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See detailEffect of water availability on milking frequency and yield of dairy cows milked in pastures by an automatic milking system.
Dufrasne, Isabelle ULg; Robaye, Vincent ULg; Knapp, Emilie ULg et al

Poster (2012)

Nowadays farmers have to manage larger herds but at the same time, want to benefit from a normal social life. The automatic milking system (AMS) can be a solution. Its use can reduce physical labour and ... [more ▼]

Nowadays farmers have to manage larger herds but at the same time, want to benefit from a normal social life. The automatic milking system (AMS) can be a solution. Its use can reduce physical labour and allow flexibility. This technology can result in a reduction in grazing even though grazing is considered as a natural practice of the cows which is appreciated by the consumers. However, the milking frequency is decreased when outdoor grazing rather than an indoor feed systems is combined with automatic milking system (AMS) are combined compared to an indoor system. On pasture, cows tend to visit the AMS by group and enter in close succession. Improved cow traffic would allow increased milking frequency and avoid long waiting before milking. In this aim, effect of water availability in the grazing paddocks on the frequencies of cow visits to was tested. [less ▲]

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See detaileffets de la substitution totale du tourteau d’arachide par la fève de coton glandless sur les performances zootechniques de poulets de chair au sénégal
Diaw, Mamadou; Dieng, Abdoulaye; Mergeai, Guy ULg et al

in Revue d'Elévage et de Médecine Vétérinaire des Pays Tropicaux (2012), 65(1-2), 17-23

The performances of broilers fed a diet in which the groundnut cake was totally replaced by glandless cottonseed kernels (FCG) were compared to those of animals fed an experimental control diet (Tém_E), a ... [more ▼]

The performances of broilers fed a diet in which the groundnut cake was totally replaced by glandless cottonseed kernels (FCG) were compared to those of animals fed an experimental control diet (Tém_E), a commercial diet (Tém_C), and a very simple diet containing only corn, FCG and a mineral and vitamin concentrate. From the start, the Tém_C and FCG animals showed the highest growths. After 43 days of breeding, there were major differences in body weights between the groups, essentially caused by differences in feed intake, so that the best growth rates were not necessarily linked to better feed conversion ratios. Low body weights, low intakes and high mortality levels were observed with the simple diet. [less ▲]

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See detailProfil des vendeurs de viande de chasse et évaluation de la biomasse commercialisée dans les marchés municipaux de Brazzaville, Congo.
Mbete, Roger Albert; Banga-Mboko, Henri; Ngokaka, Christophe et al

in Tropical Conservation Science (2011), 4(2), 203-217

The consumption of wildlife meat is an important source of animal protein for rural and urban population in Congo. A survey on bushmeat trade was undertaken in 21 municipal markets during four weeks, in ... [more ▼]

The consumption of wildlife meat is an important source of animal protein for rural and urban population in Congo. A survey on bushmeat trade was undertaken in 21 municipal markets during four weeks, in Brazzaville. The objective of this study was to define the traders’ profile and to evaluate the quantities of games and meat merchandised on the municipal markets. The study methodology combined two approaches: a quantitative one using a questionnaire as principal tool for collecting data, and a qualitative one associating informal survey methods via individual or group interviews. The results showed that women were the most involved in this trade (52%). Markets trader’s monthly income was estimated at 210,428 (US$420) ± 49,128 (US$98,256) FCFA. On average, the bushmeat traders’ were 39 ± 10 years old and 69% of them attended the two levels of secondary education. During four weeks, 3,711 animal carcasses were recorded on the 21 surveyed markets, representing almost 35,790 kg of biomass. Overall, 35 animal species were identified, including 9 the hunting of which was prohibited. The mammals constituted 93.8% of total number of hunted animals, with three dominant orders as the artiodactyls (49.2%), the rodents (22.6%) and the primates (17.7%), of which the Cephalophus, the Potamochoerus, the Atherurus and the Cercopithecus were the most represented. It was also noticed that trapping, an activity which leads to great losses, becomes very important, followed by be helpful alternatives to meet Congolese demand for bushmeat. For a sustainable management of the Congo’s faunic resources, this study suggests the introduction gun-hunting. The Congo-Ocean Railway and the National Road n°2 were used regularly in the transportation of game, to a 72% level. The district of Niari, Lekoumou, Sangha and Pool were the main sources of supply. At the present time, the meat quantities offered in Brazzaville markets don’t seem to be reduced because hunting areas extend always further, often to the detriment of protected areas. Despite the fact that such business squarely growths and shows evidence of overexploitation, activities promoting game farming and breeding of domestic species, in Brazzaville suburbs, are needed to mitigate the impact of bushmeat trade. [less ▲]

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See detailLes co-produits de la graine de coton en alimentation du poulet de chair
Diaw, Mahamadou Tandiang; Dieng, Abdoulaye; Mergeai, Guy ULg et al

in Annales de Médecine Vétérinaire (2011), 155

Cottonseed by-products arevery high in nutrients and theirchemical composition varieshighly according to the varietiesof cotton and the various treatmentsaiming at extracting oil.Their use in animal ... [more ▼]

Cottonseed by-products arevery high in nutrients and theirchemical composition varieshighly according to the varietiesof cotton and the various treatmentsaiming at extracting oil.Their use in animal nutrition, andparticularly in broilers, is especiallylimited by the free gossypolwhich can damage varioustissues and also decreases theperformances of growth and dietefficiency. The incorporation ofcottonseed meal in broilers dietmay be increased following chemicalbinding of free gossypol,but these methods have drawbacks.Ferrous sulfate denaturesfeed and the use of lysine to bindgossypol is limited by the expensivenessof this product while thebiological fermentation is verycomplex and inapplicable, as tonow, on a large way. Glandlessvarieties could be incorporatedat a very high level in diets andtherefore could contribute todecrease the protein feed requirements.Unfortunately, agronomicconstraints associated to thesecrops have limited the research inthis way. The production of varietiesin which gossypol secretionwould be inhibited before theseed germination should alleviatethe limitations associated to cottonby-products. [less ▲]

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See detailEffects of environmental factors on yield and milking number in dairy cows milked by an automatic system located in pasture
Dufrasne, Isabelle ULg; Robaye, Vincent ULg; Knapp, Emilie ULg et al

Poster (2011)

Nowadays, farmers have to manage larger herds but want, at the same time, benefit from a normal social life. The milking robot can bring solutions. Its use can reduce physical labour and allow flexibility ... [more ▼]

Nowadays, farmers have to manage larger herds but want, at the same time, benefit from a normal social life. The milking robot can bring solutions. Its use can reduce physical labour and allow flexibility. This technology results in a reduction in grazing even through grazing appears as a natural practice which is appreciated by the consumers. This project aims to develop strategies to use milking robots in pasture in order to benefit from advantages regarding feeding costs as well as animal welfare and health. It aims to study the effects of grass height, animal, days in milk, rotation cycle number and distance from grazed paddocks on daily milk yield and milking number of grazed cows. [less ▲]

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See detailGrowth performances, carcass and organs characteristics and economics results of growing indigenous senegal chickens fed diets containing various levels of leuceana leucocephala (Lam.) leaves meal (2011)
Ayssiwede, Simplice; Chrysostome, C.A.A.M.; Zanmenou, J.C. et al

in International Journal of Poultry Sciences (2011), 10(9), 1132-1145

The aim of this study carried out from September to December 2010 was to evaluate the effects of Leuceana leucocephala leaves meal inclusion in the diets on growth performances, carcass and organs ... [more ▼]

The aim of this study carried out from September to December 2010 was to evaluate the effects of Leuceana leucocephala leaves meal inclusion in the diets on growth performances, carcass and organs characteristics and economics results of growing indigenous Senegal chickens. One hundred and four (104) indigenous Senegal chicks of 4 weeks old were randomly allocated into four groups of 26 chicks each with similar body weight. Each group subdivided in two repetitions of 13 birds, corresponded to each of the four (4) dietary treatments LL0, LL7, LL14 and LL21 containing respectively 0, 7, 14 and 21% of Leuceana leaves meal in substitution of groundnut cake meal. During the experiment (5-17th week old), zootechnical parameters of birds and economical data were recorded and analyzed per dietary treatment. At the end of the 13 weeks trial, the final Live Body Weights (LBW) were 864 g, 1166.48 g, 905 g and 887.16 g/bird, the Average Daily Weight Gain (ADWG) were 7.77 g, 10.88 g, 8.15 g and 8.10 g/day, the Daily Feed Intake (DFI) of 39.86 g, 51 g, 40.39 g and 44.75 g/bird and the Feed Conversion Ratio (FCR) of 7.04, 5.54, 6.27 and 6.80 respectively for birds fed LL0, LL7, LL14 and LL21 diets. The Leuceana leaves meal inclusion in the diets up to 21% had not caused any adverse effect on LBW, ADWG, DFI, FCR, mortality, carcass and organs characteristics in birds compared to their controls. Apart from the dark yellowing of abdominal fat of carcasses from birds fed LL21 diet, significantly better growth performances, feed costs and economic margins were recorded in birds fed LL7 and LL14 diets. Thus, these two dietary treatments were the only most economically profitable (respectively 214 and 48 FCFA/kg carcass of additional profit) compared to the control. [less ▲]

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See detailEffects of Moringa oleifera (Lam.) leaves meal incorporation in diets on growth performances, carcass characteristics and economics results of growing indigenous senegal chicken
Ayssiwede, Simplice; Dieng, Abdoulaye; Bello, H et al

in Pakistan Journal of Nutrition (2011), 10(12), 1132-1145

The purpose of this study carried out from July to October 2010 was to assess the effects of Moringa oleifera leaves meal inclusion in diets on growth performances, carcass and organs characteristics and ... [more ▼]

The purpose of this study carried out from July to October 2010 was to assess the effects of Moringa oleifera leaves meal inclusion in diets on growth performances, carcass and organs characteristics and economics results of growing indigenous Senegal chickens. Ninety six (96) indigenous Senegal chicks of 5 weeks old were randomly allocated into four groups of 24 chicks each with similar body weight. Each group subdivided in two repetitions of 12 birds, corresponded to each of the four (4) dietary treatments MO0, MO8, MO16 and MO24 containing respectively 0, 8, 16 and 24% of Moringa leaves meal in substitution of groundnut cake meal. During the experiment (6-17th week old), zootechnical parameters of birds and economical data were recorded and analyzed per dietary treatment. At the end of the 12 weeks trial, the final Live Body Weights (LBW) were 721.60 g, 911.70 g, 812.85 g and 720.05 g/bird, the average daily weight gain (ADWG) were 6.49 g, 8.77 g, 7.61 g and 6.50 g/day, the Daily Feed Intake (DFI) of 39.10 g, 39.76 g, 36.28 g and 34.24 g/bird and the Feed Conversion Ratio (FCR) of 7.58, 5.75, 6.11 et 7.24 respectively for birds fed MO0, MO8, MO16 and MO24 diets. The Moringa leaves meal inclusion in the diets up to 24% had not caused any adverse impact on LBW, ADWG, FCR, mortality, carcass and organs characteristics in birds compared to their controls. Except the significantly decrease of DFI obtained in birds of MO16 and MO24 treatments, significantly better growth performances, feed costs and economic margins were recorded in birds fed MO8 and MO16 diets. Thus these two dietary treatments were the only most economically profitable (respectively 357 and 206 FCFA/kg carcass of additional profit) compared to the control. [less ▲]

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See detailHousehold bushmeat consumption in Brazzaville, the Republic of the Congo.
Mbete, Roger Albert; Banga-Mboko, Henri; Racey, Paul et al

in Tropical Conservation Science (2011), 4(2), 187-202

Wildlife meat is an important source of animal protein for rural and urban populations in Congo. Quantitative and qualitative surveys on the consumption of bushmeat were undertaken in Brazzaville in 2006 ... [more ▼]

Wildlife meat is an important source of animal protein for rural and urban populations in Congo. Quantitative and qualitative surveys on the consumption of bushmeat were undertaken in Brazzaville in 2006, in about 1,050 urban households. The main objective was to establish the profiles of consumers and of species concerned. The results showed that 88.3% of the surveyed households consumed bushmeat. Their average size was 5.7 ± 3.2 persons. The average monthly income of an urban consumer with a permanent job was 98,334 (US$197) ± 84,306 (US$169) FCFA. It appeared that households preferred to consume bushmeat for two major reasons: the taste or flavor (67.8%) and food habits (14.7%). Meat from mammals was preferred, the top three orders of this class being artiodactyls (48.3%), rodents (28.3%), and primates (13.0%). Some of them are listed as threatened in Congo Brazzaville and are included in the IUCN Red List. The results showed that in Brazzaville, bushmeat consumption remains important and is determined by socio-economic parameters. The promotion of game farming, and breeding of domestic species such as poultry and fish, in the Brazzaville suburbs could help to meet Congolese demand for bushmeat. [less ▲]

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See detailNutrient Composition of Some Unconventional and Local Feed Resources Available in Senegal and Recoverable in Indigenous Chickens or Animal Feeding
Ayssiwede, Simplice Bosco; Zanmenou, J. C.; Issa, Y. et al

in Pakistan Journal of Nutrition (2011), 10(8), 707-717

This study was carried out to assess the nutrient composition of some unconventional and local feed resources available in Senegal so as to use them as protein supplement sources in the diets of ... [more ▼]

This study was carried out to assess the nutrient composition of some unconventional and local feed resources available in Senegal so as to use them as protein supplement sources in the diets of indigenous chickens to enhance their productivity. Ten (10) unconventional and local ingredients from Senegal including leguminous leaves (Leuceana leucocephala, Cassia tora, Moringa oleifera, adansonia digitata, Sesbania rostrata), cucurbit (Citrullus vulgaris) and roselle (Hibiscus sabdariffa) seeds, red and white cowpea (Vigna unguiculata seeds) and cockroaches (Blatta orientalis) were collected, sun-dried, processed into meal and analyzed for their chemical and macro-mineral composition using internationally established procedures. The results showed that the samples Dry Matter (DM) percent ranged from 89.3% (red cowpea) to 94.9% (C. vulgaris). The Crude Protein (CP) content ranged from 24.7% (white cowpea) to 61.9% (cockroaches meal), with A. digitata leaves having the lowest value (12.9%). Citrullus and Hibiscus seeds meal recorded the highest (38.8% and 18.9%) Ether Extract (EE) values, followed respectively by cockroaches (11.1%), Moringa (9.8%), Leuceana (6.4%) and Sesbania leaves meal (5.1%), while the others were below 4.5%. The crude fiber (CF) content was globally high in the leaves, ranging from 11.7% (M. oleifera) to 16.8% (C. tora) while that of seeds and cockroaches ranged from 1.9% (white cowpea) to 19% (Citrullus seeds). A. digitata leaves gave the highest ash content (25.2%), followed by Cassia (15.2%), Moringa (13.6%), Leuceana (11.4%) and Sesbania leaves (7.1%), while the others were below 5.6%. The metabolizable energy (ME) value calculated for seeds and cockroaches meal ranged from 3161 kcal/kg DM (cockroaches) to 4270 kcal/kg DM (C. vulgaris) and that of leaves from 1873 (A. digitata) to 2888.9 kcal/kg DM (M. oleifera). Cassia leaves contained the highest level of calcium (3.1%), followed by Adansonia and Leuceana (1.81%), Moringa and Sesbania leaves (1.41%), whilst cockroaches, Hibiscus and Citrullus seeds meal recorded respectively 0.93, 0.81 and 0.55% of phosphorus. These results showed that all the ingredients samples contained appreciable quantities of all dietary nutrients tested for which more or less make them partial or complete substitutes for the conventional feed sources. [less ▲]

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See detailNitrogen excretions in dairy cows on a rotational grazing system: effects of fertilization type, days in the paddock and time period.
Dufrasne, Isabelle ULg; Robaye, Vincent ULg; Istasse, Louis ULg et al

in Schnyder, Hans; Isselstein, J.; Taube, F. (Eds.) et al Grassland in a changing world (2010, September)

The present study aims to quantify nitrogen (N) excretions in dairy cows on a rotational grazing system with different types of fertilization (mineral N, slurry and compost) after 3 or 5 days in the ... [more ▼]

The present study aims to quantify nitrogen (N) excretions in dairy cows on a rotational grazing system with different types of fertilization (mineral N, slurry and compost) after 3 or 5 days in the paddock and during two different periods in June and September. Individual samples of faeces and urine were collected to assess N excretions from cows in the paddocks. The urea content in milk from the tank or from the individual cows was also measured. N intake was higher on day 3 compared to day 5 (465 vs 425 g d-1, P<0.001) and in September as compared to June (488 vs 425 g d-1, P<0.001) but was not influenced by the fertilization type. The amount of excreted urinary N was significantly higher in the mineral N group than in the two other groups (272 vs 226 g d-1; P<0.001). The N excretion in faeces and urines decreased with days (92 vs 84 g d-1, P<0.01; 256 vs 228 g d-1, P<0.001 respectively for days 3 and 5). Urinary N excretion was lower in June than in September (181 vs 302 g d-1, P<0.001) while the N excretion in the faeces was higher (96 vs 80 g d-1, P<0.01). [less ▲]

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See detailGrazing with a mobile milking robot
Dufrasne, Isabelle ULg; Robaye, Vincent ULg; Istasse, Louis ULg et al

in Schnyder, Hans; Isselstein, J.; Taube, F. (Eds.) et al Grassland in a changing world (2010, September)

The size of dairy cow herds in Europe is increasing. Farmers have to manage larger herds but want, at the same time, benefit from a normal social life. So, the milking robot can bring solutions. Its use ... [more ▼]

The size of dairy cow herds in Europe is increasing. Farmers have to manage larger herds but want, at the same time, benefit from a normal social life. So, the milking robot can bring solutions. Its use can reduce physical labour and allow flexibility. During the past 10 years, the number of milking robots has been increased in Europe. In farm practice, this technology has resulted in a reduction in the amount of grazing even though grazing appears as a natural practice which is appreciated by the consumers. At the experimental farm of the University of Liège, we are developing the concept of a mobile milking robot in collaboration with a private company. This prototype will allow cows to graze and could be moved to different locations on pastures during the grazing season. The prototype will be used indoors during the end of the winter season and will be moved outdoor during the 2010 grazing season. The feasibility of this prototype has to be tested in the field. Milk production and quality, the number of visits and the grazing parameters will be recorded. Different equipments in view to attract the cows to the robot as the presence of a cow brush, the location of the drinking point, will be compared. The behaviour of animals will be also assessed. [less ▲]

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See detailUtilisation digestive et métabolique et valeur nutritionnelle de la farine de feuilles de Cassia tora (Linn.) incorporée dans la ration alimentaire des poulets indigènes du Sénégal
Ayssiwede, Simplice Bosco; Chrysostome, Christian; Ossebi, W. et al

in Revue de Médecine Vétérinaire (2010), 161(12), 549-558

In the prospect of the Cassia tora leaves meal recovering as a protein ingredient source for diets of Senegal indigenous chickens, a study was carried out to determine their nutrient utilisation and ... [more ▼]

In the prospect of the Cassia tora leaves meal recovering as a protein ingredient source for diets of Senegal indigenous chickens, a study was carried out to determine their nutrient utilisation and nutritional value. Twenty adult Senegal indigenous chickens were housed in metabolic cages and allotted in four groups of five birds each. The groups were corresponding to four dietary treatments (CT0, CT5, CT10 and CT15) containing respectively 0, 5, <br />10 and 15% of cassia leaves meal in substitution of groundnut cake meal. The cassia leaves are relatively rich in protein (27.4% DM), crude fibre (16.8% DM), NDF (25.7% DM) and ash (15.2% DM), particularly in calcium (3.1%) and potassium (1.3% DM). It contained 3.8% DM, 36.8% DM and 2050.47kcal/kg DM of ether extract, nitrogen-free extract and metabolizable <br />energy, respectively. Except for fat, the inclusion of Cassia tora leaves meal in the indigenous poultry diets until 15% has no significant adverse effect on nutrient and energy utilization, feed intake, average daily weight gain and feed conversion of the Senegal indigenous poultry. It significantly improved the crude fibre and ash utilization from 5% dietary treatment (CT5). [less ▲]

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See detailEffect of groundnut cake substitution by glandless cottonseed kernels on broilers production: animal performance, nutrient digestibility, carcass characteristics and fatty acid composition of muscle and fat
Diaw, Mamadou Tandiang; Dieng, Abdoulaye; Mergeai, Guy ULg et al

in International Journal of Poultry Sciences (2010), 9(5), 473-481

A study has been conducted with broilers to assess, during the rainy season, the effects of groundnut cake substitution by glandless Cottonseed Kernel (CSK), at levels of 0, 25, 50 and 75%. The ... [more ▼]

A study has been conducted with broilers to assess, during the rainy season, the effects of groundnut cake substitution by glandless Cottonseed Kernel (CSK), at levels of 0, 25, 50 and 75%. The substitution improved linearly feed intake and animal growth, as well as carcass component weights and allometric parameters. The CSK increased the C18:2 n-6 to C18:1 n-9 ratio, as well in diet as in meat and subcutaneous fat. In order to explain the observed performances, the possibility is considered that broilers used preferentially C18:2 n-6 fatty acids for their metabolism. Complete glandless cottonseed kernels are probably highly valuable for broilers production in warm and wet conditions. [less ▲]

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See detailTowards a revison of the dairy cow's standard for nitrogen production: justification and what are consequences for soil link rate of dairy farms
Lambert, Richard; De Toffoli, M.; Dufrasne, Isabelle ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2010), 14

Towards a revison of the dairy cow's standard for nitrogen production: justification and what are consequences for soil link rate of dairy farms. At present, the dairy cow's standard of nitrogen ... [more ▼]

Towards a revison of the dairy cow's standard for nitrogen production: justification and what are consequences for soil link rate of dairy farms. At present, the dairy cow's standard of nitrogen production in Walloon region is 90 kg per year. This standard is used to calculate the "soil link rate" of farms, a balance between the organic nitrogen to be spread on land and the quantity legally authorized considering grassland and arable land area. This standard is appreciably lower than that fixed by other member states and was criticized by the European Commission during the negotiations having ended in the second program of sustainable nitrogen management. Further to new studies, it seems that the gaseous loss of nitrogen averages in buildings and during the storage is weaker than the 15% value which was used to justify this 90 kg standard. It also seems that there are big differences of average dairy production and average rate of urea according to the agricultural regions and consequently that regional production standards correspond better to the reality. On basis of these mean values, the dairy cow's annual productions of nitrogen vary between 81 kg per year in grassy region of Fagne and 99 kg per year in Haute Ardenne and in grassy region from Liege. For the Walloon region in general, the average production is 94 kg per year. The adoption of different values of dairy cow's nitrogen production by region would lead to an increase of 8% of the soil link rate of dairy farms in Haute Ardenne and of 7% in grassy region from Liege and a decrease of 7% in grassy region of Fagne. [less ▲]

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See detailInfluence of the fertilization type, the day in the paddock and the month on nitrogen rejections in dairy cows
Dufrasne, Isabelle ULg; Istasse, Louis ULg; Robaye, Vincent ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2010), 14

Influence of the fertilization type, the day in the paddock and the month on nitrogen rejections in dairy cows. The present study aims to quantify nitrogen (N) rejections in dairy cows on a rotational ... [more ▼]

Influence of the fertilization type, the day in the paddock and the month on nitrogen rejections in dairy cows. The present study aims to quantify nitrogen (N) rejections in dairy cows on a rotational grazing system with different types of fertilization (compost, slurry and mineral N) at two different days in the paddock (days 3 and 5) and during two different periods (June and September). Grass yield and height were measured along with the chemical composition. The live weight was recorded when the cows moved into the paddock and milk yields was recorded at each milking. N intakes were measured on the basis of the energy requirement. When the cows were in the paddocks, individual samples of faeces and urine were collected to assess N rejections. The urea content in milk from the tank or from the individual cows was also measured. N intake was higher on day 3 than on day 5 and in September as compared with in June but was not influenced by the fertilization. The amount of N produced in milk was not influenced either by the fertilization, by the day on the paddock or by the month. The amount of urinary N was significantly higher in the N mineral group than in the two other groups. The N excretion in faeces and urines was higher on day 3 than on day 5. In June, the N excretion by the urine was lower than in September while the N excretion by the faeces was higher. Equations were calculated in order to estimate the N excretion by the urine in grazing dairy cows from the urea content in milk of a group of cows. [less ▲]

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See detailEffect of exogenous circulating anti-bPL antibodies on bovine placental lactogen measurements in foetal samples.
Alvarez Oxiley, Andrea Vivian ULg; Melo de Sousa, Noelita ULg; Hornick, Jean-Luc ULg et al

in Acta Veterinaria Scandinavica (2010), 52

BACKGROUND: The involvement of placental lactogen (PL) in the regulation of foetal growth has been investigated in different species by in vivo immunomodulation techniques. However, when circulating ... [more ▼]

BACKGROUND: The involvement of placental lactogen (PL) in the regulation of foetal growth has been investigated in different species by in vivo immunomodulation techniques. However, when circulating antibodies are present together with the hormone, the procedure for hormonal measurement becomes considerably complex. The aim of this study was the immunoneutralization of bovine placental lactogen (bPL) concentrations in bovine foetal circulation by direct infusion of rabbit anti-bPL purified immunoglobulins (IgG) via a foetal catheter (in vivo study). The ability of a RIA based on guinea pig anti-bPL antiserum, for the measurement of bPL concentrations in samples containing exogenous rabbit anti-bPL immunoglobulins, was also analyzed in in vitro and in vivo conditions. METHODS: Six bovine foetuses were chronic cannulated on the aorta via the medial tarsal artery. Infusion of rabbit anti-bPL IgG was performed during late gestation. Pooled rabbit anti-bPL antisera had a maximal neutralization capacity of 25 microg bPL/mL of immunoglobulin. Interference of rabbit anti-bPL immunoglobulin with radioimmunoassay measurement using guinea pig anti-bPL as primary antibody was first evaluated in vitro. Polyclonal anti-bPL antibodies raised in rabbit were added in foetal sera to produce 100 samples with known antibodies titers (dilutions ranging from 1:2,500 till 1:1,280,000). RESULT(S): Assessment of the interference of rabbit anti-bPL antibody showed that bPL concentrations were significantly lower (P < 0.05) in samples added with dilutions of rabbit antiserum lower than 1:80,000 (one foetus) or 1:10,000 (four foetuses). It was also shown that the recovery of added bPL (12 ng/mL) was markedly reduced in those samples in which exogenous rabbit anti-bPL were added at dilutions lower than 1:20,000. Concentrations of foetal bPL were determined in samples from cannulated foetuses. In foetuses 1 and 6, bPL concentrations remained almost unchanged (<5 ng/mL) during the whole experimental period. In Foetus 3, bPL concentrations decreased immediately after IgG infusion and thereafter, they increased until parturition. CONCLUSION(S): The use of a bPL RIA using a guinea pig anti-bPL as primary antiserum allowed for the measurement of bPL concentrations in foetal plasma in presence of rabbit anti-bPL IgG into the foetal circulation. Long-term foetal catheterization allowed for the study of the influence of direct infusion of anti-bPL IgG on peripheral bPL concentrations in bovine foetuses. [less ▲]

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See detailStudy on environmental factors influencing the urea content of cow milk in Wallonia (Belgium)
Dufrasne, Isabelle ULg; Istasse, Louis ULg; LAMBERT, René ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2010), 14

Study on environmental factors influencing the urea content of cow milk in Wallonia (Belgium). The urea content in tank milk is currently assessed in Wallonia (Belgium) for all milk producers by the ... [more ▼]

Study on environmental factors influencing the urea content of cow milk in Wallonia (Belgium). The urea content in tank milk is currently assessed in Wallonia (Belgium) for all milk producers by the Comite du lait. A statistical analysis was carried out on 5,675,758 data collected over the 2002-2008 period in order to study the variation in the urea content in milk from cows according to the months of the years and the agronomy areas. The data were analyzed with a linear model (proc GLM) including the fixed effects of the area, the month of sampling, the year and the interactions. The fat and proteins contents in milk were used as covariables. The average urea content in milk over the six years was 258 mg.l(-1). A proportion of 19% of the contents were over 350 mg.l(-1)and 10% over 400 mg.l(-1). The model explained 35% of the variation of the urea content. Within the model, the agronomy area was the most explicative component (44%). It was followed by the area-month interaction (18.6%), the protein content (17.8%) and the month (10.5%). The variation of the urea content in milk could be mainly explained by the differences in the diets offered to the lactating dairy cows according to the agronomy areas. The composition of the diets varies with the crops produced and therefore with the agronomy area. Higher urea contents were observed in areas with a lot of pastures (grazing areas) than in the arable areas. In the grazing areas, feedstuffs higher in protein than in energy are consumed by the cows: the excess of protein is probably the reason for the higher urea content. The feedstuffs produced in the arable areas are more various with more diversified and balanced diets. The season influenced also the urea content, a higher urea content being observed during the summer period as compared with the winter period. The changes could be explained by dietary differences between the indoor winter period and the grazing period in Summer. During the indoor period, the dairy cows are offered normally a complete diet which is more balanced than during the grazing period. [less ▲]

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See detailVers une révision de la norme de production d'azote de la vache laitière : justification et conséquences sur le taux de liaison
Lambert, Richard; De Toffoli, M.; Dufrasne, Isabelle ULg et al

in Marcoen, Jean Marie; Vandenberghe, Christophe (Eds.) Acte de l'atelier "Nitrate - Eau" (2010)

Towards a revison of the dairy cow’s standard for nitrogen production: justification and what are consequences for soil link rate of dairy farms. At present, the dairy cow’s standard of nitrogen ... [more ▼]

Towards a revison of the dairy cow’s standard for nitrogen production: justification and what are consequences for soil link rate of dairy farms. At present, the dairy cow’s standard of nitrogen production in Walloon region is 90 kg per year. This standard is used to calculate the “soil link rate” of farms, a balance between the organic nitrogen to be spread on land and the quantity legally authorized considering grassland and arable land area. This standard is appreciably lower than that fixed by other member states and was criticized by the European Commission during the negotiations having ended in the second program of sustainable nitrogen management. Further to new studies, it seems that the gaseous loss of nitrogen averages in buildings and during the storage is weaker than the 15% value which was used to justify this 90 kg standard. It also seems that there are big differences of average dairy production and average rate of urea according to the agricultural regions and consequently that regional production standards correspond better to the reality. On basis of these mean values, the dairy cow’s annual productions of nitrogen vary between 81 kg per year in grassy region of Fagne and 99 kg per year in Haute Ardenne and in grassy region from Liege. For the Walloon region in general, the average production is 94 kg per year. The adoption of different values of dairy cow’s nitrogen production by region would lead to an increase of 8% of the soil link rate of dairy farms in Haute Ardenne and of 7% in grassy region from Liege and a decrease of 7% in grassy region of Fagne. [less ▲]

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See detailEtude de facteurs environnementaux influençant la teneur en urée dans le lait de vaches en Wallonie (Belgique)
Dufrasne, Isabelle ULg; Istasse, Louis ULg; Lambert, Richard et al

in Marcoen, Jean Marie; Vandenberghe, Christophe (Eds.) Actes de l'Atelier "Nitrate - Eau" (2010)

Study on environmental factors influencing the urea content of cow milk in Wallonia (Belgium). The urea content in tank milk is currently assessed in Wallonia (Belgium) for all milk producers by the ... [more ▼]

Study on environmental factors influencing the urea content of cow milk in Wallonia (Belgium). The urea content in tank milk is currently assessed in Wallonia (Belgium) for all milk producers by the Comité du lait. A statistical analysis was carried out on 5,675,758 data collected over the 2002-2008 period in order to study the variation in the urea content in milk from cows according to the months of the years and the agronomy areas. The data were analyzed with a linear model (proc GLM) including the fixed effects of the area, the month of sampling, the year and the interactions. The fat and proteins contents in milk were used as covariables. The average urea content in milk over the six years was 258 mg.l-1. A proportion of 19% of the contents were over 350 mg.l-1and 10% over 400 mg.l-1. The model explained 35% of the variation of the urea content. Within the model, the agronomy area was the most explicative component (44%). It was followed by the area-month interaction (18.6%), the protein content (17.8%) and the month (10.5%). The variation of the urea content in milk could be mainly explained by the differences in the diets offered to the lactating dairy cows according to the agronomy areas. The composition of the diets varies with the crops produced and therefore with the agronomy area. Higher urea contents were observed in areas with a lot of pastures (grazing areas) than in the arable areas. In the grazing areas, feedstuffs higher in protein than in energy are consumed by the cows: the excess of protein is probably the reason for the higher urea content. The feedstuffs produced in the arable areas are more various with more diversified and balanced diets. The season influenced also the urea content, a higher urea content being observed during the summer period as compared with the winter period. The changes could be explained by dietary differences between the indoor winter period and the grazing period in Summer. During the indoor period, the dairy cows are offered normally a complete diet which is more balanced than during the grazing period. [less ▲]

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