Search

The average life span of dairy cows in the Netherlands is 5.8 years. The main reasons for involuntary culling in dairy cows are infertility, mastitis and locomotion disorders. These disorders often start during the first weeks of lactation due to the inability of the cow to cope with the metabolic changes of the new lactation. The main objective of the present study was to determine the value of the Fourier-transform infrared spectroscopy (FTIR) mid-infrared profile of milk samples taken from dairy cows in the first weeks of lactation 1) as an indicator of the metabolic state in early lactation; and 2) as a predictor of dairy cow’s survival to next lactation. Results showed that cows that reach the next lactation have a higher blood NEFA concentration and a higher milk production with less variation between days. In conclusion, survival of the complete lactation was related with milk performance and metabolic status of dairy cows in early lactation., De gemiddelde levensduur van melkkoeien in Nederland is 5,8 jaar. De voornaamste redenen voor onvrijwillige afvoer van melkvee zijn onvruchtbaarheid, mastitis, en klauw- en beenproblemen. Deze gezondheidsproblemen hebben vaak ook een relatie met de eerste weken van de lactatie vanwege een moeilijke lactatiestart of problemen bij de koe om zich aan te passen aan de nieuwe lactatie met stofwisselingsstoornissen als gevolg. Het doel van deze studie was om de waarde te bepalen van Fourier-transform infrared spectroscopy (FTIR) profielen van melk in begin lactatie voor 1) indicatie van metabole status van de koe in begin lactatie; en 2) als voorspeller van het succesvol afronden van de lactatie. De resultaten laten zien dat koeien die de volgende lactatie bereikten aan het begin van de lactatie een hogere concentratie vetzuren in het bloed hadden en een hogere melkproductie met minder variatie tussen dagen.

Shortening or omitting the dry period of dairy cows improves metabolic health in early lactation and reduces management transitions for dairy cows. The success of implementation of these strategies depends on their impact on milk yield and farm profitability. Insight in these impacts is valuable for informed decision-making by farmers. The aim of this study was to investigate how shortening or omitting the dry period of dairy cows affects production and cash flows at the herd level, and greenhouse gas emissions per unit of milk, using a dynamic stochastic simulation model. The effects of dry period length on milk yield and calving interval assumed in this model were derived from actual performance of commercial dairy cows over multiple lactations. The model simulated lactations, and calving and culling events of individual cows for herds of 100 cows. Herds were simulated for 5 years with a dry period of 56 (conventional), 28 or 0 days (n = 50 herds each). Partial cash flows were computed from revenues from sold milk, calves, and culled cows, and costs from feed and rearing youngstock. Greenhouse gas emissions were computed using a life cycle approach. A dry period of 28 days reduced milk production of the herd by 3.0% in years 2 through 5, compared with a dry period of 56 days. A dry period of 0 days reduced milk production by 3.5% in years 3 through 5, after a dip in milk production of 6.9% in year 2. On average, dry periods of 28 and 0 days reduced partial cash flows by €1,249 and €1,632 per herd per year, and increased greenhouse gas emissions by 0.7% and 0.5%, respectively. Considering the potential for enhancing cow welfare, these negative impacts of shortening or omitting the dry period seem justifiable, and they might even be offset by improved health.