Broiler response model to estimate the economic importance of dietary feed enzymes

The purposes of this research were: 1) a bio-assay to evaluate the effects of 2 feed enzymes (Hostazym X) and Avizyme 1505) on the performance of Cobb broilers; and 2) to calculate the economic value from the technical response data. A broiler response model that includes benefits from improved performance and incorporates the expected changes in output from Hostazym X and Avizyme 1505 is presented. Each of the 4 diets [1) Basal (corn, dried grains with solubles, and soybean meal based diet with 1,360 kcal/lb), 2) Basal+ Hostazym X, 3) Basal+ Avizyme 1505, 4) Basal+30 kcal/lb] was fed to 8 pens of 24 straight run Cobb chicks. Supplementing the basal diet with either enzyme showed significant effects on growth and feed efficiency. Quadratic equations were fitted through the response points for 49 d broilers: Body weights and feed intakes were: Basal, 6.085, 11.446; Basal+ Hostazym X, 6.231, 11.359; Basal+ Avizyme 1505, 6.165, 11.288; Basal+30 kcal, 6.455lb, 11.535 lb, respectively. Target live weights were compared at 4, 6 and 8 lb, chicken prices at $0.68 and $1.0/lb and feed costs at $200 and $400/ton. The value of feed savings by adding Hostazym X ranged from $6.92/ton for 4.0 lb broilers fed $200 feed, to $17.52/ton for 8.0 lb broilers fed $400 feed. The value of extra meat by adding Hostazym X ranged from $21.19/ton for 6.0 lb broilers selling for $0.68/lb, to $32.76/ton for 8.0 lb broilers selling for $1.0/lb. The value of feed savings by adding Avizyme 1505 ranged from $5.58/ton for 4.0 lb broilers fed $200 feed, to $12.09/ton for 8.0 lb broilers fed $400 feed. The value of extra meat from AZ1 ranged from $16.97/ton for 6.0 lb broilers selling for $0.68/lb, to $24.95/ton for 8.0 lb broilers selling for $1.0/lb. The value of the extra salable meat from feeding enzymes is 2 to 3 times greater than feed savings. Enzyme value is directly dependent on the costs of feed and meat value, and indirectly on reduced environmental costs for feed production and reduced unutilized nutrients (pollution) per lb of meat (not included in this analysis).     

考虑养分变异性的最低成本饲料配方模型

饲料原料中养分的变异性会影响到配合饲料的质量。可以用正态分布模型来描述养分的变异性。通过非线性随机规划模型(SP)盛带有安全裕量的线性规划模型(LPMS)可以在饲料配方过程中对原料的变异性加以处置。SP模型的可行域是凸性的,这使其成为一种有效的寻找全局最优解的算法。拟制配方过程中若以相同的置信水平来满足养分在饲粮中的含量时,SP模型比LPMS模型有着更好的准确性和更低的饲粮成本。利用SP模型可针对饲粮中养分的含量分布加以优化,并且为饲料产品质量的持续稳定性提供可靠的保障。     

Reducing phosphorus concentration in pig diets by adding an environmental objective to the traditional feed formulation algorithm

A multi-objective optimization method based on the traditional least-cost formulation program was developed to reduce both feed cost and total phosphorus (P) content in pig feeds. The objective function of the proposed method comprises a traditional economic term and a term that assigns a cost (β) to the excess and unavailable P (EUP) in the diet, the latter estimated by the difference between P requirements and available P supplied by the diet. To evaluate this method, feeds for growing (20–65 kg live weight) and finishing pigs (65–105 kg) formulated with two balanced protein levels (90 and 130 g/kg) and two available phosphorus levels (3.2 and 2.6 g/kg) were evaluated in two economic contexts (France and Quebec) over a 12-month period (June 2002–May 2003). Microbial phytase was added to the feeds at rates of 0, 250, 500 and 750 phytase units. All feed formulas contained the required available P and other nutrients. The increase in β reduced the total P and EUP in feed formulas. During the period studied, EUP decreased by 5% or more for an increase in feed cost of about 1.5% in France and 1% in Quebec. For some months however, the economically optimal solution was close to a solution that produces substantially less EUP at slightly higher cost. For example, in nearly half of the months, a reduction of 10% or more was achieved in Quebec for the same 1% increase in ingredient cost. The reduction in EUP with increasing β occurred independently of the addition of microbial phytase. The combined effect of microbial phytase incorporation and the proposed feed formulation method on EUP reduction is almost additive. Thus, the combined use of these two techniques can promote the sustainability of the swine industry by contributing to the reduction of P excretion in swine operations with small increases in feeding cost. The proposed method can be applied to minerals other than P or to other livestock production systems in which mineral excretion can be estimated from feed composition.     

Feed preference in pigs: effect of selected protein, fat, and fiber sources at different inclusion rates

Three double-choice feeding experiments were conducted to study the effect of different feedstuffs on feed preference in pigs. Fifteen protein sources, 6 fat sources, and 3 fiber sources were evaluated in Exp. 1, 2, and 3, respectively. Pigs were offered a series of double choices between a common reference diet and the diet with the ingredient under evaluation. The reference diet contained a soybean meal product with 56% CP (SBM-56), sunflower oil, and wheat bran, which were considered as the feedstuffs of reference for the protein, fat, and fiber sources, respectively. Preference, expressed as percentage of the tested diet to total feed intake, was affected by feedstuff nature and by its inclusion rate. In Exp. 1, feeds with fish meal at 50 and 100 g·kg?1, dried porcine hydrolyzed protein at 50 g·kg?1, and lupine, soybean meal with 44% CP, and dried skim milk at 100 g·kg?1 were preferred (P < 0.05) to the reference feed with SBM-56. On the contrary, relative to SBM-56, an avoidance (preference less than 50%) was observed for potato protein at all inclusion rates tested, rapeseed meal and acid milk whey at 100 and 200 g·kg?1, and dried porcine hydrolyzed protein, soybean protein concentrate, wheat gluten, and sunflower meal at 200 g·kg(-1). The storage of dried skim milk, soybean protein concentrate, and potato protein for 10 mo resulted in a reduction (P < 0.001) of their preference values. In Exp. 2, the feed with palm oil (at 30 g·kg?1) was preferred (P < 0.05), whereas feeds with linseed oil (at 30 and 100 g·kg?1) and soybean oil (at 100 g·kg?1) were avoided (P < 0.05) when contrasted with the reference feed with sunflower oil. Finally, in Exp. 3 diets with dehydrated alfalfa and sugar beet pulp at 130 g·kg?1 had a reduced (P < 0.05) preference compared with the reference diet with wheat bran. It is concluded that feedstuff nature, inclusion rate, and freshness affect feed preference in pigs. Feedstuff preferences should be taken into account during diet formulation, particularly at critical stages such as immediately after weaning.     

Evaluating critical factors to the economic feasibility of semi-intensive pig rearing in western Kenya

The purpose of this research is to assess how season, ADG, opportunity costs of farm-grown feeds, pig weight, and butcher price variation impact the economic potential of semi-intensive pig rearing. We developed a unique algorithm that emulates least-cost pig feeding and used it to assess the impact of the aforementioned factors on farmers’ maximum revenue and profit potential when pigs are sold to local butchers in western Kenya. When considered as independent factors influencing feed costs to grow a pig to a market weight of 30 kg, variation in ADG, opportunity cost of feed, and weaning season resulted in feed cost differences of up to 982, 947, and 379 Kenyan shillings (KES), respectively. The variation in revenues attributable to butcher or butcher negotiation and seasonal variance of butcher prices for a 30 kg pig was 744 and 225 KES, respectively. Feed items most commonly chosen for least-cost feed rations were small dried fish, cooked ground maize, whole maize, millet, cassava foliage, sweet potato vines, bone meal, avocado, and mango. Smallholder farmers who can feed pigs to reach higher ADG have lower opportunity costs of feeds and/or who effectively bargain with butchers can benefit from semi-intensive pig rearing. Farmers without access to at least some zero-cost feeds and farmers with opportunity costs of feeds exceeding 50 % of the market price will not earn positive returns from semi-intensive pig rearing.     

蛋氨酸形式和饲粮蛋白质水平对黄羽肉鸡生产性能的影响

选用1日龄快长型岭南黄羽肉鸡公雏1500只,随机分为5个处理,每处理6个重复,每重复50只鸡,分别饲喂以下5种饲粮:正常蛋白质加Alimet饲粮(处理1)、正常蛋白质加DLM饲粮(处理2)、低蛋白质(比正常水平降低约1.5个百分点)加Alimet饲粮(处理3)、低蛋白质加DLM组饲粮(处理4)、正常蛋白质未加蛋氨酸饲粮(处理5)。结果表明,在等摩尔量有效成分添加基础上,Alimet比DLM更有利于提高黄羽肉鸡生长性能,降低饲料成本和死亡率;饲粮蛋白质水平和蛋氨酸形式对43～63日龄和0～63日龄黄羽肉鸡生长性能的影响存在互作效应,表现为在正常蛋白质水平时添加Alimet对黄羽肉鸡生长性能的改善效果优于DLM,且更有利于降低饲料成本,而在低蛋白质水平时添加Alimet和DLM则无显著差异;在本试验条件下,降低饲粮蛋白质水平会对黄羽肉鸡的生长性能、饲料成本和成活率产生不利影响。     

Response to Varying Dietary Energy and Protein With or Without Enzyme Supplementation on Growth and Performance of Leghorns: Growing Period

Bovans White Leghorn pullets were utilized to evaluate the use of an enzyme cocktail from 0 to 126 d of age. Dietary treatments varied in CP, ME, and enzyme (EZ) supplementation. Feed intake, BW gain, and feed conversion ratio data were gathered in addition to determining nutrient retention and digestibility during the trial. Cumulatively, feed consumption was decreased by EZ supplementation when added to a required ME diet. Body weight gains were similar across dietary treatments; however, cumulative feed conversion ratio was significantly improved with EZ supplementation. Interactions regarding nutrient retention and digestibility were numerous. Similar responses were noted for energy and protein retention values during the trial with changes in response to dietary treatments as the pullets aged. Compared with feeding an industry applicable diet (required ME/CP without EZ − $0.27/lb gain), all dietary treatments reduced production costs with significant reductions when reducing CP. Lowest feed cost ($)/lb gain and percent excreta N was feeding pullets a diet with reduced ME and CP supplemented with EZ ($0.262/lb gain; 5.19% N). Possible further reductions in ME or dietary CP, or both, with EZ supplementation may prove to be even more economical and environmentally friendly.     

饲料样品粗蛋白质测定过程中应注意的几个问题

粗蛋白质测定是饲料分析教学、配合饲料生产的一个重要实验.饲料样品粗蛋白质含量的高低,是评定饲料营养价值的重要指标之一,决定着配合饲料及饲料原料的成本和价值.在饲料样品粗蛋白质测定过程中称样、消化、转移、蒸馏、滴定等环节应特别注意的几个问题,是作者多年从事饲料分析工作的实践体会,每一步都关系到粗蛋白质测定结果的正确与否,直接影响饲料的质量和生产成本.     

“杜湖”商品瘦肉猪蛋白质适宜营养水平的研究

本研究通过四次共620头猪的饲养试验,一次消化试验和144头猪的屠宰测定,就蛋白质营养水平问题,对杜湖猪<杜洛克×湖北白猪杂交一代>肥育性状和胴体性状的影响进行了研究。试验在等能量水平下,CP以2％的梯度、育肥前期由10.5％递增至18.7％,育肥后期由10.5％递增至16.8％。结果表明,饲养杜湖猪适宜蛋白质水平为:前期CP14.5％(含赖氨酸0.7％),能蛋比26.7:1;后期CPl2.5％(含赖氨酸0.54％),能蛋比32:1。     

Evaluation of mobile nylon bag technique for determining apparent ileal digestibilities of protein and amino acids in growing pigs

The mobile nylon bag technique (MNBT) may offer a simple, rapid means for assessing ileal AA digestibility of pig feed ingredients. In the present study, the effects of washing bags recovered from digesta, the amount and fineness of feeds, and feed trypsin inhibitor activity on apparent ileal digestibilities (AID) of CP and AA were determined with the MNBT. Twenty-four ileorectal anastomosed pigs (Yorkshire x Chinese Black barrows, 30 kg initial BW), of which 12 were fitted with duodenal T-cannulas, were used. Not washing the bags recovered from ileal digesta resulted in a reduction (P < 0.05) in apparent ileal digestibilities of CP and AA determined by MNBT. Washing the bags for more than 4 min overestimated (P < 0.05) the apparent ileal digestibilities of CP and AA compared with those determined with the anastomosed pigs. Sample size and fineness of grinding also affected (P < 0.05) apparent ileal digestibilities of CP determined by MNBT. The apparent ileal digestibilities of CP determined by MNBT were reduced (P < 0.05) when sample size exceeded 0.75 g and when feed was ground through screens with a mesh size of more than 1.0 mm. The closest agreement between results obtained by MNBT and a conventional ileal digestibility assay occurred when 0.75 g of feed ground through a 1.0-mm mesh screen was used per bag and bags were washed for 2 min after retrieval from digesta. Further studies are warranted to investigate the use of the mobile nylon bag technique for predicting the ileal digestibilty of AA for feeds containing antinutritional factors.     

应用近红外技术快速测定饲料原料氨基酸含量

本文对近红外(Near-InfraredReflectanceSpectroscopy,简称NIRS)技术测定饲料原料氨基酸含量的方法、测定结果的准确性及其在饲料生产中的应用、存在的问题与对策进行了简单的概述。结果表明,NIRS技术测定饲料原料氨基酸含量,具有快速、准确、成本低的特点。饲料厂可以利用NIRS技术对主要饲料原料氨基酸含量进行在线监测,调整配方和采购策略,降低生产成本,提高产品质量。     

Development of an in vitro incubation technique for the estimation of the utilizable crude protein (uCP) in feeds for cattle.

An in vitro incubation technique based on the first stage of the in vitro digestion technique published by Tilley and Terry (1963) was developed to estimate the utilizable crude protein (uCP) of single feeds and feed mixtures as non ammonia-N after 24 h of incubation. The results of 25 feed samples showed that there was a significant relationship between the uCP values calculated by regression based on in vivo data sets (Y, CP [g.kg-1 DM]) and those measured by the in vitro incubation technique (X, CP [g.kg-1 DM], 24 h incubation): y = 0.85x + 18.0, r2 = 0.84, P < or = 0.001. It was concluded that it can be possible to determine the uCP value of single feeds or feed mixtures by this in vitro incubation technique and to estimate the uCP value of feeds by this regression equation.     

利用EXCEL进行猪饲料配方

本文主要介绍了如何利用 Microsoft Office 软件中的 Excel 进行"规划求解"配方设计,分析了养分项目及资源的影子价格对饲料成本的影响,并以猪饲料配方为例进行详尽的演示。从中可以看出,利用 Excel 进行线性规划设计饲料配方,具有灵活、简便、快捷、直观等特点,既可节省购买配方软件的资金,又能直观地完成最低成本配方的任务。     

Ruminal protein degradation and protein value of feeds

The relationship between dry matter (DM) degradation and crude protein (CP) degradation in the dairy cow's rumen was determined with a view to defining the protein value of feeds for ruminants. The nylon bag technique was applied for these studies. For all the feeds investigate (green fodder and preserves from cocks-foot, ryegrass, alfalfa/grass and meadow grass, as well as alfalfa, extracted soybean meal) a significantly positive relationship was found to exist between the levels of DM and CP degradation (r = 0.73 to 1.0). The regression coefficient b1 (CP degradation as regressor) was found to average 0.87. The positive relationship between DM degradation and CP degradation implies that microbial protein amount and unfermented feed protein at the duodenum are negatively correlated. Model calculations show that, on account of the compensation between microbial protein and feed protein at the duodenum, in feeds with a CP concentration below 200 g/kg DM, the extent of ruminal protein degradation does not exert a marked influence on duodenal protein passage. The partial calculation of the duodenal protein supply on the basis of undegraded feed protein and microbial protein, as practiced in the new models of protein evaluation, leads to systematic errors unless the relationship between DM degradation and CP degradation is considered.     

Effect of Dietary Mannan Oligosaccharide from Bio-Mos or SAF-Mannan on Live Performance of Broiler Chickens

A 42-d broiler pen trial was conducted to evaluate the effects of dietary mannan oligosaccharide (MOS) from either of 2 commercial products, Bio-Mos (Alltech Inc., Nicholasville, KY) or SAF-Mannan (S. I. LeSaffre, Cedex, France) each at 2 levels of inclusion on live performance. The MOS, derived from the outer portion of yeast cell walls, is reported to have several beneficial modes of action including 1) pathogen adsorption (agglutination); 2) improved intestinal integrity (e.g., villi height); and 3) immune modulation. Diets were fed in 3 phases, and treatments included a control, 2 Bio-Mos treatments (1.0 kg/ton in starter and 0 or 0.5 kg/ton in grower and finisher feeds), and 2 SAF-Mannan treatments (0.5 kg/ton in starter and 0 or 0.5 kg/ton in grower and finisher feeds), according to the manufacturers’ recommendations. Birds fed Bio-Mos at 1.0/0.5/0.5 (starter/grower/finisher) kg/ton diets had significantly greater BW at 42 d than birds fed control or SAF-Mannan-supplemented diets, whereas results for the Bio-Mos 1.0/0/0 kg/ton diets were intermediate. Supplementation of diets with Bio-Mos at 1.0/0.5/0.5 kg/ton may improve broiler BW at market ages compared with the unsupplemented diets. Feed consumption was lower from 0 to 21 d in the SAF-Mannan treatments compared with other treatments. No significant differences were found for feed conversion or mortality for any of the treatments. Overall, Bio-Mos had a greater effect on bird BW compared with the other variables measured.     

基于目标规划的马饲料配方研究

中国马业正处在由传统向现代转型的初级阶段,科学的饲料配方对现代马业发展具有重要意义。作者通过对马每日的营养需求和饲料配方模型要素的分析和研究,构建了基于目标规划的马饲料配方模型。该配方模型对马需要的各项营养物质,包括干物质、消化能、粗蛋白质、钙、磷等进行优化,保证马每日对营养物质的数量、质量及其相互比例的需要,同时兼顾饲料成本;作者以速度赛用马和休闲骑乘马两种类型马为例说明基于不同饲养标准的马饲料配方的设计过程,进一步验证了该饲料配方模型的有效性。本研究对马饲料配方模型的研究具有一定的参考价值。     

Evaluation of Nutritive Value of Unconventional Feed in Anhui Province and the Surrounding Areas Using CNCPS

This study was conducted to evaluate the nutritive value of unconventional feed in Anhui province and the surrounding areas using Cornell net carbohydrate and protein system (CNCPS).Total 21 unconventional feeds were collected from different sites in Anhui (Hefei, Lu'an, Anqing, Tongling, Bozhou and Suzhou citys), Henan (Xinyang city), Heilongjiang province as well as Gansu province, and the carbohydrate and the protein ingredients of feeds were calculated respectively using the provided formula in CNCPS.The results showed that, SCP/CP of peanut stalk from Suzhou was the highest (55.92%) and that of wheat stalk from Hefei was the lowest (6.85%); Rape stalk from Hefei had the highest value of ADL (23.16%) while straw from Hefei had the lowest value (4.14%).As to the true protein, shoot shell from Hefei was in the highest level (99.83%), while wheat stalk from Suzhou had the lowest value (44.96%); In terms of unavailable fiber content, oray from Suzhou was the highest (47.94%), and takenoko pocket from Hefei was the lowest (10.74%).The experimental results showed that the CNCPS could comprehensively evaluate the nutritive value of unconventional feed and reflecte the pros and cons of unconventional feed in Anhui province and the surrounding areas.It was suggested that the method of CNCPS could be used in the evaluation of feedstuff in Anhui province.     

Study on the Horse Feed Formulation Based on Goal Programming

Chinese horse industry is in the early stage of transition from traditional horse industry to modern horse industry. Scientific feed formula is of great practical significance to the development of modern horse industry. In this paper, the horse feed formula model based on the goal programming was constructed by analyzing and researching the horse's daily nutrition demand and the component elements of feed formula model. The formula optimized the horse's various nutrients, including dry matter, digestible energy, crude protein, calcium and phosphorus, ensured that the number of nutrients, quality and the proportion of their daily needs, and took into account the cost of feed also. Two different types of horses, race horse and riding horse were used to describe the design process for horse feed formulations based on different feed standards, and the effectiveness of the feed formula model was verified at the same time. The study would provide some reference value for the study of horse feed formula model.     

用CNCPS体系评定安徽及其周边地区非常规饲料的营养价值

试验旨在评定安徽及其周边地区非常规饲料的营养价值,应用康奈尔净碳水化合物—蛋白质体系(CNCPS)提出的碳水化合物和蛋白质分类方法,对安徽省的合肥市、六安市、安庆市、铜陵市、亳州市、宿州市和河南省信阳市及甘肃省、黑龙江两省采集的21个非常规饲料样品进行常规营养成分分析,并通过CNCPS方法计算出饲料碳水化合物和蛋白质组分。结果显示,宿州花生桔秆可溶性蛋白占粗蛋白质(SCP/CP)比例最高(55.92%),合肥麦秸最低(6.85%);合肥油菜秸秆木质素(ADL)最高(23.16%),合肥稻草ADL最低(4.14%)。蛋白质中真蛋白的含量以合肥笋壳最高(99.83%),以宿州麦秸最低(44.96%);碳水化合物中不可利用纤维(CC)以宿州花生壳最高(47.94%),以合肥笋兜最低(10.74%)。结果表明,CNCPS体系较全面的评定了非常规饲料的营养特性,反映了非常规饲料的优劣程度,可作为安徽地区饲料营养价值评定方法。     

Necrotic enteritis: Applications for the poultry industry

Considering market demands concerning the decreased use of growth promoters and anticoccidial drugs in feed formulations, the poultry industry has been trying to reduce or eliminate the inclusion of subtherapeutic doses of antimicrobials into feed. Formulating diets not only to meet birds’ nutrient requirements for growth but also for gastrointestinal health parameters is increasingly important. Maintenance and enhancement of intestinal integrity is essential for bird performance when antimicrobials are not included in feed, as commercial poultry face numerous enteric pathogen challenges. Necrotic enteritis has reemerged as an important disease of poultry in recent years. The reduction in the use of antimicrobials in poultry feeds has been attributed as one of the main contributing factors for the increasing incidence of necrotic enteritis (NE) in commercial poultry. Mortality due to NE is extremely high (1% daily mortality), which results in great economic losses. Economic losses due to NE are not only associated with high mortality, but also associated with decreases in bird performance and FE, particularly in subclinical cases of NE. Birds that survive NE outbreaks usually have a reduced ability to digest and absorb nutrients due to extensive damage to the mucosal lining, which ultimately results in reduced profitability.