Frequency of unsuccessful milkings in automatic milking rotary : effect on milk yield, lactose content and somatic cell count at udder quarter level

Detta är en Uppsats för yrkesexamina på avancerad nivå från SLU/Dept. of Animal Nutrition and Management

Sammanfattning: Developments in milk production are heading towards fewer but larger herds where the milking process is often fully automated. Automatic milking systems were launched in the 1990’s and in the year 2010 the Automatic Milking Rotary (AMR) was introduced. As a rule there are no supervision personnel present during the milking event in systems with automatic milking. This means that there is a risk that cows can be incompletely milked in one or more udder quarters, for example if the robots fail in attaching the milking cups or if the cow kicks off the milking unit. Incomplete or missed milking can lead to reduced milk yield and/or milk leakage, which can increase the risk for mastitis. This is important to each dairy farmer’s milk production as well as the udder health of each individual cow. The present study is composed of two experiments. The purpose of Experiment 1 was to investigate the frequency and cause of unsuccessful or incomplete milking in the AMR. Experiment 1 was carried out on a herd of 171 cows and included eight milkings (four days) and one day for recording udder conformation and assessing teat position and condition. The frequency and causes of unsuccessful or incomplete milking were registered in a template. In addition, the possibility of a relationship between milk somatic cell count (SCC) and kick off of the milking cups was investigated. The results of Experiment 1 showed a relationship between udder conformation and failed attachment of milking cups was noted. The results also showed that 82.6% of the milkings in AMR were successful in the 1st milking attempt. The primary cause of unsuccessful milkings in the 1st and 2nd milking attempts was failed attachment of the milking cups, mainly on the right back teat. When the number of milkings that were unsuccessful in the 2nd milking attempt was added to the number of successful milkings in the 1st milking attempt, the result was approximately 96% successful milkings. However, 43 milkings were noted as approved by the AMR during the 1st milking attempt even though disturbances, e.g. failed attachment of milking cups, kick off of milking unit, and/or tramp on milking tube, occurred. When these 43 milkings were added to the unsuccessful milkings after the 2nd attempt (60 milkings), the final milking result was 93.1% successful milkings. Experiment 2 was based on two different treatments, Treatment A and Treatment B, with 11 cows in each treatment group. The cows in the study had SCC ≤ 150 000 cells/ml milk per udder quarter. The purpose of the study was to investigate how one or three purposely omitted milkings on one udder quarter impacted milk yield, lactose content, and milk SCC. The design was a within udder comparison. One udder quarter (right front) was exposed to a treatment, while the adjacent quarter (left front) was the control quarter. Differences between treated and control udder quarter was calculated and tested if the difference differed from zero. Treatment A was carried out for 28 milkings (14 days) and Treatment B for 36 milkings (18 days). Treatment A was based on one purposely omitted milking on right front udder quarter and Treatment B three omitted milkings on right front udder quarter with three milkings between the omitted milkings. At udder quarter level, a significant difference between front udder quarters were observed in milk yield, lactose content and SCC during the first days after treatment, where milk yield and lactose content decreased while SCC increased in the treated udder quarter. The difference between quarters disappeared at the end of the experimental period. The present study shows the importance for all four udder quarters to be completely milked on every milking session. Further development of the AMR and further research on the effects and recovery period of unsuccessful and incomplete milking is needed. Future research should involve a greater number of cows and a wider variation in udder health to more exactly evaluate effect on milk yield and udder health

  HÄR KAN DU HÄMTA UPPSATSEN I FULLTEXT. (följ länken till nästa sida)