Effect of daily movement of dairy cattle to fresh grass in morning or afternoon on intake, grazing behaviour, rumen fermentation and milk production

Twenty Holstein cows were split into two equal groups to test the effect of daily move to a previously ungrazed strip after morning milking (MA) or afternoon milking (AA) on herbage intake, grazing behaviour, rumen characteristics and milk production using a randomized block design with three periods of 14 days each. Milking took place at 06.00 and 16.00 h. The chemical composition of grass was similar between treatments, but an interaction between treatment and time of sampling was found in all variables except acid detergent lignin (ADL). The most pronounced differences existed in sugar content. Grass sugar content was greatest following afternoon milking. However, the difference in sugar content in grass was much larger in MA (158 v 114 g/kg dry matter (DM) at 16.00 and 06.00 h, respectively) than in AA (147 v 129 g/kg DM at 16.00 and 06.00 h, respectively). Neutral detergent fibre (NDF) was significantly higher at 06.00 h than at 16.00 h (469 v 425 g/kg DM) in AA, but was equal between morning and afternoon in MA (453 g/kg DM). Herbage intake, determined using the n-alkane technique, did not differ between treatments. Grazing behaviour observed using IGER graze recorders were similar between treatments, except for ruminating time, bite rate and the number of ruminations and boli per period of the day. However, interactions between treatment and time in grazing behaviour variables were found. Grazing time was longer and number of bites was greater following allocation to a new plot (after milking in the morning in MA or milking in the afternoon in AA) when compared to allocation to the same plot after the subsequent milking per treatment (after milking in the afternoon or morning in MA and AA, respectively). In comparison to AA, grazing time in MA was more evenly distributed during the day but lower during the night. The combined effects of differences in grazing behaviour and chemical composition of the grass between treatments in different periods of the day probably caused higher intake of sugars in AA, resulting in a significantly higher non-glucogenic to glucogenic volatile fatty acid ratio (NGR) in the rumen in AA than MA. Milk fat content was lower in MA than AA, but milk production and milk protein and lactose content did not differ. In conclusion, time of allocation to a fresh plot altered the distribution of grazing behaviour variables over the day, and affected NGR and milk fat content, but herbage intake and milk production were not change

Feeding and grazing management for dairy cattle: opportunities for improved production

An adequate feed intake is an important prerequisite to realize high milk production in dairy cows, especially during grazing. The analysis of feed intake behaviour can assist in understanding variation in daily intake and in improving its prediction. Indeed, our results indicated that differences in feed intake behaviour were more pronounced when varying the type of roughage than when varying the type of concentrate. Dry matter intake (DMI) was reduced when a ration high in grass silage was fed, but milk production was only numericaly affected. Grazing management might result in increased herbage intake and higher intake of nutrients from herbage by improved nutritional composition of herbage. In the first grazing experiment, herbage DMI was indeed increased when allocating cows daily (1Da) to a new grazing plot compared to every four days (4D) allocation, but only when pasture mass on offer and sward surface height (SSH) were high. Grazing time increased numerically and ruminating time decreased between days in the 4D treatment, coinciding with differences in rumen fermentation characteristics and milk composition. Milk yield was greater in 1Da than in 4D, but milk fatty acid (FA) composition, potentially influencing human health, showed hardly any difference. In a subsequent experiment, herbage DMI was again greater when allocating twice daily (2D) compared to once daily (1Db), especially when SSH was high. Grazing behaviour was more equally distributed in 1Db than in 2D and milk yield was increased in 2D compared to 1Db at high SSH, but as before milk FA composition hardly differed between treatment. The last grazing experiment aimed to take advantage of the higher sugar contents of grass in the afternoon than in the morning. It showed that grazing behaviour and herbage intake were similar between morning (MA) and afternoon allocation (AA), but cows receiving a fresh plot in the afternoon had a longer evening meal than cows receiving a fresh plot in the morning. This, in combination with differences in diurnal chemical composition of the grass between treatments probably caused higher intake of sugars in AA, resulting in a higher milk fat content. However, milk production remained unaffected. In conclusion, the results of this thesis indicate that short-term feed intake behaviour is related to DMI and therefore may be a helpful tool in optimizing DMI and milk production in high-production dairy cows. Increased pasture allocation frequency improves intake and milk yield in grazing dairy cows, especially when offered SSH is high enough. In intensive stripgrazing systems, reallocation of dairy cows following afternoon milking instead of morning milking has no added value. <br/

Meer melk bij vaker omweiden

Tijdens weidegang is voldoende voeropname essentieel voor hoge melkproducties. Vaker omweiden zorgt voor een hogere voeropname, maar alleen bij voldoende gewashoogte, zo blijkt uit een promotiestudie van Wageningen Universiteit. Het effect van ’s avonds in plaats van ’s ochtends inscharen is beperk

Machine learning for estimation of building energy consumption and performance:a review

Ever growing population and progressive municipal business demands for constructing new buildings are known as the foremost contributor to greenhouse gasses. Therefore, improvement of energy eciency of the building sector has become an essential target to reduce the amount of gas emission as well as fossil fuel consumption. One most eective approach to reducing CO2 emission and energy consumption with regards to new buildings is to consider energy eciency at a very early design stage. On the other hand, ecient energy management and smart refurbishments can enhance energy performance of the existing stock. All these solutions entail accurate energy prediction for optimal decision making. In recent years, articial intelligence (AI) in general and machine learning (ML) techniques in specic terms have been proposed for forecasting of building energy consumption and performance. This paperprovides a substantial review on the four main ML approaches including articial neural network, support vector machine, Gaussian-based regressions and clustering, which have commonly been applied in forecasting and improving building energy performance

Dagelijks omweiden geeft meer melk

Dagelijks omweiden geeft meer melk 04 apr 2006 10:14 Melkkoeien die dagelijks worden omgeweid, nemen meer gras op en produceren meer melk dan koeien die om de vier dagen worden omgeweid. Dat blijkt uit onderzoek van Sander Abrahamse, onderzoeker rundveevoeding aan Wageningen Universiteit. Hij is bezig met een vierjarig onderzoek naar de relatie tussen het voeropnamegedrag van melkvee en de pensfermentatie. Het onderzoek omvat zowel stal- als graasproeven. In een van de graasproeven werd het vierdaags omweiden zes periodes lang vergeleken met stripgrazen. Daarbij werd gewerkt met twee groepen van tien koeien met een vergelijkbaar lactatiestadium. De gemiddelde drogestofopname uit gras lag bij de stripgraasgroep duidelijk hoger dan bij de vierdaagse groep (16,5 kilo tegenover 15,8 kilo). Daarbij gaf de stripgraasgroep per dag ook 8,7 procent meer melk: 25 tegenover 23 kilo. Bron: Agrarisch Dagbla

Dagelijks omweiden geeft meer melk

Dagelijks omweiden geeft meer melk 04 apr 2006 10:14 Melkkoeien die dagelijks worden omgeweid, nemen meer gras op en produceren meer melk dan koeien die om de vier dagen worden omgeweid. Dat blijkt uit onderzoek van Sander Abrahamse, onderzoeker rundveevoeding aan Wageningen Universiteit. Hij is bezig met een vierjarig onderzoek naar de relatie tussen het voeropnamegedrag van melkvee en de pensfermentatie. Het onderzoek omvat zowel stal- als graasproeven. In een van de graasproeven werd het vierdaags omweiden zes periodes lang vergeleken met stripgrazen. Daarbij werd gewerkt met twee groepen van tien koeien met een vergelijkbaar lactatiestadium. De gemiddelde drogestofopname uit gras lag bij de stripgraasgroep duidelijk hoger dan bij de vierdaagse groep (16,5 kilo tegenover 15,8 kilo). Daarbij gaf de stripgraasgroep per dag ook 8,7 procent meer melk: 25 tegenover 23 kilo. Bron: Agrarisch Dagbla

De invloed van de samenstelling van het winterrantsoen op het voeropnamepatroon van melkkoeien in verschillende lactatiestadia en het effect hiervan op penskarakteristieken

Naast rantsoensamenstelling is het voeropnameniveau sterk bepalend voor de soort nutriënten die aan de intermediaire stofwisseling van een koe worden aangeboden. Het voeropnameniveau wordt op haar beurt weer beïnvloed door het voeropnamepatroon. Het voeropnamepatroon verandert in afhankelijkheid van rantsoensamenstelling en ook als gevolg van het lactatiestadium. De doelstelling van dit onderzoek was om bovengenoemde hypotheses te testen. Voeropname niveau, patroon van voeropname en processen in de pens zijn gemeten aan melkvee die 5 rantsoenen, verschillend in type koolhydraat, ontvingen, eerst in vroege en daarna in late lactati