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Balancing food production and biodiversity conservation
Kok, A. ; Muscat, A. - \ 2019
EU
Modelling the consequences of an extended lactation on GHG emissions and economics in dairy cows
Kok, A. - \ 2019
Evaluation of customized dry period management in dairy cows
Kok, A. ; Hoeij, R.J. van; Kemp, B. ; Knegsel, A.T.M. van - \ 2019
In: Book of Abstracts of the 70th Annual Meeting of the European Federation of Animal Science. - Wageningen Academic Publishers (EAAP books of abstracts ) - ISBN 9789086863396 - p. 536 - 536.
Food and biodiversity impacts of conservation scenarios on Dutch agricultural land
Oostvogels, V.J. ; Kok, A. ; Olde, E.M. de; Ripoll Bosch, R. - \ 2019
In: Book of Abstracts of the 70th Annual Meeting of the European Federation of Animal Science. - Wageningen Academic Publishers (EAAP books of abstracts ) - ISBN 9789086863396 - p. 349 - 349.
Customising dry period management: consequences for milk yield, body condition and disease incidence
Knegsel, A.T.M. van; Hoeij, R.J. van; Kemp, B. ; Kok, A. - \ 2019
In: Proceedings of the 17th International Conference on Production Diseases in Farm Animals. - Bern, Switserland : University of Bern - ISBN 9783906813936 - p. 147 - 147.
Advantages of shortening and omitting of the dry period are an improved energy balance and metabolic status in early lactation and potentially also an improved fertility (Van Knegsel et al., 2013). Disadvantages, however, are a reduction in milk yield in the subsequent lactation, loss of opportunity for selective dry cow therapy (DCT) and, in case of omitting of the dry period, reduction in concentration of antibodies in colostrum. Moreover, response of dairy cows to different dry period lengths was related to individual cow characteristics, like parity (Annen et al., 2004), milk yield level or SCC level (Van Hoeij et al., 2016). Therefore, it can be hypothesized that customising dry period management for individual cows could mitigate negative impacts of shortening and omitting the dry period on milk production and udder health, and at the same time retain benefits from both a dry period as well as benefits from a short or no dry period. In this study, we aimed to evaluate two decision trees to customize dry period length and selective DCT based on parity, milk production and SCC in late lactation.
Customising lactation length: impact of calving interval, parity, and lactation persistency on milk production of dairy cows
Burgers, Eline ; Kok, A. ; Goselink, R.M.A. ; Knegsel, A.T.M. van - \ 2019
In: Proceedings of the 17th International Conference on Production Diseases in Farm Animals. - Bern, Switserland : University of Bern - ISBN 9783906813936 - p. 148 - 148.
The transition period around calving is a critical phase for a dairy cow. Large changes in both physiology and management increase the risk for disease. In most modern dairy systems a cow faces this transition period every year, as a one-year calving interval (CI) is usually aimed for. Increasing CI reduces the relative amount of transition periods for a cow, thereby potentially reducing the risk for disease and improving fertility. Drawback of an increased CI is a possible reduction in milk yield although estimated effects of an increased CI on milk yield differ among studies. Some farmers in the Netherlands deliberately increase CI by increasing the voluntary waiting period for insemination (VWP), using various strategies to select cows that may benefit from an increased CI. This study aims to gain insight in cow characteristics that can be used to optimize CI for individual cows by assessing how CI, parity, and persistency impact milk production.
Review: Dry period length in dairy cows and consequences for metabolism and welfare and customised management strategies
Kok, A. ; Chen, Juncai ; Kemp, B. ; Knegsel, A.T.M. van - \ 2019
Animal 13 (2019)S1. - ISSN 1751-7311 - p. S42 - S51.
Shortening or omitting the dry period improves the energy balance and metabolic status of dairy cows in early lactation. Metabolic, behaviour and welfare effects throughout lactation, however, are unclear. The current paper reviews long-term metabolic and welfare consequences of short and no dry period, as well as feeding strategies and individual cow characteristics that could support in optimising management of cows with a short or no dry period. The paper will conclude with impacts of short and no dry periods at herd level and in practice. Energy balance after no or a short dry period is more positive during the complete subsequent lactation. After the initial improvement in early lactation, cows after no dry period tend to fatten and may have a too low lactation persistency to be continuously milked until the onset of the subsequent lactation. Reducing dietary energy level for cows with no dry period reduced fattening during the complete lactation but did not improve lactation persistency. Feeding a more lipogenic diet for cows with a short or no dry period did not affect the energy balance or lactation persistency during the complete lactation, although a lipogenic diet resulted in lower plasma insulin and IGF-1 concentration and greater plasma growth hormone concentration, compared with a glucogenic diet. Effects of dry period length on udder health are ambiguous, whereas short and no dry periods improved fertility in most studies. Omission of the dry period changed behaviour of cows both before and after calving, with a longer lying time and greater feed intake after calving, suggesting a better adaptation to a new lactation. Individual cow characteristics like parity, genotype, prepartum body condition score, and milk yield level determined the metabolic response of cows to a short or no dry period. In conclusion, short or no dry periods increase the energy balance in the complete lactation. Feeding strategies can be used to limit fattening of cows with no or short dry period, but the studied feeding strategies did not increase lactation persistency. Improved fertility and behavioural changes around calving suggest a better adaptation to a new lactation in case of no dry period. Customised dry period lengths for individual cows could improve metabolic status of cows at risk of a severe negative energy balance while minimising milk losses.
‘Droogstand afwegen per individuele koe’: Korte droogstand kost melk, minder ziekten
Hoeij, Renny van; Kok, Akke ; Knegsel, Ariette van - \ 2019

Kan de droogstand korter dan de traditionele zes tot acht weken? Wageningen
UR toont aan dat rigoureus kiezen voor korter of niet droogzetten te veel
productie kost, maar wel positief uitpakt voor de gezondheid. De onderzoekers
stellen dat de optimale droogstandsstrategie verschilt per individuele koe. Om
dit te bepalen, ontwikkelden ze een beslismodel.

Droogstand op maat kan antibioticagebruik en ziekte bij koeien reduceren
Kok, Akke ; Hoeij, Renny van; Kemp, Bas ; Knegsel, Ariette van - \ 2019

'Droogstand op Maat', een beslismodel op basis van individuele koekenmerken, kan de melkproductieverliezen na het verkorten of weglaten van de droogstand beperken en de gezondheid van koeien verbeteren. Dat blijkt uit een onderzoek uitgevoerd door Wageningen University & Research in samenwerking met de Universiteit Utrecht en de University of Bern in Zwitserland.

Relationship between metabolic status and behavior in dairy cows in week 4 of lactation
Hoeij, R.J. van; Kok, A. ; Bruckmaier, R.M. ; Haskell, M.J. ; Kemp, B. ; Knegsel, A.T.M. van - \ 2019
Animal 13 (2019)3. - ISSN 1751-7311 - p. 640 - 648.
continuous milking - dry period length - feeding behavior - lactogenic hormones - sensor technology

Blood metabolite and hormone concentrations are indicative of metabolic status, but blood sampling and analysis is invasive and time-consuming. Monitoring behavior can be done automatically, and behaviors may also be used as indicators of metabolic status. The aim of this study was to analyze the relationships between metabolic status and feeding behavior, lying behavior, motion index and steps of dairy cows in week 4 postpartum. Behavioral data from 81 Holstein-Friesian cows were collected using computerized feeders and accelerometers, and blood samples were collected for analysis of free-fatty acid (FFA), β-hydroxybutyrate (BHB), glucose, insulin, IGF-1 and growth hormone (GH) concentrations. First, cluster analysis was performed to categorize cows as having poor, average, good or very good metabolic status based on their plasma FFA, BHB, glucose, insulin, IGF-1 and GH concentration. Subsequently, the performance and behavior of cows in clusters with poor, average and good metabolic status were compared using GLM. Cows with a poor or average metabolic status tended to have greater fat-and-protein-corrected milk yield than cows with good metabolic status. Furthermore, cows with a poor metabolic status had a lower energy balance and dry matter intake (DMI) than cows with an average or good metabolic status and had a lower number of meals than cows with good metabolic status. Daily number of visits to the feeder and lying time tended to be positively related with metabolic status. Feeding rate (kg/min), daily meal time (min/day), number of lying bouts per day, steps and motion index were not related with metabolic status. In conclusion, better metabolic status in dairy cows in early lactation was associated with a greater DMI, increased feeding activity and a tendency to more time spent lying, compared with poor metabolic status. These results suggest that compromised metabolic status is reflected in altered cow's behavior in week 4 of lactation.

Customising dry period length: metabolic and behavioural effects
Knegsel, A.T.M. van; Kok, A. ; Kemp, B. - \ 2018
In: International Workshop on the Biology of Lactation in Farm Animals. - - p. 15 - 15.
Shortening or omitting the dry period improves the energy balance and metabolic status of dairy cows in early lactation. Apart from early lactation, however, metabolic and welfare effects are less beneficial or unclear. Cows tend to fatten in late lactation or have limited persistency to be continuously milked for a second lactation. Moreover, the dry period in late lactation is often considered to be a rest period for the cow, and the consequences of omitting the dry period for the cow are unknown. Also, the metabolic response to a short or no dry period differs between cows. The current paper gives an overview of our work concerning short and no dry periods in relation with: 1. feeding strategies to limit fattening and increase lactation persistency; 2. behaviour of cows in the months around calving; and 3. individual cow characteristics that determine metabolic status of cows after a short or no dry period.Reducing dietary energy level for cows with no dry period did not affect lactation persistency, but reduced the energy balance and weekly body weight gain during 44 weeks of lactation. Feeding a more lipogenic diet for cows with a short (30-d) or no dry period did not affect lactation persistency or the energy balance during the complete lactation, although a lipogenic diet resulted in lower plasma insulin and IGF-1 concentration and greater plasma growth hormone concentration, compared with a glucogenic diet.
No dry period resulted in a 1 hour shorter lying time before calving, but in a 1 hour longer lying time and greater feed intake after calving, compared with a short dry period.Individual cow characteristics like parity, body condition score at calving, DGAT-1 genotype, and milk yield level determined the metabolic response of cows to a short or no dry period, compared with a conventional (60-d) dry period.
In conclusion, feeding strategies can be used to limit fattening of cows with no or short dry period, but the studied feeding strategies had limited value to increase lactation persistency. Behavioural changes around calving suggest a better adaptation to a new lactation for cows with no dry period, compared with a short dry period. Individual cow characteristics could be used to develop a cow-specific management system for the dry period.
Eerste fase van onderzoeksproject ‘Droogstand op maat’ afgerond
Kok, Akke - \ 2018

Verkorten of weglaten van de droogstand bij melkkoeien heeft geringe gevolgen voor economie en milieu, en biedt mogelijkheden om welzijn en gezondheid van koeien met een goede uiergezondheid verder te verbeteren. Die conclusie wordt getrokken na het afronden van de eerste fase van het project Droogstand op Maat, waarbij in een experiment op Dairy Campus en bij een netwerk met 16 Nederlandse melkveehouders waarbij doelbewust de droogstand is verkort of weggelaten voor ten minste een gedeelte van de koeien.

No dry period: consequences for dairy cows, cash flows, and climate
Kok, Akke - \ 2018
Behaviour in relation to energy balance and metabolic status in dairy cows
Kok, Akke - \ 2018
Droogstand op Maat - fase 2 : Evaluatie beslismodellen voor droogstandsmanagement
Kok, A. ; Hoeij, R.J. van; Kemp, B. ; Knegsel, A.T.M. van - \ 2018
Wageningen : Wageningen University, leerstoelgroep Adaptatiefysiologie - 17
No dry period: consequences for dairy cows, cash flows, and climate
Kok, A. ; Knegsel, A.T.M. van; Middelaar, C.E. van; Hogeveen, H. ; Kemp, B. ; Boer, I.J.M. de - \ 2018
In: Book of abstracts of the 69th Annual Meeting of the European Federation of Animal Science. - Wageningen : Wageningen Academic Publishers (Book of abstracts 24) - ISBN 9789086863235 - p. 442 - 442.
A systematic review of research on biodiversity in European livestock systems
Kok, A. ; Boer, I.J.M. de; Ripoll Bosch, R. - \ 2018
In: Book of Abstracts of the 69th Annual Meeting of the European Federation of Animal Science. - Wageningen Academic Publishers (EAAP Book of Abstracts ) - ISBN 9789086863235 - p. 342 - 342.
The decline of biodiversity is a major concern to scientists, society, and policy makers in the European union (EU). The EU Biodiversity Strategy (2010) aims to halt the loss of biodiversity in the EU by 2020. One target to reach this aim is to increase the contribution of agriculture to maintain and enhance biodiversity. According to reports, however, no significant overall progress has been made to meet this target. Moreover, agriculture is both reported to reduce and to enhance biodiversity. To enhance biodiversity in agriculture, we need to understand how biodiversity is measured in the existing studies, and to map relations between agricultural land use and biodiversity. We aimed to
(1) review indicators used in science to measure biodiversity in EU livestock systems, and (2) to review described effects of livestock on biodiversity. We conducted a systematic review in Scopus and Web of Science. The search for research articles that assessed impacts of livestock on biodiversity yielded 857 articles after deduplication, which was narrowed down to 163 relevant articles. Species abundance and species diversity were commonly used state indicators of biodiversity across scales. Modelling studies also used aggregated indicators with biodiversity values that were directly linked to land use. Most studies focussed on the impact of grazing ruminants on biodiversity, either for food production or nature conservation purposes. Pigs and poultry were mainly studied in relation to local ammonia emissions. Only few studies considered impacts of land use for feed production on biodiversity. We argue that the traditional pressure-state-response framework to categorize indicators of biodiversity does not provide clear actions to enhance biodiversity in agriculture. Instead, we propose the use of comparators (e.g. grazing intensity levels) in relation with state measures of biodiversity. This review can help to identify commonly used indicators of biodiversity, and provide insight in quantitative relations between agricultural land use and biodiversity.
Droogstand op maat : verkorten van de droogstand van melkvee: effecten op vervetting en persistentie, uiergezondheid, dierenwelzijn, melkproductie, economie en milieu
Knegsel, A.T.M. van; Hoeij, R.J. van; Kok, A. - \ 2018
Wageningen : Wageningen University, leerstoelgroep Adaptatiefysiologie - 98
Koe start lactatie beter zonder droogstand
Kok, Akke - \ 2018

Een hogere voeropname en een lagere melkgift in vroege lactatie. Dat zijn opvallende kenmerken van het doormelken van koeien, in plaats van ze droog te zetten. Dit kan leiden tot minder uitval volgens onderzoeker Akke Kok van Wageningen University & Research.

Gering effect verkorten of weglaten droogstand
Kok, Akke - \ 2018

Gemiddeld over 5 jaar, verminderde het verkorten of weglaten van de droogstand de netto opbrengst met € 12 en € 16 per koe per jaar en werden broeikasgasemissies per eenheid melk met 0.8% en 0.5% verhoogd.

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