Management of photoperiod in the dairy herd for improved production and health

Abstract

Environmental influences on lactation efficiency are frequently associated with reductions in milk output. Heat stress, for example, leads to depressed feed intake and, subsequently, losses in production. Conversely, cold stress may limit nutrients available for milk synthesis. Fortunately, one environmental factor, photoperiod, can exert a positive effect on dairy performance when managed properly. Long days have consistently been shown to improve milk yield during established lactation. In addition, photoperiod management can be used to improve heifer growth and maximize accretion of lean tissue, including mammary parenchyma. There is, however, evidence of refractoriness to long day stimulation. Recent work has focused on the dry period as a time when photoperiod manipulation can influence subsequent milk production. In contrast to lactating cows, multiparous cows benefit from exposure to short days when the dry period is followed by long days or natural photoperiod after calving. Similarly, primiparous animals also respond positively to short days late in pregnancy when subsequently exposed to long days during lactation. Furthermore, emerging evidence suggests that short days positively influence immune function in cattle. Mechanistically, it appears that prolactin has a causal relationship with the observed dairy performance effects during the dry period and on immune function, via altered sensitivity to prolactin through differential expression of prolactin receptor in multiple tissues. The objectives of this paper include a review of fundamental aspects of photoperiod physiology, integration of applied and basic research findings, and development of management recommendations for the entire life cycle of the dairy cow to optimize performance.

Seasonal variations in the composition of Holstein cow’s milk and temperature–humidity index relationship

“…Another possible factor influencing the percentage of fat and protein in the milk is the level of milk yield. As is well known, milk yield is affected by photoperiod and increases in correlation with increasing day length (Stanisiewski et al, 1985;Dalh and Petitclerc, 2003); it is therefore plausible to believe that for the latitudes considered in this study, the reduction in milk components recorded in spring might be related to the increase in milk yield as a response to the increasing photoperiod, with a consequent dilution effect on protein and fat concentrations. The higher milk yield in spring in the study area is testified by official statistic data (www.CLAL.it).…”

Association between age at first calving, year and season of first calving and milk production in Holstein cows

“…The seasonal effect was partly due to richer winter feed during a period that is more representative of lactation than winter or spring calving. Increasing the photoperiod also helped to improve milk production (Dahl and Petitclerc, 2003), but did not seem to counteract the feeding effect of spring calving.…”

“…According to Nianogo et al (1991), this effect is not only due to the type of feeding in early lactation, but can also stem from other factors such as heat stress or photoperiod (Dahl and Petitclerc, 2003). In Israel, Barash et al (1996) found that milk production was stimulated by autumn calving and reduced by spring calving; these observations are hard to explain in physiological terms and more research is needed.…”

Regulation of Mammary Development as It Relates to Changes in Milk Production Efficiency

“…As will be discussed in a later section of this chapter, exposure of lactating dairy cows to long day photoperiod (16h light; 8h dark) increases milk production, and exposure of late-pregnant cows to short day photoperiod (8h light; 16h dark) increases milk production in the subsequent lactation Dahl & Petitclerc, 2003). It was initially thought that this effect was mediated by melatonin.…”