oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Residual feed intake in beef cattle
Arthur, J P.F.;Herd, R.M.;
Revista Brasileira de Zootecnia , 2008, DOI: 10.1590/S1516-35982008001300031
Abstract: providing feed is a major input cost in beef production, hence improvements in the efficiency of feed utilisation will reduce the cost of production. residual feed intake (rfi) is a measure of feed efficiency, and is defined as the difference between an animal's actual feed intake and its expected feed intake based on its size and growth. it is independent of the level of production, and the lower the value the more efficient the animal is. this paper examines the current state of knowledge on rfi. available information indicates that postweaning rfi is moderately heritable, and that selection for low rfi will result in progeny that consume less feed for the same level of production as progeny of high rfi cattle. under ad libitum feeding, rfi is phenotypically independent of growth traits. there is a weak genetic relationship between rfi and fatness but additional studies are needed to assess the magnitude of this relationship in different breeds, sexes, ages and feeding regimes. residual feed intake is believed to represent inherent variation in basic metabolic processes which determine efficiency. economic analyses of genetic improvement schemes that incorporate testing of individuals for rfi have yielded substantial economic benefits over and above existing schemes that do not include rfi testing. selection for low rfi has an additional benefit of reducing greenhouse gas emissions by cattle.
Climate Change Concern to Cattle Feed in Bangladesh
Ferdous Ahmed,Abul Quasem Al-Amin,Gazi Mahabubul Alam,Che Hashim Hassan
Journal of Animal and Veterinary Advances , 2012, DOI: 10.3923/javaa.2012.1946.1953
Abstract: This research focuses the climate change concerns for livestock feeding management in Bangladesh as it causes strange behavior and variation of cattle diets and feed shortages in the last two decades. It is obvious from the recent literature that Bangladesh is one of the most climate change vulnerable country of the world to climate change. It causes cattle feed shortages, modification in major production of yields, alteration in a variety composition of rangeland and edifying variety of cattle feed setback. The climate change concern to cattle feed in Bangladesh are now real and need to overcome the problems by the subject to current research effort and value. Therefore, in this study specific justification is used to figure out the factors that are responsible and discussed the national lacking, required action, limitation and possible alternative options. Moreover, following on the national lacking, required action and limitations, this study incorporated a framework of approach and strategies for the policy makers of Bangladesh.
Feed efficiency of Nellore cattle selected for postweaning weight
Castilhos, André Michel de;Branco, Renata Helena;Corvino, Tatiana Lucila Sobrinho;Razook, Alexander George;Bonilha, Sarah Figueiredo Martins;Figueiredo, Leopoldo Andrade de;
Revista Brasileira de Zootecnia , 2010, DOI: 10.1590/S1516-35982010001100023
Abstract: two nellore herds were compared, one selected for greater postweaning weight and the other, control, selected for average postweaning weight, to evaluate the effects of 29 years of selection on feed efficiency. sixty nellore males (41 selected and 19 control) averaging 205 kg and 267 days of age were evaluated in individual pens during performance test. performance and dry matter intake were used to determine the following feed efficiency traits: feed conversion; residual feed intake; residual gain; partial growth efficiency; relative growth rate and kleiber ratio. after the 112-day experimental period, control animals showed lower body weight when compared to selected animals, however, they did not differ for dry matter intake (% of body weight), rib-eye area and fat thickness at the 12th rib subcutaneous region and on the rump region. dry matter intake (kg/day) and average daily weight gain from selected animals were, respectively, 19.4% and 26.4% higher than the control ones. the highest average daily weight gain by selected animals promoted significant improvement, around 6%, on feed conversion; 70 g/day on residual gain; and 17% on kleiber rate. the other feed efficiency traits (residual feed intake, partial growth efficiency and relative growth rate) did not differ between herds. the 29-year selection for post-weaning weight did not affect feed efficiency of nellore cattle.
Modeling cadmium in the feed chain and cattle organs  [PDF]
van der Fels-Klerx, I.,R?mkens, P.,Franz, E.,van Raamsdonk, L.
Biotechnologie, Agronomie, Société et Environnement , 2011,
Abstract: The objectives of this study were to estimate cadmium contamination levels in different scenarios related to soil characteristics and assumptions regarding cadmium accumulation in the animal tissues, using quantitative supply chain modeling. The model takes into account soil cadmium levels, soil pH, soil-to-plant transfer, animal consumption patterns, and transfer into animal organs (liver and kidneys). The model was applied to cattle up to the age of six years which were fed roughage (maize and grass) and compound feed. Cadmium content in roughage and cadmium intake by cattle were calculated for six different (soil) scenarios varying in soil cadmium levels and soil pH. For each of the six scenarios, the carry-over of cadmium from intake into the cattle organs was estimated applying two model assumptions, i.e., linear accumulation and a steady state situation. The results showed that only in the most extreme soil scenario (cadmium level 2.5 mg.kg-1, pH 4.5), cadmium exceeded the EC maximum tolerated level in roughage. Assuming linear accumulation, cadmium levels in organs of cattle up to six years of age, ranged from 0.37-4.03 mg.kg-1 of fresh weight for kidneys and from 0.07 to 0.77 mg.kg-1 of fresh weight for livers. The maximum tolerated levels in one or both organs were exceeded in several scenarios. When considering organ excretion of cadmium, internal cadmium levels in organs were approximately one order of magnitude lower as compared to the results of the linear accumulation model. In this case only in the most extreme soil scenario, the maximum tolerated level in the kidney was exceeded. It was concluded that the difference between the two assumptions (linear model versus a steady state situation to estimate cadmium carry-over in cattle) is negligible in the animal's first five years of life, but will become relevant at higher ages. For the current case, the linear approach is a good descriptor for worst case situations. Furthermore, this study showed that quantitative supply chain modeling is an effective tool in assessing whether or not a specific combination of soil properties would lead to unacceptable contaminant levels in feedstuffs and animal products in the view of animal and human health.
Efficiency of feed nitrogen conversion in dairy cattle herds
Davide Biagini,Carla Lazzaroni
Italian Journal of Animal Science , 2010, DOI: 10.4081/ijas.2009.s2.265
Abstract: To evaluate the effect of feasible strategies to mitigate dairy herd’s environmental impact in a homogeneous area, the actual level of N excretion and conversion efficiency was determined in fifteen farms located in the North-West of Italy. Main factors affecting N efficiency (feeds consumption and composition, live weight, productions, milk urea and reproductive indexes) were recorded for cows (C), heifers (H, 12-24 months) and young heifers (YH, 6-12 months). N requirements, retention, excretion and efficiency were calculated. N excretion was respectively 131.39, 60.88 and 47.49 kg/year/head for C, H and YH and 14.07 kg/year per litre of milk in C. Feed N conversion efficiency was respectively 28.40, 8.90 and 6.64 in C, H and YH. In the studied farms N efficiency could be increased acting on the most important factors affecting N utilisation, so reducing the environmental impact of dairy cattle.
Availability Analysis of A Cattle Feed Plant Using Matrix Method  [PDF]
Deepika Garg,Jai Singh,Kuldeep Kumar
International Journal of Engineering , 2009,
Abstract: A matrix method is used to estimate the probabilities of complex system events by simplematrix calculation. Unlike existing methods, whose complexity depends highly on the systemevents, the matrix method describes the general system event in a simple matrix form.Therefore, the method provides an easy way to estimate the variation in system performancein terms of availability with respect to time.Purpose- The purpose of paper is to compute availability of cattle feed plant .A Cattle feedplant consists of seven sub-systems working in series. Two subsystems namely mixer andpalletiser are supported by stand-by units having perfect switch over devices and remainingfive subsystems are subjected to major failure.Methodology/approach- The mathematical model of Cattle feed plant has been developedusing Markov birth – death Process.The differential equations are solved using matrix methodand a C-program is developed to study the variation of availability with respect to time.Findings- The study of analysis of availability can help in increasing the production andquality of cattle feed. To ensure the system performance throughout its service life, it isnecessary to set up proper maintenance planning and control which can be done afterstudying the variation of availability with respect to time.
Physical Characteristics of Pressed Complete Feed for Dairy Cattle  [cached]
M. Munasik,C. Imam Sutrisno,Syaiful Anwar,Caribu Hadi Prayitno
International Journal of Science and Engineering , 2013, DOI: 10.12777/ijse.v4i2.4566
Abstract: The study was aimed to evaluate the physical characteristics of the pressed complete feed in the forms of cube, cylinder and ball. The study was conducted to get a complete feed of dairy cows that can be developed commercially. The evaluation was done on a physical test : bulkiness, hardness and hygroscopic properties of pressed complete feeds. The results of this research showed that the bulkiness of pressed complete feed in the forms cubes, cylinders and balls were between 0.20 up to 0.48 liter/kg; the hardness of pressed complete feed, cylinders and balls were 3 lbs up to 14 lbs; the hygroscopic factor of pressed complete feed in the forms cubes, cylinders and balls were around 1.10% up to 9.69%. The pressed complete feed in the forms of cube and cylinder are better than the form of ball in physical characteristics. doi: 10.12777/ijse.4.2.2013.61-65
Genetic relationship between feed efficiency and profitability traits in beef cattle
RR Van der Westhuizen, J Van der Westhuizen, SJ Schoeman
South African Journal of Animal Science , 2004,
Abstract: Genetic selection to improve feed efficiency aims to reduce the cost of feeding costs in beef cattle production and thereby improve profitability. The aim of this study was to estimate genetic (co)variances to compare residual feed intake (RFI) and feed conversion ratio (FCR) with growth, reproductive and profitability traits measured in growth tests of young bulls. The heritability estimated for FCR was 0.34 and for RFI 0.31 with a genetic correlation estimate of 0.75 between the traits. The estimated genetic correlation between profitability and FCR and RFI were -0.92 and -0.59, respectively. The genetic correlations and expected correlated responses between RFI and FCR with post-wean profitability (M-value) suggest that indirect selection for M-value through the direct selection for FCR and/or RFI will result in slower genetic progress in M-value than direct selection for M-value. However, where the M-value cannot be calculated and/or direct selection for M-value is not possible, it would be better to select indirectly for M-value through the use of FCR rather than RFI. South African Journal of Animal Science Supp 2 2004: 50-52
Developing a genome-wide selection model for genetic improvement of residual feed intake and carcass merit in a beef cattle breeding program
ZhiYao Zeng,GuoQing Tang,JiDeng Ma,Graham Plastow,Stephen Moore,SongJia Lai,XueWei Li,ZhiQuan Wang
Chinese Science Bulletin , 2012, DOI: 10.1007/s11434-012-5325-6
Abstract: Residual feed intake (RFI) and carcass merit (CM) are both complex traits emerging as critical targets for beef genetic improvement. RFI and CM traits are difficult and expensive to measure and genetic improvement for these traits through traditional selection methods is not very effective. Therefore, genome-wide selection using DNA markers may be a potential alternative for genetic improvement of these traits. In this study, the efficiency of a genome-wide selection model for genetic improvement of RFI and CM was assessed. The Illumina Bovine50K bead chip was used to genotype 922 beef cattle from the Kinsella Beef Research Ranch of the University of Alberta. A Bayes model and multiple marker regression using a stepwise method were used to conduct the association test. The number of significant SNP markers for carcass weight (CWT), carcass back fat (BF), carcass rib eye area (REA), carcass grade fat (GDF), lean meat yield (LMY), and residual feed intake (RFI) were 75, 54, 67, 57, 44 and 50, respectively. Bi-variate analysis of marker scores and phenotypes for all traits were made using DMU Software. The genetic parameter for each trait was estimated. The genetic correlations of marker score and phenotype for CWT, BF, REA, GDF, LMY and RFI were 0.75, 0.69, 0.87, 0.77, 0.78, and 0.85, respectively. The average prediction accuracies of phenotypic EBV for the six traits were increased by 0.05, 0.16, 0.24, 0.23, 0.17 and 0.19, respectively. The results of this study indicated that the two-trait marker-assisted evaluation model used was a suitable alternative of genetic evaluation for these traits in beef cattle.
Radiation-hygiene control of imported foodstuffs and cattle feed  [PDF]
Slavata Branislava,Vitorovi? Gordana,D?oni? Slobodan
Veterinarski Glasnik , 2002, DOI: 10.2298/vetgl0204237s
Abstract: The increasingly frequent use of nuclear energy in peacetime, experimental nuclear and thermo-nuclear explosions, as well as accidents in nuclear plants lead to an increased and unequal distribution of radioactive substances in the environment. Mankind is in this way threatened not only by environmental irradiation, but also by consuming contaminated food and water which contain radionuclides whose concentrations are above the level of natural radioactivity. From the aspect of the veterinary profession, the most important task is to organize the protection of domestic animals and their products from radioactive contamination. This work presents the results obtained by measurements of the activity level of 137Cs in products of animal origin and cattle feed, in samples obtained from border crossings in Yugoslavia and partly in Macedonia during the period from 1990 until 1999. Examined import samples were taken from cheese, prok, and corn and the activity level of 137Cs was within the permitted legal levels - less than 1 Bq/kg. However, powdered milk was found to contain an activity level of 137Cs from 1,22-7,27 Bq/kg, and saltwater fish from 1,10-3,30 Bq/kg, so that these products could not be released for sale under the Official Gazette of the FRY, Number 53/91.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.