Evaluating the Protein Value of Fresh Tropical Forage Grasses and Forage Legumes Using In Vitro and Chemical Fractionation Methods

Simple Summary Various methods for estimating post-ruminal crude protein supply have been developed for temperate ruminant feedstuffs. However, their adequacy (i.e., accuracy and precision) to predict the post-ruminal crude protein supply of tropical forages is still questioned. Therefore, the objectives of the present study were: (1) to assess the adequacy of the in vitro and chemical methods to predict post-ruminal crude protein supply from fresh tropical forage, and (2) to identify nutritional composition variables that can predict post-ruminal crude protein supply. The in vitro method can estimate post-ruminal protein supply in tropical forages with moderate to high but not very slow passage rates. Available regression equations developed for temperate ruminant feedstuffs were not adequate enough to predict the post-ruminal protein supply of tropical forages. Instead, equations developed in the present study appear to predict the post-ruminal protein supply of tropical forages with reasonable adequacy. Abstract The objectives of the present study were (1) to assess the adequacy of the in vitro and chemical methods to predict post-ruminal crude protein supply (PRCP) from fresh tropical forage, and (2) to identify PRCP supply predictors. Twenty-three fresh forage grasses and 15 forage legumes commonly used in domestic cattle feeding in the tropics and subtropics were incubated in the rumen of cows to determine ruminal crude protein (CP) degradation. The PRCP supply was calculated from in situ rumen-undegraded CP and in vitro organic matter digestibility (i.e., reference method), from ammonia-nitrogen release during in vitro incubation (i.e., in vitro method), and from the concentrations of chemical CP fractions (i.e., chemical method). The adequacy was evaluated using error-index and dimensionless parameters, and stepwise regression was used to select PRCP predictors. Adequacy ranged from poor to moderate (0.53 to 0.74) for the in vitro method being lower for forage legumes at a slow rumen passage rate (0.20), and even poorer (0.02 to 0.13) for the chemical method. Hence, the in vitro method can estimate PRCP supply in tropical forages with moderate to high but not with slow passage rates. Equations developed in the present study appear to predict PRCP supply with reasonable adequacy

Evaluation of a Binary Classification Approach to Detect Herbage Scarcity Based on Behavioral Responses of Grazing Dairy Cows

In precision grazing, pasture allocation decisions are made continuously to ensure demand-based feed allowance and efficient grassland utilization. The aim of this study was to evaluate existing prediction models that determine feed scarcity based on changes in dairy cow behavior. During a practice-oriented experiment, two groups of 10 cows each grazed separate paddocks in half-days in six six-day grazing cycles. The allocated grazing areas provided 20% less feed than the total dry matter requirement of the animals for each entire grazing cycle. All cows were equipped with noseband sensors and pedometers to record their head, jaw, and leg activity. Eight behavioral variables were used to classify herbage sufficiency or scarcity using a generalized linear model and a random forest model. Both predictions were compared to two individual-animal and day-specific reference indicators for feed scarcity: reduced milk yields and rumen fill scores that undercut normal variation. The predictive performance of the models was low. The two behavioral variables “daily rumination chews” and “bite frequency” were confirmed as suitable predictors, the latter being particularly sensitive when new feed allocation is present in the grazing set-up within 24 h. Important aspects were identified to be considered if the modeling approach is to be followed up.Peer Reviewe

What is needed for reducing the greenhouse gas footprint?

Livestock production is responsible for a large amount of greenhouse gas (GHG) emissions. However, numerous approaches have been developed to reduce these emissions and thus lower environmental pollution caused by livestock husbandry. This article shows where interventions are possible and which hurdles have to be cleared in implementing the various measures needed

Digestibility and metabolizable energy of selected tropical feedstuffs estimated by in vitro and prediction equations

In vivo determination of digestible organic matter (dOM) and metabolisable energy (ME) concentrations of feeds is laborious and expensive, whereas analysis of their nutrient contents is routinely performed. Prediction equations based on the chemical composition of feeds can be a compromise. This study compared dOM and ME estimates of tropical feeds derived from selected equations (Yan and Agnew, 2004; Stergiadis et al., 2015a; Stergiadis et al., 2015b; AFRC, 1993) with those determined by the in vitro gas production method (Menke and Steingass, 1988). Samples of supplement feedstuffs (n = 12) and the herbaceous and ligneous vegetation on native pastures (n = 12) were collected in Lower Nyando, Kenya, over two seasons of one year. Samples were analysed for dry matter (DM; in % of fresh matter), crude ash, crude protein, ether extract, neutral and acid detergent fiber (NDF, ADF) (all in % of DM). Gross energy was determined by calorimetry. Nutrient concentrations varied across all samples with 8.5 – 87.9% DM, 5.2 – 16.8% crude ash, 36.7 – 74.1% NDF, 25.5 – 39.4% ADF, 3.2 – 14.2% crude protein, and 0.6 – 4.5% ether extract. The gross energy, in vitro dOM, and ME concentrations were 14.5 – 18.8 MJ/kg DM, 26.3 – 54.5%, and 3.8 – 8.4 MJ/kg DM, respectively. Compared with the in vitro method, all nutrient-based equations overestimated dOM (P 0.5). Nutrient-based equations do not sufficiently account for differences in nutrient availability, an aspect better simulated in vitro. Further development and/or validation of nutrient-based equations might be needed to more accurately predict dOM and ME of tropical feeds. AFRC. 1993. Wallingford: CAB International. Stergiadis et al. 2015a. J Dairy Sci, 98(5), 3257–3273 Stergiadis et al 2015b. Brit J Nutr, 113(10), 1571–1584. Yan and Agnew. 2004. J Anim Sci., 82, 1367–1379

„Abends wie ein Bettler“ gilt nicht für Kühe

Forscherinnen und Forscher haben sich gefragt: Wann und wie lange sollten Kühe auf der Weide sein, damit der Aufwuchs optimal ausgenutzt wird. Kauschlagsensoren und GPS-Daten lieferten erste Antworten: Vor allem abends fressen die Tiere besonders viel und lange

Mahepiimaveiste karjatamine Baden-Württembergi liidumaa erinevates kohtades: praktilise uurimisprojekti tulemused ja soovitused

Karjatamine on mahepiimafarmides muutumas üha olulisemaks – isegi nendes farmides, kus esmapilgul ideaalsed karjatamistingimused puuduvad. Näiteks väga kuivadel aastatel, nagu seda oli 2018. aasta, kui karjatamisperioodi ajal on pidevalt kuumad ilmad ja sademete hulk väike, siis on ka rohumaade saagikus väga madal. Uuringud on aga näidanud, et ka sellistes tingimustes on karjatamisel oma potentsiaal, mida ei tohiks alahinnata. Viimast püütaksegi antud teabelehe kaudu selgitada

Bio-Milchviehweidehaltung auf unterschiedlichen Standorten in Baden-Württemberg: Ergebnisse und Handlungsempfehlungen aus einem Praxisforschungsprojekt

Pasture grazing is gaining in importance for organic dairy farms - even for farms that do not offer ideal conditions at first glance. For example, in very dry years like 2018, which was characterised by little precipitation during the grazing season combined with heat and the associated low forage yields. However, studies have shown that these locations also have a potential that should not be underestimated, which is to be demonstrated with the help of this fact sheet

Bio-Milchviehweidehaltung auf unterschiedlichen Standorten in Baden-Württemberg: Mit Zufütterung die Weidenutzung gezielt optimieren

GrazyDaiSy is a European participatory research project involving eight partner countries. In Germany, it was carried out by the University of Hohenheim and the organic farming associations Bioland and Demeter. The aim was to research regionally adapted systems for pasture-based organic dairy farming. In the other countries, research was also carried out on the topics of animal health and cow-calf contact system

On-farm examination of sainfoin supplementation effects in dairy cows in a roughage-based feeding system: Indicators of protein utilisation

A case study was conducted with the objective to determine the effects of the tanniferous legume sainfoin (Onobrychis viciifolia) on protein utilisation of dairy cows, which were exposed to excessive dietary crude protein during autumn pasture grazing in a zero-concentrate feeding system. The study was conducted under practical conditions, deliberately accepting a certain lack of controllable variables. In order to assess a system applicable in practice, relatively small amounts of sainfoin were offered, and graded supply levels were compared by varying the duration of offer instead of dietary concentration. Within one dairy herd of 60 Swiss Fleckvieh cows, 30 individuals were chosen and randomly allocated to three groups balanced for milk yield, milk urea concentration, days in milk and parity. Over a period of 5 weeks, 2 kg per cow and day of sainfoin pellets were provided either intermittently, for 2 × 5 days (SST) in weeks 3 and 5 of the experiment or continuously over 35 days (SLT). A control group (CON) received 2 kg per cow and day of ryegrass pellets during the 5 weeks. The entire herd grazed on a protein-rich natural sward and was kept overnight in an open-space barn receiving fresh grass and hay ad libitum. Experimental pellets were offered individually twice per day in buckets. Feed, milk, faeces and urine samples were collected in weeks 0 (baseline), 3 and 5. Milk was analysed for fat, protein and urea, urine for purine derivatives, creatinine and nitrogen, and faeces for protein, fibre and particle fractions. During three sampling weeks, chewing activity was recorded by sensor halters. Treatment SST increased rumination time in the first half of the day, which was the only treatment effect on intake and rumination behaviour. Milk fat and protein yields were greater in SST compared to CON, but no treatment effect on concentration and yield of milk urea was found. The proportion of particle fractions in faeces was smaller in both sainfoin treatments compared to CON. In urine, the ratio of purine derivatives to creatinine tended to be higher in SST than in CON, and total urinary nitrogen excretion was lower, indicating a slightly better protein efficiency in SST. In summary, the study revealed small positive effects on protein metabolism and yield when sainfoin was applied short-term over two short periods, whereas long-term application had no effect