Prediction of dry matter intake by feedlot beef cattle under tropical conditions

2020 ◽  
Author(s):  
H. M. da Silva ◽  
A. B. Donadia ◽  
L.F. Moreno ◽  
A.S. de Oliveira ◽  
E. H. B. K. Moraes ◽  
...  
2021 ◽  
Author(s):  
Geferson Antonio Fernandes ◽  
André Soares de Oliveira ◽  
Cláudio Vieira de Araújo ◽  
Victor Rezende Moreira Couto ◽  
Kamila Andreatta Kling de Moraes ◽  
...  

Abstract A meta-analytic study was conducted to develop and evaluate models for the prediction of pasture dry matter intake (DMIpasture) by beef cattle in tropical conditions. 804 individual observations of DMIpasture were used, taken from 23 studies through analysis of mixed models, including the study as a random effect. To evaluate the accuracy and precision of the new models proposed as well as for the models of Azevedo et al., (2016) and Minson and McDonald (1987), an independent databank with 87 means from treatments of 21 experiments (n = 888 animals) was used. Three prediction models were adjusted: Model I (Animal Information), Model II (Animal Information + Supplement) and Model III (Animal Information + Supplement + Pasture). The proposed models presented similarity for the average square root of the prediction error. The inclusion of the predictive variables for supplementation (supplement dry matter intake - DMIsupplement - % of the body weight and crude protein intake through supplement) with the variables for the animal (BW0,75 and average daily gain) and of the pasture (% of crude protein) in Model III improves accuracy and precision and provides higher determination and correlation coefficients, and agreement than the other proposed models. Similarly, it was found to be more accurate and precise than the equations of Azevedo et al., (2016) and Minson and McDonald (1987), which presented lower precision and accuracy than the proposed models. The DMIpasture for beef cattle in tropical conditions is more accurate and precise when the information for the animal, supplement and pasture is included.


2010 ◽  
Vol 39 (8) ◽  
pp. 1801-1809 ◽  
Author(s):  
José Augusto Gomes Azevêdo ◽  
Sebastião de Campos Valadares Filho ◽  
Douglas dos Santos Pina ◽  
Mario Luiz Chizzotti ◽  
Rilene Ferreira Diniz Valadares

The study was carried out to develop and to evaluate new equations to predict dry matter intake (DMI) of Nellore and Zebu-crosses cattle using meta-analysis procedure. The data used to estimate the parameters were collected from independent performance experiments using growing and fattening Nellore and Zebu-crosses cattle, and they were compiled from 561 experimental units. Before proposing an equation to predict DMI, it was observed that the genetic group was a source of statisticaly significant variation. Therefore, equations to predict dry matter intake in the Zebu-Crosses and Nellore cattle were independently developed. The regression equations for Zebu-crosses cattle were: DMI = -2.6098 + 0.08844BW0.75 + 4.4672ADG - 1.3579ADG2 and DMI = -1.0094 + 0.01608BW + 4.4363ADG -1.2548ADG2. The regression equations for Nellore cattle were: DMI = -2.7878 + 0.08789BW0.75 + 5.0487ADG - 1.6835ADG2 and DMI = -1.3559 + 0.0159BW + 5.6397ADG - 1.8494ADG2. In order to evaluate fitted equations, it was utilized data from independent experiments published from 2005 to 2008 in the Revista Brasileira de Zootecnia. The equations (DMI) for Nellore overpredicted dry matter intake for estimates lower than 7 and higher than 10 kg·d-1. For Zebu-crosses cattle, dispersions of 3 kg d-1 were observed when extreme intakes were evaluated, however, when the equation included BW 0.75, the intercept did not differ from zero and the slope did not differ from 1. It is not possible to fit only one equation for preditcting DMI for beef cattle in tropical conditions, because there are differences between Zebu and Zebu-crosses. Fitted equations that include ADG and BW 0.75 should be used as an alternative method to predict dry matter intake of Zebu-crosses and Nellore beef cattle in tropical conditions.


Author(s):  
C.L. Thorp ◽  
R.W.J. Steen ◽  
A.R.G. Wylie ◽  
J.D. McEvoy ◽  
C. Shaw

Studies have shown that reducing energy intake by restricting dry matter intake (DMI) at a constant forage: concentrate (F:C) ratio is more effective at increasing carcass lean and reducing carcass fat content than is reducing energy intake by increasing the F:C ratio (1). Research at this Institute has also shown that, per megajoule of digestible energy (DE), diets restricted in this manner are 45 % more efficient at producing carcass lean.The mechanism by which these methods of restriction result in these differences in carcass composition has previously been assumed to be that of rumen fermentation. More recently however, the significance of rumen fermentation in controlling the carcass composition of beef cattle has been questioned (2,3).The aim of this experiment was to examine the effect of decreasing the F:C ratio, at constant DE and DMI, on both rumen and endocrinological parameters, in particular the hormones insulin and insulin like growth factor-1 (IGF-1), in finishing beef steers.


2003 ◽  
Vol 83 (4) ◽  
pp. 787-792
Author(s):  
E. K. Okine ◽  
D. H. McCartney ◽  
J. B. Basarab

The accuracy of predicted CowBytes® versus actual dry matter intake (DMI) and average daily gain (ADG) of 407 Hereford × Angus and Charolais × Maine Anjou (445.6 ± 36 kg) feeder cattle using digestable enery acid detergent fiber (DE) estimated from the (ADF) content [Laboratory analysis method (LAB)] and from values determined in vivo (INVIVO method) was examined. The diet consisted of a 73.3% concentrate diet, 22.0% barley silage, 1.6% molasses, and 3.1% feedlot supplement fed ad libitum (as-fed basis). The calculated DE values of the feed were used to predict the metabolizable energy (ME), net energy of maintenance (NEm), and net energy of gain (NEg) of the diet. These energy values were then used in CowBytes® to predict dry matter intake (DMI), ADG, and days on feed (DOF) necessary to meet targeted quality grade of AA and weights of 522 and 568 kg for the heifers and steers, respectively. There was no effect of gender and prediction method interaction (P > 0.10) on any of the variables measured. There were no (P > 0.05) differences in predicted DMI by either the INVIVO or LAB method but both methods underestimated DMI actually consumed by the cattle by 6.8 and 4.9% (P = 0.007), respectively. Indeed, regression values from these predictive methods and actual DMI were (P < 0.05) different from the one-to-one relationship expected by definition. In spite of the higher actual DMI, the actual ADG of the cattle was 14 and 11% (P = 0.0004) lower than was predicted by either the INVIVO or LAB methods. A possible reason for the lower ADG could be an overestimation of DE of the diet. Thus, if available, users of CowBytes® should use actual DMI from their experience in ration formulation. In addition, the effects of environmental temperature on digestibility of diets should be taken into consideration when using the DE of the diet as determined from in vivo digestibility trials or calculated from chemical analyses in determining the DMI of feedlot cattle. Key words: Beef cattle, performance, CowBytes®, National Research Council


1981 ◽  
Vol 96 (2) ◽  
pp. 483-485 ◽  
Author(s):  
C. Shorrock

The determination of in vitro dry-matter digestibility (DMD) of grass and pasture legumes under both temperate and tropical conditions is well established (Tilley & Terry, 1963; Minson & McLeod, 1972). One application of the in vitro DMD estimation of pasture samples is, together with an estimate of faecal output, the measurement of the herbage dry-matter intake of grazing cattle. Pasture samples are usually collected with oesophageal fistulated cattle. This technique is well documented and has been reviewed by a number of authors (Langlands, 1975; Minson et al. 1976).


BMC Genomics ◽  
2014 ◽  
Vol 15 (1) ◽  
pp. 1004 ◽  
Author(s):  
Mahdi Saatchi ◽  
Jonathan E Beever ◽  
Jared E Decker ◽  
Dan B Faulkner ◽  
Harvey C Freetly ◽  
...  

1969 ◽  
Vol 73 (3) ◽  
pp. 365-372 ◽  
Author(s):  
T. J. Forbes ◽  
A. M. Raven ◽  
J. H. D. Irwin

SummaryAn experiment was carried out in which young beef cattle were given diets containing different levels of coarsely milled (1 in screen) barley straw. The proportions of straw used were 0, 10, 20, 30, 40 and 50 % and the performance of animals on these diets was compared with that of similar animals on an all concentrate diet. Each diet was given ad libitum to six animals. There was a significant linear decline in live-weight gain with increasing straw intake, the rate of decline being 0·62 ± 0·133 kg per week for each 10 % increase in the level of straw in the diet. The dry matter conversion ratio increased linearly with increasing straw intake, the rate of increase being 0·65 ± 0·186 units for each 10 % increase in straw in the diet. Dry matter intake was significantly (P < 0·001) affected by the proportion of straw in the diet. Although dry matter intake increased to a maximum at a level of 18·8% straw in the diet there was no significant increase in the intake of digestible organic matter (DOMI). There was a significant (P < 0·001) linear decline of 0·19 ± 0·04 kg DOMI with each 10% increase in straw in the diet. There was a significant linear decline in chilled carcase weight to the extent of 5·7 ± 0·096 kg for each 10% increase in straw. The killing-out percentage based on unfasted live weight declined significantly as the percentage of straw in the diet rose from 20 to 30%. However, when the killing-out percentage was calculated on the basis of live weight at slaughter less rumen contents there was no significant difference between treatments.


Author(s):  
R.W.J. Steen

The efficient production of lean beef suitable for current consumer demand necessitates effective rationing of beef cattle. Feeding standards for beef cattle given by ARC (1980) predict that a reduction in energy intake produces a large reduction in performance with little effect on the energy or fat contents of the gain. However previous studies have shown that diets containing a high proportion of grass silage may sustain lower levels of performance and result in a greater proportion of fat in the gain in both calves and finishing cattle, than when similar quantities of energy and protein are given in the form of high-concentrate diets. The effects of a change in energy intake on performance and carcass composition of beef cattle are therefore likely to depend on whether this change is achieved by restricting the quantity of food given or changing the forage: concentrate ratio of a diet given ad libitum.The present experiment was carried out to examine the effects of forage:concentrate ratio in the diet and ad libitum versus restricted dry matter intake on the performance, carcass composition and efficiency of lean meat production by steers.


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