[Treatment, clinical course and outcome of tibial neuropathy in German Holstein cows]. / Behandlung, Verlauf und Therapieerfolg der Neuropathie des Nervus tibialis bei Deutsch-Holstein Kühen.

OBJECTIVE: As a follow-up to a previous study on the incidence, history and clinical findings of tibial neuropathy (TN), the present work aimed at describing the treatment and prognosis of this disease. MATERIALS AND METHODS: Of 88 German Holstein dairy cows with unilateral (UTN, n = 71) or bilateral (BTN, n = 17) TN, 68 (56 UTN, 12 BTN) with a complete data set were analyzed. They were retrospectively assigned to one of four groups: no treatment - spontaneous healing within 48 h (Spontaneous, 5 UTN), no bandage (0Cast, 8 UTN, 3 BTN) or treatment with anti-inflammatory drugs and support bandage (StV, 3 UTN) or fiberglass cast (Cast, 40 UTN, 9 BTN). Treated cows were re-examined five times (14, 21, 28, 42 and 56 days after the first presentation). The plasma activity of creatine kinase was measured at the last re-examination in 29 cows similar to measurement at day 0. RESULTS: The observed overall success rate of treatment of cows with UTN was considerably higher compared with untreated cows (Cast 98 % and StV 100 % vs. 0Cast 62 %). By comparison, the observed difference between treated and untreated cows with BTN was not so clear (78 % vs. 67 %). Recovering cows exhibited a calculated longer median survival time than cows that did not recover (545 d vs. 100 d). Plasma creatine kinase activities were increased initially and returned within the reference interval (434 U/l and 152 U/L) following treatment. CONCLUSIONS: Cows with ETN have an excellent prognosis provided that treatment with anti-inflammatory drugs and stabilizing bandage is administered. In cows with BTN, the prognosis depended on the type and degree of the primary injury. Loss of skin sensitivity indicated a poor prognosis. From an economic standpoint, treatment of TN is indicated provided that the prognosis is good. In cows that had healed clinically, the average survival time extended into the following lactation. CLINICAL RELEVANCE: This study highlights the advantages of a support bandage for the treatment of cows with TN. Compared with other peripheral neuropathies, muscle damage appears to be of particular importance in TN.

Effects of an intensive experimental protocol on health, fertility, and production in transition dairy cows.

Animal experimentation is required to investigate complex physiological relationships and facilitates development of evidence-based knowledge. However, experimental protocols can interfere with the daily routine of the animals, result in stress and pain, and have adverse effects on health and production. The goal of this study was to investigate the effects of an intensive experimental protocol on health traits and production in transition dairy cows. Eighty experimental dairy Holstein cows (EXP group) underwent serial protocol-based clinical and ultrasonographic examinations, puncture of the jugular vein for blood collection or drug application, and liver biopsy samples, 14 d before until 42 d after parturition. Controls (CTR group) included 206 cows from the same herd, which fulfilled the same inclusion criteria and were kept under the same production management but were not handled for the purpose of this study. Procedure-related effects with a potentially negative effect on health and production were recorded. Furthermore, production, fertility and culling traits of the 2 groups (CTR, EXP) were compared. Most procedure-related adverse effects were associated with transcutaneous liver biopsies and included diffuse inflammation of the skin incision in 11.9% (42 of 320), abscessation of the skin or subcutis in 4.6% (11 of 240), and increased liver echogenicity of the biopsy site in 10.4% (27 of 240). The experimental procedures had a negative effect on milk yield at the start [days in milk (DIM) 5-50, difference: 2.3 kg, standard error (SE): 0.8 kg] and end of lactation (DIM 251-300, difference: 2.0 kg, SE: 1.0 kg; DIM 301-350, difference: 2.3 kg, SE: 1.2 kg) resulting in a lower 305-d milk yield in the EXP group than in the CTR group (difference: 472 kg, SE 214 kg). The milk fat % was higher in the EXP group than in the CTR group from 251 DIM onward (DIM 251-300, difference: 0.20%, SE: 0.09%; DIM 301-350, difference: 0.41%, SE: 0.17%). Also, the somatic cell score was higher in the EXP group than in the CTR group, during early (5-50 DIM, difference: 0.43, SE: 0.22) and from mid-lactation onward (DIM 151-200, difference: 0.43, SE: 0.2; DIM 201-250, difference: 0.49, SE: 0.22; DIM 251-300, difference: 0.55, SE: 0.25; DIM 301-350, difference: 0.61, SE: 0.28). Experimental procedures had no effect on first service conception rate and time to pregnancy, but had a positive effect on stillbirth rate with fewer stillbirths in the CTR group (0%) than in the EXP group (3.9%). Furthermore, experimental handling had no effect on time to culling or type of culling, whereby poor production was a more frequent reason noted for culling in the EXP group. Procedure-associated impairment of production in dairy cows is rarely reported and allows the estimation of the effects of such a study protocol on animal health and production. As a limitation for the interpretation of the results, the number of animals included and conduction in one single herd have to be considered.

Qualitative and Quantitative Changes in Total Lipid Concentration and Lipid Fractions in Liver Tissue of Periparturient German Holstein Dairy Cows of Two Age Groups.

Fatty liver syndrome (FLS) is a common disease in high-producing dairy cows. Studies in humans suggest that the different hepatic lipid fractions play a role in this context. In dairy cows, little is known about the composition of fat stored in the liver, its periparturient dynamics, and the effect of cows' age. Therefore, our goal was to generate primary data in healthy cows to serve as reference values for future studies. Eight healthy German Holstein cows (2nd lactation, n = 3; ≥3rd lactation, n = 5) were examined 14 d antepartum and 7, 28, and 42 d postpartum. The examinations included clinical assessment, liver biopsy, blood sampling, and recording of milk yield. Total lipids (TL) in liver tissue were measured gravimetrically. The TL were separated into lipid fractions (triacylglycerol, TAG; phospholipids, PL; non-esterified fatty acids, NEFA; and cholesterol esters) using thin-layer chromatography, followed by gas chromatography for fatty acid determination. Concentrations of NEFA, ß-hydroxybutyrate, and cholesterol were analyzed in blood. Concentrations of TL, TAG, NEFA, and cholesterol esters in liver tissue and NEFA in blood increased in the periparturient period. The older cows had higher hepatic TL, TAG, and PL concentrations, higher relative hepatic concentrations of TAG in TL, higher NEFA concentrations in blood, a greater decrease in body condition, and higher milk yields between d 9 and 40 than the younger cows. We proposed that due to higher milk yield, older cows mobilized and deposited more fat in the liver, and the increase in hepatic TAG concentration was longer-lasting than in younger cows. Higher levels of structural lipids (PL) in older cows could be explained by higher demand for storage of TAG and cholesterol esters in lipid droplets or for the export of TAG via very-low-density lipoproteins. Results show that hepatic fat storage is a reversible process and does not necessarily cause clinical disease. Nevertheless, older cows have a more sustained and greater increase in hepatic TAG concentration, which may explain their increased risk of FLS. The results are limited in their extrapolation due to the small sample size and thereby possible selection bias but present a valuable basis for future studies.

[Incidence, history and clinical findings of tibial neuropathy in German Holstein cows]. / Vorkommen, Vorbericht und klinisches Bild der Neuropathie des Nervus tibialis bei Deutsch-Holstein-Kühen.

OBJECTIVE: The aim of this study was to document the occurrence, history, and clinical findings of tibial neuropathy in German Holstein dairy cows in order to yield information regarding the importance and etiology of this disorder in dairy herds in Central Germany. MATERIALS AND METHODS: This prospective study was undertaken between January 2013 and October 2017 and included 88 German Holstein dairy cows with unilateral (UTN, n = 71) or bilateral (n = 17, BTN) tibial neuropathy. Data were collected from the history as well as the clinical and laboratory examinations. Three grades of paresis were defined. RESULTS: The percentage of cows with tibial neuropathy among all German Holstein dairy cows presented with disorders of the locomotor system in the study period amounted to 2.2 %. UTN was seen predominantly following dystocia or as a result of prolonged lateral recumbency in consequence to a primary disease. The majority of cases of BTN occurred in association with the resumption of cyclicity following calving. These were accompanied by clinical signs of a cauda equina syndrome. Increased plasma activities of creatine kinase (UTN 98 %; BTN 100 %) and aspartate aminotransferase (UTN 89 %; BTN 100 %) were observed in nearly all affected cows. CONCLUSIONS: Tibial neuropathy is a regularly occurring disorder in dairy herds in Central Germany. The condition results in pain and locomotor impairment and therefore constitutes a welfare concern. UTN and BTN have different causes, and the history combined with clinical signs (severity of paresis) provides etiological information. Increased enzymatic activities suggest a muscular involvement in the disease process.

[Validation of a cow-side blood test for beta-hydroxybutyrate concentration in dairy cows]. / Überprüfung eines Schnelltestsystems zur Erfassung der Betahydroxybutyrat-Konzentration im Blut von Milchkühen.

OBJECTIVE: Clinical ketosis is common during the dairy cows' transition period and is responsible for considerable economic loss. Early identification of cows with subclinical ketosis is the first step for maintaining the health and productivity of dairy cows. The goals of the study were two-fold: The first was to examine the usefulness of a mobile test device as a cow-side test; and the second was to compare BHB concentrations measured by the ketometer using capillary blood and blood collected from the coccygeal vessels with values determined by a reference method in the laboratory using jugular blood. MATERIAL AND METHODS: Blood samples were collected from a jugular vein or the coccygeal vessels in 81 dairy cows at 7 time points (14 and 7 days pre-partum and 7, 14, 21, 28, and 42 days post-partum) for kinetic enzymatic measurement of BHB concentration in the laboratory. Blood samples were concurrently collected from the coccygeal vessels or by pricking the vulvar lip at the transition of the skin to the mucosa (capillary blood) to determine BHB concentration using the WellionVet BELUA ketometer (MED TRUST GmbH, Marz, Austria). RESULTS: Initial errors in operating the ketometer were quickly eliminated with experience. BHB concentrations of jugular blood measured in the laboratory were 0.07 mmol/l lower than those measured in coccygeal blood. The mean BHB concentration measured in coccygeal and capillary blood using the WellionVet BELUA ketometer did not significantly differ but were 0.13 and 0.12 mmol/l respectively, lower than the mean jugular vein concentrations measured in the laboratory. CONCLUSION: The WellionVet BELUA ketometer is useful for determination of BHB concentration in cows provided that the manufacturer's specifications are followed. Capillary blood is best collected at the transition from the vulvar skin to its mucosa. The device generates rapid results that correlate well with BHB concentrations determined in the laboratory and with the results obtained from different blood collection sites. It is ideally suited for monitoring dairy cows for subclinical ketosis using capillary or coccygeal blood.

[Cortisol concentration before, during and after sham foot trimming in German Holstein cows - the suitability of different matrices]. / Kortisolkonzentration bei Deutsch-Holstein-Kühen vor, während und nach der Klauenbehandlung im Durchtreibestand ­ Eignung verschiedener Matrizes.

OBJECTIVE: The objective of this study was to determine whether changes in cortisol concentration measured in blood serum (KoB) of cows exposed to an acute stressor shows a correlation to cortisol concentrations in saliva (KoS), tears (KoT) and milk (KoM) as well as the concentration of cortisol metabolites in feces (KoK). MATERIALS AND METHODS: In 10 healthy German Holstein cows, sham foot trimming (sKB) including the movement/fixation of the cows through/in a foot trimming chute was used as a model for acute stress. KoB, KoS, KoT, KoM and KoK were measured once a day for 10 days. During sKB, performed on day 4, KoB and KoT were measured at the initiation of foot trimming (minute 0) as well as 15, 25, 30, 40, 50, 60 and 80 minutes later. Additionally, KoK was measured 480, 540, 600 and 660 minutes after the start of sKB. RESULTS: KoB and KoT increased during sKB and reached a maximum at 60 minutes followed by a decrease. KoK increased after sKB and reached a maximum at 660 minutes. There was a significant correlation between KoB and KoT, KoK and KoB and a trend towards a significant correlation between KoK and KoT during sKB. KoB and KoT were significantly correlated (area under the curve, minute 0-10, p = 0.04). KoB decreased significantly from day 1 to day 4 (p < 0.01). On day, 5 KoB (p = 0.03) and KoK (p < 0.01) were significantly higher. KoS and KoT served as good proxies for KoB throughout the study, and KoK and KoB exhibited similar profiles. There were several differences between the profiles of KoM and KoB. During the 10-day measurement period, a significant positive correlation was detected between KoB and KoS (p = 0.002) as well as between KoB and KoT (p = 0.002). CONCLUSIONS AND CLINICAL RELEVANCE: The collection of tear fluid and saliva for determination of cortisol concentrations are non-invasive alternatives to blood sampling. Calm handling of cows may reduce their stress reaction and thus improve animal welfare.

[Effect of different pain management protocols on the health status of German Holstein heifer calves undergoing hot iron disbudding]. / Einfluss der thermischen Enthornung mit unterschiedlichem Schmerzmanagement auf die Gesundheit von Kälbern.

OBJECTIVE: Hot iron disbudding of calves is a stressful and painful procedure. Previous parts of an ongoing comprehensive study on disbudding in dairy calves dealt with various types of pain management and the direct effects of the procedure on physiological, biochemical and behavioral processes. The goal of this study part was to investigate the effects of the disbudding procedure per se, pain management and the age of the calf at the time of disbudding on the health status of the calf. MATERIALS AND METHODS: A total of 337 German Holstein heifer calves were used for this prospective, randomized and triple-blinded study. The calves were disbudded at 4-10 days or at 15-28 days of age. Each calf was randomly assigned to one of 9 treatment groups, which differed with respect to pain management (sedation, local anesthesia, nonsteroidal antiinflammatory drugs, placebo). All but the sham-disbudded calves underwent hot iron disbudding and all calves were monitored clinically before and until 4 weeks after the procedure. The findings were analyzed using valuation scores and a threshold model of the SAS software. RESULTS: Disbudding exhibited adverse effects on respiratory health. Calves undergoing sham disbudding experienced the lowest incidence of respiratory disease and calves that did not receive any anesthesia or pain medication displayed the highest frequency. All treatments showed mitigating effects on the incidence of respiratory tract diseases, however the effects varied with the type of pain management. Fever was less common in calves that were disbudded early in life than calves that underwent disbudding at an older age. CONCLUSION: Disbudding of young calves poses a risk to respiratory health. If breeding of polled offspring is not possible or when farming of horned cattle is not feasible, the risk of respiratory disease induced by disbudding can be minimized by adequate pain management. Disbudding of very young calves is feasible and recommended. CLINICAL RELEVANCE: The present study underlines the importance of optimal pain management during disbudding of dairy calves.

[Assessment of different pain management methods for the treatment of claw lesions in Meat Merino ewes]. / Bewertung verschiedener Methoden des Schmerzmanagements während der Behandlung von Klauenlederhaut-Läsionen bei weiblichen Merinofleischschafen.

OBJECTIVE: Pain management during veterinary procedures is a significant component of animal welfare and has legal as well as ethical implications. Even though regional intravenous anaesthesia (RIVA) is an accepted method for painful procedures involving the distal digits of sheep, this anaesthetic technique is rarely applied in the field. The primary goal was to investigate the feasibility, safety and efficacy of RIVA in sheep. A secondary goal was to examine whether the anaesthetic procedure can be improved by combining RIVA with sedation and whether these methods have a positive effect on the postoperative wellbeing of the animals. METHODS: A total of 36 Meat Merino sheep with contagious interdigital dermatitis and 12 healthy control sheep were used. Behaviour was observed during treatment of the lame sheep using various pain management protocols and during routine claw trimming of the healthy sheep, and all the sheep were observed after the procedures. The observed behaviours were assessed using scores and the scores compared among the animals of the 4 study groups (RIVA, sedation with xylazine hydrochloride + RIVA, placebo, control). RESULTS: RIVA was successfully conducted in sheep. Local reactions at the application sight and in the tourniquet area in 2 animals resolved completely. A significant reduction in defensive movements during the painful procedure confirmed the efficacy of RIVA. Stress-associated behaviours, including head shaking and idle chewing, occurred with a similar frequency in RIVA and placebo animals, leading to the conclusion that stress levels due to the handling in dorsal recumbency were comparable between these 2 groups. Sedation reduced the frequency of pain- and stress-associated behaviours, including guarding, favouring limbs, vocalisation, idle chewing and bruxism. Xylazine hydrochloride-RIVA animals displayed better weight-bearing in the affected limb, better food uptake and ruminated more postoperatively than sheep from the other study groups. CONCLUSION: RIVA in sheep is straightforward, safe and effective. Additional sedation reduces the stress and pain response. This pain and stress management has a positive effect on the postoperative wellbeing of sheep.

[Detection and assessment of acute and chronic pain in Meat Merino ewes using ethological parameters]. / Erfassung und Bewertung von akutem und chronischem Schmerz anhand ethologischer Merkmale bei weiblichen Merinofleischschafen.

OBJECTIVE: The assessment of pain in sheep is a clinical challenge, because being a prey species, they tend to mask it. Since pain in animals cannot be measured directly, various methods are applicable to detect its effects on physiological, biochemical and ethological processes. Clinicians experienced in behavioural assessment are able to reliably determine the level of pain endured by an animal. The objective of this study was to identify behaviours that reflect acute and chronic pain as well as stress in sheep. METHODS: The behaviour of 36 Meat Merino ewes with contagious footrot (contagious interdigital dermatitis) was analysed during normal activities in the flock and during footrot treatment, which included claw trimming to remove abnormal horn. The behaviour during treatment was compared with that of 12 healthy control sheep of the same breed during routine foot trimming. Grading of the observed behaviours was made using a numerical score. The occurrence of footrot was defined as, and equated with, chronic pain, and treatment was equated with acute pain. For the assessment of stress induced by the manipulative treatment, the data of the healthy sheep were taken as a comparison. RESULTS: The strongest indications of chronic pain were non-weight bearing lameness of an affected limb, shifting of weight and abnormal gait patterns. Additionally, sheep with footrot urinated more frequently than healthy animals. Stress-related bruxism occurred in healthy and ill sheep during foot trimming, but not during normal activities in the flock. Tail wagging and strong defensive movements of all limbs commonly occurred during footrot treatment. Head shaking appeared to be primarily stress-related in association with dorsal recumbency on the tilt table, but was exacerbated by pain elicited by hoof trimming. CONCLUSION: The behaviours selected in this study were useful for the identification of chronic and acute pain in sheep; however, correct interpretation of behavioural changes requires an experienced individual.

Impact of α-amylase supplementation on energy balance and performance of high-yielding dairy cows on moderate starch feeding.

In dairy cows, exogenous α-amylase is suggested to improve starch utilization and positively affect performance and health traits linked to energy balance and fertility. In a 1-year feeding experiment, 421 cows were orally supplemented with α-amylase (treatment: 12.5 g/kg dry matter (DM) addition rate to a concentrated feed) or non-supplemented (control) on the basis of an ad libitum total mixed ration (TMR). Every cow was allocated to a high- (≥32 kg milk/day) or late-lactation group (<32 kg milk/day), in which the TMR starch content was 220 ± 20.8 g/kg DM and 183 ± 24.8 g/kg DM, respectively. The energetic effect of α-amylase supplementation seemed to be exclusively related to the high-lactation stage (5-100 days in milk) in primiparous cows, where the daily milk yield was 32 ± 0.49 versus 31 ± 0.50 kg per cow in the treatment versus control group (P < 0.05). The pluriparous cows did not benefit from the supplementation that way. In neither primiparous nor pluriparous cows, was the milk composition, the fat-to-protein ratio, the somatic cell score, the backfat thickness, serum total bilirubin, ß-hydroxybutyrate and the fertility found to be systematically affected by α-amylase supplementation.

[Herd-specific estimation of milk yield reduction due to recurrent clinical mastitis]. / Herdenspezifische Schätzung der Milchleistungsminderung durch wiederholte klinische Mastitis.

To decide about investments in preventive measures improving udder health it is important that the farmer knows the monetary loss due to mastitis on his specific farm. The Saxon dairy herd improvement association (Sächsischer LandeskontrolIverband e.V., LKV) is developing a computer program called "Daten- und Informationsplattform Tier (DIT)"which determines - among other analyses - the milk loss caused by mastitis for a specific herd based on individual cow's mastitis and daily milk yield data. The present article introduces the linear mixed model which is taken as a basis for calculating the reduction in performance through clinical mastitis. The short and long term decrease in daily milk yield is described by expanding the lactation curve model of Ali and Schaeffer (1987). For falculating the short term drop, the model includes the laps of time in days since the mastitis incident as secon-ddegree polynomial. The coefficients are estimaged specifically for the first respectively every following case of mastitis (class of episode). Classes of episode are also considered calculating the long term decrease by estimating lactation curves without mastitis as well as corresponding to the classes of episode. By integrating the statistic software R (R Development Core Team, 2012) into the processes of the DIT the estimation of the farm specific model parameters is largely automated on the servers of the LKV.Thereby, milk yield can be estimated for every day in milk according to episode number and laps of time since the incident or with no mastitis incident respectively for a particular period of time in a specific dairy herd. The loss resulting from reduced performance due to clinical mastitis is specified by adding up the differences and can serve as a valuable basis for management decisions.

Effects of conjugated linoleic acids and dietary concentrate proportion on performance, milk composition, milk yield and metabolic parameters of periparturient dairy cows.

The study aimed to examine effects of supplemented conjugated linoleic acids (CLA) to periparturient cows receiving different concentrate proportions ante partum (a.p.) to investigate CLA effects on lipid mobilisation and metabolism. Compared to adapted feeding, a high-concentrate diet a.p. should induce a ketogenic metabolic situation post partum (p.p.) to better understand how CLA works. Sixty-four pregnant German Holstein cows had ad libitum access to partial mixed rations 3 weeks prior to calving until day 60 p.p. Ante partum, cows received control fat (CON) or a CLA supplement at 100 g/d, either in a low-concentrate (CON-20, CLA-20) or high-concentrate diet (CON-60, CLA-60). Post partum, concentrate proportion was adjusted, 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 situation p.p. was not achieved and therefore impacts of CLA could not be examined. Live weight, milk yield and composition, blood parameters remained unaffected by the treatments. Only a slightly reduced milk fat yield (not significant) was recorded for Group CLA-20. The proportion of trans-10,cis-12 (t10,c12) CLA in milk fat was significantly increased in CLA-groups compared to CON-groups. With the exception of a reversible CLA effect on milk fat in Group CLA-20, no post-treatment effects occurred. Dry matter intake (DMI) of Group CLA-60 was highest before calving, resulting in a significantly improved estimated energy balance after calving. Ante partum, net energy intakes were significantly increased in high-concentrate groups. Overall, supplemented CLA preparation did not relieve metabolism and lipid mobilisation of early lactating cows. But feeding CLA in a high-concentrate diet a.p. seems to increase DMI and thereby improve the energy balance of cows immediately after calving.

Lucerne silage in high yielding dairy cows: effect of parity and analysis of reasons in mixed-parity group housing using random regression test-day models.

A study with high-yielding dairy cows was re-analysed in order to test the suitability of lucerne silage separately for primi- and multiparous cows as an alternative to grass silage in maize-based total mixed rations (TMR). Lactation curves were fitted using random regression test-day models for energy corrected milk (ECM) and dry matter intake (DMI) as well as for number and duration of feeder visits (NFV and DFV, respectively). Existing models for ECM and DMI were extended by animal-specific random effects, which were formulated in their dependency on days in milk. For NFV and DFV random regression models were applied for the very first time. The chosen approach of statistical analysis permitted comparisons of the lactation curves as well as of least square means for sub-periods to answer nutritional questions. Whilst primiparous cows had generally lower DMI and ECM as compared to multiparous cows, only in primiparous cows a negative effect of lucerne TMR on ECM was observed, especially in early lactation. Nutritional factors should be rejected because of very similar ECM between the various TMR in multiparous cows. Traits of feeding behaviour indicated that particle size could contribute to the decreased ECM. Even more impact on the lower ECM should be addressed to domination behaviour of multiparous cows. The resulting restlessness of primiparous cows caused a reduced intake per minute spent at the feeder. Further studies should focus on optimising the proportion and chopping length of lucerne in the diet and to improve flock management to maximise feed intake of primiparous cows. Generally, statistical analysis of lactation data became a very complex issue. It seems inevitable that nutritionists and statisticians team up to address this problem.

Ruminal fermentation patterns and parameters of the acid base metabolism in the urine as influenced by the proportion of concentrate in the ration of dairy cows with and without Fusarium toxin-contaminated triticale.

Feeding a total mixed ration with 50% concentrate and a mean deoxynivalenol (DON) concentration of 5.3 mg/kg DM to 13 German Holstein cows in early lactation (Myco group) resulted in alterations in the ruminal fermentation patterns (lower molar percentage of acetate and isobutyrate, higher molar percentage of valerate) compared to the 14 control cows (Period 1, 11 weeks). In the Myco group, significantly lower ruminal pH value occurred in weeks 4 and 8 and lower minimum pH values critical for developing subacute ruminal acidosis were detected. Accordingly, the net acid base excretion in the urine and the base-to-acid ratio were lower (significant in week 8 only). These effects probably resulted from a higher dry matter intake and are not related to the presence of Fusarium toxin. In Period 2, the same 27 cows plus five additional cows were divided into four groups over 18 weeks. The effects of an elevated concentrate proportion of 60% were tested with and without Fusarium toxin (Control-60, 0.4 mg DON/kg DM and Myco-60, 4.6 mg DON/kg DM) and compared to two groups fed 30% concentrate (Control-30, 0.6 mg DON/kg DM and Myco-30, 4.4 mg DON/kg DM). As expected, a high concentrate proportion significantly affected the ruminal fermentation patterns. Net acid base excretion and base-to-acid ratio did not reveal a distinct concentrate effect and the ruminal pH values were on a high level in all groups when ruminal fluids were taken after 3-5 hours of feed restriction (median between 6.8 and 7.2). Additional effects were observed on the profile of short chain fatty acids in the presence of Fusarium toxin at both concentrate levels. This indicates a switch in the microbial community due to direct mycotoxin effects and/or indirect effects of the Fusarium infection related alterations in the physico-chemical properties of the infected cereal on ruminal microbes.

On the effects of the concentrate proportion of dairy cow rations in the presence and absence of a fusarium toxin-contaminated triticale on cow performance.

The aim of the present study was to investigate the effects of a deoxynivalenol (DON) contaminated ration with a concentrate proportion of 50%, on the performance of dairy cows (Period 1), and to examine the effects when the concentrate proportion was elevated to 60% compared to a ration with 30% concentrates (Period 2). In Period 1, 13 lactating German Holstein cows (Myco group, on average 29 days in milk) were fed the experimental diet (on average 5.3 mg DON/kg DM) as total mixed ration over 11 weeks, while another 14 cows (on average 33 days in milk) received a control diet. Both rations contained 50% concentrates (on DM basis). In Period 2 (18 weeks), the same 27 cows plus five additional cows were divided into four groups: Control-30 (30% concentrates), Myco-30 (30% concentrates, 4.4 mg DON/kg DM), Control-60 (60% concentrates), Myco-60 (60% concentrates, 4.6 mg DON/kg DM). The overall performance level was characterised by a mean daily DM intake of 17.9 kg and a mean daily milk production of 26.7 kg fat corrected milk (FCM) in Period 1 and 17.3 kg DM intake and 24.5 kg FCM in Period 2, respectively. In both periods cows fed the Fusarium toxin-contaminated diets consumed more DM (in Period 2 only significant for group Myco-30) resulting from stimulating effects on the ingesta passage rate of the natural contaminated Fusarium-infected triticale. In Period 1, cows fed the Fusarium toxin-contaminated diet had a significantly higher milk yield, milk urea and somatic cell count, whereas milk fat and protein concentration and fat-to-protein-ratio (FPR) were significantly lower. In Period 2, on a low concentrate level, FCM was significantly higher in group Myco-30. On a high concentrate level, group Myco-60 produced significantly more milk, but milk fat and protein concentration, FPR and milk urea were significantly lower. A concentrate proportion of 60% had a depressing effect on milk fat concentration but was significantly more pronounced in the presence of Fusarium toxin-contaminated and Fusarium damaged-triticale.

Statistical analysis of test-day milk yields using random regression models for the comparison of feeding groups during the lactation period.

Random regression models are widely used in the field of animal breeding for the genetic evaluation of daily milk yields from different test days. These models are capable of handling different environmental effects on the respective test day, and they describe the characteristics of the course of the lactation period by using suitable covariates with fixed and random regression coefficients. As the numerically expensive estimation of parameters is already part of advanced computer software, modifications of random regression models will considerably grow in importance for statistical evaluations of nutrition and behaviour experiments with animals. Random regression models belong to the large class of linear mixed models. Thus, when choosing a model, or more precisely, when selecting a suitable covariance structure of the random effects, the information criteria of Akaike and Schwarz can be used. In this study, the fitting of random regression models for a statistical analysis of a feeding experiment with dairy cows is illustrated under application of the program package SAS. For each of the feeding groups, lactation curves modelled by covariates with fixed regression coefficients are estimated simultaneously. With the help of the fixed regression coefficients, differences between the groups are estimated and then tested for significance. The covariance structure of the random and subject-specific effects and the serial correlation matrix are selected by using information criteria and by estimating correlations between repeated measurements. For the verification of the selected model and the alternative models, mean values and standard deviations estimated with ordinary least square residuals are used.

Concentrations of cholesterol oxidation products in raw, heat-processed and frozen-stored meat of broiler chickens fed diets differing in the type of fat and vitamin E concentrations.

The present study was performed to investigate the effect of dietary fat and vitamin E on concentrations of cholesterol oxidation products (COP) in broiler muscle. A total of 144 1-d-old broiler chicks were fed diets with either palm oil, soyabean oil or linseed oil and vitamin E concentrations of 20, 40 or 200 mg/kg for 35 d. COP concentrations were analysed in raw, heat-processed (180 degrees C, 20 min) and frozen-stored (-20 degrees C, 6 months) breast and thigh muscles. COP concentrations were influenced by dietary vitamin E concentration, dietary fat, treatment and type of muscle (P<0.001). Increasing the dietary vitamin E concentration generally reduced the concentration of COP. This effect was strongest in broilers fed linseed oil and weakest in broilers fed palm oil; the effect of vitamin E was also stronger in heated muscles than in raw or frozen-stored muscles. Moreover, the concentration of COP in thigh muscle was more strongly influenced by dietary vitamin E than that in breast muscle. COP concentrations in muscles were on average highest in broilers fed linseed oil and lowest in broilers fed palm oil, but the effect of the dietary fat also depended on the vitamin E concentration, the treatment and the type of muscle. In conclusion, our study shows that dietary fat and vitamin E influence the concentrations of total COP in broiler muscle. However, the effects of these factors were not only influenced by interactions between each other, but also depended on the treatment of the muscle and the type of muscle.

Supplementation of sows with L-carnitine during pregnancy and lactation improves growth of the piglets during the suckling period through increased milk production.

Recent studies showed that piglets of sows fed diets supplemented with L-carnitine grow faster during the suckling period than piglets of control sows fed diets without L-carnitine. This study was undertaken to investigate the effect of L-carnitine supplementation in sows on milk production and milk constituents. An experiment was performed in which two groups of 20 gilts each were fed diets with or without supplemental L-carnitine during pregnancy (0 vs. 125 mg L-carnitine daily/sow) and lactation (0 vs. 250 mg L-carnitine daily/sow). The experiment was continued over two reproductive cycles. L-carnitine-treated sows had larger litters (P<0.01) and higher litter weights (P<0.05) than control sows. Piglets of L-carnitine-treated sows had lower birth weights (P<0.05) but grew faster during the suckling period (P<0.01) and were heavier (P<0.05) at weaning than piglets of control sows. L-carnitine-treated sows had higher milk yields on d 11 and 18 of lactation than control sows (P<0.05). Milk of L-carnitine-treated sows had higher concentrations of total and free carnitine than milk of control sows (P<0.001); concentrations of fat, protein and lactose and the amounts of gross energy in the milk did not differ between the two groups of sows. The amounts of protein (P<0.05) and lactose (P<0.05) were higher in L-carnitine-treated sows than in control sows; the amount of energy secreted with the milk tended to be higher in carnitine-treated sows than in control sows (P<0.10). The study suggests that piglets of carnitine-treated sows grow faster during the suckling period than those of control sows because they ingest more nutrients and energy with the milk.