Camilla Kielland

Housing system and herd size interactions in Norwegian dairy herds; associations with performance and disease incidence

BackgroundAccording to the Norwegian animal welfare regulations, it has been forbidden to build new tie-stall barns since the end of 2004. Previous studies have shown that cow performance and health differ between housing systems. The interaction between housing system and herd size with respect to performance and disease incidence has not been evaluated.MethodsCow performance and health in 620 herds housed in free-stall barns were compared with in 192 herds housed in tie-stall barns based on a mail survey and data from the Norwegian Dairy Herd Recording and Cattle Health Systems. The housing systems herds were comparable with respect to herd size (15-55 cows). Associations between performance/disease incidence and housing system, herd size and year of building the cow barn were tested in general linear models, and values for fixed herd size of 20 and 50 cows were calculated. On the individual cow level mixed models were run to test the effect of among others housing system and herd size on test-day milk yield, and to evaluate lactation curves in different parities. All cows were of the Norwegian Red Breed.ResultsAverage milk production per cow-year was 134 kg lower in free-stall herd than in tie-stall herds, but in the range 27-45 cows there was no significant difference in yields between the herd categories. In herds with less than 27 cows there were increasingly lower yields in free-stalls, particularly in first parity, whereas the yields were increasingly higher in free-stalls with more than 45 cows.In free-stalls fertility was better, calving interval shorter, and the incidence rate of teat injuries, ketosis, indigestions, anoestrus and cystic ovaries was lower than in tie-stalls. All of these factors were more favourable in estimated 50-cow herds as compared to 20-cow herds. In the larger herd category, bulk milk somatic cell counts were higher, and the incidence rate of mastitis (all cases) and all diseases was lower.ConclusionThis study has shown that there is an interaction between housing system and herd size, and that performance and health is not universally better in small free-stalls than in tie-stalls.

Attitudes of veterinary students to pain in cattle

Three hundred veterinary students were divided randomly into two groups to answer a questionnaire inquiring how painful they considered 23 conditions affecting cattle (seven of which were illustrated) to be, on either a numerical rating scale (NRS) or a visual analogue scale (VAS). The individual responses were used to assess whether cluster analysis could be used to divide the population into distinct groups. The ratios of men to women in the two groups were similar. The NRS scores ranged from 1 to 10 and the VAS scores ranged from 0 to 10. The conditions that were illustrated with a picture had a wider range of scores (2·65 to 9·0 v 2·67 to 7·93) and a slightly higher mean score (5·71 v 5·34) than those without pictures. Fracture of the tuber coxae, dystocia requiring the help of two people, and serious mastitis, were scored as the most painful conditions in adult cattle. Using the median score of each student as an outcome, their sex and year of enrolment and the scoring scale were significant. Women scored 0·9 points higher than men. Cluster analysis revealed two distinct groups in both the VAS and NRS, but the distribution was more even among the students using the VAS. This group was used in further analysis, and one cluster had the most men and more students with several siblings.

A small outbreak of human cryptosporidiosis associated with calves at a dairy farm in Norway

Cryptosporidiosis is rarely diagnosed in Norway. This is the first report of a human outbreak in Norway and involved 3 calves and 5 people. Sequencing studies were performed. Although 4 of the people acquired their infections from the calves, the other probably became infected from other calves or contaminated pens.

Housing conditions and management practices associated with neonatal lamb mortality in sheep flocks in Norway

A study was conducted in order to obtain information about sheep farms in Norway and to identify housing and management characteristics that were risk factors for neonatal mortality of lambs 0-5 days of age. A questionnaire was submitted to sheep farmers, who provided demographic data and information on sheep housing conditions and feeding and management practices. Our description of farms is based on the questionnaire responses received from 2260 farmers. Data on lamb mortality during the preceding lambing season were available for those flocks that were enrolled in the Norwegian Sheep Recording System. Some flocks where the number of lambing ewes was less than 20 or greater than 400 were excluded. The total number of flocks included in the analysis of neonatal mortality was 1125. An increase in the mean number of live-born lambs per ewe per flock was associated with increasing neonatal mortality. Factors independently associated with increased neonatal survival were continuous monitoring of the ewes during the lambing season, active support to ensure sufficient colostrum intake of the lambs, feeding a combination of grass silage and hay compared with grass silage alone, and supplying roughage at least twice per day versus only once. Increased survival was also observed in flocks where the farmer had at least 15 years of experience in sheep farming. Flocks in which the Spæl breed predominated had lower odds for neonatal deaths compared to flocks in which the Norwegian White breed predominated. In conclusion, measures in sheep flocks targeted at feeding practices during the indoor feeding period and management practice during lambing season would be expected to reduce neonatal lamb mortality.

Milk Production, Reproductive Performance, Milk Somatic Cell Count and Disease Incidences in Alternative Housing Systems for Dairy Cows

The purpose of the present study was to compare performance and health in tie-stalls and loose housing, and to identify related risk factors in loose housing units. Results are presented from an epidemiological study based on housing data from a mail survey and production, reproduction and health data from Milk Recoding including the Cow Health Card System. The material included a total of 808 free-stalls and 196 tie-stalls. Milk production was significantly lower, reproductive performance better and the incidence of ketosis and teat injuries lower in the free-stall compared to tie-stall herds. A wider variability in disease incidence was recorded in the free-stall herds. In the free-stall group, the following factors had significant effects: Warm/cold housing (lower milk production in cold housing), roughage feeding system (higher milk production with automatic feeding) and cubicle flooring (higher milk production and lower somatic cell counts with mattresses). More in-depth analyses of the present material will be performed on the individual cow level. The study identified some general risk factors related to performance and health in loose housing. These factors will be studied in more detail in the second phase of the research programme.

Cataracts in the Norwegian Buhund—current prevalence and characteristics

OBJECTIVE To evaluate prevalence and characteristics of cataracts in the Norwegian Buhund breed 20 years after high reported prevalence of especially pulverulent nuclear cataracts (PNCs). ANIMALS STUDIED Two hundred and fifty Norwegian Buhund dogs in Norway, Sweden, and Denmark (117 males and 133 females) with previously unknown eye health status were included. Forty-five dogs had multiple examinations (two to six times over a 6-year period). Median age was 4.4 years [0.2-15.2] at first examination and 5.3 years [0.2-15.2] at last examination. PROCEDURES All dogs underwent regular screening for inherited eye diseases. RESULTS At the last observation of each dog, 52.4% were affected by PNC, categorized as minimal (33 of 250 dogs; 13.2%), mild (31 dogs; 12.4%), moderate (38 dogs; 15.2%), or pronounced (29 dogs; 11.6%). Moderate or pronounced changes were only seen in older dogs, and progressive changes were identified in some of the re-examined dogs. Some dogs, free of lenticular changes at early examinations, were affected by PNC at re-examinations. The odds for finding PNC increased with dogs age up to approximately 8 years. Presumably inherited cataracts other than PNC were found in 53 dogs (21.2%) with cortical (17.6%) and posterior polar (6.4%) locations as the most common ones. CONCLUSIONS The high prevalence of PNC in the breed reported 20 years ago persists. PNCs are not always visible in young dogs, and the rate of progression varies. The prevalence of other types of cataract is also high, but cataracts rarely cause loss of vision in this breed.

The effects of building design on hazard of first service in Norwegian dairy cows

Reproductive inefficiency is one of the major production and economic constraints on modern dairy farms. The environment affects onset of ovarian activity in a cow postcalving and influences estrus behavior, which in turn affects a stockpersons ability to inseminate her at the correct time. This study used survival analysis to investigate effects of building design and animal factors on the postpartum hazard of first service (HFS) in freestall-housed Norwegian Red cows. The study was performed on 232 Norwegian dairy farms between 2004 and 2007. Data were obtained through on farm measurements and by accessing the Norwegian Dairy Herd Recording System. The final data set contained data on 38,436 calvings and 27,127 services. Univariate Cox proportional hazard analyses showed that herd size and milk yield were positively associated with HFS. Total free accessible area and free accessible area available per cow year were positively associated with the HFS, as was the number of freestalls available per cow. Cows housed on slatted floors had a lower HFS than those housed on solid floors. Conversely, cows housed on rubber floors had a higher HFS than cows on concrete floors. Dead-ending alleyways reduced the hazard of AI after calving. A multivariable Cox proportional hazards model, accounting for herd management by including a frailty term for herd, showed relationships between hazard of postpartum service and explanatory variables. Animals in herds with more than 50 cows had a higher HFS [hazard ratio (HR)=3.0] compared with those in smaller herds. The HFS was also higher (HR=4.3) if more than 8.8 m(2) of space was available per cow year compared with herds in which animals had less space. The HFS after calving increased with parity (parity 2 HR=0.5, parity ≥3 HR=1.7), and was reduced if a lactation began with dystocia (HR=0.82) or was a breed other than Norwegian Red (HR=0.2). The frailty term, herd, was large and highly significant indicating a significant proportion of the variation resides at herd level. The hazard of first insemination decreased with time for all predictive variables, except dystocia. This study shows that providing adequate environmental conditions for estrus behavior is imperative for reproductive efficiency and after herd management factors and time from calving have been accounted for. Thus, optimizing building design for reproductive efficiency is of significant importance when constructing new cattle housing.

Risk Factors for Cow Mortality in New Norwegian Dairy Cattle Free Stalls

S OF THE PROCEEDINGS 155 centrations of SP after castration suggested a likely association with nociception. These results may affect assessment of animal well-being in livestock production systems. Risk Factors for Cow Mortality in New Norwegian Dairy Cattle Free Stalls Olav Østerås and Camilla Kielland Department of Production Animal Clinical Sciences, The Norwegian School of Veterinary Science, Oslo, Norway Mortality in dairy cattle is of major concern and indicates a serious welfare problem. The overall goal was to investigate the risk of mortality associated with the building period and the first years after a construction of a new freestall barn and to see if mortality in dairy cows relates to other health measures. A database including 232 free-stall barns built from 1996 to 2005 was used. All lactations starting with a calving two years before the construction year until 2008 were included in the study. The parity number; breed; calving difficulties; the next calving date or removing date from the herd, as well as reasons for removing; together with herd size; bulk-milk somatic cell count (BMSCC); incidence of clinical mastitis (CM); and milk yield per cow-year were extracted from the database in the Norwegian Dairy Recording System. The reasons for removal (culling) were grouped into death or not. These data were used in survival analyses with dependent variable being the time from calving until death or censoring. The data were censored at 15 days before next calving or at removal from the herd for reasons other than death. Observation period was set to be maximum 305 days. Cows who lived at January 1, 2008, were censored at that day. If the cow died later than these 305 days, she was classified as “not died.” All together, 68,458 lactations were included. Of these lactations 707 (1.03%) ended in death. Parity, calving difficulties, breed, calving year, BMSCC, and CM were identified as risk factors associated with death. The calving date in relation to construction year was not a risk factor per se; however, when analyzing only culled cows the proportional rate of death was significantly reduced from 2 years after construction year. Correspondence should be sent to Olav Østerås, Department of Production Animal Clinical Sciences, The Norwegian School of Veterinary Science, P.O. Box 8146, Dep., Oslo, Norway N-0033. Email: olav.osteras@veths.no D ow nl oa de d by [ D r K en ne th S ha pi ro ] at 0 8: 03 0 9 Ju ne 2 01 5