meat replacement by spent laying hen meat on the quality parameters and sensorial properties.

2. Five formulations were developed: control (CON) containing 100% chicken meat and 4 levels of chicken meat replacement with spent laying hen meat: 25% (T25), 50% (T50), 75% (T75) and 100% (T100).

3. Appearance, texture, succulence, flavour and overall consumer acceptance were analysed. Parameters such as moisture, ash, fat and protein content, pH, cooking loss and colour parameters (lightness (L*), redness (a*), yellowness (b*)) were analysed, as well as the texture properties (hardness, elasticity, cohesiveness and chewiness).

4. Statistical analysis did not reveal significant (P > 0.05) differences in chemical composition and colour parameters among formulations. On the other hand, CON treatment showed the lowest (P < 0.05) cooking loss (20.45%) that increased as spent laying hen meat increased in the formulation (24.92% vs. 27.65% vs. 28.12% vs. 33.05%, for T25, T50, T75 and T100 batches, respectively).

5. Regarding textural parameters, T75 and T100 formulations presented higher (P < 0.05) hardness and chewiness compared to the other ones.

6. Concerning to sensorial characteristics, the T100 formulation presented the lowest average scores (P < 0.05) for all attributes studied. However, the other batches (T25, T50 and T75) did not show significant differences for appearance, texture, succulence, flavour and overall acceptability attributes compared with the CON formulation.

7. The results indicated that the substitution of up to 75% of chicken meat by spent laying hen meat did not decrease the sensory acceptance of the sausages by consumers, demonstrating that this level of substitution in sausages allows better use of spent laying hen meat.     

Tenderisation of spent hen meat using ginger extract.

1. The purpose of this work was to study the effect of ginger extract (GE) on tenderness of spent hen meat. 2. Spent hen meat chunks at either the pre- or post-chilled stage were marinated with different concentrations (0%, 1%, 3% and 5% v/w) of GE and were evaluated after 24 h of treatment. 3. GE treatment increased the pH, moisture, cooking yield, total pigments, water holding capacity, collagen solubility, protein extractability, muscle fibre diameter and decreased the shear force values. 4. The electrophoretic pattern of muscle proteins revealed extensive proteolysis and reduction in number of protein bands in GE treated samples. 5. Tenderness scores were higher in samples treated at post-chilled stage. Of the different concentrations of GE examined, 3% was found optimum for tenderisation.     

Behavioural differences between laying hen populations selected for high and low efficiency of food utilisation

1. The effects on behaviour of selecting light-hybrid laying hens for high and low efficiency of food utilisation were investigated. Efficiency of food utilisation was measured as the proportional deviation of observed food consumption from expected food consumption. 2. Videograms of the day-time behaviour of 48 to 53-week-old individually caged hens from the F3 generation were analysed by instantaneous sampling. 3. Low-efficiency hens spent more time food-pecking, walking, pacing, and showing escape and aggressive behaviour than did high-efficiency hens. High-efficiency hens spent more than twice as much time resting and sleeping, and were never observed pacing prior to laying. 4. These differences were larger during the 2 h before laying than at other times of day. 5. Low-efficiency hens had poorer plumage, especially on the neck and the breast, and the poorer the plumage the more agitation they showed. 6. Time spent food-pecking was negatively correlated with laying frequency. 7. Differences in the occurrence of specific behaviour patterns, particularly those symptomatic of pre-laying frustration, partly explained differences in efficiency of food utilisation. Selection for higher efficiency of food utilisation might eliminate hens which are most frustrated prior to laying in cages.     

Determination of nitrogen balance in goats fed a meal produced from hydrolyzed spent hen hard tissues

To provide an economically viable and environmentally sound method for disposing of spent laying hens, we manufactured a proteinaceous meal from the hard tissue fraction of mechanically deboned laying hens (primarily feathers, bones, and connective tissue). We hydrolyzed the hard tissue and coextruded it with soybean hulls to create a novel feather and bone meal (FBM) containing 94.2% DM, 23.1% CP, 54.5% NDF, and 7.3% fat (DM basis). We evaluated the FBM in supplements for meat goats in which it provided 0, 20, 40, or 60% of the N added to the supplement compared with a negative control supplement with no added N source. The remainder of the N was contributed by soybean meal (SBM). Supplementation of N resulted in greater DMI than the negative control (P = 0.005), and DMI changed quadratically (P = 0.11) as FBM increased in the supplement. Digestibility of DM was similar in all diets, including the negative control (P > 0.10). Fiber digestibility increased linearly as dietary inclusion of FBM increased (P = 0.04 for NDF, P = 0.05 for ADF), probably as a result of the soybean hulls in the FBM. Nitrogen digestibility declined linearly from 60.5% with 0% FBM to 55.6% with 60% FBM (P = 0.07), but N retention changed by a quadratic function as FBM replaced SBM (P = 0.06). Negative control goats had less N digestibility (P < 0.001) and N retention (P = 0.008) than N-supplemented goats. Feather and bone meal had a greater proportion of ruminally undegradable B(3) protein than SBM (23.1 vs. 0.3% of CP, respectively). Ruminal VFA and pH were unaffected by replacing SBM with FBM, but supplying no source of N in the concentrate resulted in reduced total VFA in ruminal fluid (P = 0.04). Ruminal ammonia concentration increased quadratically (P = 0.07) as FBM increased, reflecting increased intake, and it was much less in unsupplemented goats (P < 0.001). Serum urea had less variation between 0 and 4 h after feeding in goats receiving 40 or 60% of added N as FBM in comparison with those receiving only SBM or 20% FBM. Feather and bone meal promoted a more stable rumen environment, possibly because of reduced rates of protein degradation within the rumen. A palatable by-product meal for ruminants can be made from spent laying hen hard tissue, one that supports N metabolism similar to that of traditional protein sources.     

Effect of cinnamon essential oil on the microbiological and physiochemical characters of fresh Italian style sausage during storage

In order to study the effect of cinnamon essential oil (CEO) on the microbiological and physiochemical characters of fresh Italian style sausage, CEO (0%, 0.1%, and 0.5%, v/w) was added into ground meat, cased, and stored at 4°C. Lipid oxidation, instrument color, total viable aerobic counts, Enterobacteriaceae, biogenic amines, and total volatile basic nitrogen (TVB‐N) were investigated during 10 days (day). Results showed that CEO treatments had lower thiobarbituric acid reactive substances (TBARS), b* value, aerobic and Enterobacteriaceae counts, biogenic amine contents, and TVB‐N and higher a* values at 4, 6, 8, and 10 days compared to the control, whereas 0.5% CEO treatment had better effect than 0.1% CEO. CEO improved color shelf‐life by inhibiting lipid oxidation and prevented the increase in biogenic amines and TVB‐N by reducing microbial counts of fresh sausage during storage. This study suggested that CEO could be applied in the food industry to improve the shelf‐life of meat products.     

菌糠的营养价值及其在动物生产中的应用

针对菌糠的营养成分组成和影响菌糠营养成分的因素,以及近年来菌糠在畜禽生产中的应用进行介绍。     

An experimental study of the utilisation, by the laying hen, of dietary energy partially supplied as animal fat

Experiments were carried out at two centres in which laying hens were fed diets containing up to 28.25 per cent tallow and in which an attempt was made to maintain a fairly constant calorie : protein ratio. The most satisfactory production was obtained on a diet containing 3.5 per cent added fat in one experiment and 7.5 per cent added fat in the other experiment. Food conversion efficiency (kg food/kg eggs) increased with increasing dietary fat content.

The efficiency of ME utilisation (Mcal/kg egg) decreased with increasing dietary ME content. The data indicate that at the higher levels of fat addition the net utilisation of ME was decreased.

In both experiments mean egg weight was increased by the addition of tallow to the diet whilst at the highest level of addition there was a very high mortality.     

Occurrence of Salmonella enteritidis in the U.S. commercial egg industry: report on a national spent hen survey.

In order to estimate the prevalence and distribution of Salmonella enteritidis in U.S. commercial egg-production flocks, a survey of spent laying hens was conducted over a 3-month period. Seven of the 10 largest spent-hen processing plants in the United States participated. Ceca were sampled twice weekly from birds presented for slaughter at these plants. Samples were cultured for Salmonella and S. enteritidis, and S. enteritidis isolates were phage-typed. Overall, 23,431 pooled cecal samples were collected from a total of 406 layer houses. Salmonella (any serotype) and S. enteritidis were recovered from 24% and 3% of the pooled samples, respectively. The distribution of S. enteritidis phage types was consistent with data reported by others. Regionally, the estimated prevalence of S. enteritidis-positive houses (i.e., at least one positive sample found in a house) for the Northern, Southeastern, and Central/Western regions was 45%, 3%, and 17%, respectively. Overall, the prevalence of Salmonella-positive houses was 86%.     

Chitin utilisation by broilers and its effect on body composition and blood metabolites

1. Little is known about the ability of farmed poultry to digest chitin and derive nutrients from the ingestion of insects. 2. Commercial chitin derived from crustacean shell waste was found to contain 373 g crude protein, 265 g ash, 23.5 g ether extract, 130 g calcium and 16.4 g phosphorus per kg, on an air-dry basis. 3. It was included in diets at 0, 25, 50 and 75 g chitin per kg and fed to 320 1-d-old broiler males, over a 21-d period. There were no statistically significant treatment effects on weight gain or feed efficiency. Apparent digestibility of chitin protein was 0.48, 0.50 and 0.45, at the 25, 50 and 75 g per kg inclusions, respectively. Mean AME and AMEN values of chitin were determined as 8.97 and 8.86 MJ/kg. 4. In a subsequent study, mean TME and TMEN values of chitin were determined to be 8.23 and 8.21 MJ per kg, respectively. Addition of chitinase to the diet increased TME and TMEN of chitin to 8.81 and 8.79 MJ per kg, respectively (P<0.05). True digestibility of chitin protein was determined to be 0.87. 5. Triglyceride concentrations in liver and breast meat were significantly reduced by chitin inclusion. No significant differences in carcase yield at 21 d of age were found. Serum cholesterol and triglycerol concentrations were reduced significantly by dietary chitin, the lowest levels being observed at the 50 g per kg inclusion level. 6. These findings indicate the ability of modern poultry to digest chitin but suggest that the ingestion of insects is not an important source of nutrients, at least from the exoskeleton.     

循环式吸入麻醉装置的制作及其对大鼠麻醉效果

设计并制作1台用于大鼠的循环式吸入麻醉装置,并对大鼠的麻醉效果进行手术验证。利用CDR绘图软件设计麻醉装置样图,然后收集所需材料根据设计样图组装吸入麻醉装置。随机选取10只SD大鼠,使用本装置将其麻醉进行常规手术(开腹探查和胃切开术),术中记录麻醉各个阶段的时间,并用生理监测仪连续动态监测大鼠呼吸(RR)、心率(HR)、血氧(SpO_2)、收缩压(SBP)、平均动脉压(MAP)和体温(t),同时观察大鼠镇静、镇痛和肌松效果,以评价麻醉装置的安全性和可用性。根据设计样图完成了吸入麻醉装置的连接和组装。用该装置对大鼠麻醉诱导的时间为(2.20±0.45) min,达到外科麻醉所需时间为(2.12±0.36) min,麻醉维持和苏醒时间分别为(45.18±0.12),(2.40±0.55) min,麻醉总时间为(51.40±0.24) min。术中大鼠镇静、镇痛、肌松弛效果良好,在手术后10,20,30,45 min时HR、SpO_2、RR、T、SBP、MAP均保持平稳,各项生理指标在每个时间点都无显著性差异(P0.05)。该吸入麻醉装置对大鼠麻醉效果确实、安全可控,麻醉诱导和苏醒时间较快,可完全满足手术对麻醉的要求。     

A comparative study of energy utilisation by the laying hen from diets containing a high proportion of fat and diets made up mainly from carbohydrate sources

An experiment was carried out in which laying hens were fed diets containing about 30 per cent tallow at three protein levels. Productive performances of hens on these diets were compared with those of hens fed either a diet containing 15 per cent arachis oil, a diet containing 15 per cent sucrose or a conventional cereal‐based control diet.

It was found that the best performance was obtained with hens fed the control diet. Gross energetic efficiency of egg production was slightly lower in the birds fed the diets containing arachis or sucrose. It appeared that the lower efficiency was due to the higher mean body weight of birds on these diets. Egg size was significantly increased by feeding the diet containing arachis oil.

Performance of hens given diets containing tallow was unsatisfactory. For each diet egg production was significantly less than that recorded for the control diet and the gross energetic efficiency of egg production was much lower than that on the control diet.     

从质构角度考察干酪凝乳工艺参数

本文应用质构仪对影响干酪凝乳的主要因素(乳处理温度、牛乳的pH、凝乳温度、凝乳酶添加量以及钙的添加与否)进行研究，通过对凝乳物性的测试并结合生产实际，最终确立了最佳凝乳工艺参数：乳处理温度72℃，16s、凝乳酶添加量5／100000、温度31℃、正常牛乳pH、添加或不添加氯化钙。本研究为凝乳工艺的确立提供了量化依据。     

DDGS在蛋鸡和肉鸡日粮中的应用

DDGS(干酒糟及其可溶物)是谷物生产酒精的副产品,富含蛋白质、磷、维生素等营养成分。本文主要介绍了DDGS的营养特性及其在蛋鸡和肉鸡日粮中的应用。     

Posture and heart rate in the domestic hen

When unanaesthetised fowls were hung upside down on shackles the heart‐rate immediately rose by about 30 per cent; on re‐inverting them after 2, 4 or 6 min it returned rapidly to normal. It behaved similarly in anaesthetised birds save that the response to inversion was somewhat smaller and slower, depending on the depth of anaesthesia, and there was some over‐compensation before return to normal. It is concluded that the effect was probably a response to changes in the activity of baroreceptors in the cardiovascular system and that the data do not disclose evidence of serious distress.     

Update: prevalence of Salmonella in pork sausage

One hundred seventy-five samples of fresh pork sausage representing thirty-five different commercial brands from six different retail stores were examined for the presence of salmonellae by standard enrichment, plating, biochemical and serological techniques. Contamination levels varied from 0 to 50% among stores and from 0 to 28% among brands. Prior research implied reduced prevalence of salmonellae in fresh pork sausage; however, these results indicate no variation in prevalence since 1969.     

夏季蛋鸡中暑的诊治

夏季蛋鸡中暑轻者导致产蛋下降、重者鸡只大批死亡,给蛋鸡养殖业带来巨大的经济损失.本文以一起海兰褐蛋鸡中暑病例为题材,从发病情况、临床症状、剖检病理变化、实验室检查、诊断、防治等六个方面对该情况做了详尽阐述,对提高夏季产蛋鸡经济效益具有一定的参考价值.