Effects of early energy and protein restriction on growth performance, clinical blood parameters, carcass yield, and tibia parameters of broilers

financially supported by the Science and Technology Develop Project of Northern Jiangsu, China （BN2015136）;the Priority Academic Program Development of Jiangsu Higher Education Institution, China

Dietary sources and levels of selenium supplements affect growth performance,carcass yield,meat quality and tissue selenium deposition in broilers

This study examined the effects of sources and levels of selenium(Se)on performance,carcass parts yield,meat quality and tissue Se concentration in broilers.A total of 960 one-day-old male broilers were divided into 8 treatments in a 4 x 2 factorial arrangement.Chicks were penned in groups of 20 with6 pens per group.Selenium sources were sodium selenite(SS),Se enriched yeast(SY),DLselenomethionine(SM)and nano-selenium(NS)and dietary supplemental Se levels were 0.1 and0.3 mg/kg diet.The average daily gain(ADG),average daily feed intake(ADFI),feed:gain ratio,mortality,and carcass parts yield were not affected by dietary treatments.The level of 0.3 mg/kg Se decreased lightness and increased yellowness of the breast and thighs(P<0.001).Nano-selenium improved yellowness,redness and meat quality(P<0.05).The interactive effects of sources and the levels of Se affected Se retention(P<0.001).Inorganic Se showed poor retention compared to other sources of Se;and NS showed equal retention with the organic sources.With consideration to meat quality responses,NS had a more signific:ant positive effect compared to SS as an inorganic source of Se.Overall,NS and organic sources of Se resulted in better meat quality compared with the inorganic source.Moreover,the highest Se retention percentage was achieved by supplementation of NS followed by organic sources at0.1 mg/kg compared to SS.

Carcass Traits, Meat Yield and Primal Meat Cuts from Arsi, Harar, Ogaden and F1 Jersey*Horro Crossbred Bulls Fed Corn Silage Based Similar Finishing Diet

This study was conducted with the objective to determine carcass traits, meat yield, and primal meat cuts of Arsi, Harar, Jersey*Horro crossbred, and Ogaden cattle breeds at Haramaya University, Ethiopia. A total of 12 bulls of four cattle breeds (3 Arsi, 3 Harar, 3 F1 Jersey*Horro crossbred and 3 Ogaden) with almost similar ages were randomly assigned to four treatments in a completely randomised design (CRD). Data on carcass traits, meat yield, and primal meat cuts were analyzed using the General Linear Model (GLM) of the Statistical Analysis Software (SAS) 9.4 version. The overall averages of live body weight, hot carcass weight, chilled carcass weight, dressing percentages based on hot carcass weight, and rib eye area of experimental cattle breeds were 215.58 kg, 102.93 kg, 99.56 kg, 47.61%, and 8.13 inch2, respectively. The hot carcass weight and chilled carcass weight of the Ogaden (136.57;133.30 kg, resp.) breed were higher (p < 0.01) compared to other experimental cattle breeds. Dressing percentages based on hot carcass weight were higher (p < 0.05) for the Ogaden (49.61%) and Arsi (49.82%) cattle breeds compared to Harar and Jersey*Horro crossbred (45.73%, 45.27%, resp.) cattle breeds. The average meat yield and proportion of meat yield of cattle breeds were 77.52 kg and 77.46%, respectively. With a linear regression coefficient of prediction (R2) ranging from 52.26% to 93.58%, primal meat cuts significantly (p dicted meat yield. In conclusion, the breed of cattle had a significant (p 0.05) influence on live body weight, hot and chilled carcass weight, dressing percentage, rib eye area, subcutaneous fat thickness, meat yield, and the weights of most primal meat cuts. The Ogaden cattle breed had a higher and better meat yield, carcass traits, and most primal meat cuts compared to other experimental cattle breeds. Furthermore, the inclusion of corn silage in the diet of fattening bulls improved the carcass and meat yield. Therefore, the performance of Ogaden cattle compared to other and previous studies suggests the possibility of using this breed for export purposes in addition to Borana and Harar cattle breeds in the future.

Carcass and Meat Characteristics of Bulls from Arsi, Boran, Harar and Holstein Frisian Crosses Cattle Breeds Finished under Similar Level of Concentrate Supplementation

A study was conducted to evaluate the effect of age and breeds (Arsi, Borana, HF-Cross and Harar) on carcass and meat characteristics of bulls finished under similar feeding conditions. The feeding experiment was conducted for 90 days at Beef farm of Haramaya University. In this experiment, 24 bulls were fed with roughage (60%) which contained grass hay and wheat straw and concentrate (40%) which contained wheat bran, noug (gucia abysica) cake, maize grain, limestone, salt and ruminant premix. The bulls were transported to Bishoftu ELFORA export abattoir for slaughter following the procedure of the abattoir. The result of the study revealed that the average slaughter weight, hot carcass weight, cold carcass weight, shrink loss, commercial dressing and true dressing percentage were 179.1 kg, 86.8 kg, 82.7 kg 4.7%, 48.8% and 78.3%, respectively. Total edible and nonedible offal were significantly (P < 0.01) influenced by breed and age. Pelvic fat was significantly (P < 0.01) influenced by breeds. Meat yield percentages of Arsi, Boran, Harar, and HF-crossbred were 78.1%, 77%, 72.8% and 77.2% respectively. Meat yield was predicted from fat thickness and ribeye area with 61% accuracy. Arsi bulls attained the highest (78%) meat yield at early age but decreased by 0.713 rate as age of animals advanced by one digit whereas the meat yield from other breeds showed increment in meat yield percentage with the rate of 1.98, 1.1 and 0.1 for cross, Borana and Harar breed bulls, respectively as age advanced. Yield from fore shank, sirloin, top and bottom sirloin primal cuts were affected by breed. Arsi breed had higher meat bone ration than cross breed. Retailed meat yield was significantly (P < 0.001) predicted from rib area and subcutaneous fat thickness (P < 0.001) with a coefficient of determination 61%, from live animal trait and primal cuts with a coefficient of determination 89.56% and 94.78% respectively. Arsi bulls can be used for beef purpose at 2 - 3 years, as the meat percentage decreases thereafter;while bulls from Boran, cross breed and Harar breeds can be used up to 5 years of age. Meat to bone ratio indicated that HF-Crossbred was less appropriate for beef purpose than other breed bulls in this study. The rate of pH decline was not influence (P > 0.05) by age and breed in the current study.

Carcass Characteristics of Guinea Fowl Raised under Intensive System and Fed Diets Containing Yellow Maize, Millet and White Sorghum as Energy Sources

This study investigated carcass characteristics of guinea fowl reared under intensive system and fed diets containing yellow maize, millet and white sorghum as energy sources compared to commercial broiler diets (control). A completely randomized design was used where 160 guinea fowl keets were randomly assigned to four dietary treatments. Data were analyzed using Procedure General Linear Model in Statistical Analysis Software (version 9.0). Results showed that dietary treatment did not (p > 0.05) influence carcass characteristics of guinea fowl at the same age. However, carcass characteristics significantly (p < 0.05) increased with age. From 6 to 16 weeks of age carcass dressed weight of guinea fowl increased from 301.73 ± 9.49 g to 1003.65 ± 26.77 g;288.18 ± 9.49 g to 952.58 ± 26.77 g;305.00 ± 9.49 g to 976.55 ± 26.77 and 292.81 ± 9.49 g to 970.08 ± 26.77 g for control, maize, millet and sorghum diets, respectively. Carcass yield slightly increased from 69.93% ± 3.67% to 72.81% ± 2.67%;73.85% ± 3.67% to 76.31% ± 2.67% and 70.55% ± 3.67% to 72.37% ± 2.67% for control, millet and sorghum diets, respectively. Carcass yield of guinea fowl on maize diet decreased with age (76.18 ± 3.67 to 71.68 ± 2.67). Other parameters including empty gizzard, heart, liver, drumstick, thigh, back and breast increased with guinea fowl age for all the dietary treatments. Maize, sorghum or millet diets can be used in guinea fowl diets without affecting carcass characteristics. Further studies on the acceptance of meat by consumers and cost-benefit analysis of the dietary treatments should be conducted to enable formulation of guinea fowl diets using local feed resources.

Effect of Age and Breeds of Cattle on Carcass and Meat Characteristics of Arsi, Boran, and Harar Cattle in Ethiopia

The objective of this study was to determine the effect of age and breed of cattle on carcass and meat characteristics in Ethiopia. A total of 39 (Arsi 11, Boran 14 and Harar 14) cattle breeds with age categories of <3, 4 - 6, and 7 - 9 years were used for the study. The bulls were purchased from their respective production system of mixed crop livestock system (Arsi and Harar) and Ranch (Boran). Parameters such as live and carcass weight, meat yield percent, fat characteristics, and primal beef cuts were evaluated. Complete randomized design was used for the study. The live weight of bulls at <3, 4 - 6 and 7 - 9 years ranged 135 - 183, 167 - 181, and 155 - 433 kg, respectively. The carcass weight, dressing percentage, meat yield percent, forequarter, hindquarter, rib eye area, and fat thickness ranged 57 - 209.73 kg, 41.8% - 51.6%, 32% - 58%, 11.7 - 56.42 kg, 14.04 - 45.34 kg, 4.78 - 10.25 square inches and 0.18 - 0.38 inches, respectively. At an early age category (<3 years) meat yield percentage of Arsi, Boran and Harar breeds were 50.86, 30 and 18.72, respectively, and as age category shifted from one age category to the next Harar increased by 13× and Boran by 2.9× and Arsi decreased by -0.93×. The mean rib percentage of Arsi, Boran and Harar were in the range of 7.98 - 9.57, 8.62 - 10.44 and 7.08 - 8.83, respectively. Breed and age of bulls had significantly affected primal meat cuts. Meat yield was predicted from live and hot carcass weight with coefficient determination (R2) of 70.66% and 74.75%, respectively. From the study, it was concluded that age and breeds of cattle had significantly influence on carcass and meat characteristics. Therefore, to determine whether variations were due to genetic or environmental cause’s evaluation of the three breeds under similar feeding condition was recommended.

青绿甜高粱秸秆替代部分全价饲粮对鹅生长性能、屠宰性能及肉品质的影响

通过研究青绿甜高粱秸秆替代不同比例的基础饲粮对四川白鹅生长性能、屠宰性能及肉品质的影响,探索建立利用青绿甜高粱秸秆替代鹅部分全价基础饲粮的饲喂技术。选取360只28日龄的四川白鹅(公母各半,(1.11±0.008)kg),随机分为对照组、试验I组、试验II组、试验III组、试验IV组、试验Ⅴ组6个处理组,每个组6个重复,每个重复10只鹅。对照组自由采食全价基础饲粮,不补饲青绿甜高粱秸秆;试验Ⅰ~Ⅴ组分别饲喂对照组日采食量96%、92%、88%、84%和80%的基础饲粮,同时自由采食青绿甜高粱秸秆。试验至70日龄结束。结果表明:1)试验I、II组末重和平均日增重与对照组相比无显著差异(P>0.05),对照组、试验I组平均日增重显著高于试验III、IV、Ⅴ组(P<0.05)。2)试验Ⅰ~Ⅴ组屠宰率、胸肌率、腿肌率与对照组相比无显著差异(P>0.05);与对照组相比,试验Ⅰ~Ⅴ组腹脂率均显著降低(P<0.05),试验I、IV和V组皮脂率显著降低(P<0.05),试验Ⅰ~Ⅴ组的肌胃指数均显著升高(P<0.05)。3)与对照组相比,试验Ⅰ~Ⅴ组胸肌粗蛋白质、肌内脂肪和肌苷酸含量均无显著差异(P>0.05),试验I^III组总氨基酸、必需氨基酸、鲜味氨基酸,饱和脂肪酸、不饱和脂肪酸含量均无显著差异(P>0.05)。综合考虑生长性能、屠宰性能和肌肉品质等指标,对于28~70日龄四川白鹅,利用青绿甜高粱秸秆替代部分全价饲粮是可行的,替代比例以4%~8%最好。

日粮添加糙米和米糠对鹅生长性能、屠宰率及消化道发育的影响

试验旨在研究日粮添加糙米和米糠对鹅生长性能、屠宰率及消化道发育的影响。选择28日龄体重接近,健康的雄性扬州鹅120只,随机分为3组,每组40只,每个重复10只鹅。对照组饲喂以玉米、豆粕、苜蓿草粉为基础的饲粮:处理1组饲喂以玉米、豆粕、糙米、统糠为基础的日粮;处理2组饲喂以玉米、豆粕、精米和米糠为基础的日粮,试验共进行42 d。结果显示:对照组与处理1组颗粒粒径分布较一致,其中处理2组有更多的颗粒分布在0.45~0.90 mm,分布在0.20~0.45 mm的颗粒较少,处理2组颗粒分布在1.25 mm及以上的颗粒要高于对照组和处理1组。处理2组平均日增重在28~70 d显著高于对照组(P<0.05);处理3组鹅生长全期(28~70 d)平均日增重显著高于对照组和处理1组(P<0.05);处理2、3组鹅生长全期(28~70 d)料重比显著低于对照组(P<0.05)。与对照组相比,处理1组和处理2组显著提高了70 d鹅体重(P<0.05)。日粮添加糙米和米糠对鹅屠宰率、净堂屠宰率、胸肌率、腿肌率和腹脂率均无显著影响(P>0.05)。与对照组和处理1组相比,处理2组显著降低空肠、回肠和整个小肠的相对重量(P<0.05)。处理1组和处理2组较对照组显著降低了空肠、回肠和整个小肠的长度(P<0.05),而处理2组与对照组较处理1组显著降低了十二指肠、空肠和整个小肠的相对长度(P<0.05)。结果表明:精米+米糠型日粮对鹅消化道相对长度的影响与玉米型日粮一致,但精米+米糠或糙米+统糠型日粮可以提高日增重及降低料重比。精米或糙米+统糠或米糠作为鹅饲料原料具有替代玉米的潜能,同时可以降低饲料成本。

安格斯牛×秦川牛F1代产量分级模型的研究

本研究旨在对中长期育肥的安格斯牛×秦川牛F1代的胴体性状指标进行筛选并建立其产量分级模型。随机选取115头发育正常、健康无病的育肥牛屠宰后测定胴体性状指标,采用相关分析和因子分析对其进行筛选并建立产肉率预测模型。结果表明,胴体重、后躯部位肉重、眼肌面积、背膘厚是胴体产量分级的重要指标;将其与产肉率进行多元线性回归,得到胴体产量分级模型,产肉率(%)=41.372―0.046×胴体重+0.403×后躯部位肉重―0.049×眼肌面积+0.334×背膘厚(R2=0.850),经回归诊断和t检验证明该模型预测结果良好,预测值和实测值间差异不显著。结果提示,建立的产量分级模型可用于安格斯牛×秦川牛F1代产量的预测,为开展雪花牛胴体分级提供科学依据。

巴美肉羊生长发育和胴体等级肉产量研究

选择4、6、8月龄巴美肉羊各10只,与同月龄的小尾寒羊、苏尼特羊进行对比屠宰实验,分别测定并计算其体尺指标(体长、体高、胸围)、体尺指数(体型指数、胸围指数、体躯指数)和胴体等级分割肉质量,即一级肉(后腿肉和腰肉)、二级肉(肋肉和肩颈肉)、三级肉(腹下肉),确定巴美肉羊在生长发育和胴体等级肉产量方面是否具有优越性。结果表明:巴美肉羊的胸围、胸围指数和体躯指数均显著大于同月龄小尾寒羊和苏尼特羊(P<0.05),且随着月龄增加,该类指标的增加速率也快于对照组肉羊。同时,6、8月龄巴美肉羊的各等级肉质量均显著大于同月龄对照组肉羊(P<0.05),且随着月龄增加,其优质肉块的增长速率也大于其他肉块。因此,巴美肉羊与小尾寒羊和苏尼特羊相比,具有良好的前躯和躯干相对发育能力以及该品种肉羊良好的优质肉块的产肉性能。

猪的Ag-NOR_s与其肥育性能相关研究

对猪的Ag—NOR_s与其肥育性能相关分析结果表明,二者间呈显著负相关。猪品种的Ag—NOR_s均数、8Ag—NOR_s^+平均染色体型频率与日增重和瘦肉率间的相关系数分别为-0.5968(P<0.01)和一0.6235(P<0.005);-0.6550(P<0.005)和-0.7036(P<0.001);个体的Ag—NOR_s均数、8Ag—NOR_s^+染色体型频率与日增重的相关亦高达-0.6591(P<0.05)和-0.4984(0.1>P>0.05)。Ag—NOR_s有可能作为一项选种指标,用于猪肥育性能的选择。

美国胴体产量方程对我国牛胴体产肉量评定的适用性研究

用ＳＡＳ软件对７头商品牛的屠宰数据进行了统计分析，通过产肉率方程的估算值与实测值的相关分析，初步认为，以第１１肋后缘截面指标套用美国胴体产肉率方程估算我国牛胴体产率是不可行的。

日本胴体产肉率方程对我国牛胴体评价的适用性研究

用ＳＡＳ软件对１５２头商品牛的屠宰数据进行统计分析。通过产肉率方程的估测值与实测值的相关及回归分析，初步认为，日本方程对我国晋南牛胴体产率具有一定的预测作用，预测准确率为６６．７８％，但高估了约１０个百分点。但对鲁西牛、杂交牛（西门达尔×南阳牛）、北牛等无预测作用。

静原鸡屠宰性能研究

为保护甘肃省静原鸡种质资源和遗传多样性,研究其肉用价值,本试验对静原鸡的屠宰性能进行了测定。结果表明,静原鸡180日龄公鸡平均宰前重为2.85kg,母鸡2.22kg,差异显著(P<0.01)。180日龄母鸡的腹脂率高于公鸡,而宰前重、半净膛重、全净膛重、胸肌重、腿肌重、屠宰率、全净膛率、腿肌率等性状公鸡优于母鸡,差异均达显著水平(P<0.01)。总之,静原鸡具有较好肉用性能,有较大开发价值和发展前景。

Economic Analysis of the Use of Restrictive Food Management in the Cultivation of Tilapia(Oreochromis niloticus)in a Recirculation System

The development of more adequate food programs regarding the intensity and duration of the restriction can be an effective way to minimize the effects of exaggerated food consumption and its negative consequences for the economy of the business.In this sense,juvenile Nile tilapia(Oreochromis niloticus)(137±3 g)were submitted to different feeding strategies in a recirculation system.Five feeding strategies were tested in subsequent weekly cycles:continuous feeding;skipping one meal a week;suppression of two non-consecutive meals a week;suppression of three non-consecutive meals a week;suppression of four non-consecutive meals a week.Productive performance,feed consumption in the post-restriction period and economic indicators were evaluated through projections and profitability analyses.Compensatory intake occurred in all tested groups,so that the total feed intake(FI)did not differ significantly between them(p>0.05).Moderate food restriction provided a linear increase in the relative gross margin for each treatment with each change in salary level,as well as greater profitability when compared to the respective control group(p<0.05).

西门塔尔牛的推广价值与利用途径

西门塔尔牛引入甘肃省10多年来改良本地牛效果显著,生产性能逐步提高。肥育120天的18月龄F_1、F_2和F_3阉公牛日增重分别为1.069、1.118和1.222kg,比本地牛提高45.28～130.57％(P<0.01);胴体重216.91、214.91和248.68kg,提高29.67～116.90％(P<0.01),屠宰率58.03％、57.46％和58.46％,提高4.73～11.46％,F_1、F_2母牛泌乳期标准乳产量为1596.70、1831.00kg,分别比本地牛提高54.15％、111.81％(P<0.01)。乳脂率分别为4.99％和3.75％。西杂牛饲料利用效率高,役用性能好,适应性强,具有较高的推广价值。应消除顾虑,作为当家品种在全省积极扩大受配数量和比重。

辽育白牛胴体产肉量预测模型研究

为了快速且准确的预测辽育白牛胴体产肉量,进而建立完善的胴体分级体系,本试验对60头辽育白牛进行屠宰胴体分割试验,分别测量了胴体重(X_1),第5肋侧厚度(X_2),第5~6肋眼肌宽高乘积(X_3),第5~6肋眼肌面积(X_4),第12肋侧厚度(X_5),第12~13肋眼肌宽高乘积(X_6),第12~13肋眼肌面积(X_7),肾脏油、心脏油和膈肌油之和(X_8),后腿围(X_9)和大腿肌肉厚(X_10)等与产肉量、产肉率相关的10项指标,利用SPSS 19.0软件对数据进行相关分析和线性回归分析。结果显示,X_1、X_8与产肉量和产肉率相关性最强,依此推导出2个可信度高、实践中方便应用的产肉量预测方程:1产肉量(眼肌宽高乘积)=0.809X_1+0.158X_6+0.857X_8-13.967(R^2=0.986);2产肉量(眼肌面积)=0.779X_1+0.318X_7+0.933X_8-17.779(R^2=0.990)。

不同温度下氨对疫病动物尸骸废水厌氧消化的影响

采用厌氧折流板反应器处理疫病动物尸骸废水,研究了反应器由中温(35℃)逐步升至高温(55℃)时的运行特性.结果表明,升温至45℃和55℃时,厌氧处理效率显著降低,将有机负荷由35℃时的6.0 kg COD·(m^3·d)^(-1)降至55℃时的2.4 kg COD·(m^3·d)^(-1)并没有得到恢复,高温厌氧COD去除率相比中温下降了24%,甲烷产率下降了33%,出水挥发性脂肪酸(VFAs)增加了1.9倍.升温过程中,厌氧产甲烷菌受到了游离氮(FAN)的抑制导致甲烷产率显著降低.当温度由35℃升至55℃时,反应器p H值由7.63升至8.22,FAN由98 mg·L^(-1)升至340 mg·L^(-1),VFAs由235 mg·L^(-1)积累至684 mg·L^(-1),p H、FAN和VFAs三者的协同作用导致反应器在高温状态下处于"抑制稳态".与中温厌氧相比,高温菌对FAN的耐受性更强.当p H值为8.2时,FAN对中温菌的IC50为324 mg·L^(-1),对高温菌则达到453 mg·L^(-1),但这一优势不能抵消升温所引起的FAN抑制效应.这是疫病动物尸骸废水高温厌氧消化效率显著低于中温的主要原因.