Use of n-alkanes to estimate feed intake in ruminants: a meta-analysis.

Precise techniques to estimate feed intake by ruminants is critical to enhance feed efficiency and to reduce greenhouse gas emissions and nutrient losses to the environment. Using a meta-analysis, we evaluated the accuracy of the n-alkane technique to predict feed intake in cattle and sheep, and assessed the relationships between feed intake and fecal recovery of n-alkanes. The database was composed of 28 studies, including 129 treatments (87 and 42 for cattle and sheep, respectively) and 402 animals (232 cattle and 170 sheep) fed at troughs, from published studies. Relationships between observed (in vivo measurement) and predicted feed intake by C31:C32 and C32:C33 n-alkane pairs were evaluated by regression. Meta-regression addressed the relationships between the difference in fecal recovery of n-alkane pairs and the error in intake estimation, as well as the amount and duration of C32 n-alkane dosing. Regression of observed intake on n-alkane-based estimates revealed good relationships in cattle (adjusted R² = 0.99 for C31:C32, and adjusted R² = 0.98 for C32:C33; P < 0.0001) and in sheep (adjusted R² = 0.94 for C31:C32, and adjusted R² = 0.96 for C32:C33; P < 0.0001). Fecal recovery of natural n-alkanes showed coefficient of variation about 15 and 16% for C31 and C33, respectively in cattle. In sheep, the coefficient variation was 8 and 14% for C31 and C33, respectively. The relationships between the difference of fecal recovery of n-alkane pairs and the error in feed intake estimation in cattle were characterized by an adjusted R² = 0.83 for C31:C32 (P < 0.0001) and adjusted R² = 0.93 for C32:C33 (P < 0.0001). In sheep, they were characterized by an adjusted R² = 0.69 for C31:C32 (P < 0.001) and adjusted R² = 0.76 for C32:C33 (P < 0.001). The n-alkane technique provided reliability for estimating feed intake in cattle and sheep in barn experiments. The present meta-analysis demonstrated that without correction for differences in fecal recovery of n-alkane pairs, deviation in feed intake prediction would occur. However, further research is necessary to determine the relationship between the n-alkane dosing procedure (daily amount and duration of dosing) and fecal recovery of n-alkane.

[1]  P. Celi,et al.  Effects of dietary fat on fertility of dairy cattle: A meta-analysis and meta-regression. , 2015, Journal of dairy science.

[2]  P. Garnsworthy,et al.  Estimation of dry matter intake by n-alkanes in dairy cows fed TMR: effect of dosing technique and faecal collection time , 2014 .

[3]  Eduardo Brito de Azevedo,et al.  Use of faecal components as markers to estimate intake and digestibility of grazing sheep , 2014 .

[4]  A. Laidlaw,et al.  An evaluation of contrasting C32 alkane dosing and faecal sampling regimes to estimate herbage dry matter intake by beef cattle , 2014, The Journal of Agricultural Science.

[5]  M. Gao,et al.  Use of the N-alkanes to Estimate Intake, Apparent Digestibility and Diet Composition in Sheep Grazing on Stipa breviflora Desert Steppe , 2014 .

[6]  W. Hendriks,et al.  Estimation of feed intake and digestibility in cattle consuming low-quality tropical roughage diets using molasses-based n-alkane boluses , 2012 .

[7]  H. Gonda,et al.  Two drying methods of bovine faeces for estimating n-alkane concentration, intake and digestibility: A comparison , 2012 .

[8]  J. Peyraud,et al.  N-alkanes v. ytterbium/faecal index as two methods for estimating herbage intake of dairy cows fed on diets differing in the herbage: maize silage ratio and feeding level. , 2012, Animal : an international journal of animal bioscience.

[9]  P. Hofstetter,et al.  Does body size of dairy cows, at constant ratio of maintenance to production requirements, affect productivity in a pasture-based production system? , 2011, Journal of animal physiology and animal nutrition.

[10]  G. Huntington,et al.  Use of plant hydrocarbons as markers to estimate voluntary intake and digestibility in beef steers , 2011 .

[11]  R. Reis,et al.  The validity of n-alkanes to estimate intake and digestibility in Nellore beef cattle fed a tropical grass (Brachiaria brizantha cv. Marandu) , 2011 .

[12]  D. Andueza,et al.  Validation of the n-alkane and NIRS techniques to estimate intake, digestibility and diet composition in sheep fed mixed lucerne: ryegrass diets , 2008 .

[13]  M. Galyean,et al.  Effects of Dietary Neutral Detergent Fiber on Intakes of Dry Matter and Net Energy by Dairy and Beef Cattle: Analysis of Published Data , 2008 .

[14]  T. Duffield,et al.  A meta-analysis of the impact of monensin in lactating dairy cattle. Part 2. Production effects. , 2008, Journal of dairy science.

[15]  K. Osoro,et al.  Estimation of feed intake and apparent digestibility of equines and cattle grazing on heathland vegetation communities using the n-alkane markers , 2007 .

[16]  D. Cuddeford,et al.  Validating the alkane pair technique to estimate dry matter intake in equids , 2007, The Journal of Agricultural Science.

[17]  Hailing Luo,et al.  The effects, in sheep, of dietary plant species and animal live weight on the faecal recovery rates of alkanes and the accuracy of intake and diet composition estimates obtained using alkanes as faecal markers , 2006, The Journal of Agricultural Science.

[18]  J. P. Fontenot,et al.  Use of N-alkanes to estimate intake and digestibility by beef steers , 2005 .

[19]  A. Elgersma,et al.  Comparison of techniques for estimating herbage intake of grazing dairy cows. , 2005, Journal of dairy science.

[20]  S. López,et al.  Effects of carrier matrix and dosing frequency on digestive kinetics of even‐chain alkanes and implications on herbage intake and rate of passage studies , 2004 .

[21]  D. Veira,et al.  Estimation of faecal output, digestibility, and intake using a controlled release capsule of alkanes in early and late lactation dairy cows fed two levels of concentrate , 2004 .

[22]  A. Pell,et al.  Accuracy of estimates of herbage intake of lactating cows using alkanes: comparison of two types of capsules , 2004 .

[23]  K. Osoro,et al.  Estimation of feed intake by cattle using controlled-release capsules containing n-alkanes or chromium sesquioxide , 2004, The Journal of Agricultural Science.

[24]  J. Hargrove,et al.  Nutritional Significance and Metabolism of Very Long Chain Fatty Alcohols and Acids from Dietary Waxes , 2004, Experimental biology and medicine.

[25]  Gerry C. Emmans,et al.  The ability of the n-alkane technique to estimate intake and diet choice of sheep , 2003 .

[26]  D. Reid,et al.  Using molasses as an alternative to controlled release devices for administering n-alkane markers to cattle , 2003 .

[27]  S. Nia,et al.  Evaluation of n-alkanes as markers for estimation of dry matter intake and digestibility in steers consuming all-forage or forage-concentrate diets , 2002 .

[28]  N R St-Pierre,et al.  Invited review: Integrating quantitative findings from multiple studies using mixed model methodology. , 2001, Journal of dairy science.

[29]  A. Sibbald,et al.  Effect of dosing regime on intake estimation using the n-alkane technique in sheep fed pelleted grass meal. , 2000 .

[30]  P. Garnsworthy,et al.  Estimation of intake and digestibility of forage-based diets in group-fed dairy cows using alkanes as markers , 1999, The Journal of Agricultural Science.

[31]  A. Hameleers,et al.  THE USE OF N-ALKANES TO ESTIMATE HERBAGE INTAKE AND DIET COMPOSITION BY DAIRY COWS OFFERED A PERENNIAL RYEGRASS/WHITE CLOVER MIXTURE , 1998 .

[32]  E. O'riordan,et al.  Effect of litter size on herbage intake at pasture by ewes and their progeny , 1991 .

[33]  Robert W. Mayes,et al.  The use of dosed and herbage n-alkanes as markers for the determination of herbage intake , 1986, The Journal of Agricultural Science.

[34]  P. Carvalho,et al.  Use of N -Alkane Technique to Estimate Sheep Dry Matter Intake , 2020 .

[35]  W. Wales,et al.  Evaluation of the n-alkane technique for estimating herbage dry matter intake of dairy cows offered herbage harvested at two different stages of growth in summer and autumn , 2019, Animal Feed Science and Technology.

[36]  M. Rodehutscord,et al.  Faecal alkane recoveries from multi-component diets and effects on estimates of diet composition in sheep. , 2008, Animal : an international journal of animal bioscience.

[37]  H. Dove,et al.  Using plant wax markers to estimate diet composition and intakes of mixed forages in sheep by feeding a known amount of alkane-labelled supplement , 2007 .

[38]  K. Osoro,et al.  Accuracy of the n-alkane technique for intake estimates in beef cattle using different sampling procedures and feeding levels , 2007 .

[39]  J. Mann,et al.  Kikuyu (Pennisetum clandestinum) intake determined by alkanes administered in a xantham gum suspension , 2003 .

[40]  H. Dove,et al.  Using n-alkanes and known supplement intake to estimate roughage intake in sheep , 2002 .

[41]  M. Kreuzer,et al.  The accuracy of intake estimation based on the use of alkane controlled-release capsules and faeces grab sampling in cows , 2000 .

[42]  H. Dove,et al.  USING SYNTHETIC OR BEESWAX ALKANES FOR ESTIMATING SUPPLEMENT INTAKE IN SHEEP , 1998 .

[43]  H. Dove,et al.  Plant wax components: a new approach to estimating intake and diet composition in herbivores. , 1996, The Journal of nutrition.

[44]  H. Dove,et al.  The use of plant wax alkanes as marker substances in studies of the nutrition of herbivores: a review , 1991 .

[45]  F. E. Ryan.  Kikuyu (Pennisetum Clandestinum) , 1956 .