Net energy of corn,soybean meal and rapeseed meal in growing pigs

Background: Two experiments were conducted to estimate the net energy(NE) of corn, soybean meal, expel er-pressed rapeseed meal(EP-RSM) and solvent-extracted rapeseed meal(SE-RSM) using indirect calorimetry and to validate the NE of these four ingredients using pig growth performance.Methods: In Exp.1, 24 barrows(initial BW = 36.4 ± 1.6 kg) were allotted to 1 of 4 diets which included a corn basal diet,a corn-soybean meal basal diet and two rapeseed meal diets containing 20% EP-RSM(9.5% ether extract) or SE-RSM(1.1% ether extract) substituted for corn and soybean meal. The design allowed the calculation of NE values of corn,soybean meal and rapeseed meals according to the difference method. In Exp.2, 175 growing pigs(initial BW = 36.0± 5.2 kg) were fed 1 of 5 diets for 28 d, with five pigs per pen and seven replications(pens) per treatment in order to validate the measured energy values. Diets were a corn-soybean meal diet and four diets including 10% or 20% EP-RSM and 10% or 20% SE-RSM.Results: The NE of corn, soybean meal, EP-RSM and SE-RSM were 12.46, 11.34, 11.71 and 8.83 MJ/kg DM, respectively. The NE to ME ratio of corn(78%) was similar to tabular values, however, the NE to ME ratios of soybean meal(70%) and rapeseed meal(76%) were greater than tabular values. The greater NE value in EP-RSM than in SE-RSM is consistent with its higher EE content. Increasing EP-RSM or SE-RSM did not affect the growth performance of pigs and the caloric efficiency of NE was comparable for al diets.Conclusions: The NE of EP-RSM was similar to soybean meal, and both were greater than SE-RSM. The DE, ME and NE values measured in Exp.1 are confirmed by results of Exp. 2 with comparable caloric efficiencies of DE, ME or NE for all diets.

猪理想蛋白质理念及应用

了解猪对氨基酸的需求和猪对饲料中添加氨基酸的反应,对于设计饲料配方非常重要。氨基酸的需求量很大程度上是由蛋白质在体内的最大沉积决定的,对于哺乳母猪来说,还和乳汁的分泌量和乳中蛋白质的含量有关。氨基酸需要可以用剂量反应来测定,但研究方案、判断标准的选择、统计模型均会影响氨基酸需要的评估。本文从理想蛋白质入手,重点介绍了使用正确的通用方式表述动物的氨基酸需要量和饲料氨基酸的价值,以及评估氨基酸需要和理想蛋白质模型的实验室方法。

Integrative analysis of indirect calorimetry and metabolomics profiling reveals alterations in energy metabolism between fed and fasted pigs

Background: Fasting is a simple metabolic strategy that is used to estimate the maintenance energy requirement where the energy supply for basic physiological functions is provided by the mobilization of body reserves.However, the underlying metabolic components of maintenance energy expenditure are not clear. This study investigated the differences in heat production(HP), respiratory quotient(RQ) and plasma metabolites in pigs in the fed and fasted state, using the techniques of indirect calorimetry and metabolomics.Methods: Nine barrows(45.2 ± 1.7 kg BW) were fed corn-soybean based meal diets and were kept in metabolism crates for a period of 14 d. After 7 d adaptation, pigs were transferred to respiratory chambers to determine HP and RQ based on indirect calorimetry. Pigs were fed the diet at 2,400 k J ME/(kg BW0.6·d) during d 8 to 12. The last 2 d were divided into 24 h fasting and 48 h fasting treatment, respectively. Plasma samples of each pig were collected from the anterior vena cava during the last 3 d(1 d while pigs were fed and 2 d during which they were fasted).The metabolites of plasma were determined by high-resolution mass spectrometry using a metabolomics approach.Results: Indirect calorimetry analysis revealed that HP and RQ were no significant difference between 24 h fasting and 48 h fasting, which were lower than those of fed state(P < 0.01). The nitrogen concentration of urine tended to decrease with fasting(P = 0.054). Metabolomics analysis between the fed and fasted state revealed differences in15 compounds, most of which were not significantly different between 24 h fasting and 48 h fasting. Identified compounds were enriched in metabolic pathways related to linoleic acid metabolism, amino acid metabolism,sphingolipid metabolism, and pantothenate and Co A biosynthesis.Conclusion: These results suggest that the decreases in HP and RQ of growing pigs under fasting conditions were associated with the alterations of linoleic acid metabolism and amino acid metabolism. The integrative analysis also revealed that growing pigs under a 24-h fasting were more appropriate than a 48-h fasting to investigate the metabolic components of maintenance energy expenditure.

InraPorc模型和NRC模型中猪的氨基酸需要量

某种程度上,研究理想蛋白质模型的方法应该是一种动态的方式。本文比较了Inra Porc模型和NRC模型在猪不同生长阶段的氨基酸需要量;阐述了配制日粮配方是根据需要量或是生长性能以及选择何种模型需要使用者去更好地判断。

以遗传潜力推算最佳生长及经济效益的生猪饲料配方及自动化饲喂计划

饲养策略是针对整个猪群,这必然会导致自然资源的低效利用,甚至可能会扩大猪在屠宰时的个体差异。通过管理猪群均匀度做到精准饲喂有助于提高动物生产系统的效率。这个解决办法依赖于对营养供给与动物生产性能之间的精准预测、生产性能的持续监测和调节营养供给的饲喂系统。

Interaction between Live Yeast and Dietary Rumen Degradable Protein Level: Effects on Diet Utilization in Early-Lactating Dairy Cows

Four early lactating Holstein cows were used to study the effect of live yeast (LY, Actisaf&reg;CNCM I-4407, Lesaffre Feed Additives, Marcq en Baroeul, France) supplementation on diet digestive utilization of dairy cows receiving concentrated corn silage-based diets with two rumen-degradable protein (RDP) levels. For a 33 d period, cows were fed a total mixed ration (TMR) containing an adequate level (AL) of RDP or a low level (LL, 30% below AL) by using soybean meal or tanned soybean meal, respectively: for 21 d with no LY addition followed by 12 d during which LY was added to the diet. The pH and redox potential (Eh) were recorded and ruminal fluid samples were collected over 3 consecutive days. Feces were collected individually over 48 h and individual dry matter intake (DMI) was measured for determining apparent nutrient digestibility. The effective degradability of individual feed ingredients composing both diets was evaluated with nylon bags technique. Structure of the ruminal bacterial community was studied and diversity index was calculated. Digestibility of organic matter (OM) and crude protein (CP) were lower for LL than those for AL. With LY, digestibility of OM and CP was increased: +2.4 and +0.8 points, for AL, and +3.7 and +5.9 points for LL, respectively. Live yeast reduced dietary N ruminal degradation with both AL and LL. Ruminal pH and Eh were lower with AL compared to LL: 5.95 and –167 mV vs. 6.13 and –144 mV. Live yeast increased ruminal total volatile fatty acids (VFA) (+8.6%), C2 (+10%), and C4 (+35%) contents for LL and decreased that of C3 (?9.8%) for AL. Neither the structure of bacterial populations of the rumen nor the diversity index (Shannon) was altered by treatments. Those results suggested a specific interest in using LY in RDP deficient diets for early lactating cows.

Proteomic analysis of adipose tissue during the last weeks of gestation in pure and crossbred Large White or Meishan fetuses gestated by sows of either breed

Background: The degree of adipose tissue development at birth may influence neonatal survival and subsequent health outcomes. Despite their lower birth weights, piglets from Meishan sows(a fat breed with excellent maternal ability) have a higher survival rate than piglets from Large White sows(a lean breed). To identify the main pathways involved in subcutaneous adipose tissue maturation during the last month of gestation, we compared the proteome and the expression levels of some genes at d 90 and d 110 of gestation in purebred and crossbred Large White or Meishan fetuses gestated by sows of either breed.Results: A total of 52 proteins in fetal subcutaneous adipose tissue were identified as differential y expressed over the course of gestation. Many proteins involved in energy metabolism were more abundant, whereas some proteins participating in cytoskeleton organization were reduced in abundance on d 110 compared with d 90. Irrespective of age,24 proteins differed in abundance between fetal genotypes, and an interaction effect between fetal age and genotype was observed for 13 proteins. The abundance levels of proteins known to be responsive to nutrient levels such as aldolase and fatty acid binding proteins, as wel as the expression levels of FASN, a key lipogenic enzyme, and MLXIPL, a pivotal transcriptional mediator of glucose-related stimulation of lipogenic genes, were elevated in the adipose tissue of pure and crossbred fetuses from Meishan sows. These data suggested that the adipose tissue of these fetuses had superior metabolic functionality, whatever their paternal genes. Conversely, proteins participating in redox homeostasis and apoptotic cel clearance had a lower abundance in Meishan than in Large White fetuses. Time-course differences in adipose tissue protein abundance were revealed between fetal genotypes for a few secreted proteins participating in responses to organic substances, such as alpha-2-HS-glycoprotein, transferrin and albumin.Conclusions: These results underline the importance of not only fetal age but also maternal intrauterine environment in the regulation of several proteins in subcutaneous adipose tissue. These proteins may be used to estimate the maturity grade of piglet neonates.

Oat bran and wheat bran impact net energy by shaping microbial communities and fermentation products in pigs fed diets with or without xylanase

Background: Dietary fiber can be fermented in gut of pigs and the end products of fermentation were short-chain fatty acids(SCFA). The SCFA had positive effects on gut bacteria and host immune system. In addition, SCFA can provide a part of available energy for pigs. However, there were limited reports on the relationship between dietary fiber, gut bacteria, and energy metabolism. Therefore, this study investigated how dietary fiber and enzyme addition impacted energy metabolism by acting on the microbial community and SCFA.Methods: Wheat bran(WB) was added to the corn-soybean meal-based diet at the levels of 12% and 27%, and oat bran(OB) at 15% and 36%. One of each diet was supplemented with or without 5000 U/kg feed of xylanase, so a total of 10 diets were allotted to 60 growing pigs(initial body weight: 27.2 ± 1.2 kg) using a randomized complete block design. The experiment was conducted in 10 consecutive periods using 6 similar open-circuit respiration chambers. Each pig was used for one 20-day period. During each period, six pigs were allowed 14 d to adapt to the diets in metabolic cages followed by 6 d(from d 15 to d 20) in respiration chambers to measure heat production(HP).Results: Pigs fed 36% OB diets had greater(P < 0.05) nutrient digestibility and net energy(NE) values compared to those fed 27% WB diets. Apparent digestibility coefficients of dry matter(DM) and crude protein(CP) were lower(P < 0.05) in pigs fed 27% WB diets compared with those fed 12% WB diets. Enzyme addition improved(P < 0.05)the NE values(11.37 vs. 12.43 MJ/kg DM) in diets with 27% WB. Supplementation of xylanase did not affect NE values for basal diets, OB diets and 12%WB diets. Compared with diets with 36% OB, pigs fed 27% WB-based diets excreted more total SCFA, acetate and propionate(expressed as g/kg feed DM) in fecal samples of pigs(P < 0.05).Pigs in the WB diets had greater proportion of phylum Bacteroidetes while phylum Firmicutes were greater in pigs fed OB diets(P < 0.05). Pigs fed WB diets had greater(P < 0.05) abundance of Succinivibrio and Prevotella, which were associated with fiber degradation and SCFA production.Conclusion: Our results indicated diets supplied by high level of OB or WB promote the growth of fiber-degrading bacteria. The differences in fiber composition between WB and OB led to differences in nutrient digestibility and bacterial communities, which were ultimately reflected in energy metabolism. Enzyme supplementation improved nutrient digestibility as well as NE values for 27% WB diets but not for other diets, which indicated that effects of enzyme were related to type and level of dietary fiber in diets.

Corrigendum to“Methodologies for energy evaluation of pig and poultry feeds:A review”[Animal Nutrition volume 8(2022),185-203]

The authors have realized that an error repeated 4 times in this paper.The corrected version should be the following.

Methodologies for energy evaluation of pig and poultry feeds:A review

The cost of feed represents an important part of the total cost in swine and poultry production(>60%)with energy accounting for at least 70%of feed cost.The energy value of ingredients or compound feeds can be estimated as digestible(DE),metabolisable(ME)and net energy(NE)in pigs and ME and NE in poultry.The current paper reviews the different methods for evaluating DE,ME and NE of feeds for monogastric animals and their difficulties and limits,with a focus on NE.In pigs and poultry,energy digestibility depends on the chemical characteristics of the feed,but also on technology(pelleting,for instance)and animal factors such as their health and body weight.The ME value includes the energy losses in urine that are directly dependent on the proportion of dietary N excreted in urine resulting in the concept of ME adjusted for a zero N balance(MEn)in poultry.For poultry,the concept of true ME(TME,TMEn),which excludes the endogenous fecal and urinary energy losses from the excreta energy,was also developed.The measurement of dietary NE is more complex,and NE values of a given feed depend on the animal and environmental factors and also measurement and calculation methods.The combination of NE values of diets obtained under standardised conditions allows calculating NE prediction equations that are applicable to both ingredients and compound feeds.The abundance of energy concepts,especially for poultry,and the numerous feed and animal factors of variation related to energy digestibility or ME utilisation for NE suggest that attention must be paid to the experimental conditions for evaluating DE,ME or NE content.This also suggests the necessity of standardisations,one of them being,as implemented in pigs,an adjustment of ME values in poultry for an N retention representative of modern production conditions(MEs).In conclusion,this review illustrates that,in addition to numerous technical difficulties for evaluating energy in pigs and poultry,the absolute energy values depend on feed and animal factors,the environment,and the methods and concepts.Finally,as implemented in pigs,the use of NE values should be the objective of a more reliable energy system for poultry feeds.