Prediction of the energy value of cattle diets based on the chemical composition of the feeds under tropical conditions

doi:10.1016/j.anifeedsci.2007.05.008

Animal Feed Science and Technology

Volume 143, Issues 1–4, 22 May 2008, Pages 127-147

https://doi.org/10.1016/j.anifeedsci.2007.05.008 Get rights and content

Abstract

Determination of the energetic contribution of different chemical components of cattle diets based on the content of total digestible nutrients (TDN) has been suggested by several authors and was adopted by the NRC [National Research Council (NRC), 2001. Nutrient Requirements of Dairy Cattle, seventh ed. Academic Press, Washington]. The main objective of that proposal is to overcome the high costs and the extended time of traditional in vivo digestion assays. Although theoretically based, the summative system adopted by the NRC [National Research Council (NRC), 2001. Nutrient Requirements of Dairy Cattle, seventh ed. Academic Press, Washington] has been shown to be inaccurate in predicting the TDN content of individual feeds or diets under tropical conditions. Therefore, a new model, that also uses a summative approach, was developed but it was based on data obtained in the tropics. The new model consists of equations that predict the digestible fractions of ether extract (n = 108), crude protein (n = 93), non-fibrous carbohydrates (n = 84), and neutral detergent fibre (n = 164). Non-fibrous components were evaluated by the Lucas [Lucas, H.L., 1960. Relations Between Apparent Digestibility and the Composition of Feed and Feces. 1: A Quantitative Theory. North Caroline State College, Raleigh] test to obtain true digestibility coefficients, and by the factorial system to distinguish between truly digested and metabolic fractions. Fibre components were evaluated using an adaptation of the surface law to obtain the indigestible fraction and a meta-analysis approach to obtain digestibility coefficients of the potentially digestible fraction. The estimates obtained with the new model were validated and compared to those produced with the model adopted by the NRC [National Research Council (NRC), 2001. Nutrient Requirements of Dairy Cattle, seventh ed. Academic Press, Washington] for cattle managed under tropical conditions. Data from four trials, two with lactating cows (n = 63) and two with growing and finishing cattle (n = 44) were used. The estimates produced with the two models were compared based on the decomposition of the mean square prediction error. It can be concluded that the new model was more accurate in predicting TDN values than the NRC [National Research Council (NRC), 2001. Nutrient Requirements of Dairy Cattle, seventh ed. Academic Press, Washington] model under tropical conditions.

Introduction

The calculation of digestibility estimates is a basic aspect of the quantification of the energy value of feeds or diets, which permits the adequate balance of diets to meet the requirements for animal maintenance and production. The estimation of the energy content of different feeds or diets offered to cattle based on their chemical composition has been suggested by several investigators (Conrad et al., 1984, Weiss et al., 1992, Van Soest, 1994). The main objective of that proposal is to overcome the high costs and extended time of traditional in vivo digestion assays (Detmann et al., 2006a).

On the basis of this approach, the National Research Council (NRC, 2001) adopted a method for the estimation of the total digestible nutrients (TDN) content of feeds, which consists of a system of summative equations. In this system, each group of chemical components (ether extract—EE, crude protein—CP, non-fibrous carbohydrates—NFC, and neutral detergent fibre—NDF) is included in a submodel to obtain estimates of the truly digested fractions, with subsequent correction for the level of feed intake and, when necessary, for metabolic faecal losses. However, although theoretically based (Conrad et al., 1984, Weiss et al., 1992), the summative system adopted by the NRC (2001) has been shown to be inaccurate in predicting the TDN content of feeds or diets under tropical conditions (Rocha et al., 2003, Campos, 2004, Detmann et al., 2004a, Oliveira, 2005).

Recently, four submodels aimed at the prediction of the apparently digestible fractions of CP, EE, NFC and NDF have been developed and validated under tropical conditions (Detmann et al., 2004a, Detmann et al., 2006a, Detmann et al., 2006b, Detmann et al., 2006c, Detmann et al., 2007). Joining these submodels could provide a new summative system that could be able to accurately predict TDN content, generating an alternative to the model adopted by the NRC (2001) that can be applied to feeds or diets offered to cattle in the tropics.

In this context, the objective of the present study was to compare the efficiency of prediction of the apparently digestible fractions of CP, EE, NFC and NDF, and to validate the estimates of dietary TDN content obtained with the NRC (2001) model and with the new summative system developed under tropical conditions.

Section snippets

Description of the new model: submodels for non-fibrous components

The submodels applied to non-fibrous components (EE, CP, and NFC) were developed based on the Lucas test (Lucas and Smart, 1959) to obtain true digestibility coefficients and on the factorial system (Blaxter and Mitchell, 1948, Lucas, 1960) to distinguish between metabolic faecal fractions and truly undigested fractions.

Using these approaches, the apparently undigested faecal mass of the different non-fibrous components (EE, CP or NFC) can be summarized as: $F = U + M + E$ where F is the faecal mass

Results

The relationship between observed values and those predicted by the new submodels for the different apparently digestible fractions are shown in Fig. 1.

Comparison between the digestible fractions predicted by the two models revealed lower MSPEs associated with the new submodels for all components analysed (Table 3). The estimates for apparently digestible EE obtained with the submodel of Weiss et al. (1992) presented a high MPE compared to those obtained with the new submodel as indicated by a

Discussion

The main difference observed between the submodels applied to the prediction of apparently digestible EE is how the truly digestible fraction of EE was obtained. For the submodel of Weiss et al. (1992) and NRC (2001) (Eqs. (17a), (17b)), the mean non-fatty acid EE content in ruminant diets is approximately 10 g/kg DM (Weiss et al., 1992). This value permits the estimation of dietary fatty acid content by simple subtraction of a constant, also assuming that the true digestibility of dietary fatty

Conclusions

The new submodels proposed here provide more accurate and precise estimates of the digestible fractions of EE, CP, NFC, and NDF compared to those provided by Weiss et al. (1992) and NRC (2001) submodels. The summative system originated from the new submodels permits a more accurate estimation of the TDN content of diets offered to cattle under tropical conditions.

Acknowledgement

The authors wish to thank the Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico (CNPq) for financial support.

References (41)

M.S. Allen
Effects of diet on short-term regulation of feed intake by lactating dairy cattle
J. Dairy Sci.
(2000)
J.I. Arroquy et al.
Effect of types of non-fiber carbohydrates on in vitro forage fiber digestion of low-quality grass hay
Anim. Feed Sci. Technol.
(2005)
J.A. Arroyo-Aguilu et al.
Nutrient digestibility of lower-fiber rations ruminant animal
J. Dairy Sci.
(1972)
H.R. Conrad et al.
Estimating net energy lactation from components of cell solubles and cell walls
J. Dairy Sci.
(1984)
G. Licitra et al.
Standardization of procedures for nitrogen fractionation of ruminant feeds
Anim. Feed Sci. Technol.
(1996)
D.G. Mayer et al.
Regression of real-world data on model output: an appropriate overall test of validity
Agric. Syst.
(1994)
F.L. Mould et al.
Associative effects of mixed feeds. I: Effects of type and level of supplementation and the influence of the rumen pH on cellulolysis in vivo and dry matter digestion of various roughages
Anim. Feed Sci. Technol.
(1983)
R.A.M. Vieira et al.
Application of non-linear models in the description of in situ degradation profiles of the elephant grass (Pennisetum purpureum Schum., Mineiro variety)
Anim. Feed Sci. Technol.
(1997)
W.P. Weiss et al.
A therotically-based model for predicting total digestible nutrient values of forage and concentrates
Anim. Feed Sci. Technol.
(1992)
Association of Official Analytical Chemistry (AOAC)
Official Methods of Analysis
(1990)

K.L. Blaxter et al.

The factorization of the protein requirements of ruminants and of the protein values of feeds, with particular reference to the significance of metabolic fecal nitrogen

J. Anim. Sci.

(1948)

L.S. Cabral et al.

Protein fractions of tropical feeds and their digestion rates estimated by means of incubation with ruminal proteases

Braz. J. Anim. Sci.

(2000)

Campos, P.R.S.S., 2004. Estimativas do valor energético de alguns volumosos e da digestibilidade da fibra em detergente...

Chizzotti, M.L., 2004. Avaliação da casca de algodão para novilhos de origem leiteira e determinação da excreção de...

M.A.L. Costa et al.

Validation of NRC (2001) equations for estimation of energy value of feeds in Brazilian conditions

Braz. J. Anim. Sci.

(2005)

E. Detmann et al.

Validation of predictive equations for neutral detergent fiber indigestible fraction in tropical grasses

Braz. J. Anim. Sci.

(2004)

E. Detmann et al.

Evaluation of acid detergent insoluble protein as estimator of undegradable fraction of crude protein for tropical forages

E. Detmann et al.

Estimation of ether extract digestibility in diets of ruminants: a model under Brazilian conditions

Braz. J. Anim. Sci.

(2006)

E. Detmann et al.

Estimation of crude protein digestible fraction in cattle diets under Brazilian conditions

Braz. J. Anim. Sci

(2006)

E. Detmann et al.

Estimation of nonfiber carbohydrates digestibility in cattle using the Lucas Test approach under Brazilian conditions

Braz. J. Anim. Sci.

(2006)

Cited by (28)

Predicting enteric methane production from cattle in the tropics
2020, Animal
Citation Excerpt :
In addition, lower RSR values were observed when including GEd. This finding highlights the need to develop nutrition models that estimate energy value of diets with tropical feeds (Detmann et al., 2008; Valadares Filho et al., 2016). The best performance of GEN equations could be due to the wider range of predictor values when combining LAC with GCNL (Table 1), resulting in lower ER% and slope bias (Table 4; Figure 4).
Accurate estimates of methane (CH₄) production by cattle in different contexts are essential to developing mitigation strategies in different regions. We aimed to: (i) compile a database of CH₄ emissions from Brazilian cattle studies, (ii) evaluate prediction precision and accuracy of extant proposed equations for cattle and (iii) develop specialized equations for predicting CH₄ emissions from cattle in tropical conditions. Data of nutrient intake, diet composition and CH₄ emissions were compiled from in vivo studies using open-circuit respiratory chambers, SF₆ technique or the GreenFeed® system. A final dataset containing intake, diet composition, digestibility and CH₄ emissions (677 individual animal observations, 40 treatment means) obtained from 38 studies conducted in Brazil was used. The dataset was divided into three groups: all animals (GEN), lactating dairy cows (LAC) and growing cattle and non-lactating dairy cows (GCNL). A total of 54 prediction equations available in the literature were evaluated. A total of 96 multiple linear models were developed for predicting CH₄ production (MJ/day). The predictor variables were DM intake (DMI), gross energy (GE) intake, BW, DMI as proportion of BW, NDF concentration, ether extract (EE) concentration, dietary proportion of concentrate and GE digestibility. Model selection criteria were significance (P < 0.05) and variance inflation factor lower than three for all predictors. Each model performance was evaluated by leave-one-out cross-validation. The Intergovernmental Panel on Climate Change (2006) Tier 2 method performed better for GEN and GCNL than LAC and overpredicted CH₄ production for all datasets. Increasing complexity of the newly developed models resulted in greater performance. The GCNL had a greater number of equations with expanded possibilities to correct for diet characteristics such as EE and NDF concentrations and dietary proportion of concentrate. For the LAC dataset, equations based on intake and animal characteristics were developed. The equations developed in the present study can be useful for accurate and precise estimation of CH₄ emissions from cattle in tropical conditions. These equations could improve accuracy of greenhouse gas inventories for tropical countries. The results provide a better understanding of the dietary and animal characteristics that influence the production of enteric CH₄ in tropical production systems.
Biodegradation characteristics and nutrient availability of newly developed carinata seeds in comparison with canola seeds in dairy cattle
2018, Animal Feed Science and Technology
Citation Excerpt :
Regarding seed coat color effect, it is possible that other factors might be involved in the absence of difference between brown and yellow seeds for this trait. The estimation of the energy value of either feeds or diets allows the adequate balance of diets to meet the requirements for animal maintenance and production (Detmann et al., 2008). Bell (1993) observed that the presence of fibre could dilute the digestible nutrients in canola meal.
This study aimed to investigate physiochemical and nutritional characteristics of newly developed yellow and brown carinata seeds in comparison with newly developed yellow and brown canola seeds provided by Agriculture and Agri-Food Canada (Saskatchewan, Canada), and commercial canola seeds (COMM) accounting 4 new lines and 1 commercial line. Each line obtained from two different sources was used to determine dry matter (DM), crude protein (CP), ether extract (EE), NDF, ADF and non-fibre carbohydrate (NFC). The CNCPS was used to predict rumen degraded and undegraded organic matter (OM), CP and NDF, the in situ degradation and intestinal digestibility of the nutrients were determined in order to establish the nutritional values of carinata and canola seeds for dairy cattle. The results showed that CP and NPN contents were greater (P < 0.05), while EE, NDF, ADF and ADL were lower (P < 0.05) for carinata than canola seeds. Total glucosinolates were greater (P < 0.01) in carinata than canola seeds. The digestible energy at a production level (DE_p3x) and metabolizable energy at a production level (ME_p3x) were lower (P < 0.05) for carinata than canola seeds. Carinata showed greatest rumen undegraded protein (RUP) and effective degradability (ED) of OM and CP. Considering seed coat color, yellow carinata seed had higher EDCP (232 g/kg DM) than brown carinata (191 g/kg DM). Higher truly absorbed rumen-synthesised microbial protein in small intestine (AMCP) was obtained for carinata seeds, while truly absorbed rumen-undegraded feed protein in small intestine (ARUP) was similar between carinata and canola seeds, but lower for commercial canola. Metabolizable protein (MP) was greater for carinata (137 g/kg DM) than canola (125 g/kg DM) and commercial (116 g/kg DM) regardless seed coat color. Carinata seeds showed higher feed milk value (FMV) (2.8 kg milk/kg feed) than canola (new and commercial) seeds. There was no effect of seed coat color (P > 0.05) on ARUP, MP and FMV, but yellow seed showed greater EE content than brown seeds (P = 0.20). In conclusion, newly developed carinata seeds showed higher CP and glucosinolates, but lower EE and fibre contents comparing to canola (new and commercial) seeds. Carinata seeds could be considered as a ruminant feed due to higher CP, energy, digested protein supply, AMCP, MP and FMV.
Investigating the effects of sex of growing Nellore cattle and crude protein intake on the utilization of recycled N for microbial protein synthesis in the rumen by using intravenous <sup>15</sup>N<sup>15</sup>N-urea infusion
2017, Animal Feed Science and Technology
Citation Excerpt :
According to Dong et al. (2014), N intake can be used as the primary variable to predict N excretion quickly and routinely, although factors such as availability and synchronization between energy and N in the rumen can affect microbial protein synthesis and, consequently, N excretion (Valadares Filho et al., 2010). The TDN is an indirect method of quantifying the energy value of feedstuffs or the diet in order to meet requirements for the maintenance and production of animals (Detmann et al., 2008). Thus, the inclusion of the variable TDN intake in the equations to estimate N losses could help with the adjustment of the energy:N ratio when formulating diets.
The aim of this study was to investigate the effect of sex and levels of dietary crude protein (CP) on the recovery of ¹⁵N in microbial protein as well as to evaluate nitrogen balance compounds and variables related to urea renal handling in Nellore cattle. Four Nellore bulls and four Nellore heifers, fitted with rumen cannulas, were distributed in a two 4 × 4 Latin square design. The four experimental diets differed in levels of CP: 90.0, 110.0, 130.0, and 150.0 g/kg on a dry matter basis. Continuous intravenous infusion of ¹⁵N¹⁵N-urea solution was provided at a rate of 0.30 mmol urea/h followed by determination of ¹⁵N in ruminal bacteria, ammonia (NH₃), and feces to determine the incorporation of recycled N in rumen bacteria. The increased dietary CP revealed a linear increase (P < 0.05) in total digestible nutrients (TDN), total digestibility of CP and neutral detergent fiber (NDF), retained nitrogen, urinary excretion of urea-N, amount of filtered and absorbed urea (g/day), and plasmatic concentrations of urea-N. Fecal excretion of N presented a linear increase (P < 0.05) in relation to dietary CP. Rumen NH₃ concentration increased in a linear fashion (P < 0.05), and rumen ¹⁵N-NH₃ contents and fecal ¹⁵N contents decreased in a linear fashion (P < 0.05) with increasing dietary CP. The regressions NH₃ = 23.6183 × e^(0.0104×NI) and ¹⁵N-NH₃ = −0.00062 × NI + 0.1219 were obtained in order to calculate rumen NH₃ concentrations (mg/l) and ¹⁵N-NH₃ (atom percent excess), respectively, as a function of N intake (NI, g/day). The contents of total-N and ¹⁵N did not differ between liquid-associated bacteria (LAB) and particle-associated bacteria (PAB). There was no effect of sex (P > 0.05) on the percentage of infused ¹⁵N that was recovered from feces and bacteria. There was no effect of dietary CP level on the percentage of ¹⁵N infused in plasma that was recovered from feces. However, there was a decreasing linear effect of the level of dietary CP (P < 0.05) on the percentage of ¹⁵N infused in the jugular vein recovered from bacteria. We concluded that microbial protein synthesis was not affected by sex. The LAB and PAB had the same total-N content and recovery of infused ¹⁵N-urea. The greater recovery of infused intravenous ¹⁵N-urea on microbial protein synthesis in a low CP diet suggests greater urea recycling in association with this diet.
Evaluation of total and non-fatty ether extract in feeds and cattle feces using two analytical methods
2011, Animal Feed Science and Technology
Citation Excerpt :
Functional knowledge of the capacity of a food or feed to supply energy begins by measuring the components capable of providing energy to ruminant animals. Although found in lower concentrations than other components for the majority of food produced under tropical conditions, ether extract (EE) is able to produce energetic levels similar to other components due to its greater caloric concentration (Detmann et al., 2006, 2008). Laboratory evaluation of EE content is based upon organic solvent extractions of nonpolar food components.
The objective of this study was to evaluate ether extract (EE) concentrations, pigments, and wax in forages (n = 14), concentrates (n = 23), and cattle feces (n = 100) using extraction methods recommended by Association of Official Analytical Chemists (AOAC; method 920.39) and American Oil Chemist's Society (AOCS; method Am 5-04). The EE contents were compared by adjusting a linear regression model for each sample type. For the feces and forage samples, the EE contents produced by the AOCS method were greater (P<0.05) compared to those obtained using the AOAC method. No differences between methods were observed in EE content of concentrates (P>0.05). Concentration of vegetable pigments and wax were evaluated by using analysis for variance. Vegetable pigments were lower (P<0.05) in the post-extraction residues using the AOCS method, than the AOAC method, indicating greater participation of vegetable pigments in the EE. No differences were observed between the methods in wax concentration of the post-extraction residues (P>0.05). The quantification method of the EE content that is recommended by AOCS is not suggested for analyses of forage and feces of ruminants because it possibly increases the removal of non-fatty material, mostly pigments, in comparison to the method recommended by AOAC.
Evaluation of indirect methods to estimate the nutritional value of tropical feeds for ruminants
2010, Animal Feed Science and Technology
The objective was to determine digestible fraction values of several tropical forages used in ruminant diets in the tropics through in vivo digestion in order to estimate the metabolizable energy (ME) content of these forages using several methods and predictive equations, and to assess the relationship between in situ neutral detergent fibre (NDF) degradability and in vivo NDF digestibility. In the experiment, 28 confined Nellore heifers 293 ± 46.0 kg live weight, were fed chopped sugar cane, sugar cane silage, soybean silage, mombaça silage (Pannicum maximum cv. Mombaça), corn silage, Tifton-85 hay (Cynodon spp.) and chopped elephant grass (Penissetum purpureum cv. Cameroun). Forages with crude protein (CP) below 70 g/kg DM were supplemented with urea and ammonia sulphate (9:1). The feeding period lasted 12 days, consisting of 7 days for adaptation and 5 for total fecal collection. The ME estimated from NRC (2001) was based upon chemical component fractions and the same system using digestible NDF (NDF_d) after 48 h of in vitro incubation (NRC₄₈) was examined. The UC Davis (UCD) approaches based on several chemical components and an in vitro NDF digestion at 30 and 48 h of incubation, respectively, UCD₃₀ and UCD₄₈, were evaluated. The other UCD approach (UCD Gas), which predicts ME from in vitro gas produced after 24 h (24 h Gas), 48 h (48 h Gas) and 72 h (72 h Gas) of incubation, was also examined. The equations developed under tropical conditions by Detmann also calculate digestible energy from the apparent digestible fractions of crude protein (CP_ad), ether extract (EE_ad), non-fibre carbohydrates (NFC_ad) and neutral detergent fibre (NDFad) (Detmann 1). The equations proposed in Detmann 1 were used again, but the estimator was changed to apparently digestible CP (CP_ad) (i.e., Detmann 2). The poor results associated with the descriptive levels of probability compared to the null hypotheses show the inadequacy of the UCD₃₀, NRC₄₈, 24 h Gas and UCD gas models in predicting ME of these forages. The highest accuracy was with the NRC, Detmann 1 and Detmann 2 models as reflected in the lowest estimates of MSPE (6.297; 6.274; 6.236, respectively) and the lowest bias (0.458; 0.040; 0.162, respectively) among all models evaluated. For the CP_ad, a similarity was verified between the estimates with the submodel proposed by the NRC (2001), as well as by the Detmann 2 submodel and in vivo observations. The submodels proposed by the NRC (2001) and Detmann diverged from the observed values of digested levels of EE. Similarities between observed and estimated values in the NDF_d diet levels occurred. However, a higher predictive adequacy occurred in the Detmann 1 submodel. The same behavior occurred in estimates obtained for digestible fractions of NFC, suggesting that both models satisfactorily estimate the NFC_ad, with a higher prediction adequacy associated with the lowest bias in the Detmann 1 submodel. The systems based upon chemical composition, such as NRC (2001) and Detmann allowed accurate estimates of ME but higher precision and accuracy occurred in the Detmann submodels for predicting the ME value of tropical feeds.
Fertilization type and regrowth age of Tithonia diversifolia on ruminal parameters
2023, Agronomia Mesoamericana

View all citing articles on Scopus

^☆: This paper is part of a special issue entitled “Mathematical Methods that Predict the Effects of Feed Characteristics on Animal Performance” guest edited by Essi Evans, Daniel Sauvant and Peter Udén.

View full text

Prediction of the energy value of cattle diets based on the chemical composition of the feeds under tropical conditions☆

Abstract

Introduction

Section snippets

Description of the new model: submodels for non-fibrous components

Results

Discussion

Conclusions

Acknowledgement

J. Dairy Sci.

Anim. Feed Sci. Technol.

J. Dairy Sci.

J. Dairy Sci.

Anim. Feed Sci. Technol.

Agric. Syst.

Anim. Feed Sci. Technol.

Anim. Feed Sci. Technol.

Anim. Feed Sci. Technol.

Official Methods of Analysis

The factorization of the protein requirements of ruminants and of the protein values of feeds, with particular reference to the significance of metabolic fecal nitrogen

J. Anim. Sci.

Protein fractions of tropical feeds and their digestion rates estimated by means of incubation with ruminal proteases

Braz. J. Anim. Sci.

Validation of NRC (2001) equations for estimation of energy value of feeds in Brazilian conditions

Braz. J. Anim. Sci.

Validation of predictive equations for neutral detergent fiber indigestible fraction in tropical grasses

Braz. J. Anim. Sci.

Evaluation of acid detergent insoluble protein as estimator of undegradable fraction of crude protein for tropical forages

Estimation of ether extract digestibility in diets of ruminants: a model under Brazilian conditions

Braz. J. Anim. Sci.

Estimation of crude protein digestible fraction in cattle diets under Brazilian conditions

Braz. J. Anim. Sci

Estimation of nonfiber carbohydrates digestibility in cattle using the Lucas Test approach under Brazilian conditions

Braz. J. Anim. Sci.