Metabolic profiles in five high-producing Swedish dairy herds with a history of abomasal displacement and ketosis

Background

Body condition score and blood profiles have been used to monitor management and herd health in dairy cows. The aim of this study was to examine BCS and extended metabolic profiles, reflecting both energy metabolism and liver status around calving in high-producing herds with a high incidence of abomasal displacement and ketosis and to evaluate if such profiles can be used at herd level to pinpoint specific herd problems.

Methods

Body condition score and metabolic profiles around calving in five high-producing herds with high incidences of abomasal displacement and ketosis were assessed using linear mixed models (94 cows, 326 examinations). Cows were examined and blood sampled every three weeks from four weeks ante partum (ap) to nine weeks postpartum (pp). Blood parameters studied were glucose, fructosamine, non-esterified fatty acids (NEFA), insulin, β-hydroxybutyrate, aspartate aminotransferase, glutamate dehydrogenase, haptoglobin and cholesterol.

Results

All herds had overconditioned dry cows that lost body condition substantially the first 4–6 weeks pp. Two herds had elevated levels of NEFA ap and three herds had elevated levels pp. One herd had low levels of insulin ap and low levels of cholesterol pp. Haptoglobin was detected pp in all herds and its usefulness is discussed.

Conclusion

NEFA was the parameter that most closely reflected the body condition losses while these losses were not seen in glucose and fructosamine levels. Insulin and cholesterol were potentially useful in herd profiles but need further investigation. Increased glutamate dehydrogenase suggested liver cell damage in all herds.     

Copper deficiency and effects of copper supplementation in a herd of red deer (Cervus elaphus)

Copper (Cu) deficiency was diagnosed in a Norwegian red deer (Cervus elaphus) herd subsequent to deaths due to emaciation in late autumn 1999. The animals had free access to salt licks containing 3000 mg Cu/kg. An evaluation of the herd revealed poor calf growth rate, low weights of adult hinds, dull and light-coloured hair coats and cases of diarrhoea. The herd was subsequently monitored throughout a three-year period of Cu-supplementation. The monitoring regimen included clinical observation, copper serum examination, weighing, faecal parasitological examination, and reproduction control by ultrasound. During the period January 2000 to May 2001, the animals were treated with Cu oxid capsules (1 g CuO/10 kg liveweight) at 2–4 months intervals, with the exception of March to September 2000. The animals were fed continuously with Cu-enriched concentrates containing 300 mg Cu/kg, at a rate of 1/2 kg per head and day, from May 2001 to January 2003. Following both copper supplementation regimens adequate serum Cu concentrations were measured, and markedly improved body weights, coat quality and reproductive results were observed, except for the period from March to September 2000 when no treatment was given. The results showed that in a deer herd, with a diet low in Cu, supplementation with CuO capsules had to be given at intervals of a few months to maintain adequate serum Cu levels. Free access to Cu-containing salt licks did not meet the animals'' Cu demand. Good and stable results were achieved by the daily feeding of Cu-enriched concentrates.     

How are the salmon lice (Lepeophtheirus salmonis Krøyer, 1837) in Atlantic salmon farming affected by different control efforts: A case study of an intensive production area with coordinated production cycles and changing delousing practices in 2013–2018

The aims of the present study were to describe the salmon lice (Lepeophtheirus salmonis Krøyer, 1837) situation in an intensive salmon production area in mid‐Norway and to consider implications of changing practices of how salmon lice infestation can be controlled. The results in this study suggest that there are steps that can be carried out to keep salmon lice under control even during years when the temperature facilitates a quick salmon lice development. The present work indicates that the use of cleaner fish can delay the time it takes adult female lice to reach 0.1 per salmon in the beginning of a production cycle. It suggests that the timing of cleaner fish deployment into salmon cages can influence its effectiveness in controlling salmon lice. It also gives caution to letting salmon lice develop unchecked, even at levels far below the current lice limit, because of the difficulties to control salmon lice when the external infection pressure is too high. This study took place during a rapid change in delousing methods, in an area with coordinated salmon production. Despite its exploratory nature, this study offers insights into the salmon lice fluctuations in relation to efforts aimed at controlling it.     

Effects of maturity stage and feeding strategy of whole crop barley silage on intake, digestibility and milk production in dairy cows

Five diets containing concentrate, grass silage and whole crop barley silage (WCBS) harvested at different maturity stages were fed to 15 multiparous dairy cows in an incomplete change-over design over three periods. Three diets contained 10.7 kg dry matter (DM) concentrate, 4 kg DM grass silage, and ad libitum access to WCBS harvested at either the heading stage (B1), the early milk stage (B2) or the early dough stage (B3) of maturity. The other two diets contained 10.7 kg DM concentrate, whereas grass silage and WCBS at heading were mixed at two different ratios with a DM content of WCBS of either 0.30 (M1) or 0.70 (M2), and the mixtures were fed ad libitum. Intakes of DM (kg day^− 1: B1 = 21.0, B2 = 20.6 and B3 = 20.0) and neutral detergent fibre (NDF; kg day^− 1: B1 = 7.0, B2 = 6.4 and B3 = 6.3) decreased, whereas starch intake increased (kg day^− 1: B1 = 3.1, B2 = 3.5 and B3 = 4.0) with increasing maturity at harvest. The apparent organic matter (OM) digestibility (g kg^− 1: B1 = 800, B2 = 774 and B3 = 729) decreased with increasing maturity stage, and consequently so did the digestible OM intake. Milk (kg day^− 1: B1 = 27.2, B2 = 26.1 and B3 = 25.9) and energy corrected milk (ECM; kg day^− 1: B1 = 31.0, B2 = 29.4 and B3 = 28.2) yields, and protein concentration (g kg^− 1: B1 = 37.1, B2 = 36.4 and B3 = 36.0) decreased with increasing maturity stage of the WCBS. When cows were fed diet B3 the milk fat concentration decreased (46.4 g kg^− 1) compared to diets B1 (49.3 g kg^− 1) and B2 (49.4 g kg^− 1). The difference in ECM yield between diets B1 and B3 was due to a combined effect of lower milk yield, and lower protein and fat concentrations. This was caused by the higher starch and lower NDF intakes with diet B3, which decreased the milk fat concentration. Moreover, a lower energy intake of diet B3 due to lower OM digestibility decreased milk protein concentration and milk yield. Mixing WCBS at the heading stage with grass silage (M2) decreased digestibility, compared to feeding the forages separately (B1). However, the differences were small and may be a result of soil contamination at harvest of some of the silages, which made the method with using incomplete faecal collection and internal marker acid insoluble ash less reliable. Including WCBS at the heading stage at 0.30 or 0.70 of forage DM did not affect DM intake or diet digestibility, probably because the grass silage in the study was very similar in energy content to the WCBS harvested at heading.     

Analyses of the impact of changes in atmospheric deposition and climate on forest growth in European monitoring plots: A stand growth approach

During the last 15 years a number of studies have shown increasing forest growth in central Europe, rather than a decline as was expected due to negative effects of air pollution. We have here used data from intensive monitoring plots spread over Europe for a five year period in order to examine the influence of environmental factors on forest growth. Evaluations focussed on the influence of nitrogen, sulphur and acid deposition, temperatures, precipitation and on a drought index calculated as deviation from the long-term mean. The study included the main tree species Norway spruce, Scots pine, common beech as well as European and sessile oak and was based on data from 363 plots. As many other factors besides nitrogen and temperature influence tree growth, expected stem volume increments were modelled using site productivity, stand age and a stand density index. Relative volume increment was then calculated as actual increment in % of expected increment. The site productivity, assumed to be given by site conditions and past environmental conditions, was either taken from expert estimates or computed from site index curves from northern, central and southern Europe. The model explained between 18% and 39% of the variance with site productivity being positively related and age negatively related to actual increment. The various models and statistical approaches were fairly consistent, and indicated a fertilizing effect of nitrogen deposition, with slightly above one percent increase in volume increment per kg of nitrogen deposition per ha and year. This was most clear for spruce and pine, and most pronounced for plots having soil C/N ratios above 25. Also, we found a positive relationship between relative increment and summer temperature, i.e. May–August mean temperature deviation from the 1961–1990 means. The cause–effect relationship here is, however, less certain. Other influences were uncertain. Possibly, sulphur and acid deposition have effects on growth, but these effects are obscured by, and outweighed by the positive effect of nitrogen deposition, because of collinearity between these variables. Drought effects were uncertain also, and one reason for this might be large uncertainties in the precipitation data: precipitation measured on some 50% of the plots correlated poorly with the precipitation data obtained from Europe-wide databases. The major finding of this study was a positive relationship between higher than normal volume increment on one hand and nitrogen deposition on the other hand.     

Temperature‐dependent feed requirements in farmed blue mussels (Mytilus edulis L.) estimated from soft tissue growth and oxygen consumption and ammonia‐N excretion

Feed requirements were estimated from specific growth rates in standardized soft tissue dry weight (SGR_DW’) and atomic O:N ratios for mussels fed seven rations of microalgae (5–735 μg C h^?1 ind^?1) at 7 and 14°C respectively. The mean oxygen consumption and ammonia‐N excretion rates were significantly higher at 14°C (0.29 μg O² and 27.3 μg N ind^?1 h¹) compared with those at 7°C (0.16 μg O² and 11.4 μg N ind^?1 h^?1) (P < 0.05), resulting in O:N ratios between 3 and 45 at 7°C and 7 and 28 at 14°C. Low O:N ratios indicate protein catabolism and an unfavourable condition, whereas high ratios indicate that carbohydrate is the primary energy source. The measured SGR_DW’ suggests minimum feed requirements of ~240 and ~570 μg C ind^?1 h^?1 for weight maintenance at 7 and 14°C, with corresponding O:N ratios of 24 and 16, respectively, indicating a more stressed condition at 14°C. A 0.5% SGR_DW’ day^?1 was obtained by ~565 (O:N = 29) and ~680 (O:N = 23) μg C ind^?1 h^?1 at 7 and 14°C respectively. A positive and significantly higher SGR_DW’, with the lowest feed ration at 7°C compared with a negative SGR_DW’ at 14°C (P < 0.05), indicated that storage time can also possibly be prolonged at low temperatures if the mussels are not fed.     

Feasibility of using rare earth elements (REEs) to mark and identify escaped farmed Atlantic salmon Salmo salar L.

A series of rare earth elements (REEs) were evaluated as potential markers in scales of Atlantic salmon 1⁺ and 0⁺ smolt by addition of these elements to the feed. Chlorides of 5 REEs were tested, alone or in combination: lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd) and dysprosium (Dy). The labelled‐diets contained 125 or 250 mg REE kg^?1 feed and were administered for up to 10 weeks. Fish scales were collected and analysed by inductively coupled plasma‐mass spectrometry (ICP‐MS) before start, 5 and 10 weeks after labelling started and finally 2 or 4 months after marking. The results demonstrated that the five tested elements were clearly incorporated into the scales of the fish fed the supplemented diets. Uptake and concentrations increased gradually during the feeding period, and no principal differences were found between the two smolt types. Combining 2 REEs in the same feed did not affect the incorporation of either of them. After a ‘dilution’‐period of 2–4 months the concentrations of all markers (except La) in the scales of the treated‐fish were still significantly higher than those of the untreated‐fish. The background concentrations of the tested markers and some other elements were also measured and found to give interesting information.     

Sensory quality and chemical composition in carrots: A multivariate study

Carrots from designed trials and organic and conventional farms were analysed for sensory quality and chemical composition. The data were combined in principal component analyses and partial least squares regression for exploration of the main factors responsible for the variation in quality. One of the most important factors was fertilization. Carrots grown with no fertilizer and carrots fertilized with 40–80 kg nitrogen ha^?1 as mineral fertilizer or 20–72 tons ha^?1of organic fertilizer contained more total sugars and total flavour strength, less crispness, crude protein, true protein and carotene, and had a lower pH, compared with carrots fertilized with 100–192 kg nitrogen ha^?1 as mineral fertilizer. Location site was also very important in the explanation of the total variation and was a composite factor of precipitation, temperature in June, growth system and length of growth period. Soil type, amount of organic fertilizer, use of pesticides and temperatures in July and August seemed to be of less importance.     

Proteolytic and Lipolytic Enzymes from Larvae of Oedemagena Tarandi (L.)

Some biological properties of proteolytic and lipolytic enzymes of the larval stages of Oedemagena tarandi (L.) were examined. While the proteinase titres seemed to vary only slightly from one larval stage to another, the lipase titres of the first larval stage seemed to be much greater than those of the second and third larval stages. The zymogram technique used showed only one proteinase, which was inhibited by all the biological inhibitors tested. Bacteriological examinations of the external surfaces and internal organs of the different larval stages showed only a very sparse flora.