Computer-controlled milk feeding of group-housed calves: the effect of milk allowance and weaning type.

Calves fed by computer-controlled milk feeders are often weaned gradually by reducing the size of the milk portions. However, reducing the number of milk portions instead may lower calves' occupation of the milk feeder and stimulate their concentrate intake, especially when they are offered a high milk allowance. Before weaning, but not during weaning, the calves on low milk allowance occupied the milk feeder more, consumed more concentrates, and had a lower daily gain.

A stochastic model simulating pathogen-specific mastitis control in a dairy herd.

The objective of this study was to develop a model simulating mastitis control in dairy herds and to investigate how sensitive the model is when varying the effect parameters according to the uncertainty. The model simulates 9 pathogen-specific mastitis types, each of which can be subclinical or clinical. The clinical cases can be 1 of 4 severities defined according to the effect of the mastitis case: mild, moderate, severe, and permanent effect.

Improving cryopreservation systems.

Cryopreservation of oocytes and embryos is a crucial step for widespread practical application of other techniques in domestic animal embryology. However, in contrast to the rapid development of procedures in the eighties and early nineties of the last century, new advancements with profound practical consequences have only been recently achieved. As a result of a long and controversial development, an alternative group of methods, vitrification, has proved its efficiency and practicality in the past few years.

Infrared thermography and ultrasonography to indirectly monitor the influence of liner type and overmilking on teat tissue recovery.

Eight Danish Holstein cows were milked with a 1-mm thick specially designed soft liner on their right rear teat and a standard liner mounted under extra high tension on their left rear teat. Four of the animals were overmilked for 5 min. Rear teats were subjected to ultrasound examination on the first day and to infrared thermography on the second day.

Evaluation of cooling strategies for pumping of milk - impact of fatty acid composition on free fatty acid levels.

Cooling strategies for pumping of raw milk were evaluated. Milk was pumped for 450 s at 31 degrees C, or pumped after cooling to 4 degrees C and subsequently subjected to various incubation times. Two types of milk were used; i.

Visual scoring of clots in foremilk.

The necessary unequivocal and generally accepted definitions of normal and abnormal milk are not available. A precise definition is needed in order for companies to develop sensors to detect and sort abnormal milk at the time of milking. Experts at a workshop defined abnormal milk to be that from cows whose foremilk had changed in homogeneity or was coloured by blood.

Salt diffusion and distribution in meat studied by 23Na nuclear magnetic resonance imaging and relaxometry.

This study introduces the use of combined 23Na magnetic resonance imaging (MRI) and 23Na NMR relaxometry for the study of meat curing. The diffusion of sodium ions into the meat was measured using 23Na MRI on a 1 kg meat sample brined in 10% w/w NaCl for 3-100 h. Calculations revealed a diffusion coefficient of 1 x 10(-5) cm2/s after 3 h of curing and subsequently decreasing to 8 x 10(-6) cm2/s at longer curing times, suggesting that changes occur in the microscopic structure of the meat during curing.

Molecular characterization of major histocompatibility complex class I (B-F) mRNA variants from chickens differing in resistance to Marek's disease.

In this study, the relative distributions of two alternatively polyadenylated chicken major histocompatibility complex (MHC) mRNA isoforms of approximately 1.5 and 1.9 kb were analysed in spleen cells from chickens homozygous for the MHC haplotypes B21 and B19v1 as well as in heterozygous B19v1/B21 birds.

Visual scoring of milk mixed with blood.

Sorting of normal and abnormal milk at time of milking is done visually for conventional milking systems, but more concrete standards are needed when milking is done in automatic milking systems (AMS). Several panel tests were carried out to find out how different consumer groups, milkers and advisors look at and respond to the visual appearance of milk mixed with blood, in order to set a limit for what they think is acceptable. It is concluded from the test panel results that milk samples with 0.

The effects of dry period versus continuous lactation on metabolic status and performance in periparturient cows.

It has been argued that dairy cows with a high genetic milk production potential can maintain high milk production even with total omission of the dry period. Further, when omitting the dry period, cows are believed to experience fewer metabolic changes during the transition from late gestation to early lactation compared with cows having a traditional dry period. The performance and metabolic response to omission of the dry period for cows with an expected peak milk yield higher than 45 kg/d were studied in 28 Holstein dairy cows.

Expression of genes involved in regulation of cell turnover during milk stasis and lactation rescue in sow mammary glands.

We studied the transcription of selected genes involved in the regulation of cell turnover during milk stasis and lactation rescue in individual mammary glands of sows and evaluated the timeframe for lactation rescue and the subsequent productivity of rescued glands. Suckling was prevented in two glands from each of five sows by taping them the day after farrowing for 1 or 3 d (Closed 24 h and Closed 72 h glands, respectively). After removing the tape, Closed 24 h glands were suckled until weaning.

Quarter health, milking interval, and sampling time during milking affect the concentration of milk constituents.

Eleven Danish Holstein cows were used to examine the effects of quarter health (healthy vs. unhealthy), milking interval (12 vs. 6 h), and sampling time during milking on the concentration of 8 milk constituents [acetone, beta-hydroxybutyrate (BHBA), N-acetyl-beta-D-glucosaminidase (NAGase), somatic cell count (SCC), urea, fat, protein, and lactose].

Changes in freezing point of blood and milk during dehydration and rehydration in lactating cows.

We studied the influence of short-term changes in water intake in 4 lactating Holstein cows on diurnal fluctuation of packed cell volume (PCV), freezing point of blood (FPblood), freezing point of milk (FPmilk), and the relationship between changes in FPblood and FPmilk. The experiment lasted 108 h and was divided into 3 periods: 1) control (38 h); 2) dehydration/rehydration with 4 consecutive 12-h sequences: 8 h without water, 0.5-h access to water, 1.

Dietary creatine monohydrate affects quality attributes of Duroc but not Landrace pork.

Increased creatine content in the muscle may delay post mortem lactate formation and postpone the pH decline, hence potentially improving the water-holding capacity (WHC). Duroc and Landrace pigs were supplemented with 0, 12.5, 25 or 50g creatine monohydrate (CMH)/d for 5 days prior to slaughter.

Rye bread enhances the production and plasma concentration of butyrate but not the plasma concentrations of glucose and insulin in pigs.

The present investigation was undertaken to study the gastrointestinal and physiologic properties of diets based on soft and crisp wheat and rye breads similar in dietary fiber (DF; 230-235 g/kg dry matter) but with different proportions of the main DF polymers: in wheat, cellulose, and in rye, arabinoxylans (AX). The 2 diets provided all macronutrients; consequently, they had lower fat and sugar contents and a higher DF content than human mixed diets. The nutritional properties were studied in experiments in which pigs with cannulated ilea and catheterized portal veins and mesenteric arteries served as models for humans.

To what extent do variabilities in hormones, metabolites and energy intake explain variability in milk yield?

The objective of the present paper is to describe the extent to which variability in milk yield can be explained by variability in plasma hormones, metabolites and DE intake. Results from a study including 317 cows and 634 lactations were used. Detailed registration of performance was carried out on these cows and 10,809 plasma samples analyzed for selected hormones and metabolites.

Effect of feed particle size and feed processing on morphological characteristics in the small and large intestine of pigs and on adhesion of Salmonella enterica serovar Typhimurium DT12 in the ileum in vitro.

A 2 x 2 factorial experiment with pigs was undertaken to investigate the effect of particle size (fine and coarse) and feed processing (pelleted and nonpelleted) on morphological characteristics in the small intestine, cecum, and colon of pigs and on the adhesion of Salmonella enterica serovar Typhimurium DT12 to the ileum in vitro. Ninety-six pigs (average BW = 33 +/- 7 kg) were fed the experimental diets. After 4 wk, 24 pigs were selected (six pigs per diet) and euthanized, and tissue samples were taken from the mid and distal small intestine, cecum, and distal colon.

Predicting risk of ketosis in dairy cows using in-line measurements of beta-hydroxybutyrate: a biological model.

Automated monitoring of individual cows to determine health status is a potentially valuable management tool, especially in large dairy herds. Herein is described the rationale, structure, and functionality of a biological model to predict risk of ketosis in individual cows using in-line measurements of the ketone body beta-hydroxybutyrate (BHBA) in milk. The model also uses acceleration in milk yield, body fatness at calving, diseases in current lactation, and incidences of ketosis in earlier lactations as additional risk factors for ketosis.

Characterisation of the gastrointestinal bacterial community in pigs fed fermented liquid feed and dry feed: composition and fermentation capacity (phenotypic fingerprint).

Feeding pigs with fermented liquid feed (FLF) has been shown to reduce the number of enteropathogens such as Salmonella and Brachyospira hyodysenteriae as well as coliform bacteria in general in the gastrointestinal tract (GIT). Also the commensal bacterial populations have been shown to respond to the use of FLF, e.g.

Addition of formic acid or starter cultures to liquid feed. Effect on pH, microflora composition, organic acid concentration and ammonia concentration.

Some of the charateristics of good quality fermented liquid feed (FLF) are low pH, high numbers of lactic acid bacteria, and low numbers of enterobacteria. In order to test strategies to avoid a proliferation of enterobacteria during the initial phase of FLF elaboration, two in vitro studies were carried out. Addition of various doses of formic acid or two different starter cultures were tested.

Determination of lactate dehydrogenase (LDH) activity in milk by a fluorometric assay.

Indigenous L-lactate dehydrogenase (LDH) in milk originates mainly from somatic cells, leucocytes and invading microorganisms. Its activity may be used for detection of mastitis. However, existing methods to measure LDH activity in milk both need pretreatment of the samples and still suffer from methodological problems.

Influence of supplementation of all-rac-alpha-tocopheryl acetate preweaning and vitamin C postweaning on alpha-tocopherol and immune responses of piglets.

This study was designed to test whether dietary maternal supplementation of all-rac-alpha-tocopheryl acetate during lactation and dietary vitamin C supplementation after weaning could increase the alpha-tocopherol status pre- and postweaning and the immune responses of piglets postweaning. The experiment involved 12 crossbred sows that were fed increasing levels of all-rac-alpha-tocopheryl (70, 150, and 250 IU/kg, as-fed basis) during lactation. After weaning (d 28 of age), litters were divided into two groups that were supplemented with or without vitamin C (500 mg/kg of feed, as-fed basis).

Penicillium verrucosum occurrence and ochratoxin A contents in organically cultivated grain with special reference to ancient wheat types and drying practice.

This study addresses the relationship between the ochratoxigenic strains of Penicillium verrucosum and ochratoxin A (OTA) contents in organically cultivated grain. It included 37 combined, non-dried grain samples from farmers with no drying facilities as well as 19 non-dried and 22 dried samples from six farms with on-farm drying facilities (Case studies 1-6). The study focused on the ancient wheat type spelt but also included samples of wheat, rye, barley, oats, triticale, emmer, and einkorn.

Influence of dietary zinc oxide and copper sulfate on the gastrointestinal ecosystem in newly weaned piglets.

Dietary doses of 2,500 ppm ZnO-Zn reduced bacterial activity (ATP accumulation) in digesta from the gastrointestinal tracts of newly weaned piglets compared to that in animals receiving 100 ppm ZnO-Zn. The amounts of lactic acid bacteria (MRS counts) and lactobacilli (Rogosa counts) were reduced, whereas coliforms (MacConkey counts) and enterococci (Slanetz counts, red colonies) were more numerous in animals receiving the high ZnO dose. Based on 16S rRNA gene sequencing, the colonies on MRS were dominated by three phylotypes, tentatively identified as Lactobacillus amylovorus (OTU171), Lactobacillus reuteri (OTU173), and Streptococcus alactolyticus (OTU180).