S. K. Jensen

Aarhus University | AU · Department of Animal Science

This study investigated the impact of calcium (Ca) and vitamin D supplements on bone metabolism, bone measurement, lameness, and selection rate in gilts fed five dietary treatments. Two Ca levels (6.85/6.42 [adequate; ACa] or 8.99/8.56 [high; HCa] g/kg) were combined with either 856 IU/kg vitamin D3 (Danish feeding standards; adequate; AD3) or 50 μ...

Milk production and milk fatty acid (FA) composition were followed in three Danish commercial organic dairy farms where grass clover silage was substituted with a forb-rich silage. Farms A, B, and C included a total of 50, 189, and 235 lactating dairy cows, and 20 cows in each herd were selected to record the productive performance and milk composi...

High‐starch diets may affect equine hindgut microbiota and increase blood glucose levels, which may cause unwanted physiological changes, but may also elicit behavioural changes such as increased fear reactions. The purpose of the current study was to feed a high starch (300) and low fat (43; HS_LF) or a low starch (60) and high fat (85; LS_HF, g/k...

This study investigated the influence of polyunsaturated fatty acid composition and vitamin E supplementation on oxidative status and immune responses in weanling piglets pre- and post-E. coli challenge. Suckling piglets (n = 24) were randomly selected from two litters for an oral supplementation (1 mL/day) with fish oil or hemp oil and vitamin E s...

Background Green macroalgae of the Ulva genus have gained interest as a source of protein, due to the high production potential and high proportion of essential amino acids. This review gives an overview of Ulva protein, including extraction and evaluation of protein quality in terms of nutritional value, functionality, and sensory properties with...

In postweaning calves, it is a challenge to maintain the plasma vitamin E level at or above the recommended level (3 µg/mL), which is linked to a good immune response. It has been unclear until now why the provision of solid feed with concentrations below 200 mg/kg feed of vitamin E is ineffective in maintaining the plasma vitamin E level of calves...

BACKGROUND Lucerne protein extract is a novel high‐quality protein source with excellent amino acid (AA) composition of interest for human consumption. In this study, protein from screw‐pressed lucerne juice was extracted by different precipitation methods to evaluate the effect on the chemical composition and nutritional quality of the extracted p...

The effect of heat treatment (raw or micronization) and vitamin E supplementation (0 or 200 mg/kg DM of RRR-α-tocopherol) on ruminal biohydrogenation (BH) kinetic of whole flaked rapeseed was studied using in vitro batch culture in a 2 × 2 factorial design. Experimental treatments were: whole flaked raw rapeseed without vitamin E (RR0), whole flake...

The accurate estimation of in vitro ruminal biohydrogenation (BH) kinetics of fatty acids (FA) allows for a more accurate understanding of their dynamics and develop targeted strategies to enhance desirable FA bypass. This study comprises a comprehensive evaluation of 33 nonlinear regression models to determine the most suitable model for accuratel...

Piglet survival is a major challenge in the first few days postpartum and interventions during this period may improve survival and growth. This study investigated the effects of palmitoleic acid (C16:1n-7; PA) supplementation on growth performance, body temperature, fatty acid (FA), and energy metabolism in milk-replacer-fed piglets. Forty-eight p...

Tocopherol sources in diets are often a combination of all-rac-α-tocopheryl acetate (synthetic α-tocopherol) from vitamin supplements and natural tocopherols and 2R-(4′R, 8′R)-5,7,8-trimethyltocotrienol (α-tocotrienols) from the feed sources. Synthetic α-tocopherol consists of 8 different stereoisomers including 2R-(4′R, 8′R)-5,7,8-trimethyltocol (...

Tocopherols (Toc) in cattle feed are often a combination of synthetic Toc (all-rac-α-Toc) from vitamin supplements and natural tocopherols (RRR-α-Toc) and tocotrienols (T-3) from the feed. Among different stereoisomers of all rac-α-Toc, RRR-α-Toc has the highest biological activity. Pre-absorption metabolism of Toc and T-3 in ruminants differs from...

At post-weaning calves, it is a challenge to maintain plasma vitamin E level at or above the recommended level (3 mg/mL), which is related to a good immune response. It has been unclear until now why the provision of solid feed with concentrations below 200 mg/kg feed of vitamin E is not effective in maintaining the plasma vitamin E of calves above...

Changing milk fatty acid (FA) profile is of great interest due to beneficial effect of linolenic acid (C18:3n-3, ALA), linoleic acid (C18:2n-6, LA) and conjugated LA (CLA) on human health. Milk composition and FA composition were analyzed in three Danish commercial organic dairy farms where grass clover silage was substituted with a forb-rich silag...

Purpose Studies show that dairy fat consumed in the form of cheese reduce LDL-cholesterol concentration (LDL-c) compared to butter and mechanistic suggestions include the calcium content of cheese leading to enhanced faecal fat excretion. The aim of this study was to test the effect of varying the calcium content within a cheese, on faecal fat excr...

Introduction: Low dietary intake of vitamin E is a global public health issue. RRR-α-tocopherol (RRR-αT) is the only naturally occurring vitamin E stereoisomer, but the equimolecular mixture of all eight stereoisomers, synthetic vitamin E (S-αT), is commonly consumed. The objective of this study was to evaluate bioavailability and antioxidant acti...

Compared with annual grain and seed crops, perennial grassland has significantly lower losses of nutrients and low pesticide requirements, whilst also supporting soil carbon build‐up. Until now grassland crops have almost exclusively been fed to ruminants and horses. Our experiments on biorefining forages have produced protein of a quality equal to...

The public demand for increased sustainability and reduced climate impact of the pork production incites using high yielding local protein sources as substitutes for the imported protein used presently. Substitution must be done without compromising the productivity, which could counteract the positive effect on climate impact. The aim of the study...

The aim of the study was to investigate the effects of substituting silage of chopped grass with pulp silage of grass fractionated once or twice in a biorefinery using a screw press on fiber kinetics, protein value, and production of CH4 in dairy cows. Six lactating multiparous Holstein cows in mid-lactation (176 ± 93 d in milk), cannulated in the...

The current study examined the impact of toasting and decortication on ruminal degradation and intestinal digestibility of tocopherols in dairy cows using four ruminal and intestinal cannulated Danish Holstein cows. Cows were fed experimental diets ad libitum. Treatments were one of four different forms of rolled oat arranged in 2 × 2 factorial: wh...

The objective of the study was to quantify the effects on dry matter intake (DMI), nutrient digestibility, gas exchange, milk production, and milk quality in dairy cows fed fresh grass harvested at different maturity stages. Sixteen Danish Holstein cows in mid-lactation were divided into 4 blocks and used in 4 incomplete 4 × 2 Latin squares with 2...

In organic pig production systems, one of the main challenges is to meet the demand for resources rich in protein. Among the resources available, temperate green plants, such as forage legumes, are potential sources of energy and protein. The aim of the study was to determine the nutritional value of silages (S) from the whole plant of lucerne (L)...

Many seaweed species have a high production potential and attract interest as future protein sources. A high fiber and ash content, however, demand extraction of the protein to improve its digestibility and protein utilization in food or feed. This study explores three different approaches for protein extraction from Ulva fenestrata in order to max...

Seaweed is gaining attention as a sustainable source of protein. However, the nutritional protein quality needs further investigation to explore the potential of seaweed as a protein source. This study evaluates in vivo digestibility of six different seaweed protein products, four from Ulva sp. and two from Saccharina latissima. Ulva sp. was either...

Calves often face a lower plasma vitamin E level than the recommended level (3 µg/ml for adult cows) after weaning, a level which has been related to a good immune response. Two experiments were performed to determine the most effective source and level of vitamin E to be included in a calf starter to maintain the plasma vitamin E level above the r...

The increasing world population with improved living conditions has increased the demand for food protein. This has intensified the search for sustainable alternative plant-derived high-quality protein sources for human nutrition....

Seaweed is gaining attention as a possible alternative and sustainable source of proteins. This study investigates three protein extraction methods and their effect on protein yield and quality when applied to Ulva fenestrata. Two of the methods included alkaline extractions (pH-shifts); one version solubilizing the proteins at pH 8.5 and one solub...

It is a challenge to keep a sufficient vitamin E level (2 mg/L) in calf plasma after weaning, and this seems to be critical for a good immune response. Two experiments were performed in order to find the most efficient source and dose of vitamin E in calf starter concentrates to keep plasma vitamin E level above the critical level after weaning. Ex...

The biorefinery technology aiming at protein extraction is rising and identification of suitable plant biomass input with valuable protein compounds for extraction is needed. Forage crops have been evaluated by the Cornell Net Carbohydrate and Protein System (CNCPS), and the result used as proxy of extractable protein in a biorefinery process. This...

Calves are often lower in plasma vitamin E concentration than the recommended level (3 mg/L) after weaning, which seems to be a challenge for a good immune response. Two studies were performed investigating if a natural vitamin E supplement in the starter concentrate could increase the plasma vitamin E concentration of calves around weaning. Each s...

This study compared the meat and eating quality from fattening pigs raised in a free-range system involving two cross-breeds: Duroc x (Landrace x Yorkshire) (DYL); and Tamworth x (Landrace x Yorkshire) (TYL) and two feeding strategies (semi-ad libitum (NORM) or restrictive feeding of concentrate (80-50% of semi-ad libitum; RES)). Sixteen female pig...

The present study investigated the effect of a high proportion of different forage species in the diet, parity, milking time, and days in milk (DIM) on milk fatty acid (FA) profile, and transfer efficiency of C18:2n-6, C18:3n-3, n-6, and n-3 in dairy cows. Swards with perennial ryegrass [early maturity stage (EPR) and late maturity stage (LPR)], fe...

Biorefining is a promising method for sustainable feed production through conversion of biomass into a protein concentrate for monogastrics and fibrous pulp for ruminants. Nitrogen (N) content and recovery in pulp and protein concentrate from lucerne, red clover, white clover, perennial ryegrass and tall fescue harvested at different spring cut har...

The purpose of the study was to extract protein from organic grass-clover in a green biorefining process and perform a dose-response feeding experiment with pigs on feed utilization, performance and slaughter quality. Forty-eight pigs were fed one of four experimental diets from 1 week post-weaning to slaughter. The diets consisted of a control die...

Ulva sp. is a cosmopolitan green macroalga with fast growth and a well-balanced amino acid composition, making it an interesting potential protein resource. Generally, the protein digestibility in unprocessed raw seaweed is low, which is why extraction and concentration of the protein is needed. During protein extraction from fresh Ulva sp. using d...

Bioavailability of α-tocopherol varies with source, dose and duration of supplementation. The effect of source and dose of α-tocopherol on response of α-tocopherol stereoisomers in plasma and tissues of mink kits during the weaning period was studied. Twelve mink kits were euthanised in CO 2 at the beginning of the experiment, and 156 mink kits (12...

Protein extracted from green biomass can be a sustainable and valuable feed component for organic poultry production. Earlier studies in rats have shown high digestibility of laboratory‐scale extracted protein. The aim of this study was to test the effect of upscaling the biorefining process on composition of protein extracted from organic grass‐cl...

This experiment quantified the effect of decorticated and toasted oat (Avena sativa L.) on fatty acid (FA) supply, ruminal biohydrogenation (BH) of FA, and intestinal digestibility of FA in 4 ruminal and intestinal cannulated Danish Holstein cows. Experimental diets containing untreated oat, decorticated oat, toasted oat, and decorticated and toast...

The main objective of this study was to investigate the effects of increasing dietary supplementation of crushed sunflower seeds (CSS) in dairy cow diet on mammary expression of genes involved in de novo FA synthesis, FA desaturation, FA transport/uptake, cholesterol homeostasis, and regulation of transcription. Twenty-four cows were allocated to o...

The aim of this experiment was to investigate the effect of dietary supplementation of crushed high oleic sunflower seeds (HOS) and rumen‐protected choline (RPC) on the fatty acid (FA) profile of phospholipids and sphingomyelin and mammary transcription of genes that are important for milk fat synthesis and de novo synthesis of sphingolipids. Twent...

In colder humid areas, green forages are recognised as high protein yielding crops and have the potential to be a locally grown sustainable protein source. However, without processing, the protein cannot be properly utilised by monogastrics. By screw pressing, a pulp fraction suitable for ruminants and a protein concentrate suitable for monogastric...

Analyse environnementale de l’utilisation de sources de protéine européenne pour l’alimentation porcine. La substitution au tourteau de soja brésilien (TSB), issu en partie de zones déforestées, avec des sources de protéines européennes (SPE), est une voie à l’étude pour réduire l’impact changement climatique de l’alimentation animale. Ce travail s...

The goal was to assess the environmental impacts of new European protein sources in order to replace Brazilian (BR) soybean meal in feed. Four innovative feedstuffs (IF) were studied : Fine fraction of French rapeseed meal obtained through physical treatment (IF1), French soybean meal, obtained from dehulled soybeans and with an innovative extrusio...

Objective : Assessing the environmental consequences for animal products (pig and poultry) of using innovative protein sources to replace Brazilian soybean meal in the feed

The objective of this study was to investigate the effect of increasing dietary supplementation of crushed sunflower seed (CSS) in the diet of dairy cows on the fatty acid (FA) composition of phospholipids and sphingomyelin in milk, and on mammary transcription of genes that are important for sphingomyelin de novo synthesis. Four groups of 6 cows r...

Among different stereoisomers of all-rac-α-tocopherol, 2R-stereoisomers have higher biological activities than their 2S-stereoisomers. Two experiments were conducted to study the pharmacokinetics of stereoisomers of all-rac-α-tocopherol and investigated the discrimination and distribution of α-tocopherol stereoisomers in plasma and milk as well as...

Manipulation of rumen biohydrogenation (BH) is of great importance, since decreased BH of linolenic acid (LNA) and linoleic acid (LA) is linked to increased content of the beneficial polyunsaturated fatty acids (PUFA) in dairy products and decreased content of trans fatty acids (FAs). We hypothesized that PUFA esterified to the complex lipid fracti...

After weaning, calves often have plasma vitamin E levels lower than the recommended level (2 mg/L). Therefore, the present study was conducted to evaluate the effect of vitamin E supplementation on plasma vitamin E level and growth performance of calves around weaning. The experiment was conducted at three Danish commercial farms producing rosé vea...

The aim was to study the effect of different forage species on milk fatty acid (FA) profile in dairy cows. Swards with perennial ryegrass (early maturity stage (EPR) and late maturity stage (LPR)), festulolium (FEST), tall fescue (TF), red clover (RC), and white clover (WC) were harvested in the primary growth, wilted, and ensiled without additives...

The objective of the current study was to examine the effect of fibrous pulp and partial substitution of soybean meal with green protein concentrate from biorefining of grass-clover on dry matter intake, milk production, digestibility, and eating behavior in dairy cows compared with untreated grass-clover silage and soybean meal. Biorefining of gra...

Glyphosate is the most used herbicide in agriculture. To monitor glyphosate exposure, analytical methods have to fulfill requirements with regard to sensitivity, reproducibility, ease of handling/high-throughput and applicability to multiple biological matrices. Furthermore, the methods have to include the degradation product of glyphosate, aminome...

Monogastric animals exhibit different biological responses to structurally diverse glucosinolates and their transformation products, depending on the dietary levels. The transformations of 2-hydroxyalkenyl and aromatic glucosinolates were examined in vitro under gastric conditions, ex vivo in ligated porcine stomachs and in vivo in a rat model. Int...

Supplementary Table S1. Regression coefficients (means ± standard error) of the effect vitamin E supplementation (RRR-α-tocopheryl acetate and all-rac-α-tocopheryl acetate) on α-tocopherol content in lamb tissues.

Globally, there is an increased demand for sustainable protein sources for animal feed. Grass and forage legumes have the yield potential to become such alternatives, but the protein needs to be separated from the fibres. Red clover, white clover, lucerne and perennial ryegrass were fractionated into a green juice and a fibrous pulp in a screw-pres...

The nutritional quality of rapeseed press cakes (RPCs) in piglet feed is closely linked to its digestibility and the content of glucosinolates. This study investigates the significance of intact glucosinolate (glc) levels and degree of glc transformations on piglets performance. Four different RPCs were made from a low glc (11 µmol/g seed DM) conta...

A ratio of 1.36:1 in relative bioactivity of RRR-α-tocopheryl acetate as a natural (Nat-α-T) source to all-rac-α-tocopheryl-acetate, as a synthetic (Syn-α-T) source is generally accepted. This factor also largely reflects the difference in bioavailability. However, studies indicate that neither bioavailability of α-tocopherol stereoisomers nor rela...

When supplementing lamb diets with vitamin E, an equivalence factor of 1.36 is used to discriminate between RRR- α -tocopheryl acetate and all-rac - α -tocopheryl acetate. However, more recent studies suggest a need for new equivalence factors for livestock animals. The current study aimed to determine the effect of RRR- and all-rac - α -tocopheryl...

Abstract Background A study of herd-level risk factors for calf mortality in large Swedish dairy herds showed low serum concentrations of α-tocopherol and β-carotene in 1–7 day old calves to be more common in high mortality herds. Therefore, we aimed to investigate if calf mortality risk at herd level is associated with concentrations of α-tocopher...

With the increase in the global herd, the use of metabolic modifiers has become an important area for many researchers looking for a supraphysiological diet to improve production parameters. For improving the performance of high yielding cows, the optimal balance of all nutrients including microminerals is important. Chromium (Cr) is one of the imp...

Synthetic α -tocopherol has eight isomeric configurations including four 2R ( RSS , RRS , RSR , RRR ) and four 2S ( SRR , SSR , SRS , SSS ). Only the RRR stereoisomer is naturally synthesised by plants. A ratio of 1·36:1 in biopotency of RRR - α -tocopheryl acetate to all - rac - α -tocopheryl acetate is generally accepted; however, studies indicat...

Synthetic vitamin E as commercial source of supplementation of α-tocopherol has eight isomeric configurations including four 2R (RSS, RRS, RSR, RRR) and four 2S (SRR, SSR, SRS, SSS). Only the RRR stereoisomer has the highest biological activity. A ratio of 1.36:1 in relative bioavailability of RRR-α-tocopheryl acetate as a natural (Nat-α-T) source...

Biorefinery of grassland plants may enable the production of feed for both ruminants and monogastrics at the same time. The pulp fibre fraction from twin-screw processed white clover, red clover, lucerne, and perennial ryegrass, is a major side-stream commonly considered of low value. However, it maintains a crude protein (CP) fraction of which a h...

Soluble protein extracted from leaves and stems of grasses and forage legumes is defined as green protein. The present study was conducted to evaluate in situ green protein degradability, intestinal protein disappearance and in vitro fatty acids biohydrogenation (BH) in dairy cows. Three green protein concentrates (red clover, ryegrass, and grass c...

Background The naturally occurring α-tocopherol (α-T) stereoisomer, RRR-α-tocopherol (RRR-α-T), is known to be more bioactive than all-rac-α-tocopherol (all-rac-α-T), a synthetic racemic mixture of 8 stereoisomers. There is widespread use of all-rac-α-T in maternal supplements. Objective The aim of the study was to thoroughly describe the α-T ster...

The objective of this study was to investigate the possible beneficial effect of vitamin D repletion on certain immune parameters of vitamin D insufficient dairy cows. Twenty dairy cows in late lactation were treated daily with vitamin D in five different ways: sunlight exposure (SUN), D2 supplementation combined with sunlight exposure (D2SUN), D2...

Background: The aim was to evaluate white clover as an alternative protein source for monogastrics. White clover plant and leaves were processed using a screw-press resulting in a solid pulp and a juice from which protein was acid-precipitated. The chemical composition of all fractions was determined and digestibility of dry matter (DM) and protei...

The effect of heat treatment on biohydrogenation of linoleic acid (LA) and linolenic acid (LNA) and formation of stearic acid (SA), cis-9, trans-11 conjugated LA (CLA), trans-10, cis-12 CLA and trans vaccenic acid (VA) was studied in in vitro incubations with diluted rumen fluid as inoculum and partly defatted flaxseed (DF) and partly defatted sunf...