Light environments for dairy cows : impact of light intensity, spectrum and uniformity

Light can be used as a management tool to increase milk yield in dairy cows and improve the working conditions for barn staff. It is known that a long day photoperiod, with 16 hours of light and 8 hours of darkness, can increase milk yield in an ongoing lactation. Modern LED lighting can be designed to emit specific wavelengths, opening up possibilities for discussing the most favorable type of light for dairy cows. This thesis investigated the role of light environment and the impact of light intensity, spectral composition and uniformity on dairy cows. In initial studies, a light lab with a controlled light environment and no external light was used. The response to red, blue, and white light of increasing intensity on pupil size was evaluated in five pregnant non-lactating cows. Red light did not constrict the pupil but the other light colors did, indicating that direct stimulation of ipRGCs may be required for a pupillary response to steady background light. A five-week study on 40 pregnant and lactating cows involving 16 hours of blue, red or white light in daytime and 8 hours of dim, white light at night did not show effects of light color during daytime on milk production. Plasma melatonin concentration was higher in dim night light than in daylight for all light treatments. To examine cow movements in light of different intensity, spectrum and uniformity, 12 pregnant, non-lactating cows were tested in an obstacle course in the light lab. A dark environment did not limit the cows’ ability to walk through the obstacle course, but they reduced walking speed when subjected to non-uniform, low-intensity red light, indicating the importance of avoiding non-uniform light in dairy barns. Quantification of light environments on four Swedish dairy farms, using a range of measuring methods, showed that the light environment differed between farms, but that light of low intensity and uniformity was commonly used. Light environment is important for dairy cows, as it can affect their physiology and behavior. The light environment can be more objectively described using multiple measuring methods

Inverkan av β-agonister (ractopamine) på grisars tillväxt och köttansättning

Both authorities and consumer demands require a high standard for today’s food production. A product has to be of good quality, have an affordable price and be nutritious. A solution for pig production in the US is a feed additive that provides the opportunity to market heavier pigs with a high percentage of muscle and a low proportion of adipose tissue. The feed additive is marketed under the name Paylean® with the active substance called Ractopamine Hydrochloride (RAC), with similar characteristics as of β-adrenergic agonists. β-adrenergic agonists are banned as feed additive for animals within the EU and a hundred other countries around the world. This report will summarize whether the addition of RAC in the diet has effects on fattening pig’s physiological effects, affecting their meat quality and if it does lead to unwanted side effects. In the chemical group in which RAC is included, there are several known substances; for example epinephrine and amphetamine. There is very little research of possible health risks that RAC residues could have on humans. Some research has explained that pigs that are feed RAC receive a behavioral change as a side effect. The pigs are more active and alert and in some cases more aggressive towards other individuals. An increased heart rate and elevated levels of the hormones norepinephrine and epinephrine have also been revealed. Several scientists highlight the positive effects of RAC on daily growth, increased feed efficiency and a better carcass grading. The EU and the US have been negotiating for a trade agreement since 2013. A trade agreement between the EU and the US could lead to that EU will import pork that is produced under conditions that are not approved within the EU.Kraven från konsumenter och myndigheter är i dagens samhälle höga för produktion av livsmedel. Produkten ska vara av god kvalitet, prisvärd och näringsriktig. I USA har man tagit fram ett fodertillskott som ger möjlighet att producera mer snabbvuxna grisar med hög andel muskler och låg andel fett. Fodertillskottet säljs under namnet Paylean® där den aktiva substansen är Ractopamine hydroklorid (RAC) som har egenskaper liknande β-adrenerga agonister. β-adrenerga agonister är förbjudna som fodermedel till djur inom EU och ett hundratal fler länder världen över. Rapporten kommer undersöka om ett tillskott av RAC i fodret har någon effekt på slaktsvins fysiologiska effekter och köttkvalitet samt om det kan ge några biverkningar. Inom den kemiska grupp där RAC ingår finns flera kända substanser exempelvis adrenalin och amfetamin och det saknas forskning på eventuella hälsorisker som restsubstanser av RAC kan ha på människor. Det har upptäckts förändringar i beteende hos grisar som fått tillskott av RAC i fodret. Grisarna är framförallt mer aktiva och oroliga samt i vissa fall aggressiva mot andra grisar. En ökad hjärtfrekvens och förhöjda värden av hormonerna noradrenalin och adrenalin har också påträffats. Flera forskare framhäver de positiva effekterna av ett tillskott av RAC på daglig tillväxt, ökat foderutnyttjande samt en bättre klassificering av slaktkroppen. Sedan 2013 har det pågått förhandlingar mellan EU och USA för bildandet av ett frihandelsavtal som skulle underlätta handeln mellan de två världsekonomierna. Det kan innebära att EU i framtiden importerar griskött som är producerat under förhållanden som inte är godkända inom EU

Light for dairy cows

Cows presumably perceive light differently from humans, due to physiological dif-ferences and the eyes’ position. When designing light in dairy barns, a lux meter is the most commonly used instrument, and the design is often calculated without any daylight inlet. A lux meter has the same sensitivity spectrum of wavelengths as visi-ble light for human’s eye. Light to dairy cows is frequently discussed and it is known to affect both production and behaviour. The most commonly used method for quan-tifying light is lux meter but there are other options. The aim of this study was to investigate and compare a lux meter and other methods to measure light; a spectro-photometer and the ELF-method, with a cows’ possibility to perceive light according to existing literature. The ELF-method is an innovation to quantify light that possibly reach an eye. Several research studies have tested the effects of different light treatments on dairy cows production and welfare. However, the illuminance is often mentioned but not how the lux was measured. The results in this study showed that a lux meter is not optimal when measuring light for a dairy cow, since a lux meter does not show color occurrence nor the variation of photon flux over the wavelength spectrum. A spectrophotometer or the ELF-method would be recommended, due to the results that shows light intensities and the distribution of colors within a specific wavelength spectrum. The position of the instrument, vertical or horizontal, can affect the meas-ured values and the reliability of the measurement. To measure a cow’s field of vi-sion, the ELF method is the best option. Also, the measurements showed significant differences in light intensity between different times during one day, in a barn with daylight inlets, and great differences in light intensity in one barn. In conclusion, it is probably possible to measure light in a way that corresponds well with how light can reach the cow’s eye. Measurements either with a spectropho-tometer or with the ELF-method is recommended due to the results with light inten-sity and color occurrence. A lux meter is not the optimal choice since it does not have the same sensitivity for light as the cow’s eye. The actual light intensity treatment is of great importance when measuring how the light affect dairy cows’ production and welfare. One universal light unit when measuring light for dairy cows is requested.Kor uppfattar förmodligen ljus annorlunda än människan, på grund av fysiologiska skillnader och ögats placering. Vid planering av belysning i djurstallar är det vanlig-aste instrumentet för att mäta ljus en luxmätare och dimensioneringen är ofta beräk-nad utan påverkan av dagsljus. En luxmätare har samma känslighetsområde som syn-ligt ljus för det mänskliga ögat. Eftersom belysning i ladugårdar ofta diskuteras och det är vedertaget att ljus påverkar mjölkkors produktion och beteende, behövs meto-der att mäta ljus undersökas. Syftet med den här studien var att undersöka och jämföra en luxmätare med andra metoder att mäta ljus; en spektrofotometer och ELF-meto-den, och att jämföra mätresultaten med kors möjlighet att uppfatta ljus enligt befintlig litteratur. ELF-metoden är en innovation för att kvantifiera det ljus som förmodligen når ett öga. Flera studier har undersökt effekterna av olika ljusbehandlingar på mjölkkors pro-duktion och djurhälsa. I studierna nämns den belysningsstyrka som korna har be-handlats med men det saknas information om hur belysningsstyrkan är uppmätt. Re-sultaten i den här studien visar att en luxmätare inte är det bästa alternativet för att mäta ljus till mjölkkor eftersom luxmätaren inte visa färgfördelning eller variationen i fotonflöde över olika våglängder. Spektrofotometern eller ELF-metoden är att före-dra, tack vare att analyserna visar ljusintensiteten och färgfördelning över olika våg-längder. Instrumentets position, vertikalt eller horisontellt, vid mätning kan påverka det uppmätta värdet och trovärdigheten för mätningen. För att mäta synfältet för en ko är ELF-metoden det bästa valet. Mätningarna visade också signifikanta skillnader i fördelningen av ljusintensiteten i ett stall med dagsljusbelysning och ljusintensiteten under olika tidpunkter på dagen, i ett stall med dagsljusinsläpp. Avslutningsvis, det är förmodligen möjligt att mäta det ljus som kan nå kons öga. Metoder att föredra är en spektrofotometer eller ELF-metoden eftersom resultaten visar ljusintensiteten och färgfördelning. En luxmätare är inte att föredra eftersom den inte har samma känslighet för ljus som kons öga. Den korrekta ljusintensiteten är viktig vid mätningar hur ljuset påverkar mjölkkors produktion och djurhälsa. En universal enhet att mäta ljus till mjölkkor är därför önskvärd

Effect of light intensity, spectrum, and uniformity on the ability of dairy cows to navigate through an obstacle course

The most suitable light intensity for cows during nighttime has not been thoroughly investigated. Recommendations on the night-time lighting regimen on dairy farms differ between countries and range from light throughout the night to darkness to allow the animals a rest from artificial light. Commercial actors recommend red light for night-time lighting in cattle barns to facilitate livestock supervision with minimum disturbance for the animals. However, little is known about how light intensity, spectrum, and uniformity affect the ability of cows to navigate their indoor environment. Thus, in a change-over study with 12 pregnant, nonlactating dairy cows, we observed how the cows walked through an obstacle course under different light treatments. Obstacles were positioned differently for every run, to present a novel challenge for each light environment. Fourteen different light treatments were tested, involving intensity ranging from <0.01 (darkness) to 4.49 mu mol m(-2) s(-1), high or low uniformity, and white or red color. Light was characterized in terms of illuminance, photon flux density, spectral composition, and uniformity. Additionally, assessment of the environmental light field was used to describe each lighting condition from a bovine and human perspective. Data were analyzed in a generalized mixed model to assess whether lighting conditions affected cow walking speed or stride rate. Pair-wise post hoc comparisons showed that the cows walked at a slower speed in nonuniform red light compared with uniform white light or uniform red light. Interestingly, darkness did not alter walking speed or stride rate. The odds of different behaviors occurring were not affected by lighting conditions. In conclusion, darkness did not affect the ability of cows to navigate through the obstacle course, but medium-intensity, nonuniform red light affected their speed. Hence, cows do not necessarily need night-time lighting to navigate, even in a test arena with obstacles blocking their way, but nonuniform light distribution may have an effect on their movements

Effects of achromatic and chromatic lights on pupillary response, endocrinology, activity, and milk production in dairy cows

Artificial light can be used as a management tool to increase milk yield in dairy production. However, little is known about how cows respond to the spectral composition of light. The aim of this study was to investigate how dairy cows respond to artificial achromatic and chromatic lights. A tie-stall barn equipped with light-emitting diode (LED) light fixtures was used to create the controlled experimental light environments. Two experiments were conducted, both using dairy cows of Swedish Red and light mixtures with red, blue or white light. In experiment I, the response to light of increasing intensity on pupil size was evaluated in five pregnant non-lactating cows. In experiment II 16h of achromatic and chromatic daylight in combination with dim, achromatic night light, was tested on pregnant lactating cows during five weeks to observe long term effects on milk production, activity and circadian rhythms. Particular focus was given to possible carry over effects of blue light during the day on activity at night since this has been demonstrated in humans. Increasing intensity of white and blue light affected pupil size (P<0.001), but there was no effect on pupil size with increased intensity of red light. Milk yield was maintained throughout experiment II, and plasma melatonin was higher during dim night light than in daylight for all treatments (P<0.001). In conclusion, our results show that LED fixtures emitting red light driving the ipRGCs indirectly via ML-cones, blue light stimulating both S-cones and ipRGCs directly and a mixture of wavelengths (white light) exert similar effects on milk yield and activity in tied-up dairy cows. This suggests that the spectral composition of LED lighting in a barn is secondary to duration and intensity

En studie av fritidspedagogens yrkesroll i integrerade verksamheter

Validerat; 20101217 (root

Knowledge transfer across cultures in the manufacturing industry : A study of Scania’s global implementation of employer branding

The purpose of this paper was to examine how cultural differences affect an MNC’s knowledge transfer of the concept employer branding, and what support subsidiaries need from headquarters for the MNC to become a global employer brand. The result is based on theoretical findings of employer branding, knowledge transfer and culture, applied to interview results at Scania. The knowledge transfer of the concept employer branding involves the implementation of a global employer branding communication platform. Findings show that Scania face challenges in employer branding awareness within the MNC, knowledge transfer internalization in subsidiaries, and balance of standardization and adaptation in connection to cultural dimensions of the markets. To overcome these challenges, Scania needs to further develop relational, social and organizational contexts for the MNC to become a global premium employer brand. The thesis has high originality since it gives implications to a specific MNC regarding the specific topic employer branding in a certain time of the implementation process

Knowledge transfer across cultures in the manufacturing industry : A study of Scania’s global implementation of employer branding

The purpose of this paper was to examine how cultural differences affect an MNC’s knowledge transfer of the concept employer branding, and what support subsidiaries need from headquarters for the MNC to become a global employer brand. The result is based on theoretical findings of employer branding, knowledge transfer and culture, applied to interview results at Scania. The knowledge transfer of the concept employer branding involves the implementation of a global employer branding communication platform. Findings show that Scania face challenges in employer branding awareness within the MNC, knowledge transfer internalization in subsidiaries, and balance of standardization and adaptation in connection to cultural dimensions of the markets. To overcome these challenges, Scania needs to further develop relational, social and organizational contexts for the MNC to become a global premium employer brand. The thesis has high originality since it gives implications to a specific MNC regarding the specific topic employer branding in a certain time of the implementation process

Knowledge transfer across cultures in the manufacturing industry : A study of Scania’s global implementation of employer branding

The purpose of this paper was to examine how cultural differences affect an MNC’s knowledge transfer of the concept employer branding, and what support subsidiaries need from headquarters for the MNC to become a global employer brand. The result is based on theoretical findings of employer branding, knowledge transfer and culture, applied to interview results at Scania. The knowledge transfer of the concept employer branding involves the implementation of a global employer branding communication platform. Findings show that Scania face challenges in employer branding awareness within the MNC, knowledge transfer internalization in subsidiaries, and balance of standardization and adaptation in connection to cultural dimensions of the markets. To overcome these challenges, Scania needs to further develop relational, social and organizational contexts for the MNC to become a global premium employer brand. The thesis has high originality since it gives implications to a specific MNC regarding the specific topic employer branding in a certain time of the implementation process

Hur påverkar regeringen företagens internationella konkurrensfördelar? : En studie av den svenska miljöteknikbranschen

Sweden experienced a decline in exports of 16 percent in the period after the financial crisis. The decline has created a lot of question marks regarding the traditional exports which has started a process with the aim of finding Sweden’s next cash cow in export. Sweden adopted stringent environmental laws early which positioned them as a strong nation in environmental awareness. The stringent environmental legislation meant that the Swedish companies were required to minimize the environmental impact, which created a demand for eco-efficient products. Despite the early demand for eco-efficient products, the international success of the Swedish cleantech companies has been modest. The government can increase firms international competitiveness by encouraging, supporting and promoting activities on the domestic market. This is primarily done through implementations of various policies and incentives. The purpose of this thesis is to analyze the government’s efforts in promoting the Swedish cleantech industry. In order to give recommendations on which improvements that can be made, two perspectives will be used when analyzing the government’s efforts, the firm approach and the theoretical approach