White or red clover-grass silage in organic dairy milk production: Grassland productivity and milk production responses with different levels of concentrate

Red (RC) or white (WC) clover were grown in mixture with grasses, ensiled and offered to dairy cows in early lactation over two successive years (48 cows per year) to compare grassland yield, feed intake, milk production and milk quality. The crops were ensiled in round bales and proportional mixtures of the second and third cut prepared each year were used to ensure that the silage treatments were representative of the crop. In addition to silage type, concentrate supplementation, without and with (10 kg/day), was included as a factor in a 2 × 2 factorial, continuous experiment. Total dry matter (DM) yield, silage chemical composition and total DM intake was hardly affected by silage type. There was no effect of silage type on milk yield and milk constituents either, except for higher milk protein content (P < 0.05) on WC and higher milk fat content of C18:3n-3 (P < 0.001), C18:2n-6 (P < 0.05) fatty acids (FAs) and sum of polyunsaturated FA (P < 0.001) and lower n-6/n-3 FA ratio (P < 0.01) on RC. Concentrate supplementation increased total DM, N and net energy intakes (P < 0.001), milk yield (P < 0.001), milk fat (P < 0.01) and protein (P < 0.001) content, decreased the milk urea content (P < 0.001), and increased the milk fat content of short- and medium-chained FAs (< C16, P < 0.001), C18:0 (P < 0.01) and C18:2n-6 (P < 0.001), decreased the content of C16:0 (P < 0.05), C18:1t11 (P < 0.001) and C18:3n-3 (P < 0.001), and increased the n-6/n-3 FA ratio (P < 0.001). The effect of concentrate supplementation was not affected by silage type, except for milk protein content where the positive effect of supplementation was stronger on WC than on RC diets (P < 0.05). This study illustrates that the white- and red clover-grass mixtures investigated were widely similar with regard to their effects on grassland yield, silage intake and milk production and milk constituents, except for a higher milk fat content of C18:3n-3 and C18:2n-6 and lower n-6/n-3 FA ratio on red clover diets. Our findings also show that N conversion efficiency from feed to milk on pure forage diets is more sensitive to changes in dietary protein intake than silage diets containing cereal based concentrates.     

Growth traits of crossbreds of Ankole with Brown Swiss,Holstein Friesian,Jersey, and Sahiwal cattle in Rwanda

The objective of the study was to compare body weights and growth from birth to 18 months of age of various groups of crossbred cattle born from 1999 to 2007, being crossbreds of Ankole (A) with Brown Swiss (B), Holstein Friesian (F), Jersey (J), and Sahiwal (S). Average weights were 26.5 kg at birth, 161 kg at weaning, and 226 kg at 18 months. Both season and sex significantly affected birth weight (BW), weight at 8 and 18 months (W8 and W18), and average daily gain from weaning to 18 months (ADG18) and, unlike season, sex significantly affected average daily gain to 8 months and weaning age. The general trend was that average daily gain attained a maximum before weaning and thereafter decreased until 18 months. Least square means for AB and AF calves were comparable and significantly differed only for W18 and ADG18. AJ had the lowest BW but was comparable with AS, AJxS, and ASxJ for W8, age-adjusted weaning weight, and W18. Generally, AF was heavier than other breed groups, but the difference was smaller than expected probably because environmental conditions did not allow full expression of genetic potential for growth.     

Genetic differentiation between subpopulations of Swedish mountain (Fjäll and Fjällnära) cattle

ABSTRACT

The Swedish Mountain (Fjäll) cattle and the subpopulation Fjällnära originates from northern Sweden. They are differentiated from both traditional and commercial cattle from southern Sweden. We analysed data from the GGP HD150k SNP array and investigated genetic diversity and differences between Fjäll and Fjällnära, and between different groups of Fjällnära. We found that the Fjällnära can be divided into four groups, which are differentiated from each other and from the other Fjäll cattle. We also compared allele frequencies between different groups of Fjäll and Fjällnära for some of the functional SNPs included in the SNP array. Interestingly, the B allele of Beta lactoglobulin has a very high frequency (94%) in the Fjällnära cattle, which is significantly different from the frequency in the Fjäll cattle (60%). Comparing older samples of Fjäll cattle with more recent samples, we found a significant increase in the frequency of the B allele in Fjäll cattle.     

Impact of sedation method on the diagnosis of hip and elbow dysplasia in Swedish dogs

Our objective was to investigate the effect of sedation method on the screening result for hip and elbow dysplasia. The study was based on a questionnaire survey of routines for hip and elbow screening at Swedish veterinary clinics and results of hip and elbow status, for eight breeds (Bernese Mountain Dog, Boxer, German Shepherd Dog, Golden Retriever, Labrador Retriever, Newfoundland, Rottweiler, and Saint Bernard) recorded by the Swedish Kennel Club. In total 5877 and 5406 dogs examined for hip and elbow dysplasia, respectively, from January 2002 through March 2003 were included. We used logistic regression to examine whether the type of chemical restraint used for sedation affected the screening result for hip and elbow dysplasia. In addition to sedation method, the effects of veterinary clinic, sex, breed, and age at screening were studied.

The type of chemical restraint used for sedation affected the screening result for hip but not for elbow dysplasia. Acepromazine gave less than half the odds of hip dysplasia compared with medetomidine and butorphanol (the most common method), medetomidine alone or xylazine. Females had about 25% higher odds for developing hip dysplasia whereas males had almost 40% higher odds for developing elbow dysplasia. Saint Bernard, Newfoundland and German Shepherd Dog had the highest odds of developing hip dysplasia, whereas Rottweiler and Labrador Retriever had the lowest odds. Boxer had the lowest risk for elbow dysplasia, followed by Labrador Retriever. Saint Bernard and Rottweiler had the highest odds of elbow dysplasia. Increasing age increased the odds of both hip and elbow dysplasia, by about 2.5% per month.

Following the results in this study, recording of the type of chemical restraint used for sedation during hip screening has now become mandatory in Sweden. This makes it possible to account for the effect of sedation method in a model for prediction of breeding values for hip dysplasia.     

Variations in mucous cell numbers in gills of Atlantic salmon (Salmo salar) presmolt in commercial freshwater farms in Norway

Fish gills are heavily exposed to the external milieu and may react against irritants with different cellular responses. We describe variations in mucous cell counts in gills from healthy Atlantic salmon (Salmo salar) presmolts in five recirculating aquaculture system (RAS) farms and one flow‐through farm. Based on certain criteria, mucous cells were histologically quantified in a defined lamellar region of the gills and the counts were analysed. Immunohistochemistry (IHC) was used to investigate epithelial responses. The median number of total mucous cells in the defined region was 59 per fish. Between the farms, the medians varied from 31 to 101 with the lowest in the flow‐through farm. A regression model was fitted with “total mucous cells” as the dependent variable and with “fish length” and “fish farm” as independent variables. The proportion of variation in mucous cell counts explained by the model was twice as high when “fish farm” was included compared to only “fish length.” IHC revealed proliferative responses in coherence with high mucous cell numbers. Conclusively, the variation in mucous cell counts depends on combined farm‐related factors. Establishing a baseline for mucous cell counts is fundamental in the development of high‐throughput monitoring programmes of gill health in farmed fish.     

The effect of vertical and horizontal distribution on retention of sardine (Sardinops sagax) larvae in the Northern Benguela – observations and modelling

In the present study, a modelling experiment is conducted to simulate the transport of sardine (Sardinops sagax) eggs and larvae in the Northern Benguela. Based on historical and newly obtained data, different scenarios of vertical and horizontal distribution are applied and the effects on retention are discussed. The simulations showed that vertical and horizontal distribution were important for retention of sardine larvae in the Northern Benguela. By using age‐dependent data on vertical distribution, it was shown that retention of particles in the simulation was substantially enhanced compared with a scenario where particles were distributed in the offshore moving Ekman layer. Retention was lowest during October–December (when upwelling intensity is high) and highest during February–April (when upwelling intensity is somewhat lower). When different spawning areas were considered, highest retention was observed in an area near Walvis Bay. It is concluded that the behaviour of sardine larvae is adapted to the circulation system in the Northern Benguela in a way that promotes retention of the larvae in inshore nursery areas.     

A mixed methods inquiry: How dairy farmers perceive the value(s) of their involvement in an intensive dairy herd health management program

Background

Research has been scarce when it comes to the motivational and behavioral sides of farmers'' expectations related to dairy herd health management programs. The objectives of this study were to explore farmers'' expectations related to participation in a health management program by: 1) identifying important ambitions, goals and subjective well-being among farmers, 2) submitting those data to a quantitative analysis thereby characterizing perspective(s) of value added by health management programs among farmers; and 3) to characterize perceptions of farmers'' goals among veterinarians.

Methods

The subject was initially explored by means of literature, interviews and discussions with farmers, herd health management consultants and researchers to provide an understanding (a concourse) of the research entity. The concourse was then broken down into 46 statements. Sixteen Danish dairy farmers and 18 veterinarians associated with one large nationwide veterinary practice were asked to rank the 46 statements that defined the concourse. Next, a principal component analysis was applied to identify correlated statements and thus families of perspectives between respondents. Q-methodology was utilized to represent each of the statements by one row and each respondent by one column in the matrix. A subset of the farmers participated in a series of semi-structured interviews to face validate the concourse and to discuss subjects like animal welfare, veterinarians'' competences as experienced by the farmers and time constraints in the farmers'' everyday life.

Results

Farmers'' views could be described by four families of perspectives: Teamwork, Animal welfare, Knowledge dissemination, and Production. Veterinarians believed that farmers'' primary focus was on production and profit, however, farmers'' valued teamwork and animal welfare more.

Conclusion

The veterinarians in this study appear to focus too much on financial performance and increased production when compared to most of the participating farmers'' expectations. On the other hand veterinarians did not focus enough on the major products, which farmers really wanted to buy, i.e. teamwork and animal welfare. Consequently, disciplines like sociology, economics and marketing may offer new methodological approaches to veterinarians as these disciplines have understood that accounting for individual differences is central to motivate change, i.e. ''know thy customer''.