[Effect of a multimodal pain management protocol and age on wound healing after thermal disbudding of female German Holstein calves]. / Einfluss eines multimodalen Schmerz­managements sowie des Alters zum Zeitpunkt des Eingriffes auf die Wundheilung nach thermischer Zerstörung der Hornanlage bei weiblichen Deutsch-Holstein-Kälbern.

INTRODUCTION: Hot-iron disbudding of calves is a stressful and painful procedure and leaves a burn wound. Pain management procedures and the effects of hot-iron disbudding on biochemical markers of pain perception and stress response have been widely investigated in recent years. The aim of this study was to investigate the potential effects of pain management and age of the calf on the healing of burn wounds caused by disbudding. 327 healthy female German Holstein calves were included in this randomised, triple-blinded, prospective study. Calves were either disbudded at the age of four to 10 or 15 to 28 days using a gas-powered hot iron. Each calf was randomly allocated to one of nine possible treatment groups (BG). All calves received either the active ingredients to be tested (xylazine hydrochloride with 0.2 or 0.05 mg / kg body mass (BM) intramuscular for sedation, procaine hydrochloride (2 %) each 8 ml locally on both sides subcutaneously (SC) to the cornual nerves, meloxicam with 0,5 mg / kg BM SC for anti-inflammatory purposes) or an identical amount of saline solution (placebo). Calves in the group `thermE` and `ScheinE` received only placebo. In group `ScheinE` disbudding was simulated and in `thermE` it was carried out. The calves were clinically monitored starting one day before and ending 28 days after the procedure and the burn wounds were assessed. Both the rectal temperature and parameters of wound healing changed significantly during the study period and had characteristic profiles over time. Wound healing was not influenced by the different analgesic protocols, indicating that a multimodal analgesia does not pose a risk for wound healing after thermal disbudding. There were no observed differences between the age groups. The results of this study show, that disbudding of young calves and a multimodal pain management protocol does not affect wound healing in calves.

INTRODUCTION: L'ébourgeonnage thermique des veaux est une procédure stressante et douloureuse qui laisse une brûlure. Les procédures de gestion de la douleur et les effets de l'ébourgeonnage thermique sur les marqueurs biochimiques de la perception de la douleur et de la réponse au stress ont été largement étudiés ces dernières années. Le but de cette étude était d'étudier les effets potentiels de la gestion de la douleur et de l'âge du veau sur la cicatrisation des brûlures causées par l'ébourgeonnage. 327 veaux Holstein allemands femelles en bonne santé ont été inclus dans cette étude prospective randomisée en triple aveugle. Les veaux ont été soit ébourgeonnés à l'âge de 4 à 10 jours ou de 15 à 28 jours à l'aide d'un thermocautère à gaz. Chaque veau a été réparti au hasard dans l'un des neuf groupes de traitement possibles (BG). Tous les veaux ont reçu soit les principes actifs à tester (chlorhydrate de xylazine à 0,2 ou 0,05 mg/kg de masse corporelle (BM) par voie intramusculaire pour sédation, chlorhydrate de procaïne (2 %) 8 ml localement des deux côtés par voie sous-cutanée (SC) jusqu'aux nerfs cornuaux , méloxicam à 0,5 mg/kg de masse corporelle SC à visée anti-inflammatoire) ou une quantité identique de solution saline (placebo). Les veaux du groupe « thermE ¼ et « ScheinE ¼ ont reçu uniquement un placebo. Dans le groupe

[Cortisol concentrations in sheep before, during and after sham foot trimming on a tilt table - the suitability of different matrices]. / Kortisolkonzentrationen bei Schafen vor, während und nach der simulierten Klauenbehandlung im Kippstand ­ Eignung verschiedener Matrices.

INTRODUCTION: Matrices that can be collected non-invasively for quantification of a stress response in sheep have received little attention in the veterinary literature. This study examines the suitability of blood, tears and saliva for determining a stress response in sheep undergoing sham foot trimming on a tilt table. The cortisol concentration of blood, tears and saliva and the concentration of cortisol metabolites in faeces were measured in 13 healthy Meat Merino ewes once a day for six days. Sham foot trimming on a tilt table was used as the stressor and was done during a one-hour period on day 4; cortisol concentrations of blood and tears were measured at 0, 10, 20, 30, 40 and 60 minutes. Cortisol concentrations of blood (maximum at 30 minutes) and tears (maximum at 40 minutes) increased during the procedure and then decreased. There were significant correlations between cortisol concentrations of blood and tears (p = 0,04) during sham foot trimming (area under the curve, 0 to 60 minutes). Over the entire 6-day study period, significant correlations were seen between the cortisol concentrations of blood and tears (r = 0,55; p.

INTRODUCTION: Les marqueurs qui peuvent être collectés de manière non invasive pour quantifier une réponse au stress chez le mouton ont fait l'objet de peu d'attention dans la littérature vétérinaire. Cette étude examine la pertinence du sang, des larmes et de la salive pour déterminer une réponse au stress chez des moutons subissant un parage fictif des pieds sur une table basculante. La concentration de cortisol dans le sang, les larmes et la salive ainsi que la concentration de métabolites de cortisol dans les fèces ont été mesurées chez 13 brebis Meat Merino saines une fois par jour pendant six jours. Le parage fictif des pieds sur une table inclinable a été utilisé comme facteur de stress et a été effectué pendant une période d'une heure le jour 4; les concentrations de cortisol dans le sang et les larmes ont été mesurées à 0, 10, 20, 30, 40 et 60 minutes. Les concentrations de cortisol dans le sang (maximum à 30 minutes) et les larmes (maximum à 40 minutes) ont augmenté au cours de la procédure puis ont diminué. Il y avait des corrélations significatives entre les concentrations de cortisol dans le sang et les larmes (p = 0,04) lors du parage fictif des onglons (aire sous la courbe, 0 à 60 minutes). Sur l'ensemble de la période d'étude de 6 jours, des corrélations significatives ont été observées entre les concentrations de cortisol dans le sang et les larmes (r = 0,55 ; p < 0,001), le sang et la salive (r = 0,53 ; p < 0,001) et les larmes et la salive (r = 0,78 ; p < 0,001). La concentration fécale de métabolites de cortisol était significativement augmentée au jour 5 (p 0,05), mais la concentration de cortisol des autres supports n'a pas changé de manière significative au cours de la période d'étude de 6 jours. Le parage fictif des pieds sur une table basculante a été considéré comme un facteur de stress aigu chez les moutons en raison de l'augmentation des concentrations de cortisol dans le sang, des larmes et de l'augmentation des concentrations de métabolites de cortisol dans les selles. La concentration de cortisol dans les larmes était similaire à celle du sang et, par conséquent, la collecte de larmes représente une alternative viable et non invasive au sang pour les tests de cortisol. Le délai des pics entre la concentration maximale de cortisol dans les larmes et le sang doit être pris en compte lors de l'interprétation des résultats.

Aspects of transition cow metabolomics-Part I: Effects of a metaphylactic butaphosphan and cyanocobalamin treatment on the metabolome in liver, blood, and urine in cows with different liver metabotypes.

Dairy cows in modern production systems are at risk to develop metabolic disorders during the transition period. Reasons for individual differences in susceptibility, as well as the underlying pathomechanisms, are still only partially understood. The development of metaphylactic treatment protocols is needed. In this context, an on-farm prospective 3-fold blinded randomized study involving 80 German Holstein cows was performed throughout 1 yr. The trial involved a thorough recording of the production and clinical traits, clinical chemistry, and liver biopsies and blood and urine sampling at d 14 (mean: 12 d, range: 1-26 d) antepartum (AP), and d 7 (7, 4-13) and 28 (28, 23-34) postpartum (PP) for metabolomics analyses. Two groups received a treatment with butaphosphan and cyanocobalamin (BCC) at either the dosage recommended by the manufacturer or the double dosage (5 or 10 mL/100 kg of body weight 10% butaphosphan and 0.005% cyanocobalamin (Catosal, Bayer Animal Health), n = 20 in each group, parity: 4.2 ± 2.0 and 3.4 ± 1.3, respectively (mean ± SD)] and one group a placebo treatment (NaCl 0.9%, n = 40, parity: 4.0 ± 1.9). The animals were treated at 6 time points (7, 6, and 5 d AP, and 1, 2, and 3 d PP) via intravenous injection. Mass spectroscopy-based targeted metabolomics analysis of blood plasma and liver samples were performed using the AbsoluteIDQ p180 kit (Biocrates Life Sciences), whereas the urine samples were analyzed by nuclear magnetic resonance spectroscopy. Statistical analysis was performed using multivariate [partial least squares discriminant analysis (PLS-DA)] and univariate methods (linear mixed model). Multivariate data analysis (PLS-DA plots) of the liver metabolome revealed 3 different metabotypes (A = medium, B = minor, C = large alterations in liver metabolome profile between AP and PP status). Metabotype B animals were characterized by higher PP lipomobilization (stronger PP body condition decrease and higher blood bilirubin, fatty acids, gamma-glutamyltransferase, and triglyceride levels) and a higher occurrence of transition cow diseases, compared with the animals in metabotype C. Analysis of the feeding data showed that the period of metabotype B animals (calving in a distinct time frame) was characterized by a decreased grass silage quality. The PP liver metabolome of the metabotype C animals was characterized by higher concentrations of AA, acylcarnitines, lysoPC and sphingomyelins compared with metabotype B. For the metaphylactic treatment with BCC a dose-dependent effect was confirmed, differing between the metabotypes. In all matrices and metabotypes at various time points significant treatment effects were observed, with different profiles in clinical chemistry and as well in metabolomics data. The most clear-cut treatment effect was observed in metabotype B in the liver at 7 d PP, characterized by an increase in several acylcarnitines and phosphatidylcholines, indicating a more efficient influx and oxidation of fatty acids in mitochondria and thereby an increase in energy supply and more efficient triglyceride export in the liver. The results from the liver metabolomics analysis support the application of an indication-based metaphylactic treatment with BCC.

Aspects of transition cow metabolomics-Part II: Histomorphologic changes in the liver parenchyma throughout the transition period, in cows with different liver metabotypes and effects of a metaphylactic butaphosphan and cyanocobalamin treatment.

The aims of this study were to evaluate histopathologic changes during the transition period, describe the histopathological features of the metabotypes identified in Part I (Schären et al., 2021b), and investigate effects of a metaphylactic treatment with butaphosphan and cyanocobalamin (BCC) on the liver parenchyma. Eighty German Holstein cows (mean 305-d production: 10,957 kg, range: 6,480-15,193 kg; mean lactation number: 3.9, range: 2-9) from a commercial dairy farm in Saxony, Germany, were enrolled in a randomized, prospective, triple-blinded study. Two groups received a treatment with BCC (5 or 10 mL/100 kg of body weight 10% butaphosphan and 0.005% cyanocobalamin, Catosal, Bayer Animal Health, n = 20 each) and one group a placebo treatment (NaCl 0.9%, n = 40). Liver biopsy specimens were collected 14 d antepartum (AP) and 7, 28, and 42 d postpartum (PP), routinely processed for histologic examination, and stained with hematoxylin and eosin, Sudan III, periodic acid-Schiff, and picrosirius red stains. The sections were assessed for fat and glycogen content and degenerative, inflammatory, fibrotic, and proliferative changes. The statistical analysis included the effects of the sampling day, the lactation number, the treatment, and the metabotype (A = medium, B = minor, C = large alterations in the liver metabolome profile between AP and PP status). There was mild to moderate fat infiltration in the liver of 37% of cows in the last 2 wk AP, and moderate to severe fat infiltration in 66% of cows in the first days PP. The degree of fat infiltration increased from 2 wk AP until the end of the first week PP, and then decreased until the end of the study period, at which time about 25% of cows had moderate to severe fatty infiltration. Lipidosis was positively correlated with the severity of liver cell degeneration, and negatively correlated with the degree of glycogen deposits. Complete glycogen depletion of hepatocytes was not observed in cows, even in the presence of severe hepatic lipidosis. Moderate to severe lymphocytic hepatitis was seen in 39% of cows throughout the study period, and cows with lactation numbers 5 or greater had perisinusoidal fibrosis more often than younger cows. Severe fibrosis and cirrhosis of the liver did not occur. Metabotype B animals exhibited a higher chance of fatty infiltration, lower glycogen storage, and perisinusoidal fibrosis and for this metabotype positive correlations were calculated between increased fat deposition in the liver and marked glycogen depletion, and increased degenerative, inflammatory, fibrotic, and proliferative changes of hepatic tissue. For the treatment with BCC, no significant effect was observed. In summary, during the transition period, the liver of dairy cows is characterized by fat accumulation and glycogen depletion and histologic signs of hepatitis and hepatocyte degeneration. These histomorphologic changes were accentuated in animals exhibiting little alterations in their liver metabolome profile across the transition period (metabotype B) and support the assumption of a decreased grass silage quality as a causative factor.

Aspects of transition cow metabolomics-Part III: Alterations in the metabolome of liver and blood throughout the transition period in cows with different liver metabotypes.

The liver plays a central role in the postpartum (PP) energy metabolism of the transition dairy cow; however, studies describing the liver metabolome during this period were lacking. The aim of the presented study was therefore to compare the alterations in the liver and blood metabolome of transition dairy cows. For this purpose, an on-farm trial with 80 German Holstein cows (mean lactation number: 3.9; range: 2-9) was performed, with thorough documentation of clinical traits and clinical chemistry, as well as production data. Liver biopsies and blood samples were collected at d 14 (mean: 12 d, range: 1-26 d) antepartum (AP), d 7 (7, 4-13) and 28 (28, 23-34; mean, earliest-latest) PP for targeted mass spectroscopy-based metabolomics analysis using the AbsoluteIDQ p180 kit (Biocrates Life Sciences). Statistical analysis was performed using multivariate (partial least squares discriminant analysis) as well as univariate methods (linear mixed model). Multivariate data analysis of the liver metabolome revealed 3 different metabotypes (A = medium, B = minor, C = large alterations in the liver metabolome profile between AP and PP). In metabotype C, an increase of almost all acylcarnitines, lysophosphatidylcholines (lysoPC), sphingomyelins, and some phosphatidylcholines (PC, mainly at 7 d PP) was observed after calving. In contrast to metabotype C, the clinical data of the metabotype B animals indicated a higher PP lipomobilization and occurrence of transition cow diseases. The liver metabolome profile of these animals most likely mirrors a failure of adaptation to the PP state. This strong occurrence of metabotypes was much less pronounced in the blood metabolome. Additionally, differences in metabolic patterns were observed across the transition period when comparing liver and blood matrices (e.g., in different biogenic amines, acylcarnitines and sphingolipids). In summary, the blood samples at 7 d PP showed lower acylcarnitines and PC, with minor alterations and a heterogeneous pattern in AA, biogenic amines, and sphingomyelins compared with 14 d AP. In contrast to 7 d PP, the blood samples at 28 PP revealed an increase in several AA, lysoPC, PC, and sphingomyelins in comparison to the AP state, irrespective of the metabotype. In the liver biopsies metabotype B differed from metabotype C animals ante partum by following metabolites: higher α aminoadipic acid, lower AA, serotonin, taurine, and symmetric dimethylarginine levels, lower or higher concentrations of certain acylcarnitines (higher: C2, C3, C5, C4:1; lower: C12:1, C14:1-OH, C16:2), and lower lysoPC (a C16:0, C18:0, C20:3, C20:4) and hexose levels. In blood samples, fewer differences were observed, with lower serotonin, acylcarnitine C16:2, lysoPC (a C16:0, C17:0, C18:0 and C18:1), PC aa C38:0, and PC ae C42:2. The results show that the use of only the blood metabolome to assess liver metabolism may be hampered by the fact that blood profiles are influenced by the metabolism of many organs, and metabolomics analysis from liver biopsies is a more suitable method to identify distinct metabotypes. Future studies should investigate the stability and reproducibility of the metabotype and phenotypes observed, and the possible predictive value of the metabolites already differing AP between metabotype B and C.

Impacts of CLA and dietary concentrate proportion on blood metabolite concentration and proliferation of peripheral blood mononuclear cells of periparturient dairy cows.

The study aimed to examine effects of supplemented CLA to periparturient dairy cows receiving different concentrate proportions antepartum (a.p.) to investigate CLA effects on metabolism and immune function. Compared with adapted feeding, high-concentrate diet a.p. should induce a ketogenic metabolic situation postpartum (p.p.) to better understand how CLA works. A total of 64 pregnant German Holstein cows had ad libitum access to partial mixed rations based on concentrate and roughage 3 weeks before calving until day 60 p.p. A.p., cows received 100 g/day control fat (CON) or a CLA supplement, either in a low-concentrate (20%, CON-20, CLA-20) or high-concentrate diet (60%, CON-60, CLA-60). P.p., concentrate proportion was adjusted to 50% while fat supplementation continued. After day 32 p.p., half of the animals of CLA-groups changed to CON supplementation (CLA-20-CON, CLA-60-CON). A ketogenic metabolic state p.p. was not achieved and respective impacts of CLA could not be examined. Blood samples for isolation of peripheral blood mononuclear cells (PBMC) were collected on day -21, 7, 28 and 56 relative to calving. Blood chemistry samples were taken over the entire experimental period. Mitogen-stimulated proliferation of PBMC remained unaffected. Besides serum concentrations of triglycerides, total bilirubin, total protein, albumin and IGF-1, clinical-chemical serum characteristics remained uninfluenced by treatments. No post-supplementation effect could be observed. Measured blood metabolites and mitogen-stimulated proliferation of PBMC indicate that all groups had an increased metabolic stress around calving, whereby group CLA-20 was affected more severely. Overall, supplemented CLA did not positively affect metabolism or immune function of periparturient dairy cows. However, feeding CLA in a low-concentrate diet a.p. seems to increase liver stress around calving via reduced DMI.

Using rumen probes to examine effects of conjugated linoleic acids and dietary concentrate proportion on rumen pH and rumen temperature of periparturient dairy cows.

The study aimed to examine the influence of supplemented conjugated linoleic acids (CLA) to periparturient cows receiving different concentrate proportions antepartum on rumen pH (RpH) and rumen temperature (RT). Twenty pregnant German Holstein cows were equipped with rumen probes for continuous RpH and RT measurement in a frequency of 15 min to investigate effects of dietary concentrate and CLA around parturition and the impact of parturition itself on RpH and RT. Cows had ad libitum access to partial mixed rations, 3 weeks prior to calving until day 7 post-partum. Antepartum, cows received 100 g/day control fat (CON) or CLA supplement, either in low (20%; CON-20, CLA-20) or high concentrate diet (60%; CON-60, CLA-60). Post-partum, concentrate proportion was adjusted to 50% while fat supplementation continued. Compared with adapted feeding, high concentrate proportions antepartum tended to increase DMI and reduced RpH. Groups CON-60 and CLA-60 spent more than 4 h per day below RpH 5.6 during late pregnancy, indicating the presence of subacute rumen acidosis (SARA). The RT remained unaffected antepartum. Before calving, cows spent less time below RpH 5.6 and SARA could be detected in each group post-partum. Mean RpH increased slightly antepartum, whereas few hours before parturition a sharp decrease in RpH could be observed, accompanied with increased RT. Overall, it seems that CLA supplementation influences RpH and RT. Bearing in mind that rumen parameters fluctuate during day and herd level must be known, rumen probes for continuous RpH and RT measurement could be a useful management tool for animal health surveillance and may also help to predict parturition.

Analysis of ordered categorical data with threshold models exemplified by plumage damage scores from laying hens differing in their genotype and rearing environment.

Plumage damage scores (PDS) were assessed in laying hens of 2 genotypes (Lohmann Tradition and Lohmann Silver) at the 45th and 70th weeks of age, with scores ranging from zero (no damage) to 6 (completely denuded). This ordinally scaled categorical characteristic was recorded from different body regions of 365 hens that had experienced different housing environments (2 enrichment levels) during their rearing and laying periods. The so-called threshold model is an option for analyzing repeated ordered categorical data from individual animals. This model represents a generalized linear mixed model if the linear predictor additionally includes the animal as a random effect. This paper is intended to fill the gap between the theoretical aspects of generalized linear mixed models and their practical application in animal science. A cumulative probit model was adapted for analyzing plumage damage. The variation among birds was considered as a random effect for the analysis of cumulative probabilities. The numerical implementation of the methodology was done based on the NLMIXED procedure of the SAS statistical program. A threshold model with inhomogeneous residual variances for the latent variable was used because less plumage damages were observed up to the 45th week of age compared to the 70th week of age. Differences in PDS were evident between genotypes, age, and enrichment levels during housing periods. However, neither of the 2 enriched environments proved consistent superiority or inferiority across all traits. Major plumage damage (PDS larger than or equal to 5) was observed for the breast region in 56.6% of all birds with the Lohmann Tradition genotype and in 34.4% with the Lohmann Silver genotype when we look at the mean over all treatments. The most severe plumage damage was observed at the 70th week of age for the traits breast and housing environment without additional enrichment.

Analysis of water intake and dry matter intake using different lactation curve models.

The objective was to evaluate 6 different lactation curve models for daily water and dry matter intake. Data originated from the Futterkamp dairy research farm of the Chamber of Agriculture of Schleswig-Holstein in Germany. A data set of about 23,000 observations from 193 Holstein cows was used. Average daily water and dry matter intake were 82.3 and 19.8 kg, respectively. The basic linear mixed model included the fixed effects of parity and test-day within feeding group. Additionally, 6 different functions were tested for the fixed effect of lactation curve and the individual (random) effect of cow-lactation curve. Furthermore, the autocorrelation between repeated measures was modeled with the spatial (power) covariance structure. Model fit was evaluated by the likelihood ratio test, Akaike's and Bayesian information criteria, and the analysis of mean residual at different days in milk. The Ali and Schaeffer function was best suited for modeling the fixed lactation curve for both traits. A Legendre polynomial of order 4 delivered the best model fit for the random effect of cow-lactation. Applying the error covariance structure led to a significantly better model fit and indicated that repeated measures were autocorrelated. Generally, the best information criteria values were yielded by the most complex model using the Ali and Schaeffer function and Legendre polynomial of order 4 to model the average lactation and cow-specific lactation curves, respectively, with inclusion of the spatial (power) error covariance structure. This model is recommended for the analysis of water and dry matter intake including missing observations to obtain estimation of correct statistical inference and valid variance components.

Effects of using thermally treated lupins instead of soybean meal and rapeseed meal in total mixed rations on in vitro microbial yield and performance of dairy cows.

The objective was to study whether thermally treated lupins (TTL) can replace solvent-extracted soybean meal (SBM) and rapeseed meal (RSM) in dairy cow rations. Three total mixed rations (TMR) were used. They differed in the inclusion of the main protein feeds (TTL alone, TTL + RSM and RSM + SBM) but were equal in organic matter digestibility and metabolizable energy content. In vitro organic matter fermentation was not significantly different between the TMR. Efficiency of microbial crude protein (MCP) synthesis was significantly higher for TMR RSM + SBM than for TTL. In vitro gas production potential was similar for the three TMR. The maximal rate of gas production was achieved later in TMR TTL than in RSM + SBM. Feed intake of dairy cows was significantly lower when TMR TTL was fed than when TMR TTL + RSM or RSM + SBM were fed. Milk yield was significantly lower with the high inclusion rate of TTL in comparison with the other TMR. The contents of milk protein and milk fat were significantly lower when the two TTL containing TMR were fed in comparison with the RSM + SBM ration. Effects of TTL inclusion on MCP synthesis may affect the amino acid supply to the duodenum of cows to a greater extent than differences in the degradability of feed proteins.

Effects of the level of feed intake and ergot contaminated concentrate on ruminal fermentation and on physiological parameters in cows.

The aim of the present study was to examine the effects of ergot contaminated feed concentrate at differing levels of feed intake on ruminal fermentation, and on various physiological parameters of dairy cows. Twelve double fistulated (in the rumen and the proximal duodenum) Holstein Friesian cows were fed either a control diet (on a dry matter (DM) base: 60% maize silage, 40% concentrate) or a diet containing ergot alkaloids (concentrate contained 2.25% ergot resulting in an ergot alkaloid concentration of the daily ration between 505 and 620 (µg/kg DM) over a period of four weeks. Daily feed amounts were adjusted to the current performance which resulted in a dry matter intake (DMI) variation between 6.0 and 18.5 kg/day. The resulting ergot alkaloid intake varied between 4.1 and 16.3 (µg/kg body weight when the ergot contaminated concentrate was fed.Concentrations of isovalerate, propionate and ammonia nitrogen in the rumen fluid were significantly influenced by ergot feeding, and the amount of ruminally undegraded protein, as well as the fermentation of neutral detergent fibre, tended to increase with the ergot supplementation at higher levels of feed intake, which might indicate a shift in the microbial population. Other parameters of ruminal fermentation such as ruminai pH, fermented organic matter as a percentage of intake, or the amount of non-ammonia nitrogen measured at the duodenum were not significantly influenced by ergot feeding. The activities of liver enzymes (aspartate aminotransferase, γ-glutamyltransferase, glutamate dehydrogenase, creatine kinase) in the serum were not affected by ergot feeding. The rectal measured body temperature of the cows significantly increased after ergot administration (p=0.019). Thus, body temperature can be regarded as a sensitive parameter to indicate ergot exposure of dairy cows.

Analysis of water intake, dry matter intake and daily milk yield using different error covariance structures.

The aim of the present study was to investigate the daily measured traits milk yield, water intake and dry matter intake with fixed and random regression models added with different error covariance structures. It was analysed whether these models deliver better model fitting in contrast to conventional fixed and random regression models. Furthermore, possible autocorrelation between repeated measures was investigated. The effect of model choice on statistical inference was also tested. Data recording was performed on the Futterkamp dairy research farm of the Chamber of Agriculture of Schleswig-Holstein. A dataset of about 21 000 observations from 178 Holstein cows was used. Average milk yield, water intake and dry matter intake were 34.9, 82.4 and 19.8 kg, respectively. Statistical analysis was performed using different linear mixed models. Lactation number, test day and the parameters to model the function of lactation day were included as fixed effects. Different structures were tested for the residuals; they were compared for their ability to fit the model using the likelihood ratio test, and Akaike's and Bayesian's information criteria. Different autocorrelation patterns were found. Adjacent repeated measures of daily milk yield were highest correlated (p1 = 0.32) in contrast to measures further apart, while for water intake and dry matter intake, the measurements with a lag of two units had the highest correlations with p2 = 0.11 and 0.12. The covariance structure of TOEPLITZ was most suitable to indicate the dependencies of the repeated measures for all traits. Generally, the most complex model, random regression with the additional covariance structure TOEPLITZ(4), provided the lowest information criteria. Furthermore, the model choice influenced the significance values of one fixed effect and therefore the general inference of the data analysis. Thus, the random regression + TOEPLITZ(4) model is recommended for use for the analysis of equally spaced datasets of milk yield, water intake and dry matter intake.

[Studies on the use of lucerne silage source for high-milk-producing dairy cows]. / Zum Einsatz von Luzernesilage bei Kühen mit hoher Milchleistung.

Studies on the use of lucerne silage as a forage source for high-yielding dairy cows. It was the main objective of this study to investigate effects of lucerne silage inclusion in maize silage-based rations on dry matter intake, milk yield and metabolic parameters of high yielding dairy cows. Three total mixed rations (TMR) were used. They contained as the main forage source on a dry matter basis 41.5% maize silage and 12% grass silage (ration maize) or 18% maize silage and 29% of either grass silage (ration grass) or lucerne silage (ration lucerne). Organic matter digestibility, determined with wether sheep, was 77 and 65% for the grass and the lucerne silage, respectively. Each TMR was fed to 4 wether sheep to determine crude nutrient digestibilities. The content of net energy for lactation (NEL), as calculated from digestible crude nutrients, was (MJ/kg dry matter (DM)): 7.1 (maize), 7.2 (grass) and 6.8 (lucerne). Based on the results of a chemical fractionation of crude protein it was calculated that the content of utilisable crude protein (nXP) was not below 167 g/kg DM and that the N balance in the rumen was not negative for all 3 TMR. The TMR were fed for 169 days to at least 28 dairy cows per treatment which were in their first half of lactation. Feed intake, milk performance data and physiological indicators were measured for each individual cow. The DM intake was significantly higher in treatment lucerne (23.2 kg/d) than in treatments grass (21.2 kg/d) and maize (22.6 kg/d). Daily intakes of NEL and nXP were significantly lower in treatment grass than in the other two treatments. Milk yield was significantly higher in treatment maize (41.7 kg/d) than in treatments grass (37.3 kg/d) and lucerne (38.5 kg/d). This was associated with a significantly lower milk fat content in treatment maize (3.5%) in comparison with the other two treatments (3.9% each). Milk protein content was unaffected by treatment (3.4% on average). Similarly, the acetone content of milk was not significantly different between treatments. The beta-hydroxybutyrate content of the deproteinized blood was significantly higher in treatment lucerne at start of lactation, but this difference disappeared in subsequent parts of the experimental period. Measurements of back fat thickness indicated mobilisation and retention of energy by cows during the experimental period to be similar in all treatments. It is concluded that lucerne silage is a suitable forage source for high yielding dairy cows in spite of its low digestibility.

Effects of level of feed intake and Fusarium toxin-contaminated wheat on rumen fermentation as well as on blood and milk parameters in cows.

The aims of this study were to examine the effects of and possible interactions between dry matter (DM) intake and feeding Fusarium toxin-contaminated wheat on ruminal fermentation, serum chemical parameters and milk yield of dairy cows. Fourteen dairy cows equipped with ruminal and duodenal cannulas were analysed. All animals were fed the same ration, the daily feed amounts being adjusted to current performance. On DM basis, the ration consisted of 60% concentrate including 55% wheat [Fusarium-contaminated wheat (mycotoxin period) or control wheat (control period)] and was completed with 40% maize and grass silage. Each cow was fed the contaminated wheat [deoxynivalenol (DON), 8.21 mg/kg DM and zearalenone (ZON), 0.09 mg/kg DM] and the control wheat (0.25 mg DON/kg DM and 51 microg ZON/kg DM). As expected, a higher organic matter (OM) intake decreased the amounts of fermented crude nutrients related to the respective intakes. An increased amount of crude protein degraded (p < 0.05) and a lower molar percentage of propionate in the rumen fluid were observed when feeding the Fusarium toxin-contaminated wheat at increased OM intakes in comparison with the control wheat. The activities of serum aspartate aminotransferase (ASAT; p < 0.001), glutamate dehydrogenase (GLDH; p < 0.01) and gamma glutamyl transferase (gamma-GT; p < 0.01) increased with increasing OM intake and were not related to the mycotoxin contamination of the wheat.

On the effects of a chronic deoxynivalenol intoxication on performance, haematological and serum parameters of pigs when diets are offered either for ad libitum consumption or fed restrictively.

Wheat infected naturally with Fusarium, contaminated mainly with deoxynivalenol (DON) (16.6 mg DON/kg), was added to a total constant wheat content of 400 g/kg diet. To distinguish between differences in feed intake and specific effects of the DON contaminated diet, control and DON contaminated feed was administered for 11 weeks under ad libitum and restrictive feeding conditions to 48 pigs of both sexes, which were randomly divided into four groups (n = 12 per group). Feed intake was 2.90 kg/day, live weight gain 987 g/day and feed to gain ratio 2.77 kg/kg for the ad libitum fed control group. The group fed DON contaminated wheat ad libitum significantly consumed 15% less feed and gained 13% less live weight, while the feed to gain ratio was unaffected. Moreover, it was concluded that the lower growth performance by DON contaminated feed resulted mainly from the lower voluntary feed intake, because there were no differences in live weight gain between the groups with the restrictive feeding regimen. On the contrary, metabolizable energy, nitrogen retention digestibility of organic matter, crude protein, crude fat and crude fibre were significantly increased by 3, 10, 3, 6, 9 and 20% in the DON group respectively. Animals fed DON contaminated diets needed more time to consume the restrictive ration than the control group. For example in the first hour after feeding 85% of the control pigs had consumed all feed, but only 39% of the DON group had. There were only few differences in haematological and serum parameters, which were characterized by a high variation between individuals. DON and IgA concentrations in serum were significantly influenced by DON exposure.

Effect of dietary L-carnitine supplementation on growth performance of piglets from control sows or sows treated with L-carnitine during pregnancy and lactation.

Previous studies showed that supplementation of sows' diets with L-carnitine increases body weights of their piglets at birth. This study was performed to investigate whether piglets of sows treated with L-carnitine differ in their growth potential from that of piglets of untreated control sows after weaning. It was also investigated whether supplementation of piglets' diets with L-carnitine improves their growth after weaning. In two trials, piglets of the first litters of primiparous sows (trial 1) and the second litters of the same sows (trial 2) were divided into four groups: group 1, piglets of control sows, fed a control diet; group 2, piglets of control sows fed a diet supplemented with 30 mg L-carnitine/kg; group 3, piglets of L-carnitine-treated sows, fed a control diet; group 4, piglets of L-carnitine-treated sows fed a diet supplemented with 30 mg L-carnitine/kg. Mean initial body weights of the piglets of the four groups were identical. They were 8.5 kg in trial 1 and 12.5 kg in trial 2. Diets were fed ad libitum over a period of 35 days. Piglets from sows treated with L-carnitine did not differ in body weight gains, feed intake and gain : feed ratio from those of control sows. In trial 1, piglets supplemented with L-carnitine had higher body weight gains (p < 0.005) and showed a tendency towards a higher gain : feed ratio (p = 0.09) than piglets fed the control diets. In trial 2, no significant difference in these parameters emerged between piglets fed the diet supplemented with L-carnitine and those fed the control diet. In conclusion, this study shows that dietary L-carnitine treatment of sows does not improve the growth potential of their piglets after weaning under the conditions of equal initial body weights. The study also shows that L-carnitine supplementation of their diets improves the growth performance in light piglets of primiparous sows.

Effects of long-term storage on Fusarium toxin concentrations in wheat--sources of error of the analytical results.

The concentrations of the Fusarium toxins deoxynivalenol (DON) and zearalenone (ZON) of a heavily contaminated wheat grain batch were followed over a period of 1 year by taking samples 15 times every 28 days. The air temperature and relative humidity at the top of the wheat batch ranged between 7 and 22 degrees C and 44 and 55%, respectively, and corresponded to a variation in the moisture content of the wheat grain between 11.5 and 12.3%. None of these fluctuations were related to ZON and DON concentrations, which varied between 0.46 and 0.66 and 15.0 and 19.5 mg/kg DM. Therefore, the data were used to analyse the error sources for the analytical results. It was found that the variance proportions due to sampling and sample preparation plus analysis were not similar for DON and ZON. The variance proportion due to sampling was found to be 0.62 for ZON, which corresponded to a variance proportion of 0.38 due to sample preparation plus analysis. In contrast, the latter variance proportion for DON was estimated to be 1.0 and consequently completely superimposed the sampling error. It is concluded that long-term storage of contaminated wheat grain does not affect the concentrations of DON and ZON considering the measured fluctuations in ambient temperature, relative humidity and moisture content of the grain. Therefore, no degradation of DON and ZON occurred during the storage of wheat for a period of one year under ambient conditions. The effects of sampling and sample preparation plus analysis on the final analytical results are different for DON and ZON and require further consideration.

Evaluation and interpretation of results for three cross-over designs.

In cross-over designs, individual sequences of treatments are applied to the animals. Within such designs it is possible that every treatment could modify the effect of the subsequent treatment applied to the same animal. We compared three cross-over designs each with three treatments, three periods, and two blocks. This comparison was done with respect to the variance of the estimations of the effects and its biases caused by the interactions between the treatment and the carry over effect of the foregoing treatment. Moreover, different methods of estimating variance components and calculating the degrees of freedom were compared by means of simulation. If the animal variance component is small, then the bias of the REML estimator of the variance components is greater than one of the widespread ANOVA-estimator called 'TYPE3'. But nevertheless, the mean squared error of this estimation is smaller in the case of REML in comparison to ANOVA. Therefore, the REML method should be preferred. For calculating the degrees of freedom, the Kenward-Roger method should be used. After applying this method, the true significance level is almost equal to its required value, but if the Satterthwaite method is used, the true significance level will be too high. If the interaction (treatment x carry over) is ignored in the model although it exists, the standard error of the treatment effect estimation is too great, and, therefore, the true significance level is too small. The methods which have been evaluated are available in the SAS-procedure MIXED (SAS Institute, 1999a). To assist the investigation of cross-over designs by using this software, we developed programs for data management and data analysis. These programs are available from the first author.

Reproductive performance of sows supplemented with dietary L-carnitine over three reproductive cycles.

The effect of L-carnitine supplementation during pregnancy and lactation on the reproductive performance of sows was studied in two separate trials over three reproductive cycles. Both trials were identical in design and conduct but were performed with different animals. The trials comprised of a total of 127 sows (trial 1) and 100 sows (trial 2) which were divided into control and treatment groups. All animals were fed individually and received basic feed mixtures with low native carnitine concentrations. The rations of the sows in the treated group were supplemented with 125 mg L-carnitine per head and day during pregnancy and 250 mg L-carnitine per head and day during lactation. The animals of the control group received identical feed mixtures in identical amounts, but without the L-carnitine supplement. In the first trial, 212 litters were produced and evaluated for number and body weight of the animals, in the second trial, 173 litters were produced. L-carnitine supplementation significantly increased body weight gains of the sows between day 1 and day 85 of weaning. The number of born piglets, stillborn piglets and piglets fit for rearing was not influenced by dietary L-carnitine supplementation. However, L-carnitine supplementation significantly increased the weights of piglets and litters at birth, weight gains of litters during suckling and weights of litters at weaning. These effects of L-carnitine were seen in both trials; they were independent of the age of the sows and remained over three reproductive cycles in which the sows where continuously treated with L-carnitine. Overall, the study shows that dietary supplementation with L-carnitine during pregnancy and lactation improves the reproductive performance of sows over several reproductive cycles, independent of the age of the sows.

Simultaneous estimation of variances and covariances using REML and Henderson 3 in a selected population of White Leghorns.

1. Genetic and residual variances and covariances were estimated on performance data from 5943 lyaing hens from a 7 generation selection experiment for the traits: egg number up to day 270 (EN270), egg weight (EW), body weight at day 215 (BW), egg mass 100 g of food (EMFC), and residual food consumption (RFC) by a Henderson 3 and REML procedure. 2. Simultaneous REML estimates of all 30 components were obtained by a software package is based on numerical optimisation of the log likelihood using a multivariate animal model. Henderson 3 estimates were computed on the basis of a hierarchical sire-dam model. Estimates were generated beginning with a data set comprising only the first generation, and then successively adding one generation after the other. 3. REML estimates for heritabilities h2 on the basis of all performance records were 0.40, 0.75, 0.62, 0.21 and 0.22 for traits EN270, EW, BW, EMFC, and RFC, respectively. The corresponding Henderson 3 estimates were: 0.30, 0.57, 0.43, 0.21, and 0.20. 4. The results indicate that some REML h2 estimates are substantially different from those obtained by Henderson 3 once the data set included three generations as opposed to those based on Henderson 3.