Grassland Farming and Land Management Systems in Mountainous Regions
Proceedings of the 16th Symposium of the European Grassland Federation Gumpenstein, Austria August 29th - August 31st 2011
Edited by Erich M. Pötsch Bernhard Krautzer Alan Hopkins
Wallig Ennstaler Druckerei und Verlag Ges.m.b.H. Gröbming 2011
Grassland Farming and Land Management Systems in Mountainous Regions
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Published by Organising Committee of the 16th Symposium of the European Grassland Federation 2011 and Agricultural Research and Education Centre (AREC) Raumberg-Gumpenstein Altirdning 11 8952 Irdning Austria Copyright © 2011 AREC Raumberg-Gumpenstein All rights reserved. Nothing from this publication may be reproduced, stored in computerised systems or published in any form or any manner, including electronic, mechanical, reprographic or photographic, without prior written permission from the publisher AREC Raumberg-Gumpenstein. The individual contributions in this publication and any liabilities arising from them remain the responsibility of the authors. ISBN 978-3-902559-65-4 Layout by Brunhilde Egger Printed by Wallig Ennstaler Druckerei und Verlag Ges.m.b.H. Mitterberger Straße 36 8962 Gröbming Austria Distributed by European Grassland Federation EGF W. Kessler, Federation Secretary c/o Agroscope Reckenholz-Tänikon Research Station ART Reckenholzstraße 191 CH-8046 Zürich, Switzerland E-Mail:
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Grassland Science in Europe, Vol. 16
Feasibility and economic advantage of conserving grassland forages as wrapped bale silage in a mountain environment of Italy Tabacco E., Revello-Chion A. and Borreani G. Dep. Agronomia, Selvicoltura e Gestione del Territorio, University of Turin, Italy Corresponding author:
[email protected] Abstract In the European mountain environment 40% of dairy farms were abandoned in the last 20 years. In order to remain profitable, the farms still operating must reduce feed-input costs by maximizing the utilization of local forage resources from native grassland. Two trials were conducted at Sauze d’Oulx (Torino, Italy) with the aims of comparing two conservation systems (baled silage vs. field-cured hay) and of determining the effects of harvesting herbage for baled silage at two stages of maturity on nutritional quality, forage production costs and milk income over feed cost in comparison with field-cured hay. Total harvest costs were higher for bale silage than for hay (66 vs. 80 € Mg-1 DM), and only an earlier cutting date than in traditional haymaking could increase baled forage quality, thus enhancing milk production and income over feed costs of winter feeding. Keywords: bale silage, mountain meadow, forage quality, milk yield, costs Introduction In the European Alps 40% of all farm holdings were abandoned within the past 20 years and almost 70% of the farms still operating are run as a secondary source of income. In Italy, mountain dairy farms base their feeding system on extensive grazing in the summer period (3 to 4 months) and on supplemental confinement feeding over a large part of the year (8 to 9 months). Field-cured hay is currently the main system for forage conservation, and is normally harvested at a late stage of maturity. Due to high mechanical losses and frequent rain damage, the resulting hays may be poor in quality, and consequently the winter milk production needs to be supported with concentrates purchased from outside the production areas (Borreani et al., 2007). Wrapped bale silage has proved to be a good alternative to haymaking on smallto-medium farms in the lowlands; it can easily be mechanized and harvested with the same equipment that is used for field-cured hay, with the only addition of a plastic wrapper. The aims of this study were to compare two conservation systems of permanent mountain meadows (baled silage after 30 h of wilting and field-cured hay) and to determine the effects of harvesting herbage for baled silage at two stages of maturity on nutritional quality, forage production costs, and income over feed cost (IOFC) for cows fed baled silage in comparison with field-cured hay. Material and methods Two trials (I and II) were conducted at Sauze d’Oulx (Torino, Italy). In Trial I, bale silage (LS) and hay (LH) were produced later in the growing season, as for the local hay production. In Trial II, wrapped bales were made at an earlier harvesting time (ES) in order to improve the quality of conserved forage and to increase the potential dry matter DM intake (DMI), whereas field-cured hay (LH) was harvested at the same stage of maturity as in Trial I. In both trials, the forages were harvested from alternate windrows, half as baled silage and half as field-cured hay. The forage was baled in round bales (1200 mm diameter) and the silage Grassland Farming and Land Management Systems in Mountainous Regions
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bales were individually wrapped using six layers of polyethylene stretch film. In both trials, a herd of 40 Aosta Red Pied dairy cows was divided into two groups, balanced for parity, body weight, stage of lactation, and individual daily milk yield in a two-period crossover design (10 d for adaptation to the ration and 9 d for data collection). In Trial I, the diets included LS or LH fed ad libitum and 5.4 kg DM of grain, mineral and vitamin mix. In Trial II, diets included ES fed ad libitum and 3.5 kg DM per cow of grain, mineral and vitamin mix, or LH fed ad libitum and 5.1 kg DM per cow of grain, mineral and vitamin mix. The experimental diets were balanced for energy, protein, and minerals according to NRC requirements for 506-kg cows. Herbage samples were taken immediately before cutting. Silages and hays were sampled during the feeding trial by coring the bale from its side to a depth of about 450 mm. Samples were analysed for DM content, crude protein (CP, Kjeldahl N x 6.25), ash by ignition to 550°C, NDF, ADF and ADL, gross energy (GE) using an adiabatic calorimeter bomb, enzymatic organic matter digestibility (OMD) and net energy for lactation (NEL). Individual daily milk yields were recorded eight times (on days 2, 4, 6, and 8 of each experimental period) from both the morning and afternoon milkings, and fat and protein content were determined by Milk-O-Scan. The forage harvest costs for LH, LS and ES were evaluated using standard contractor charges and material costs (based on 2010 costs), for all the operations and materials, respectively. The budget did not include the costs of producing the crop, land charge/ rent, or the storage costs. Data were analysed, within each trial, using the ANOVA procedure of SPSS. The Duncan range test (P < 0.05) was used to interpret any significant differences among the mean values of Table 1. Result and discussion The conservation process reduced forage quality compared to that of fresh herbage, both for hay and silage (Table 1). In Trial II the baled-silage system resulted in higher quality forage due to the earlier cut and shorter wilting period than hay. Fermentation of baled silage was restricted by the DM content higher than 50% and resulted in pH of 5.72 and 5.13, lactic acid concentration of 0.78 and 1.38% of DM, and ammonia-N of 4.74 and 5.06% of total nitrogen for Trial I and II, respectively. The operating costs in the field were higher for hay than for baled silage due to the greater number of tedding treatments (3 to 4 vs. 1), in both trials (Table 2). Otherwise, the stretch film, wrapping operation and plastic disposal accounted for about 44% of the total production costs in the baled silage system and, as a consequence, the total harvesting cost was lower for hay than for baled silages, in both trials. The forage intake and the total DMI were similar in Trial I, while they were higher in ES treatment than LH treatment in Trial II. In Trial I the 3.5% fat-corrected milk (FCM) yield was higher in LH treatment than in LS treatment. In Trial II cows on the ES treatment produced more milk (1.7 kg d-1) and more 3.5% FCM (1.1 kg d-1) than cows on the LH treatment. Concentration of milk fat was higher in LH diets in Trial I, whereas milk protein was not different between diets in both trials. In Trial II, total daily feed costs were about 10% lower and milk value 8% higher when cows were fed ES than LH, whereas milk value was slightly higher (5%) for LH treatment in Trial I. As a consequence ES allowed a 0.72 €/day per cow more IOFC than LH, in Trial II; whereas, due to its higher production costs LS resulted in an IOFC 0.36 € lower than LH, in Trial I. Extrapolating figures from Trial II to a mountain dairy herd of about 100 milking cows, and hypothesizing supplementation with baled silage instead of field-cured hay for 220 days per year would potentially increase IOFC by more than 15000 € annually. It is concluded that the round bale silage preservation system offers potential to minimize harvest losses and increasing forage quality compared to conventional field-cured hay, since less handling and a 164
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shorter drying time than haymaking can greatly reduce mechanical shattering and the risk of rain damage. However, baled silage should not be considered as a replacement for conventional field-cured hay, and it needs to be coupled with earlier cutting schedules than haymaking to be effective in improving the quality of conserved forages, and thus offering the opportunity of increasing the economic profitability of indoor-feeding over winter. Table 1. Nutrient composition of herbage at cutting and of baled silage (S) and hay (H) produced at Sauze d’Oulx (Italy) in the two trials.
Trial I Trial II Herbage at cut Conserved forage Herbage at cut Conserved forage LS LH LS LH SE ES LH ES LH SE
DM, % CP, % of DM NPN, % of TN NDF, % of DM ADF, % of DM ADL, % of DM OMD, % of OM NEL, MJ kg-1 DM
29.4c 29.7c 53.6b 90.7a 7.69 20.6d 30.3c 52.2b 91.5a 6.08 8.5a 8.5a 7.9b 7.7b 0.62 12.5a 8.6c 10.7b 8.4c 1.51 21.8b 3.13 27.6ab 21.6b 32.6a 23.3b 0.46 19.2b 19.0b 43.2a 57.0b 60.3b 61.9ab 65.5a 0.97 52.1c 64.5a 57.0b 64.7a 1.46 36.0b 37.9b 42.1a 42.8a 0.59 34.2c 38.9b 38.6b 42.2a 0.73 4.6c 5.5b 5.9b 6.5a 0.12 5.1b 5.6ab 5.9ab 6.5a 0.16 64.6b 64.4b 59.5a 58.7a 0.32 68.7a 63.2b 63.6b 59.4c 0.85 5.45b 5.49b 4.98a 4.65a 0.11 6.00a 5.44b 5.88a 4.67c 0.10
LH = late hay, LS = late baled silage, ES = early baled silage, SE = Standard error.
Table 2. Harvest costs of baled silages cut at two stages of maturity (LS and ES) and of the hay (LH), and costs and returns of the feeding study in two trials at Sauze d’Oulx (Italy). Trial I Trial II LS LH P-value ES LH P-value 41 61 ** 46 63 ** Mowing, tedding, raking and baling (€ Mg-1 DM) 2 2 NS 2 2 NS Hauling and storing (€ Mg-1 DM) Wrapping (€ Mg-1 DM) 14 0 *** 17 0 *** Stretch film (€ Mg-1 DM) 14 0 *** 15 0 *** 2 3 NS 2 2 NS Plastic net (€ Mg-1 DM) Plastic disposal (€ Mg-1 DM) 2 0 ** 2 0 ** 76 66 ** 84 67 *** Total harvest costs (€ Mg-1 DM) Forage DMI (kg d-1) Total DMI (kg d-1) Milk yield (kg d-1) 3.5% fat-corrected milk (kg d-1) Milk fat (%) Milk protein (%) Forage costs (€ cow-1) Total feed costs (€ cow-1) Milk value (€ cow-1)† Income over feed cost (€ cow-1) †
9.8 9.9 NS 12.5 10.3 *** 15.2 15.3 NS 16.0 15.4 ** 12.6 12.8 NS 14.9 13.2 ** 11.7 12.3 * 13.8 12.7 *** 3.38 3.64 * 3.55 3.64 NS 3.19 3.30 NS 3.23 3.17 NS 0.74 0.65 NS 1.05 0.70 ** 2.68 2.60 NS 2.31 2.54 * 5.27 5.54 * 6.21 5.72 ** 2.58 2.94 * 3.90 3.18 **
Based on 3.5% fat-corrected milk price of 45 € t-1.
Acknowledgements The research was funded by the Regione Piemonte Project: ‘Qualità degli alimenti, gestione degli animali e tecnologia di caseificazione: esempio di filiera produttiva di alcuni formaggi DOP tipici piemontesi in zona montana’. All the authors contributed equally to this paper. References Borreani, G., Giaccone D., Mimosi A. and Tabacco E. (2007) Comparison of hay and haylage from permanent alpine meadows in winter dairy cow diets. Journal Dairy Science 90, 5643-5650. Grassland Farming and Land Management Systems in Mountainous Regions
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