An in-vitro study of aerobic changes in silages: Effects of microbial activities and impact factors

This thesis describes some observations of microbial metabolic activities that occur during the initial phase of aerobic deterioration of silages, which can affect their nutritional and hygienic quality. In vitro batch cultures were used to simulate aerobic processes that occur in these lactic acid-fermented feeds, with measurements of pH, organic acids and ethanol being used as indicators of change in metabolic activity. The use of selective antibiotics made it possible to draw conclusions on the causative microbial groups. An unexpected finding was the interaction and competition between two major bacterial and fungal representatives under semi-aerobic conditions

Mehr Milch aus Gras: Mehr Milch aus sächsischem Gras und einheimischen Eiweißfuttermitteln

Die Broschüre zeigt Anreize und Motivationen auf, die die Anteile von Grünlandfutter im Grobfutter der Milchrindrationen langfristig erhöhen helfen. Wesentliche Hemmnisse und Restriktionen wurden identifiziert und hinterfragt. Die Konflikte in Bezug auf Flächennutzung und Agrarpolitik, Tierernährung und Futterkonservierung sowie Wirtschaftlichkeit und Marktentwicklung wurden kritisch reflektiert. In Einzelfragestellungen wurden erfolgsversprechende Lösungsansätze erarbeitet und hinsichtlich ihrer Umsetzbarkeit bewertet

Chemical treatment of straw for ruminant feeding with NaOH or urea – investigative steps via practical application under current European Union conditions

Weather extremes in parts of Europe have led to a renewed search for alternative feeds for ruminants. Cereal straw presents one source of fibre, which is hard to digest due to its lignin-carbohydrate complexes. Chemical and biological treatments have been investigated to improve digestibility. Here, the applicability of alkaline treatments for farming conditions under EU legislation and their efficacy were checked. Thus, we tested caustic soda (60, 120 g kg-1straw) and urea (15, 30, 45, 60 g kg-1 straw without and with urease addition) applications both at laboratory scale and using a mixer-wagon. The nutritive value was evaluated analyzing chemical parameters including fibre components and estimating in vitro digestibility. The in vitro digestibility indicated by gas production, enzymatically soluble substrate and neutral detergent fibre digestibility (30h) was highest for the NaOH treatments, which did not differ by dose. Remoistening the straw to 600 g DM kg-1 was a precondition for the effectiveness of both treatments. Urease addition enhanced the intended ammonification when urea was applied at ≥ 30 g kg-1. An ambient temperature for urea treatment ≥ 25 °C was necessary and had to be maintained for at least 14 d post treatment. The determination of crude ash in NaOH treated feeds by the standard procedure and time overestimated the mineral fraction and had to be modified. This systematic approach provides guidance for feasible straw treatments for EU farmers. However, trials for feed acceptance and in vivo digestibility are needed to demonstrate the real effect in animals

Testing the aerobic stability of silage-based mixed rations using a multiple indicator approach

Total Mixed Rations (TMR) including silages are commonly fed to cattle in many parts of the world, but they tend to deteriorate on exposure to air, especially in the warm season. The aim of the study was to develop an easy to implement protocol in order to compare the aerobic stability of different feed mixtures for lactating dairy cattle and to test the potential of TMR stabilizing products to delay spoilage. The experimental conditions were standardized to 25 °C ambient, and the sample dry matter was adjusted to 400 g kg-1 to challenge shelf life. Temperature rise in an insulated vessel, which is frequently used when testing silages, was shown to be one promising indicator of spoilage activity. Furthermore, determination of pH, scores for visual occurrence of yeasts and moulds and condensation from 0–4 were successfully applied at the end of the 72 h period. A dosage of 4.5 l propionic acid t-1 proved suitable as a positive control when compared to 1.5 and 3.0 l t-1. The commercial products tested at the recommended dose had a similar efficacy. The stabilizing effect depended principally on the original hygienic condition of the ration. Visual evaluation plus the recording of pH, in addition to continuous temperature measurement facilitated this appraisal. Early signs of spoilage, in particular, can only be assessed by visual appraisal. Thus, an evaluation of a combination of indicators of aerobic stability is recommended

Chemical treatment of straw for ruminant feeding with NaOH or urea – investigative steps via practical application under current European Union conditions

Weather extremes in parts of Europe have led to a renewed search for alternative feeds for ruminants. Cereal straw presents one source of fibre, which is hard to digest due to its lignin-carbohydrate complexes. Chemical and biological treatments have been investigated to improve digestibility. Here, the applicability of alkaline treatments for farming conditions under EU legislation and their efficacy were checked. Thus, we tested caustic soda (60, 120 g kg-1straw) and urea (15, 30, 45, 60 g kg-1 straw without and with urease addition) applications both at laboratory scale and using a mixer-wagon. The nutritive value was evaluated analyzing chemical parameters including fibre components and estimating in vitro digestibility. The in vitro digestibility indicated by gas production, enzymatically soluble substrate and neutral detergent fibre digestibility (30h) was highest for the NaOH treatments, which did not differ by dose. Remoistening the straw to 600 g DM kg-1 was a precondition for the effectiveness of both treatments. Urease addition enhanced the intended ammonification when urea was applied at ≥ 30 g kg-1. An ambient temperature for urea treatment ≥ 25 °C was necessary and had to be maintained for at least 14 d post treatment. The determination of crude ash in NaOH treated feeds by the standard procedure and time overestimated the mineral fraction and had to be modified. This systematic approach provides guidance for feasible straw treatments for EU farmers. However, trials for feed acceptance and in vivo digestibility are needed to demonstrate the real effect in animals

Climate-Smart Crop-Livestock Systems for Smallholders in the Tropics: Integration of New Forage Hybrids to Intensify Agriculture and to Mitigate Climate Change through Regulation of Nitrification in Soil

It is widely recognized that less than 50% of applied nitrogen (N) fertilizer is recovered by crops, and based on current fertilizer prices the economic value of this “wasted N” globally is currently estimated as US$81 billion annually. Worse still, this wasted N has major effects on the environment (Subbarao et al. 2012). CIAT researchers and their collaborators in Japan reported a major breakthrough in managing N to benefit both agriculture and the environment (Subbarao et al. 2009). Termed Biological Nitrification Inhibition (BNI), this natural phenomenon has been the subject of long-term collaborative research that revealed the mechanism by which certain plants (and in particular the tropical pasture grass B. humidicola) naturally inhibit the conversion of N in the soil from a stable form to forms subject to leaching loss (NO3) or to the potent greenhouse gas N2O (Subbarao et al. 2012). Brachiaria humidicola which is well adapted to the low-nitrogen soils of South American savannas has shown high BNI-capacity among the tropical grasses tested (Subbarao et al. 2007). The major nitrification inhibitor in Brachiaria forage grasses is brachialactone, a cyclic diterpene (Subbarao et al. 2009). Reduction of N loss from the soil under a B. humidicola pasture has a direct and beneficial environmental effect. We hypothesize that this conservation of soil N will have an additional positive impact on a subsequent crop (e.g. maize). At present, recovery of fertilizer N and the impact on crop yield is not known. The main purpose of our inter-institutional and multi-disciplinary project, targeting small-scale farmers, is to develop the innovative approach of BNI using B. humidicola forage grass hybrids to realize sustainable economic and environmental benefits from integrated crop-livestock production systems

The voluntary intake in growing pigs of four ensiled forage species

Forage can potentially be food resource for pig feeding in the tropics. The palatability of silages by pigs may be better than that of fresh forage. Foliage silage contains more dry matter than green forage and has a pleasant smell. Thirty commercial pigs (47.0 ± 4.7 kg live weight LW), were used to assess the silage intake capacity of pigs when feeding the legumes Clitoria ternatea, Centrosema brasilianum, Cratylia argentea and the Brachiaria grass hybrid Mulato II. The silages were offered ad libitum as a supplement to a normal balanced diet based on maize and soy bean meal. A crossover design was applied comprising five treatments, Control and the four silage supplements respectively. Daily consumption of dry matter -expressed in g of DMkg-1 metabolic LW- were similar (p>0.05) for diets containing C. argentea, C. ternatea and the Control. Daily consumption of C. brasilianum and Brachiaria was significantly lower (p<0.001). In conclusion, C. argentea and C. ternatea silages have the potential to serve as feed supplement in pig diets

The voluntary intake in growing pigs of four ensiled forage species

Forage can potentially be food resource for pig feeding in the tropics. The palatability of silages by pigs may be better than that of fresh forage. Foliage silage contains more dry matter than green forage and has a pleasant smell. Thirty commercial pigs (47.0 ± 4.7 kg live weight LW), were used to assess the silage intake capacity of pigs when feeding the legumes Clitoria ternatea, Centrosema brasilianum, Cratylia argentea and the Brachiaria grass hybrid Mulato II. The silages were offered ad libitum as a supplement to a normal balanced diet based on maize and soy bean meal. A crossover design was applied comprising five treatments, Control and the four silage supplements respectively. Daily consumption of dry matter -expressed in g of DMkg-1 metabolic LW- were similar (p&gt;0.05) for diets containing C. argentea, C. ternatea and the Control. Daily consumption of C. brasilianum and Brachiaria was significantly lower (p&lt;0.001). In conclusion, C. argentea and C. ternatea silages have the potential to serve as feed supplement in pig diets

Alternative plant protein sources for pigs and chickens in the tropics – nutritional value and constraints: a review

In the tropics, a large number of smallholder farms contribute significantly to food security by raising pigs and poultry for domestic consumption and for sale on local markets. The high cost and, sometimes, the lack of availability of commercial protein supplements is one of the main limitations to efficient animal production by smallholders. Locally-grown forages and grain legumes offer ecological benefits such as nitrogen fixation, soil improvement, and erosion control which contribute to improve cropping efficiency. Besides these agronomical assets, they can be used as animal feeds in mixed farming systems. In this paper we review options to include locally-grown forages and grain legumes as alternative protein sources in the diets of pigs and poultry in order to reduce farmers’ dependence on externally-purchased protein concentrates. The potential nutritive value of a wide range of forages and grain legumes is presented and discussed. The influence of dietary fibre and plant secondary metabolites contents and their antinutritive consequences on feed intake, digestive processes and animal performances are considered according to the varying composition in those compounds of the different plant species and cultivars covered in this review. Finally, methods to overcome the antinutritive attributes of the plant secondary metabolites using heat, chemical or biological treatment are reviewed in respect with their efficiency and their suitability in low input farming systems