Investigating cow−calf contact in a cow-driven system: performance of cow and calf

In this research communication we describe the performance of dairy cow−calf pairs in two cow-driven CCC-systems differing in cows' access to the calves through computer-controlled access gates (smart gates, SG). We investigated cows' machine milk yield in the automatic milking system (AMS), calf growth, and intake of supplemental milk and concentrate. Two groups each with four cow-calf pairs were housed in a system with a cow area, a calf creep and a meeting area. SG's controlled cow traffic between the meeting area and the cow area where cows could obtain feed, cubicles and the AMS. Calves had ad libitum access to supplemental milk and concentrate. During the suckling phase of 31 d, cow access to the meeting area was free 24 h/d (group 1) or restricted (group 2) based on milking permission. Following the suckling phase, cow access was gradually decreased over 9 d (separation phase). During the suckling phase, cows' machine milk yield (mean ± sd) in the AMS was 11.4 ± 6.38 kg/d. In the separation phase, the yield increased to 25.0 ± 10.37 kg/d. Calf average daily gain (ADG) was high during the suckling phase: 1.2 ± 0.74 kg. During the separation phase, ADG decreased to 0.4 ± 0.72 kg which may be related to a low intake of supplemental milk. Calves' concentrate intake increased with age, and all calves consumed >1 kg/d after separation. We conclude that cows nurse the calf in a cow-directed CCC system well resulting in high ADG, and AMS milk yields were, at least, partially maintained during the suckling phase. Although the AMS yields increased in response to separation, calf ADG was decreased. A low sample size limits interpretation beyond description but provides a basis for hypotheses regarding future research into CCC-systems.publishedVersio

Subclinical ketosis in Norwegian milkproduction

Kyrne har størst risiko for å komme i negativ energibalanse i overgangsperioden fra sinku til melkeku. Det skyldes at det er utfordrende for kyrne å dekke energibehovet til den stigende melkeytelsen i ukene etter kalving. Negativ energibalanse (NEB) øker risikoen for å utvikle sykdommer, deriblant ketose. Det kan redusere melkeytelsen, og samtidig øke kostnadene til veterinærbehandling. Vi skiller mellom klinisk og subklinisk ketose. Klinisk ketose gir synlige symptomer, som gjør det lettere å diagnostisere og behandle. Den andre typen er subklinisk ketose som ikke har synlige symptomer, men som likevel kan påvirke produksjonen negativt. Målet for denne oppgaven er å kartlegge hvilke forhold ved fôring og management som øker risikoen for subklinisk ketose. Følgende hypotese ligger til grunn for oppgaven: Forekomsten av ketose er høyere enn det som blir registrert med visuelle symptomer, og veterinærbehandlinger.The cows have the greatest risk of getting into a negative energy balance during the transition period from dry cow to dairy cow. This is because it is challenging for the cows to cover the energy needs of the increasing milk yield in the weeks after calving. Negative energy balance (NEB) increases the risk of developing diseases, such as ketosis. It can reduce milk yield, and at the same time increase the cost of veterinary treatment. We distinguish between clinical and subclinical ketosis. Clinical ketosis have visible symptoms, which make it easier to diagnose and treat. The other kind is subclinical ketosis which makes no visible symptoms, yet it still can adversely affect production. The aim of this thesis is to map which conditions of feeding and management increase the risk of subclinical ketosis. The following hypothesis is the basis for this thesis: The incidence of ketosis is higher than what is registered with visual symptoms, and veterinary treatments.M-H