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Permanent grasslands are a very relevant cropping system in the North of Spain and support the main dairy farms in the country. Adaptation to climate change will be required given the projected changes of regional precipitation. To support such adaptation, modelling of these systems to generate high quality projections of the system performance is required. In the region to be simulated, grasslands are managed with a mixture of cuts and grazing. Several issues hinder the modelling of this type of systems: 1) the available data of grazing intensity presents large uncertainties; 2) there are few grassland models that allows flexibility to define a variable combination of cuts and grazing; 3) soil heterogeneity. It follows, and expands to grazing, the exercise performed by Gómara et al. (2020), who used the Pasture Simulation model (PaSim) to simulate a mown permanent grassland in the French Massif Central.The model was calibrated using data from Villaviciosa (Asturias, Spain, 5º 26' 27" W, 43° 28' 50" N, 10 m a.s.l.), located at northern Spain with a temperate climate. This calibration was used to simulate several grassland locations distributed along the Cantabrian Sea. The soil information was obtained from Trueba et al. (2000). The model was configured for the optimum management for mowing and nitrogen fertilization. The 1976-2005 period and the 2030-2059 period were selected. For the future period two representative concentration pathway emission scenarios (RCP, van Vuuren et al., 2011) were selected (i.e. RCP4.5 and RCP8.5). An ensemble of climate models will be used from the Coordinated Regional Climate Downscaling Experiment (CORDEX, Giorgi and Gutowski, 2015) bias-adjusted by using the European observational database EOBS (Haylock et al., 2008) with the empirical quantile mapping method included in the climate4R R package (Iturbide et al., 2019). Modelling was challenging due to a combination of complexity (many processes involved) and uncertainty (observed data are difficult to generate). The results of the simulation exercise allow for assessing PaSim skill to reproduce the performance of these complex systems, as well as to determine the main weaknesses of the model and the observational/experimental required to improve the modelling work.ReferencesGiorgi, F. and Gutowski, W.J., 2015. Annual Review of Environment and Resources, 40(1): 467-490.Gómara I, Bellocchi G, Martin R, Rodríguez-Fonseca B, Ruiz-Ramos M, 2020. Agricultural and Forest Meteorology, 280, 107768.Haylock, M.R., Hofstra, N., Klein Tank, A.M.G., Klok, E.J., Jones, P. and New, M., 2008. J. Geophys. Res., 113: D20119.Iturbide, M., Bedia, J., Herrera, S., Baño-Medina, J., Fernández, J., Frías, M.D., Manzanas, R., San-Martín, D., Cimadevilla, E., Cofiño, A.S. and Gutiérrez, J.M., 2019. Environ. Modell. Softw., 111: 42-54.Trueba, C., Millán, R., Schimd, T, Lago, (2000). CIEMAT. ISBN: 84-7834-370-9. Madrid.van Vuuren, D.P., Edmonds, J., Kainuma, M., Riahi, K., Thomson, A., Hibbard, K., Hurtt, G.C., Kram, T., Krey, V., Lamarque, J.-F., Masui, T., Meinshausen, M., Nakicenovic, N., Smith, S.J. and Rose, S.K., 2011. Clim. Change, 109: 5–31.

Simple Summary Dairy cattle is a source of ammonia because only 25–35% of the dietary nitrogen is used for the synthesis of milk, and the remainder is excreted through feces and urine. A reduction in dietary nitrogen is an effective way to decrease nitrogen excretions and subsequent ammonia emissions. However, this reduction should not induce a decrease in the potential yield of the cows. On the other hand, legumes are more susceptible than grasses to undergo proteolysis in the silage process due to their higher protein content. However, not all legumes have the same rate of proteolysis rate. With the main objective of improving the quality of the slurry to be used as organic fertilizer, two sequential experiments were carried out. In the first, it was intended to determine the optimal level of dietary nitrogen intake necessary for high-production dairy cows. Once this level was established, two legume silages with different proteolysis rates were evaluated. In conclusion, dairy cows producing more than 30 kg of milk per day can meet their needs with diets with 13% of protein, reducing nitrogen losses through urine. The main pathway for the excretion of dietary nitrogen provided by legume silage is the urine, and the protein of field pea silage is metabolized towards ammonia production to a larger extent than the protein of faba bean silage. Abstract Less than 30% of dairy cattle’s nitrogen ingested is retained in milk. Therefore, large amounts of nitrogen can be excreted in manure and urine with a potential environmental impact. In addition, some legume forages can be more susceptible to proteolysis during the silage process than grasses, and dairy cows fed these legume silages would excrete a larger quantity of nitrogen in slurry. The objectives of this work were to evaluate the amount of nitrogen excretion in dairy cows fed different protein levels and legume silages with a view to improve the slurry quality as a co-product that can be used as fertilizer. Two double 3 × 3 Latin square trials were carried out in order to study three different protein levels (high, medium, and low) and three different silages (grass, faba bean, and field pea). Dry matter intake, milk production, and composition were not affected by treatments. The excretion of ammonia-N in the urine was almost four times lower in the diet with the lowest protein level. The ammonia-N in the urine was twice as high with the pea silage than faba bean and grass silages. In conclusion, the diet containing 13% of protein meets the protein requirement for lactating cows producing 31 kg daily, with low nitrogen excretion in the urine, and the main pathway for the excretion of surplus nitrogen from legume silages is through urine and the metabolization of pea silage protein goes toward ammonia-N.

3 páginas, 1 tabla, 1 figura., Financial support for this study was provided by the following projects: GRUPIN-IDI/2018/000237 (Principado de Asturias) and RTA2015-00061/AEI/FEDER (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria)

The European Common Agricultural Policy promotes the sustainable use of soils through the principle of cross-compliance that links direct payments to good farming practices. Thus, it is necessary to find sustainable alternatives to the conventional management for forage production in the Atlantic Arc dairy farms. Two alternative managements (faba bean in monoculture—FB—and faba bean–Italian ryegrass intercrop—FBIR) were cultivated with organic fertilization during two consecutive years and compared to the conventional management (Italian ryegrass in monoculture—IR—under chemical fertilization) as winter crops. Maize was used as the summer crop to complete the rotations using organic and chemical fertilization, respectively. The forage yield of winter fodder was quantified. Soil samples and summer harvests were performed to analyse the physicochemical and biological parameters. The best forage yield corresponded to FBIR with 9.2 t dry matter (DM) ha−1 vs. 7.2 and 5.7 t DM ha−1 for FB and IR, respectively. The soil organic matter did not show significant differences among treatments, suggesting that it may be a poor indicator of the management influence on edaphic quality in the short term. Biological indicators were more sensitive and faster to differentiate among managements than chemical indicators. Earthworm abundance was higher in FB and FBIR than IR (p &lt, 0.001), and consequently, soil infiltration was improved with the alternative management (13.90 vs. 2.08 and 0.90 min for IR, FB and FBIR, respectively, p &lt, 0.01). As a result, the soil health diagnosis of the agroecosystem was better for alternative management.

Significant advances achieved in different sensor technologies and computer processing data have made possible to respond the needs of livestock sector, providing precise and rapid information on feed composition, being an alternative to real time quality control on compound feed the use of handheld NIRS sensors. This work aimed to evaluate two hand-held portable NIR spectrophotometers for on-site and real time analysis of nutritive parameters in raw compound feed: Phazir 1624 Polychromix Inc (PhIR) and MicroNIRTM 1700 by JDSU (MICRO). For computing data, different combinations of pre-treatments and multivariate statistical methods have been assayed to extract the valuable information of spectra data and to develop appropriate calibrations. The calibration models displayed greatest predictive capacity for Crude Protein (CP), Crude Fiber (CF) and Starch (STCH) and the determination coefficients of cross validation were 0.90–0.88 for CP, 0.85–0.91 for CF, 0.89–0.88 and 0.89–0.91 for STCH using PhIR and MICRO instruments respectively. Dry Matter showed the lowest determination coefficients of cross validation 0.67–0.73. Accuracy achieved 99–101% for both NIRS instruments and no differences were found when applying tstudent-test comparing reference and predicted data. Results obtained with both instruments were compared by using standard deviation and not significant differences were observed at the 5% level. Results so far have demonstrated the potential of these handheld NIRS instruments proposed here to estimate the individual compound feeds composition changes at farms level instantly, time avoiding the disadvantage of moving the samples to the lab.

espanolSe cuantifico el contenido de compuestos secundarios (fenoles totales y taninos condensados) del haba en monocultivo, del raigras italiano en monocultivo y del intercultivo de haba y raigras, desde forraje verde hasta su inclusion como ensilado en raciones unifeed para vacas lecheras. Se evaluo el efecto de la inclusion de estos ensilados sobre la ingestion voluntaria y sobre la produccion y composicion quimica de leche. Para ello, se asignaron al azar 3 raciones unifeed formuladas con ensilado de haba (60% de la mate - ria seca de la racion), raigras italiano (46%) e intercultivo haba-raigras (52%), a 9 vacas frisonas distribuidas en 3 grupos siguiendo un diseno en cuadrado latino de 3 x 3. El haba en monocultivo fue el forraje mas rico en compuestos secundarios. La concentracion de dichos compuestos disminuyo con los procesos de prehenificado y ensilado y se diluyo en la racion con la inclusion de nuevos ingredientes hasta no mostrar diferencias significativas entre dietas. Los valores de ingestion de materia seca de raciones no presentaron diferencias significativas entre dietas (10,29; 10,24 y 10,78 kg de materia seca d-1 para haba, intercultivo de haba-raigras y raigras italiano respectivamente). Se observaron diferencias estadisticas en la produccion de leche en beneficio de las vacas alimentadas con raciones a base del ensilado de raigras italiano (P EnglishThe content of secondary compounds (total phenols and condensed tannins) of monocultures of faba bean and Italian ryegrass and faba-ryegras intercrop, from fresh forage to silage and their later inclusion in unifeed rations for dairy cows was measured. The effects of these silages on voluntary intake, dairy production and milk chemical composition were evaluated. For this purpose, three unifeed rations were formulated with faba bean (60% of the ration dry matter), Italian ryegrass (46%) or faba-ryegras intercrop (52%) silages, and were randomly assigned to 9 Holstein-Friesian cows divided into 3 groups following a 3 x 3 Latin square design. The faba bean monoculture was the forage with the highest content in secondary compounds. The concentration of these compounds decreased through the wilting and silage processes, and their content was diluted in the ration with the inclusion of new ingredients promoting no significant differences among diets. The dry matter intake of unifeed rations did not show significant differences among diets (10.29, 10.24 and 10.78 kg dry matter d-1 for faba bean, faba-ryegras intercrop and Italian ryegrass respectively). Statistical differences were observed in milk production with the highest values for cows fed rations based on Italian ryegrass silage (P

espanolEl vacuno lechero esta inmerso desde las ultimas decadas en un proceso de intensificacion. Con la hipotesis de que el volumen de produccion esta relacionado con la intensificacion, se estudio la situacion reproductiva actual y el manejo reproductivo en ganaderias de Asturias en relacion a su volumen de produccion. Mediante entrevistas personales al 2,4% de los ganaderos titulares activos, se obtuvieron los datos reproductivos de sus animales y del uso de tecnologias reproductivas. La produccion por lactacion y vaca fue inferior en las ganaderias de menor volumen de produccion (6.656 L/vaca en las explotaciones con 500 t leche/ano, respectivamente; P500 t leche/ano (6,1 a 3,0 lactaciones/vaca; P EnglishThe dairy sector has been involved in an intensification process for the last decades. Under the hypothesis that the milk yield is related to the level of intensification of herds, the current reproductive status and reproductive technologies used in the Principality of Asturias were evaluated in relation to the size of the dairy farms. This was carried out through a survey to 2.4% of total active dairy cows stakeholders in the region to obtain reproductive data and the use of reproductive technologies. The yield per lactation and cow was lower in the farms with less production level (6,656 L) than in the rest of the farms (8,640, 9,322 and 10,070 L/cow in farms with production levels between 175-325 tonnes milk/year, 325-500 tonnes milk/year and >500 tonnes milk/year, respectively; P500 tonnes milk/year (6.1 to 3.0 lactations per cow, P

espanolLos modelos de alimentacion para la produccion de leche de vaca se clasifican tradicionalmente en base a la superficie agraria destinada al cultivo de maiz. Sin embargo, la composicion de las raciones es variable debido a la dinamica de produccion de forraje, la rotacion de cultivos, la disponibilidad de alimentos en el mercado, los requerimientos de las vacas, etc. Asi, la superficie de cultivo no siempre puede asociarse con la racion. Por ello, el objetivo de este estudio fue identificar los modelos de alimentacion efectivamente utilizados en las ganaderias de leche del Principado de Asturias. Para este proposito se seleccionaron 16 explotaciones en funcion de la superficie destinada al cultivo de maiz y al uso de pastoreo, que fueron monitorizadas desde el verano de 2014 a la primavera de 2015. Trimestralmente se registro la oferta de alimentos y la produccion de leche y se realizo una toma de muestras de alimentos y leche. Mediante analisis de cluster se describieron siete modelos de alimentacion efectivamente usados en funcion del principal ingrediente de la racion. Con independencia de la superficie agraria, el ensilado de maiz se confirma como un pilar en la dieta de las vacas de leche en varios de los modelos. Su utilizacion reduce el consumo de concentrado en la racion y puede mejorar la composicion de la leche en cuanto a proteina, lactosa y extracto seco magro EnglishThe models of dairy cow production are traditionally based on the usable agricultural area for maize culture. However, the composition of the diets varies throughout the year, because of the annual dynamic change of forage production, the forage rotation, the different cow requirements according to changes in the physiological state, etc. So, the crop area cannot always be associated with the ration. Therefore, the aim of this study was to identify the different feeding models used in dairy farms in the Principality of Asturias (Spain). In order to achieve this, sixteen dairy farms were selected according to grazing situation and the land destined for maize culture. A survey was compiled quarterly since summer of 2014 to spring of 2015. The farmers were interviewed about production and feed offered, and feed and milk were sampled. The ingredients of the ration and their amounts offered were analyzed by cluster analysis to establish actual feeding models. Seven feeding models were identified according to the main ingredient of the ration. The feeding model affects milk production, milk composition and the concentrate efficiency. Maize silage has become the mainstay of the diet in dairy farms. Increasing the amount of maize silage in the ration improves the milk content in protein, lactose and solids-nonfat, while the concentration of fat content was not affected

This Research Paper addresses the hypothesis that is possible to identify the type of feed used for dairy cows by means of the analysis of milk composition and the fatty acid profile of milk fat. Sixteen dairy farms were monitored during 1 year with quarterly visits between summer 2014 and spring 2015. Rations varied throughout the year due to annual dynamic change of forage production, forage rotation, variation of nutrient requirements according to physiological state of the animal, etc. The ingredients of the rations were analysed by cluster identifying five feeding systems based on the main ingredient of the diet: grazing, maize silage, grass silage, dry forage and concentrate. Milk composition could explain up to 91·3% of the total variability among feeding systems, while fatty acid profile could explain only up to 61·2% of total variability. However, when the sum of types of fatty acids and their ratios are taken, up to 93·5% of total variability could be explained. The maize silage system had the greatest milk yield, protein, solid non-fat and urea proportions, as well as the highest proportion of saturated fatty acid and lowest concentration of trans11 18 : 1, cis9 18 : 1 and 18 : 3 n3. Principal component analysis distinguishes the maize silage system from other feeding systems, both from milk composition and milk fatty acid profile. Concentrate system overlapped partially with the grazing, grass silage and dry forage systems. The latter systems had the highest concentrations of cis9 18 : 1, trans11 18 : 1 and 18 : 3, but there was no clear differentiation among them.

Three trials were conducted to study the effect of including in the ration of dairy cows the intercrop faba bean-rapeseed or Italian ryegrass silages on feed intake, milk quality and enteric methane emissions. Ten lactating Holstein cows, randomly allocated in two groups, were used in each trial in a crossover design. Dry matter intake and milk yield were recorded daily for each data period. Milk was sampled for analyses three times per period. Enteric methane emission was estimated applying a model that includes bodyweight, dry matter intake, nutritional values of feeds and milk composition. Concentrate and grass intake did not differ between treatments, while total mixed ration intake was higher with Italian ryegrass silage. Milk yield and protein concentration also increased with the Italian ryegrass treatment. The milk urea concentration was higher with the faba bean and rapeseed diet. Fatty acid profiles were affected by feeding strategy. Thereby, t11 18:1, c9 18:1 and total unsaturated fatty acid were higher when the intercrop silage was fed. As consequence, atherogenicity index and thrombogenicity index were lower under that treatment. Estimated enteric methane emissions did not differ between treatments. In conclusion, faba bean-rapeseed intercrop can be an alternative to Italian ryegrass to feed dairy cows. The rations formulated with the intercrop silage have potential to improve the milk fatty acid content, and show healthier profiles for consumers. However, it would be useful to study the protein content of these crops to avoid possible excess urea in milk and to maintain sustainable milk yield and milk protein content.

Small-scale dairy systems (SSDS) in Mexico represent over 78% of dairy farms and 37% of milk production. In the central highlands, many SSDS base the feeding of herds on irrigated cultivated pastures (mostly cut-and-carry), straws, and large amounts of commercial concentrates that result in high feeding costs and low economic sustainability. Intensive grazing may result in lower feeding costs when compared with cut-and-carry strategies. The high protein content of pasture may meet requirements of dairy cows with moderate milk yield (16–20 kg milk/cow.day), so that lower protein supplements, like ground maize grain, may substitute for commercial concentrates. An on-farm experiment following a participatory rural research approach was undertaken with seven farmers evaluating commercial concentrate (CC) or ground maize grain (MG) as supplement; and two pasture managements, grazing (G) or cut-and-carry (C) of irrigated ryegrass/white clover pastures to assess productive performance and feeding costs. Six farmers participated with four milking cows each and one farmer with two groups of four milking cows in a 2 by 2 factorial experiment. Daily milk yield per cow before the experiment was used as covariate. The experiment lasted 12 weeks. There is a trend in G for higher protein content in milk (P < 0.10). CC showed higher body condition score than MG with a significant interaction for body condition score with the highest body condition score in CCC (P < 0.05). Feeding costs were 15% higher per kg of milk yield and 19% per kg of energy-corrected milk under cut-and-carry but no statistical differences were detected (P > 0.05) in comparison with the grazing strategy. Supplementing with home-grown ground maize grain resulted in 28.5% higher margins per kg of milk produced. Implementing grazing involves less work burden for small-scale dairy farmers, and combined with home-grown grains as supplement is a viable option that may reduce feeding costs in these systems.

This study evaluated the effect of organic or chemical fertilization of maize on cow performance, economic outcomes, and greenhouse gas emission. Each type of maize silage according its different fertilization was used in two rations offered to two different groups of nine Friesian-Holstein cows throughout 4 months. The production cost of the maize silage was 8.8% lower for organic than for chemical fertilization. Both silages had similar nutritive value, except a higher concentration of starch in maize with organic fertilization, which allowed a reduction in the proportion of concentrate in the ration, saving 25.3 eurocents per cow in the daily ration, generating a positive balance of 21.8 eurocents per cow and day. The milk yield and composition were unaffected depending on the type of fertilization, whereas the estimation of CH4 and N2O emissions with chemical fertilization was higher than emissions with organic fertilization. As a result, it is possible to increase the sustainability and profitability of dairy production with reuse and recycling of manure.

Milk fatty acid (FA) profiles of lactating Holstein dairy cows were determined to evaluate the effects of parity (primiparous or multiparous) and the grazing time (0, 6 and 12 h), complementary to a total mixed ration, in a 2 × 3 factorial design. The interaction of parity with grazing time did not affect milk production and protein content; however, dry matter intake of herbage, total dry matter intake and milk fat content were affected by the interaction (P < 0.05). Both factors affected the milk concentration of monounsaturated FAs. The 18 : 3 cis9 cis12, 18 : 2 cis9 trans11, and 18 : 3 cis9 cis12 cis15 concentrations in milk were higher (P < 0.05) in primiparous cows. Milk 18 : 2 cis9 trans11 concentration in primiparous cows with 12 h grazing (1.17 g/100 g FA) was 44% and 57% higher than with 6 h and 0 h grazing (0.66 and 0.50 g/100 g FA, respectively). Similar pattern was observed for 18 : 3 cis9 cis12 cis15. The milk 18 : 1 trans11 concentration was higher (P < 0.05) with 6 h and 12 h grazing than without grazing. In conclusion, the parity would appear to mainly affect the proportion of short-chain FAs, and had an important influence on the proportions of 18 : 2 cis9 trans11, and 18 : 3 cis9 cis12 cis15. These FAs and also 18 : 1 trans11 were modified by grazing time.