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The genetic background of bovine αs1- and αs2-casein phosphorylation
Fang, Zih-Hua - \ 2017
Wageningen University. Promotor(en): E. Verrier; H. Bovenhuis, co-promotor(en): P. Martin; M.H.P.W. Visker. - Wageningen : Wageningen University - ISBN 9789463438148 - 141
dairy cattle - alpha-s1-casein - alpha-s2-casein - phosphorylation - milk composition - milk proteins - genetic variation - genetic factors - animal genetics - melkvee - alfa-s-1-caseïne - alfa-s-2-caseïne - fosforylering - melksamenstelling - melkeiwitten - genetische variatie - genetische factoren - diergenetica
Phosphorylation of caseins (CN) is a crucial post-translational modification allowing caseins to aggregate as micelles. The formation and stability of casein micelles are important for transporting abundant minerals to the neonate and manufacturing of dairy products. Therefore, it is of great interest to explore variation in degrees of phosphorylation of caseins and study to what extent genetic and other factors contribute to this variation. This thesis aimed to investigate the genetic background of bovine milk protein composition with a focus on phosphorylation of αs1- and αs2-CN. Two studies were conducted to quantify phosphorylation levels of αs1- and αs2-CN: one in French Montbéliarde using liquid chromatography coupled with electrospray ionization mass spectrometry and the other in Dutch Holstein Friesian using capillary zone electrophoresis. In French Montbéliarde, in addition to the known isoforms αs1-CN-8P and-9P and αs2-CN-10P to -13P, three new phosphorylation isoforms were detected, namely αs2-CN-9P, αs2-CN-14P, and αs2-CN-15P. Relative concentrations of the phosphorylation isoforms varied considerably among cows. Phenotypic correlations showed that isoforms phosphorylated at higher degrees (αs1-CN-9P and αs2-CN-12P to -14P) correlated negatively with isoforms phosphorylated at lower degrees (αs1-CN-8P, αs2-CN-10P, and -11P). Furthermore, it was shown that αs1- and αs2-CN phosphorylation profiles changed across parity and lactation, and exploitable genetic variation for the phosphorylation degrees of αs1- and αs2-CN (defined as the proportion of higher-degree isoforms in αs1- and αs2-CN, respectively) exist. In Dutch Holstein Friesian, three αs2-CN isoforms, namely αs2-CN-10P to -12P, and the phosphorylation degrees of αs1- and αs2-CN were quantified. High intra-herd heritabilities were estimated for individual αs2-CN phosphorylation isoforms and the phosphorylation degrees of αs1- and αs2-CN (ranging from 0.54 to 0.89). This suggests that genetic factors contribute substantially to observed differences in αs1- and αs2-CN phosphorylation profiles. The highly positive correlation between the phosphorylation degrees of αs1- and αs2-CN (0.94) suggest that phosphorylation of αs1- and αs2-CN is related. Additionally, a total of 10 regions, distributed across Bos taurus autosomes (BTA) 1, 2, 6, 9, 11, 14, 15, 18, 24 and 28, were detected to be associated with individual αs1- and αs2-CN phosphorylation isoforms and their phosphorylation degrees. Regions on BTA1, 6, 11 and 14 were associated with multiple traits studied. Two quantitative trait loci (QTL) regions were detected on BTA1: one affecting αs2-CN production, and the other affecting αs1-CN PD and αs2-CN PD. The QTL region on BTA6 affected only individual αs2-CN isoforms. The QTL region on BTA11 and 14 affected relative concentrations of αs2-CN-10P and αs2-CN-11P, αs1-CN PD and αs2-CN PD. Results suggested that effects of identified genomic regions on αs1-CN PD and αs2-CN PD are probably due to changes in milk synthesis and phosphorus secretion in milk.
Metabolic status, lactation persistency, and udder health of dairy cows after different dry period lengths
Hoeij, Renny van - \ 2017
Wageningen University. Promotor(en): B. Kemp; T.J.G.M. Lam, co-promotor(en): A.T.M. Knegsel; J. Dijkstra. - Wageningen : Wageningen University - ISBN 9789463438070 - 285
dairy cattle - animal health - animal behaviour - dry period - metabolism - energy balance - lactation - milk production - udders - cattle feeding - melkvee - diergezondheid - diergedrag - gustperiode - metabolisme - energiebalans - lactatie - melkproductie - uiers - rundveevoeding
Cows traditionally have a 6 to 8 week non-lactating –‘dry period’- before calving and the start of the next lactation in order to maximize milk production in the subsequent lactation. An omitted, compared with a shortened, dry period reduces milk yield and improves energy availability in cows postpartum, but effects on udder health and persistency were unclear. Cows without a dry period fattened and spontaneously dried off due to the improved energy availability. Reducing the energy availability in the feed for cows without a dry period did not affect fattening or lactation persistency in late lactation. Cows with a short or without a dry period did not receive dry cow antibiotics in this study and this did not affect udder health across the dry period or in early lactation, but seemed to impair udder health in late lactation for cows without a dry period.
Predicting methane emission of dairy cows using milk composition
Gastelen, Sanne van - \ 2017
Wageningen University. Promotor(en): W.H. Hendriks, co-promotor(en): J. Dijkstra; K.A. Hettinga. - Wageningen : Wageningen University - ISBN 9789463437097 - 266
dairy cows - dairy cattle - methane production - emission - milk composition - fatty acids - cattle feeding - fermentation - nutrition physiology - animal nutrition - pollution - melkkoeien - melkvee - methaanproductie - emissie - melksamenstelling - vetzuren - rundveevoeding - fermentatie - voedingsfysiologie - diervoeding - verontreiniging
Enteric methane (CH4) is produced as a result of microbial fermentation of feed components in the gastrointestinal tract of ruminant livestock. Methane has no nutritional value for the animal and is predominately released into the environment through eructation and breath. Therefore, CH4 not only represents a greenhouse gas contributing to global warming, but also an energy loss, making enteric CH4 production one of the main targets of greenhouse gas mitigation practices for the dairy industry. Obviously, reduction of CH4 emission could be achieved by simply reducing livestock numbers. However, the global demand for dairy products has been growing rapidly and is expected to further grow in the future. Therefore, it is critical to minimize environmental impact to produce high-quality dairy products. The overall aim of this PhD research was, therefore, to develop a proxy for CH4 emission that can be measured in milk of dairy cows.
There are currently a number of potentially effective dietary CH4 mitigation practices available for the livestock sector. The results of Chapter 3 show that replacing fiber-rich grass silage with starch-rich corn silage in a common forage-based diet for dairy cattle offers an effective strategy to decrease enteric CH4 production without negatively affecting dairy cow performance, although a critical level of starch in the diet seems to be needed. Little is known whether host genetics may influence the CH4 emission response to changes in diet. Therefore, the interaction between host DGAT1 K232A polymorphism with dietary linseed oil supplementation was evaluated in Chapter 7. The results of Chapter 7 indicate that DGAT1 K232A polymorphism is associated with changes in milk composition, milk N efficiency, and diet metabolizability, but does not affect digestibility and enteric CH4 emission, whereas linseed oil reduces CH4 emission independent of the DGAT1 K232A polymorphism.
Accurate and repeatable measurements of CH4 emission from individual dairy cows are required to assess the efficacy of possible mitigation strategies. There are several techniques to estimate or measure enteric CH4 production of dairy cows, including climate respiration chambers, but none of these techniques are suitable for large scale precise and accurate measurements. Therefore, the potential of various metabolites in milk, including milk fatty acids (MFA), as a proxy (i.e., indicators or animal traits that are correlated with enteric CH4 production) for CH4 emission of dairy cows gained interest. Until recently, gas chromatography was the principal method used to determine the MFA profile, but this technique is unsuitable for routine analysis. This has led to the application of Fourier-transform infrared spectroscopy (FTIR) for determination of the MFA profile. Chapter 2 provides an overview of the recent research that relates MFA with CH4 emission, and discusses the opportunities and limitations of using FTIR to estimate, indirectly via MFA or directly, CH4 emission of dairy cattle. The recent literature on the relationship between MFA and CH4 emission gives inconsistent results. Where some studies found a clear and strong relation, other studies consider MFA to be unreliable predictors for CH4 emitted by dairy cows. Even the studies that do find a clear relation between MFA and CH4 emissions do not describe similar prediction models using the same MFA. These discrepancies can be the result of many factors, including dietary composition and lactation stage. Additionally, literature showed that the major advantages of using FTIR to predict CH4 emission include its simplicity and potential practical application on a large scale. Disadvantages include the inability to predict important MFA for the prediction of CH4 emission, and the moderate power of FTIR to directly predict CH4 emission. The latter was also demonstrated in Chapter 9, in which the CH4 prediction potential of MFA was compared with that of FTIR using data from 9 experiments (n = 218 individual cow observations) covering a broad range of roughage-based diets. The results indicate that MFA have a greater potential than FTIR spectra to estimate CH4 emissions, and that both techniques have potential to predict CH4 emission of dairy cows, but also limited current applicability in practice. Much focus has been placed on the relationship between MFA and CH4 emission, but milk also contains other metabolites, such as volatile and non-volatile metabolites. Currently, milk volatile metabolites have been used for tracing animal feeding systems and milk non-volatile metabolites were shown to be related to the health status of cows. In Chapter 4, the relationship between CH4 emission and both volatile and non-volatile metabolites was investigated, using data and milk samples obtained in the study described in Chapter 3. In general, the non-volatile metabolites were more closely related to CH4 emissions than the volatile metabolites. More specifically, the results indicate that CH4 intensity (g/kg fat- and protein-corrected milk; FPCM) may be related to lactose synthesis and energy metabolism in the mammary gland, as reflected by the milk non-volatile metabolites uridine diphosphate-hexose B and citrate. Methane yield (g/kg dry matter intake) on the other hand, may be related to glucogenic nutrient supply, as reflected by the milk non-volatile acetone. Based on the metabolic interpretations of these relationships, it was hypothesized that the addition of both volatile and non-volatile metabolites in a prediction model with only MFA would enhance its predictive power and, thus, leads to a better proxy in milk for enteric CH4 production of dairy cows. This was investigated in Chapter 5, again using data and milk samples described in Chapter 3. The results indicate that MFA alone have moderate to good potential to estimate CH4 emission. Furthermore, including volatile metabolites (CH4 intensity only) and non-volatile metabolites increases the CH4 emission prediction potential.
The work presented in Chapters 3, 4 and 5, was based upon a small range of diets (i.e., four roughage-based diets in which grass silage was replaced partly or fully by corn silage) of one experiment. Therefore, in Chapter 6, the relationship between CH4 emission and the milk metabolome in dairy cattle was further quantified. Data (n = 123 individual cow observations) were used encompassing a large of roughage-based diets, with different qualities and proportions of grass, grass silage and corn silage. The results show that changes in individual milk metabolite concentrations can be related to the ruminal CH4 production pathways. These relationships are most likely the result from changes in dietary composition that affect not only enteric CH4 production, but also the profile of volatile and non-volatile metabolites in milk. Overall, the results indicate that both volatile and non-volatile metabolites in milk might provide useful information and increase our understanding of CH4 emission of dairy cows. However, the development of CH4 prediction models revealed that both volatile and non-volatile metabolites in milk hold little potential to predict CH4 emissions despite the significant relationships found between individual non-volatile metabolites and CH4 emissions. Additionally, combining MFA with milk volatile metabolites and non-volatile metabolites does not improve the CH4 prediction potential relative to MFA alone. Hence, it is concluded that it is not worthwhile to determine the volatile and non-volatile metabolites in milk in order to estimate CH4 emission of dairy cows.
Overall, in comparison with FTIR, volatile and non-volatile metabolites, the MFA are the most accurate and precise proxy in milk for CH4 emission of dairy cows. However, most of MFA-based models to predict CH4 emission tend to be accurate only for the production system and the environmental conditions under which they were developed. In Chapter 8 it was demonstrated that previously developed MFA-based prediction equations did not predict CH4 emission satisfactory of dairy cows with different DGAT1 genotypes or fed diets with or without linseed oil. Therefore, the greatest shortcoming today of MFA-based CH4 prediction models is their lack of robustness. Additionally, MFA have restricted practical application, meaning that most MFA retained in the current CH4 prediction models cannot be determined routinely because of the use of gas chromatography. The MFA that can be determined with the use of infrared spectroscopy are however no promising predictors for CH4 emission. Furthermore, MFA have only a moderate CH4 prediction potential. This together suggests that it might not be the best option to focus in the future on MFA alone as a proxy for CH4 emission of dairy cows.
The FTIR technique has a low to moderate CH4 prediction potential. However, FTIR has a great potential for practical high throughput application, facilitating repeated measurements of the same cow potentially reducing random noise. Results of this thesis also demonstrated that FTIR spectra do not have the potential to detect differences in CH4 emission between diets which are, in terms of forage level and quality, commonly fed in practice. Moreover, the robustness of FTIR spectra is currently unknown. Hence, it remains to be investigated whether FTIR spectra can predict CH4 emissions from dairy cows housed under different conditions from those under which the FTIR-based prediction equations were developed. It is therefore concluded that the accuracy and precision to predict CH4 emission using FTIR needs to increase, and the capacity of FTIR to evaluate the differences in CH4 emission between dairy cows and different types of diets needs to improve, in order to actually be a valuable proxy for CH4 emission of dairy cows.
Monitoring verduurzaming veehouderij 1.0 : een eerste proeve van een Monitorings-systematiek voor de 15 ambities van de Uitvoeringsagenda Duurzame Veehouderij, met initiële resultaten voor drie diersectoren en een aantal keteninitiatieven
Bos, A.P. ; Puente-Rodríguez, Daniel ; Reijs, Joan W. ; Peet, G.F.V. van der; Groot Koerkamp, Peter W.G. - \ 2017
Wageningen : Wageningen Livestock Research (Wageningen Livestock Research rapport 1045) - 113
dierenwelzijn - dierlijke productie - melkvee - varkens - pluimvee - huisvesting, dieren - diergezondheid - diergedrag - animal welfare - animal production - dairy cattle - pigs - poultry - animal housing - animal health - animal behaviour
In 2013, the governance network UDV formulated fifteen ambitions towards a sustainable livestock production. In this way, the UDV’s stakeholders defined the long-term goals of an integrated and sustainable livestock production. To what extent have these 15 ambitions been achieved? And, how substantial is the contribution of supra-legal initiatives to this process? In this report, we present the first elaboration of a monitoring system that enables the visualization of the progress made. Moreover, it also enables comparing the different livestock production systems and creates the basis for a comparison between conventional animal production and supra-legal initiatives. In this concept-report the system is applied initially to the three larger livestock production sectors in the Netherlands (i.e., dairy, pigs, and poultry) and –as far as enough data is available– to four supra-legal initiatives. The system is currently under construction. Particularly because it involves interpretation and a number of value-laden choices that –notwithstanding their current support by arguments and references to the literature– should become shared and supported by (at least) the UDV stakeholders in the near future.
Evaluatie Actieplan Stalbranden 2012-2016
Bokma-Bakker, Martien ; Bokma, Sjoerd ; Ellen, Hilko ; Hagen, René ; Ruijven, Charlotte van - \ 2017
Wageningen : Wageningen Livestock Research (Wageningen Livestock Research rapport 1035) - 80
dierenwelzijn - dierlijke productie - diergezondheid - pluimvee - varkens - melkvee - schapen - geiten - paarden - stallen - brand - voorkomen van branden - veiligheid - animal welfare - animal production - animal health - poultry - pigs - dairy cattle - sheep - goats - horses - stalls - fire - fire prevention - safety
Maatregelen om weidegang te bevorderen : inventarisatie en analyse
Blokland, P.W. ; Pol-van Dasselaar, A. van den; Rougoor, C. ; Schans, F. van der; Sebek, L. - \ 2017
Wageningen : Wageningen Economic Research (Wageningen Economic Research rapport 2017-071) - ISBN 9789463436533 - 59
dierenwelzijn - dierlijke productie - melkvee - huisvesting - weiden - animal welfare - animal production - dairy cattle - housing - pastures
Monitoring integraal duurzame stallen : peildatum 1 januari 2017
Peet, G.F.V. van der; Meer, R.W. van der; Docters van Leeuwen, H. - \ 2017
Wageningen : Wageningen UR Livestock Research (Wageningen Livestock Research rapport 1027) - 19
huisvesting, dieren - stallen - monitoring - dierlijke productie - dierenwelzijn - rundvee - melkvee - pluimvee - duurzaamheid (sustainability) - animal housing - stalls - monitoring - animal production - animal welfare - cattle - dairy cattle - poultry - sustainability
De overheid ambieert een integraal duurzame veehouderij in 2023. Daarom wordt jaarlijks een nieuw doel gesteld. Voor eind 2016 (peildatum 1 januari 2017) noemt het ministerie als ambitie dat minimaal 14% van de rundvee-, varkens- en pluimveestallen integraal duurzaam is. Deze studie laat zien dat op 1 januari 2017 in Nederland 13,6 % van alle stallen integraal duurzaam is.
Maatregelen Natuurinclusieve landbouw
Erisman, Jan Willem ; Eekeren, Nick van; Doorn, Anne van; Geertsema, Willemien ; Polman, Nico - \ 2017
Wageningen : Wageningen Environmental Research (Wageningen Environmental Research rapport 2821) - 49
landbouw - natuur - agrarische bedrijfsvoering - maatregelen - biologische landbouw - dierenwelzijn - huisvesting, dieren - dierlijke productie - melkvee - agriculture - nature - farm management - measures - organic farming - animal welfare - animal housing - animal production - dairy cattle
In deze notitie wordt een overzicht gegeven van maatregelen voor natuurinclusieve landbouw. Dit is een vorm van duurzame landbouw die optimaal gebruik maakt van de natuurlijke processen en deze integreert in de bedrijfsvoering. Natuurinclusieve landbouw begint met een gezonde bodem, produceert voedsel binnen de grenzen van natuur, milieu en leefomgeving en heeft positieve effecten op de biodiversiteit en het klimaat.
Wat zijn de mogelijkheden om een leverbotinfectie van melkvee te voorkomen?
Neijenhuis, Francesca ; Verwer, Cynthia ; Verkaik, Jan - \ 2017
Wageningen : Wageningen UR Livestock Research (Livestock Research rapport 1029) - 65
leverbot - fascioliasis - melkvee - melkveehouderij - parasitosen - infectieziekten - dierlijke productie - dierenwelzijn - diergezondheid - biologische landbouw - liver flukes - fascioliasis - dairy cattle - dairy farming - parasitoses - infectious diseases - animal production - animal welfare - animal health - organic farming
Infecties met leverbot zijn in toenemende mate een knelpunt in de diergezondheid van grazende (of vers gras gevoerde) herkauwers. Leverbotinfectie leidt tot ziekte met economische gevolgen en voor melkgevende dieren zijn geen anthelmintica vrij beschikbaar. In dit project is het leverbotinstrument ontwikkeld met als doel om veehouders inzicht en handelingsperspectief te geven ten aanzien van de leverbotsituatie op hun bedrijf. In dit rapport worden de resultaten weergegeven van het leverbotinstrument en een drietal preventieve maatregelen die zijn uitgeprobeerd.
The utility of sensor technology to support reproductive management on dairy farms
Rutten, C.J. - \ 2017
Wageningen University. Promotor(en): H. Hogeveen; M. Nielen, co-promotor(en): W. Steeneveld. - Wageningen : Wageningen University - ISBN 9789463431934 - 232
dairy cattle - dairy farms - sensors - reproduction - reproductive behaviour - animal health - calving - activity - management - dairy farming - technology - agricultural economics - melkvee - melkveebedrijven - sensors - voortplanting - voortplantingsgedrag - diergezondheid - kalven - activiteit - bedrijfsvoering - melkveehouderij - technologie - agrarische economie
Since the 1980s, efforts have been made to develop sensors that measure a parameter from an individual cow. The development started with individual cow recognition and was followed by sensors that measure the electrical conductivity of milk and pedometers that measure activity. Some sensors like activity meters, electrical conductivity, weight floors and somatic cell count sensors are commercially available. Adoption has in general been low and mainly driven by the AMS, with a clear exception for estrus detection. In practice, the economic benefits of using sensor systems has not been proven. So, to make sensors live up to their full potential there is a need for research to shift from technical development towards practical applications and integration with operational farm management. Estrus detection sensors can have a good detection performance and are currently applied by farmers in practice, therefore this thesis focusses on sensors that support reproductive management. The main objective of this thesis is to study the utility of sensor technology to support reproductive management on dairy farms. This main objective was split in five sub objectives that each study a part of the main objective and were discussed in the separate chapters of this thesis.
We demonstrated that utility of sensors for reproductive management can be found in economic benefits (estrus and calving detection), reduction of labor (calving and estrus detection) and more detailed management information (prognosis of insemination success). So, automated estrus detection aids reproductive management.
From this thesis the following conclusions can be drawn:
The developed theoretical framework describes four levels of sensor development, which should all be included in proper development of sensor systems. The literature review showed that no studies developed sensor systems with regard to management and decision support.
It was possible to improve the prediction of the start of calving compared to a model that only uses the expected calving date. However, predicting the start of calving within an hour was not possible with a high sensitivity and specificity.
There was financial merit in the use of calving detection, because the sensor system enables more timely intervention by the farmer. The uncertainty about the positive effects was large, which caused a wide range in the simulated financial benefits.
Investment in a sensor for estrus detection was on average profitable with a return on investment of 11%. Profitability was influenced most by the heuristic culling rules and the expected increase of the estrus detection rate between detection by visual observation and the sensor.
Routinely collected farm data can be used to estimate a prognosis on insemination success and be used to determine whether an individual cow has a higher or lower than average likelihood of insemination success. Integration of this prognostic model with an estrus detection sensor has potential.
Currently farmers only adopt sensors for estrus detection or because they were standard with an AMS. A reason for this is that sensor systems do not produce clear information for farmers. Sensor technology should be focused on management support of applications. Labor benefits of sensors are important for adoption of sensors by farmers, farmers value flexibility, increased family time and less physical workload as benefits. However, economic evaluations of technical solutions are unable to quantify these benefits. Sensor research should consider the preference of farmers regarding labor. For the appraisal of sensor technology new methods to value labor benefits of sensor are needed. Furthermore, in sensor development societal acceptance should be an important consideration. Animal rights activists may frame the use of sensors as a form of industrialized farming. Only using technical arguments and considerations to explain the benefits of sensors will hamper the societal acceptance of modern dairy farming. Application of sensors on dairy farms should be communicated smartly to society in terms that relate the values of citizens.
De PerceelVerdeler: optimaal verdelen van de beschikbare mest op het melkveebedrijf
Oenema, Jouke ; Verloop, Koos ; Hilhorst, Gerjan - \ 2017
Wageningen : Wageningen UR Livestock Research (Rapport / Koeien & Kansen 78) - 25
melkvee - melkveehouderij - rundveemest - kunstmeststoffen - ruimtelijke verdeling - dairy cattle - dairy farming - cattle manure - fertilizers - spatial distribution
Het verlagen van de TAN-excretie als maatregel om de ammoniakemissie op het melkveebedrijf te verminderen : methodiek voor het vaststellen van de TAN-excretie: module ‘Bedrijfsspecifieke Emissie Ammoniak’ (BEA) van de Kringloopwijzer
Šebek, L. ; Migchels, G. ; Dijk, C. van - \ 2017
Wageningen : Wageningen Livestock Research (Wageningen Livestock Research rapport 1020) - 33
melkvee - melkveehouderij - ammoniakemissie - emissiereductie - rundveevoeding - rundveemest - agrarische bedrijfsvoering - dairy cattle - dairy farming - ammonia emission - emission reduction - cattle feeding - cattle manure - farm management
Ontwikkelen beweidingsystemen bij hoge veebezetting op kleine huiskavel : beweidingsonderzoek op klei- en veengrond in 2015
Galama, P.J. ; Holshof, G. ; Reenen, K. van - \ 2017
Wageningen : Wageningen Livestock Research (Wageningen Livestock Research rapport 1016) - 51
melkvee - beweidingssystemen - zware kleigronden - veengronden - bezettingsdichtheid - melkveehouderij - nederland - dairy cattle - grazing systems - clay soils - peat soils - stocking density - dairy farming - netherlands
Breeding strategies for sustainable intensification of developing smallholder dairy cattle production systems
Kariuki, Charles Mbogo - \ 2017
Wageningen University. Promotor(en): J. Komen, co-promotor(en): J.A.M. Arendonk; A.K. Kahi. - Wageningen : Wageningen University - ISBN 9789463430951 - 134
dairy cattle - small businesses - sustainable animal husbandry - intensification - breeding programmes - progeny testing - genetic improvement - dairy performance - developing countries - melkvee - kleine bedrijven - duurzame veehouderij - intensivering - veredelingsprogramma's - nakomelingenonderzoek - genetische verbetering - melkresultaten - ontwikkelingslanden
Smallholder dairy cattle production systems in Africa are intensifying production through importation of germplasm from breeding programs conducted in temperate regions to improve commercial cow populations. Presence of genotype by environment interaction results in unfavorable correlated responses. The aim this thesis was to develop strategies for breeding programs in developing countries that can support sustainable intensification of these systems. Specific objectives were (a) to determine desired gains for breeding objective traits, (b) compare progeny testing (PT) and genomic selection (GS) selection strategies, (c) evaluate the economic performance of PT and GS selection strategies and (d) compare genetic gains for economic and non-economic breeding objectives; the Kenya dairy cattle sector was used as a working example. To account for the limited pedigree and performance recording, a five-trait breeding objective and small-sized breeding program were studied. Breeding objective traits, determined based on producer preferences, were milk yield (MY), production lifetime (PLT), calving interval (CI), fat yield (FY) and mature body weight (MBW). Producers were categorized into high intensive group, who placed highest preference on PLT and MY, and low intensity group that placed highest preferences on CI and PLT. MY and FY were the most important traits for processors. Consensus desired gains, based on weighted goal programming, were 2.51, 2.42, 0.22, 0.87 and 0.15% for PLT, MY, CI, FY and MBW, respectively. Comparison of breeding schemes shows that GS schemes had lower accuracies but gave higher responses per year due to shorter generation intervals. Besides genetic gains, economic performance underpins the adoption of selection strategies. GS schemes had between 3.2 and 5.2-fold higher cumulated genetic gain in the commercial cow population and higher gross margins compared to PT schemes. Semen storage made PT schemes more profitable but less so than GS schemes. Functional traits can increase the sustainability of resource poor smallholder systems under harsh environments. Economic breeding objectives yielded undesirable responses in functional traits. Breeding objectives based on desired gains or non-market objectives improved response in functional traits but at a monetary cost. It is concluded that sustainable productivity of smallholder systems can be improved by implementation of local breeding program based on GS, but this requires more emphasis on functional traits, which can be achieved by use of non-economic objectives.
Aspects of rumen adaptation in dairy cattle : morphological, functional, and gene expression changes of the rumen papillae and changes of the rumen microbiota during the transition period
Dieho, Kasper - \ 2017
Wageningen University. Promotor(en): Wouter Hendriks, co-promotor(en): Jan Dijkstra; Andre Bannink; J.Th. Schonewille. - Wageningen : Wageningen University - ISBN 9789463430258 - 248
dairy cattle - rumen - rumen microorganisms - morphology - gene expression - animal nutrition - dry period - lactation - melkvee - pens - pensmicro-organismen - morfologie - genexpressie - diervoeding - gustperiode - lactatie
In dairy cattle the nutrient requirements change rapidly around calving. During the dry period nutrients are required for maintenance, recovery from the previous lactation, and fetal growth. After calving, milk production commences and the energy requirements can increase by a factor 3 to ~184 MJ net energy for lactation during the first weeks of lactation, compared with the dry period, whereas feed intake doubles to ~24 kg dry matter (DM)/d compared with the dry period. In addition, high quality lactation rations are fed, usually containing a sizable portion of concentrate, thereby increasing fermentable organic matter (FOM) intake to ~14 kg/d. As a result, daily volatile fatty acid (VFA) production by the rumen microbiota increases from ~60 mol/d during the dry period to ~132 mol/d during early lactation. To maintain rumen pH at levels favorable for microbial fermentation, and prevent a negative impact on production and health, clearance of the produced VFA is essential. This mainly occurs through absorption over the rumen wall. The increase in capacity of the rumen for absorption of VFA is associated with morphological and functional changes of the rumen papillae which cover the rumen wall. However, current knowledge of these changes as they occur around calving is scarce (Chapter 1). Increasing our understanding of the adaptation of the rumen can provide new insights to optimize dairy cattle nutrition and thereby health, welfare, and production.
The objective of this thesis was to study the adaptation of the rumen to ration changes during the dry period and early lactation. Changes in rumen papillae morphology, fractional absorption rate of VFA (kaVFA), and changes in the composition of the rumen microbiota were the primary targets for study. In addition, the expression of genes and proteins associated with absorption and metabolism of VFA by the rumen epithelium were studied to better understand the relationship between functional changes and morphological changes of the papillae. Uniquely, all these aspects were studied in parallel in the same dairy cows during the dry period and early lactation using a repeated measurement setup. Two experiments were conducted. In the lactation experiment, the effect of transition from the dry period to the subsequent lactation, and the effect of early lactation concentrate build-up strategy on the adaptation of the rumen were studied. In the dry period experiment, the effect of feeding supplemental concentrate during the late dry period in order to ‘prepare’ the rumen for the lactation was studied. Treatments of both experiments were aimed at creating a difference in FOM intake (kg/d) and thereby VFA production (mol/d), as VFA production was hypothesized to affect rumen papillae development and thereby the capacity for VFA absorption.
During the lactation experiment, intake of FOM did not change during the dry period (5.7 kg/d), but increased during the subsequent lactation to 15.0 kg/d at 80 d postpartum (pp). In addition, the rapid increase in concentrate allowance resulted in a temporarily 22% greater FOM intake compared with a gradual increase at 16 d pp (Chapter 2). The total production rate of VFA, measured using an isotope dilution technique (Chapter 3), was affected by these changes in FOM intake and increased 2.3 fold to 123 mol/d after calving, compared with the dry period (53 mol/d). The temporarily greater FOM intake with the rapid increase in concentrate allowance at 16 d pp coincided with a 54% greater propionate production (34 mol/d) compared with a gradual increase in concentrate allowance, whereas acetate (66 mol/d) and butyrate (10 mol/d) production were not affected. Papillae surface area (Chapter 2) decreased by 19% between 50 d antepartum (ap) and 3 d pp to 28.0 mm2, but increased during early lactation to 63.0 mm2. Papillae surface area increased faster with the rapid increase in concentrate allowance and surface area was 38, 34 and 22% larger at 16, 30, and 44 d postpartum respectively, than with a gradual rate of increase of concentrate allowance. Histology (Chapter 2) revealed that rumen papillae and epithelium thickness decreased slightly after calving, but were not affected by the concentrate treatment. Feeding concentrate during the dry period did not affect daily FOM intake (6.0 kg/d) but did increase VFA concentration in the rumen fluid by 21 mM to 121 mM, and increased papillae surface by 29% (Chapter 4). However, the increased papillae surface area in the dry period was not maintained to the subsequent lactation period. After calving, papillae surface area increased by 50% to 58.0 mm2 at 45 d pp. The postpartum development of the rumen papillae was not affected by the treatment during the dry period. These results indicate that rumen papillae respond to changes in FOM and VFA production intake during the dry period and early lactation, and that the magnitude of this response depends on the rate of change in FOM intake.
During both experiments, kaVFA was measured using a buffer incubation technique in an empty washed rumen. During the lactation experiment (Chapter 3), in accordance with the developments in papillae surface area, the kaVFA decreased during the dry period from 0.48/h at 50 d ap to 0.34/h at 3 d pp. During the subsequent lactation, it increased rapidly to 0.56/h at 16 d pp and further to 0.72/h at 80 d pp. However, the greater papillae surface area due to the rapid increase in concentrate did not coincide with a greater kaVFA. During the dry period experiment (Chapter 4), kaVFA increased after calving by 50% to 0.48/h at 45 d pp, but the increase in papillae surface area due to supplemental concentrate during the dry period did not affect the kaVFA during the dry period (0.36/h) or the subsequent lactation. These results indicate that papillae surface area is not the limiting factor for kaVFA.
Changes in the expression of genes were studied at the mRNA level in papillae tissue from both experiments (Chapter 5). The expression of apoptosis related genes was not affected by sampling day or its interaction with treatment for both experiments, suggesting papillae proliferation during the transition period was mainly the result of an increased mitosis rate. The limited changes in the expression of genes associated with rumen epithelial transport and metabolism of VFA in dairy cows during the transition period do not suggest that these capacities of the epithelium increased per unit of surface area. Thus the major response to the increase in daily VFA production after calving was tissue proliferation. In addition, papillae from the lactation experiment were used to study expression at the protein level using immunoblotting. Results showed that expression of several proteins changed during early lactation indicating modulation of intracellular pH regulation and sodium homeostasis, and VFA metabolism. Only for one gene, a significant but weak correlation between the examined mRNA and protein expression levels was observed, indicating that care must be taken when interpreting results obtained at either level.
Ration changes associated with the transition from the dry period to lactation affected the rumen microbiota during the lactation experiment (Chapter 6). The rapid increase in concentrate allowance postpartum temporarily decreased bacterial community richness by as much as 30% compared with a gradual increase in concentrate. This transient depression in bacterial community richness with a rapid, but not a gradual, rate of increase of concentrate allowance pp indicates that the rate of change in ration composition and feed intake has a greater effect than the change in ration composition and feed intake level as such. The relative abundances of most major bacterial taxa were affected by the transition to lactation, but few were affected by the rate of increase of the concentrate allowance. The relative abundances of rumen protozoal taxa changed after calving, and were affected by the concentrate treatment. However, differences between treatments groups disappeared again when concentrate intake became similar. The archaeal community was likewise affected by both the transition to lactation and the treatment. The observed changes in rumen microbiota composition, including changes in bacterial community richness, did not appear to affect the fractional degradation rate of NDF, starch, CP, and OM measured in situ using a nylon bag technique.
The results in the present thesis show that morphologically and functionally the rumen papillae can adapt rapidly to the changes in FOM intake and daily VFA production associated with the transition from the dry period into the subsequent lactation. However, the contrast in response of rumen papillae surface area development and the fractional absorption rate of VFA to the concentrate treatments indicates that papillae surface area is not the limiting factor for VFA absorption. This proposition is further supported by the limited histological changes of the rumen epithelium and limited changes in gene expression. Considering that the capacity for absorption and metabolism of VFA per unit of papillae surface area remains similar, an extra-epithelial factor, likely visceral blood flow, limits VFA absorption. The capacity of the rumen to adapt after calving and the limited beneficial effect of supplementing concentrate during the dry period indicate that dry period feeding strategies can best be optimized for the prevention of periparturient diseases.
Effect of Comfort Slat Mats with and without valves on ammonia emission from dairy housing : case control measurements at Dairy Campus Leeuwarden
Dooren, H.J.C. van; Zonderland, J.L. ; Blanken, K. ; Bokma, S. - \ 2016
Wageningen : Wageningen UR Livestock Research (Livestock Research report 1028) - 22
dairy cattle - dairy farming - cattle housing - floor type - valves - ammonia emission - emission reduction - melkvee - melkveehouderij - huisvesting van rundvee - vloertypen - kleppen - ammoniakemissie - emissiereductie
Vroegtijdig scheiden van melkkoe en kalf : Implicaties voor gedrag en gezondheid in het licht van de gangbare praktijk
Hopster, H. ; Bergsma, Karin - \ 2016
Leeuwarden : University of Applied Sciences Van Hall Larenstein - 95
dierenwelzijn - dierlijke productie - melkvee - diergezondheid - diergedrag - huisvesting, dieren - animal welfare - animal production - dairy cattle - animal health - animal behaviour - animal housing
Vroegtijdige scheiding van melkkoe en kalf roept in de samenleving in toenemende mate vragen op over de effecten daarvan op dierenwelzijn. In de visie van de Duurzame Zuivelketen (DZK) valt de zorg voor kalveren binnen de scope van zuivelkwaliteitssystemen. Ter onderbouwing van haar beleidsvisie aangaande vroegtijdig scheiden van koe en kalf heeft de DZK in 2015 onderzoek laten doen. Dit onderzoek is uitgevoerd door het lectoraat Welzijn van Dieren van Van Hall Larenstein. Het behelst literatuur- en survey-onderzoek waarmee de stand van zaken – wetenschappelijke kennis en gangbare praktijk – rond de kwestie in kaart is gebracht. Tenslotte is door praktijkdeskundigen, onderzoekers en melkveehouders gereflecteerd op de voorlopige resultaten.
Grazing and automation : proceedings 4th Meeting EGF Working Group "Grazing" in Wageningen
Pol-van Dasselaar, A. van den; Vlieger, A. de; Hennesy, D. ; Isselstein, J. ; Peyraud, J.L. - \ 2016
Wageningen : Wageningen Livestock Research (Livestock Research rapport 1003) - 24
dairy cattle - machine milking - grazing - dairy farming - automation - melkvee - machinaal melken - begrazing - melkveehouderij - automatisering
The citizen goes shopping : a framework for the assessment and optimization of production from the perspective of society
Michalopoulos, Tassos - \ 2016
Wageningen University. Promotor(en): Alfons Oude Lansink; Michiel Korthals, co-promotor(en): Henk Hogeveen. - Wageningen : Wageningen University - ISBN 9789462579828 - 207
food production - food ethics - labelling - consumer behaviour - consumer preferences - optimization - consumer information - philosophy - political attitudes - animal production - animal ethics - cattle - dairy cattle - voedselproductie - voedselethiek - etiketteren - consumentengedrag - consumentenvoorkeuren - optimalisatie - consumenteninformatie - filosofie - politieke houding - dierlijke productie - dierethiek - rundvee - melkvee
Nowadays, product labels are often used to enable consumers choose products that are friendly to the environment and to animals, natural, healthful and socially responsible. However, certain features of commonly used labels limit their usefulness. This thesis identifies a number of these limitations and presents an innovative labeling approach designed to address them.
More specifically, the following features limit the usefulness of the commonly used “endorsement” labels: they (1) offer a single certification grade, the requirements for which (2) are ‘static’ in the sense that certification standards do not depend on the evolution of the market, (3) are voluntary, and (4) are defined by stakeholders. Consequently, common labels fail to remove information asymmetry regarding the ethical performance of non-certified products; limit the opportunities for moderately –yet positively– concerned consumers to reveal ethical preferences; fail to motivate product improvement beyond certification standard; allow the emergence of a confusing variety of overlapping labels; and allow production stakeholders to resist socially desirable certification requirements when these are unfavorable to their business. In shoft, ethical labels currently fail to unleash on ethical aspects of production the inherently ‘free-market’ dynamics according to which products and firms must continuously innovate and improve, or else become obsolete and vanish.
As an alternative, this thesis proposes and works out an innovative “comparative” labeling approach that is designed to address these limitations. The proposed type of label is (1) multi-grade or continuous, (2) dynamic, (3) mandatory, and (4) society-defined. An example of this type of label is given at Figure 1.
Figure 1: Two variations of an example intuitive color-coded label format. The variations depict different sets of product attributes, and also different aggregation levels of the Environmental Impact attribute.
This type of labeling could motivate the creation of a ‘vitruous cyrcle’ or ‘race to the top’, in which the ethical performance of products moves to the direction that society at large regards as ‘positive’. This process is outlined at Figure 2.
Figure 2: Expected effects on the environmental performance of marketed product substitutes from the introduction of the proposed labeling system, in three phases. In Phase 1, the label is introduced on product substitutes available in the market (supply). In Phase 2, the supply evolves. To the standard (negative) incentives for cost minimization, are now added (positive) incentives to avoid negative reputation and to improve further the environmental frontiers of production through innovation. In Phase 3, the label is adjusted (updated) to the evolved supply. Products that failed to improve since last update might become downgraded (blue arrows).
It is argued that the proposed labeling approach has the potential to boost ethical consumerism as a force for the ethical optimization of the market. This can be directly relevant to issues about which society is concerned, and democratically elected goverments have limited ability to regulate. Among possible uses of the method developed to assess the relative performance of substitute products, are the comparative ranking of presently available labels (so as to inform consumers on the relative impact of different certified products), the justification of the allocation of incentives and discincentives in state policy, and also the ethical optimization and promotion of own production by socially responsible suppliers. Overall, the described approach aspires to transform markets into instruments that work to the direction willed by society, so as to bring market-driven and continuous improvement for production aspects of societal concern, such as environmental and socioeconomic aspects of the real economy.
Shortening or omitting the dry period in dairy cows : effects on milk yield, energy balance, metabolic status, and fertility
Chen, Juncai - \ 2016
Wageningen University. Promotor(en): Bas Kemp, co-promotor(en): Ariette van Knegsel. - Wageningen : Wageningen University - ISBN 9789462579088 - 205
dairy cows - dairy cattle - dry period - milk yield - energy balance - metabolism - lactation - melkkoeien - melkvee - gustperiode - melkopbrengst - energiebalans - metabolisme - lactatie
During early lactation, dairy cows typically experience negative energy balance (EB) caused by the high energy requirement for milk yield, which cannot be met by feed intake. Severity of negative EB has been associated with an increased incidence of metabolic disorders and infectious diseases, subfertility, and increased culling rates. Shortening or omitting the dry period (DP) and feeding glucogenic diet could possibly improve EB in dairy cows. The objective of this thesis was to study the effects of shortening or omitting the DP on milk yield, energy balance, metabolism, and fertility over two subsequent lactations in dairy cows fed a lipogenic or glucogenic diet during early lactation. In the current study, 167 cows were assigned to three DP lengths (0, 30, or 60 days) and two early lactation diets (glucogenic or lipogenic diet), and cows were planned to have same DP length and diet over two subsequent lactations. In the first lactation after DP length and dietary treatments, shortening or omitting the DP improved EB due to a decreased milk yield in the early lactation compared with a conventional DP of 60 days. Omitting the DP or feeding a glucogenic diet improved metabolic status in early lactation. Moreover, omitting the DP increased the percentage of cows with normal resumption of ovarian cyclicity. Shortening the DP to 30 d did not influence metabolic status and fertility compared with conventional DP in dairy cows. In the first lactation, the cows with a 0-d DP had less milk but similar energy intake, leading to excessive weight gain and, therefore, high body condition score (BCS) at onset of the second lactation after DP length and dietary treatments. In the second lactation, improvement of EB in cows with a 0-d DP was less pronounced than the first lactation, which could be related to the high BCS at onset of lactation and reduced milk yield losses. Shortening or omitting the DP did not influence uterine health status, ovarian activity, and reproductive performance in the second lactation. In second lactation, feeding a glucogenic diet improved metabolic status and shortened the interval from calving to first ovulation compared with a lipogenic diet without affecting EB independent of DP length. Furthermore, shortening or omitting the DP decreased peak yield but did not influence lactation persistency in both lactations after implementation of DP treatment. In conclusion, omitting the DP improved metabolic status and resumption of ovarian activity, which was related to an improved EB in early lactation. Shortening the DP for two subsequent lactations could be achieved for most cows with limited milk yield losses. Independent of DP length, glucogenic diet improved EB and metabolic status compared with lipogenic diet in early lactation.