Magnesium is one of the most important minerals in the body and it participates in many essential processes, such as energy metabolism and protein synthezis. Magnesium deficiency in cattle may occur when they are let out for pasture in the spring, and is associated with tetany, known as grass staggers. A high yielding dairy cow often loses more magnesium daily in the milk than she has available in the body, and magnesium thereby needs to be provided in the feed to prevent the cow from being affected by deficiency symptoms. The uptake of magnesium is mainly located to the rumen and is not regulated by hormones. The surplus is excreted in the urine by the kidneys.

The purpose of this study was to find out if motion movements, e.g. number of lying bouts and lying time with a registered activity monitoring sensor can detect an impending calving and thereby be used as a measure and an indicator for an upcoming calving. For this, automatically step sensors were used and were attached to one of the cows? hind leg. The sensor registered the individual step and movement activity of the cow.

An automatic milking (AM) system should be combined with some form of controlled cow traffic to minimize the time spend on fetching cows to milking and to increase the milking frequency. By restricting the hours spent on pasture per day you optimise the AM system use during pasture period. A reason for this is becuase cows do not return to the stable for milking during night which cause that the milking unit stands empty those hours. In organic production it is required that the cows should be able to graze a certain amount of daily dry matter (DM) intake on the pasture. In the county of Dalarna where the farm is located the yield of the pasture is about 3000 kg DM per grazing season and hectar.This means that the pasture area should be 14,25 hectare to 57 milking cows.

Since feeding fodder crops to dairy cows is a heavy and time-consuming but often disregarded line of work, this study wishes to view the different possibilities that are currently available to decrease the time to feed and apply this knowledge on an existing farm. For this purpose, four farms have been studied due to what feeding systems that are currently used and how long time the feeding required. The occurring systems are either mobile, i.e. a feed mixer operated by a tractor witch feeds the cattle via a drivable fodder table, or a stationery mixer, i.e. an electrically powered mixer which fills an automatic feeder.

The incidence of many of the most common diseases in dairy cattle has been proven to be highest during the time closest to calving. It is possible that the current breeding strategy with 12 month calving intervals increases the risk for disease in dairy cattle, which is problematic concerning both animal welfare and for economic reasons. The economic incentives behind a calving interval of 12 to 13 months have mainly been based on milk- and feed- costs and no costs due to diseases or fertility disturbances have been included.The aim of this study was to see if a lengthening of the calving interval would result in lower disease frequency. The hypothesis is that cows with a planned calving interval of 15 months have a lower disease incidence than cows with a calving interval of 12 months due to less number of calvings. Therefore the difference in disease frequency should be larger when compared over a long period of time, such as over lifetime, since cows with a longer calving interval experience fewer calvings.The study was performed between August 17th, 1994, and January 24th, 2007.

Automatic rumination measuring can be applied as a health indicator in dairy farming but is also highly desirable for research purposes. This study aimed to validate the technical functionality of the product RuminActTM, which employ acoustics to monitor rumination duration. The time budget of high yielding cows was studied and possible differences in rumination time between 13 rations were interpreted. Further the study examined what affects daily rumination and rumination efficiency. The validation was performed with direct observations that were compared to the automatically recorded rumination durations.

Milk yield levels in dairy cows are influenced by many factors such as nutrition, breed, health status, management and environment. This study was conducted among small scale farmers in Zambia, where the climate can be dry for up to six months per year and cause a lack of green pasture for livestock and on-farm produced feed. The purpose of this study was to identify management factors that can influence milk yield at small scale dairy farms in Zambia, and present advice that could improve productivity, without the need of expensive investments. The study included semi-structured questionnaires presented to the farmers (n=29) including questions about cattle management and milk production. Testing of somatic cell count (SCC) with DCC (DeLaval Cell Counter) from herd milk samples (n=56) and observation of housing and animal body condition on-farm was also made.

This study investigated the effects of rubber alley flooring on cow locomotion, claw and leg health, production, cleanliness, grooming behaviour and cow exclusion rate in a free stall herd. The study was conducted in a new dairy house with a rotary milking system, with a matched group of cows on traditional scraped concrete alleys used for comparison. All claws were trimmed and lesions recorded at the beginning and end of the 4-month study. Locomotion, claw and leg health, behaviour and hygiene were observed and scored at regular intervals during the study. The results showed that cows on rubber alley floors displayed significantly (p.

Water is an essential factor for both people and animals, and access to water is therefore of great importance. The water access also largely determines the availability of food for people and feed for animals. The aim of this study was to survey the affect of water access on milk production from dairy animals. The study included nineteen farm visits that were made in the Nyando district in Kenya between February and Mars 2011. Farm visits included interviews with questions about for example number of dairy animals, milk production, water access, feed and water routines.

Methane (CH4) is a greenhouse gas (GHG) that contributes to the global warming. One of the largest sources of methane is livestock, preferably ruminants which alone counted for 30% of the total agricultural anthropogenic methane emissions in the year of 2000. The reason to why ruminants are such large contributors of methane are that the gas is produced in the rumen by enteric formation and leaves the animals by belching, exhaling or by the excreta.Diets high in concentrates can result in a lower emission of methane. Also diets with a high content of starch, such as alfalfa-grass, have a methane-decreasing. It is profitable to reduce enteric methane formation since that form of methane is unavoidably lost.

The presence of cystic ovarian follicles represents an important ovarian dysfunction and is a major cause of reproductive failure in dairy cattle. A cystic ovarian follicle is a persistent follicular-like structure on one or both of the ovaries. It is at least 2,5cm in diameter and it has to persist for at least ten days while a corpus luteum is missing. There are two kinds of cystic ovarian follicles, those who have a progesterone production and those who have not. A clear definition for this condition is lacking, probably because the heterogeneity of the clinical signs and the complexity of the disorder.

This work is a literature review along with interviews from nine suckler herds. How to reducecalf mortality in the cow herd is the focus of this paper. To get profitability of a herd, it isimportant that you get a live calf per cow and year. Good fertility of the cows thus is veryimportant. During the years 2007 - 2008, approximately 5.5% of all calves born by beef cowsdied and about 8.5% of the calves born by heifers died.

To get a good economy on the dairy farms the fertility control of heifers and cows is a crucial factor. It is also important to know which key parameters that should be tracked. In this work well established routines for heat detection have to be applied. When the dairy farmers use technical aid in estrus control it is important not to forget that technical aids can not replace the human eye. Approximately 50 % of all opportunities to inseminate are missed because clear signs of estrus have not been displayed and/or recorded. The cattle fertility has been declining over recent years. During the same time the cow?s proceeds have increased, consequently applying a higher pressure on the cow and the manager.

Today a trend can be seen towards fewer dairy farms and increasing number of cows per farm. Larger farms set a higher demand of more labour efficient milking systems. The time to enter and exit milking rotary platforms is crucial to maintain a high cow throughput. This study is a project initiated by DeLaval in order to evaluate the cow throughput and cow behaviour during entry and exit in two types of parallel external rotaries with different bail designs. The two rotaries compared were DeLaval parallel rotary PR2100 and PR3100HD.

Habituation to an automatic milking system (AMS) for cows in their first lactation differs from habituation to other milking systems. In AMS the cows are supposed to visit the milking station (MS) voluntarily. The milking takes place individually during the whole day, except when the milking system is cleaned. Milking is carried out without any human survey. The aim of the study was to describe the cow?s introduction in AMS in their first lactation.