Nitrogen Balance and Soil Nitrates in Suckler Cow Pastures Fertilised with Mineral Fertiliser, Pig Slurry or Cattle Compost

A code of good practice was established by each European member state according to the EU Nitrate Directive. In Belgium, the nitrogen (N) inputs on pastures from slurry or compost are limited to 210 kg N/ha. Bigger quantities can be applied if the farmer follows a programme of additional measurements, including soil nitrate (NO3) analysis. This investigation aimed to measure animal performance, N balance and soil NO3 in pastures fertilised with mineral N, pig slurry or cattle compost, the pastures being grazed by Belgian Blue cows and their calves

Test d'un cCapteur de mesure du temps de pâturage et de rumination sur des vaches laitières au pâturage

peer reviewedUse of automated tools on farms is increasing worldwide and there are diverse applications available including optimization of grazing through monitoring rumination and ingestion times. The objective of this study was to evaluate the accuracy of the sensor developed by Medria to estimate grazing (G) and rumination (Ru) on pasture. This sensor includes a tri-axial accelerometer and provides data every 5 minutes. The trial lasted 12 days on 12 grazing cows in the CTA (Belgium), representing 380 h of observations. The data registered by the Medria device (M) were compared with visual observation (VO). The datasets were compared using Fleiss-κ estimating the concordance of 5-min observations and linear regression analysis was used to estimate the Pearson correlation coefficients (rp) and relative prediction error (RPE). Moderate for G (κ=0.502) and poor agreement for Ru (κ=0.175) were observed. Linear relationship between VO and M was highlighted with rp: 0.793; P<0.001 for G and rp=0.32; P<0.05 for Ru. The relative error prediction was 0.16 and 0.44 for G and Ru respectively. With regards to these results, reliable data about grazing are provided on a daily basis. The reliability of rumination data was poor

Effect of bovine Azawak colostrum administration on plasma protein profile in red kid.

This study evaluated the impact of heterologous Azawak colostrum administration on plasma protein profile in red kids from Niger. Forty (40) newborn kids were affected to one of two treatments: control group (access to water and the mother) and colostrum group (access to the mother, water and additional 50 ml of colostrum Azawak/animal the day of birth, then 25ml/animal/day from the 2nd to 15th day). Blood samples (10ml/animal) were obtained at the age of 10 and 30 days by jugular puncture into EDTA vacutainer tubes. The quantification of total protein was performed by the Biuret method. The agarose gel electrophoresis was used to determine serum levels of albumin, ɑ-globulin, β1-globulin, β2-globulin, γ-globulin and finally the albumin/globulin ratio. In general, the average concentrations of these proteins obtained at both ages reached higher values in colostrum than in control group. At day 10, the colostrum group tended to show (P <0.07) higher levels for ɑ-globulin and showed higher values (P <0.04) for β1-globulin. At day 30, total protein and β2-globulins were higher in colostrum group. The administration of heterologous colostrum in kid seems to have positive effects on some plasma parameters. It would be worth to discriminate the plasma proteins derived from bovine and maternal colostra.Utilisation du Colostrum Bovin chez les petits ruminant

Effet de la permission de traite sur la circulation et la production laitère de vaches traites par un robot de traite au pâturage

peer reviewedIn dairy farms automatic milking systems and grazing, traffic to the robot is the cornerstone of profitability as higher milking frequency enhances milk yield. In this study, we investigated whether shortening the minimum milking interval (MMI), i.e., the required time between two milkings for an animal to get access to the milking unit, coupled with high concentrate allocation, could increase the daily milking frequency (MF, milking/cow/day) and consequently the milk yield of grazing cows. Two groups of cows (n = 19 and n = 20) belonging to the same herd were discriminated based on concentrate supply (high vs. low: 4 vs. 2 kg/cow/day) and then further divided on the basis of MMI (4 h vs. 6 h) so that four groups were formed (HC4 h–HC6 h–LC4 h and finally LC6 h). Higher concentrate allocation induced a rise in milk yield (MY, kg/cow/day) and allowed to stabilize it in periods of grass shortage but did not influence milking frequency, while shorter MMI (4 h) was correlated with higher MF without effect on MY. A combination of both strategies (4 h and high concentrate) improved the traffic globally to the robot. This result was linked to a reduction of refused milking and, therefore, the decrease in returns to the robot. This strategy could be advised to maximize the system’s efficiency during periods of high milk sales. When the economic conditions do not favour the increase in concentrate supply, short MMI could facilitate the traffic and increase the efficiency of returns.Autograssmilk - Innovative and sustainable systems combining automatic milking and precision grazin

Fatty acids : nomenclature and dietary sources

Fatty acids are member of the lipid family. They are aliphatic monocarboxylic acids with or without double bond. They are classified according different nomenclatures : the international systematic name, the omega nomenclature and the trivial names. Fatty acids are major compounds of oils and fats. Among the saturated fatty acids, C12, C16 and C18 fatty acids are the most widely distributed, whereas in the unsaturated fatty acids group, C18 with 1, 2 or 3 double bonds are the most important within the vegetable and animal terrestrian products. Fatty acids with 4 or more than 4 double bonds and 20 to 24 atoms of carbon are largely represented in the marine products

Validation of Dairy Cow Bodyweight Prediction Using Traits Easily Recorded by Dairy Herd Improvement Organizations and Its Potential Improvement Using Feature Selection Algorithms.

peer reviewedKnowing the body weight (BW) of a cow at a specific moment or measuring its changes through time is of interest for management purposes. The current work aimed to validate the feasibility of predicting BW using the day in milk, parity, milk yield, and milk mid-infrared (MIR) spectrum from a multiple-country dataset and reduce the number of predictors to limit the risk of over-fitting and potentially improve its accuracy. The BW modeling procedure involved feature selections and herd-independent validation in identifying the most interesting subsets of predictors and then external validation of the models. From 1849 records collected in 9 herds from 360 Holstein cows, the best performing models achieved a root mean square error (RMSE) for the herd-independent validation between 52 ± 2.34 kg to 56 ± 3.16 kg, including from 5 to 62 predictors. Among these models, three performed remarkably well in external validation using an independent dataset (N = 4067), resulting in RMSE ranging from 52 to 56 kg. The results suggest that multiple optimal BW predictive models coexist due to the high correlations between adjacent spectral points

Selenium in Cattle: A Review

This review article examines the role of selenium (Se) and the effects of Se supplementation especially in the bovine species. Selenium is an important trace element in cattle. Some of its roles include the participation in the antioxidant defense the cattle farms. The nutritional requirements of Se in cattle are estimated at 100 μg/kg DM (dry matter) for beef cattle and at 300 μg/kg DM for dairy cows. The rations high in fermentable carbohydrates, nitrates, sulfates, calcium or hydrogen cyanide negatively influence the organism’s use of the selenium contained in the diet. The Se supplementation may reduce the incidence of metritis and ovarian cysts during the postpartum period. The increase in fertility when adding Se is attributed to the reduction of the embryonic death during the first month of gestation. A use of organic Se in feed would provide a better transfer of Se in calves relative to mineral Se supplementation. The addition of Se yeasts in the foodstuffs of cows significantly increases the Se content and the percentage of polyunsaturated fatty acids (PUFA) in milk compared to the addition of sodium selenite. The enzyme 5-iodothyronine deiodinase is a seleno-dependent selenoprotein. It is one of the last proteins to be affected in the event of Se deficiency. This delay in response could explain the fact that several studies did not show the effect of Se supplementation on growth and weight gain of calves. Enrichment of Se in the diet did not significantly affect the slaughter weight and carcass yield of bulls. The impact and results of Se supplementation in cattle depend on physiological stage, Se status of animals, type and content of Se and types of Se administration. Further studies in Se supplementation should investigate the speciation of Se in food and yeasts, as well as understanding their metabolism and absorption. This constitute a path to exploit in order to explain certain different effects of Se

Construction d'une nouvelle installation de traite à la Station Expérimentale de la Faculté de Médecine vétérinaire de l'Université de Liège.

Construction d'une nouvelle installation de traite à la Station Expérimentale de la Faculté de Médecine vétérinaire de l'Université de Liège

Plateforme alimentation en vue de réduire les rejets en N et en P dans les exploitations de Wallonie.

Plateforme alimentation en vue de réduire les rejets en N et en P dans les exploitations de Wallonie