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This study aimed to estimate the optimum utilization of ruminant feed resources in tropical dry-land during dry and rainy seasons. Data concerning feed availability and quality were collected from Gunungkidul Regency of Indonesia over two seasons: the dry and rainy seasons. The JAVA program, the model, was used to estimate the availability of feed for ruminants associated with mean live weight gain (MLWG) and total live weight production (TLWP). The results showed that the maximum production in the dry season was obtained when 18% dry matter (DM) was used (MLWG 0.33 kg/animal unit (AU)/day, herd size (HS) 197 AU, and TLWP 11.94 tons/season), or in the rainy season, when 46% DM was used (MLWG 0.18 kg/AU/day, HS 1116 AU, and TLWP 37.22 tons/season). Furthermore, when only 100% was used, it could feed a maximum of 1500 AU and 2968 AU in the dry and rainy seasons, respectively. Without the transfer of feed from one season to another, a constant number, 350 AU, was obtained for HS, with a maximum TLWP of 19.16 tons/year. On the other hand, when the feed was kept constant at 34% dry matter (DM), a maximum TLWP obtained was 32.32 tons/year which is enough 420 and 820 animal units in the dry and rainy season, respectively. It was concluded that to obtain maximum TLWP in each season, only 14.5% to 46% of available DM feed should be used, as most of the available feed was of very low quality. [ABSTRACT FROM AUTHOR]

LiGAPS-Beef (Livestock simulator for Generic analysis of Animal Production Systems – Beef cattle) is a generic, mechanistic model designed to quantify potential and feed-limited growth, which provides insight in the biophysical scope to increase beef production (i.e. yield gap). Furthermore, it enables identification of the bio-physical factors that define and limit growth, which provides insight in management strategies to mitigate yield gaps. The aim of this paper, third in a series of three, is to evaluate the performance of LiGAPS-Beef with independent experimental data. After model calibration, independent data were used from six experiments in Australia, one in Uruguay and one in the Netherlands. Experiments represented three cattle breeds, and a wide range of climates, feeding strategies and cattle growth rates. The mean difference between simulated and measured average daily gains (ADGs) was 137 g/day across all experiments, which equals 20.1% of the measured ADGs. The root mean square error was 170 g/day, which equals 25.0% of the measured ADGs. LiGAPS-Beef successfully simulated the factors that defined and limited growth during the experiments on a daily basis (genotype, heat stress, digestion capacity, energy deficiency and protein deficiency). The simulated factors complied well to the reported occurrence of heat stress, energy deficiency and protein deficiency at specific periods during the experiments. We conclude that the level of accuracy of LiGAPS-Beef is acceptable, and provides a good basis for acquiring insight in the potential and feed-limited production of cattle in different beef production systems across the world. Furthermore, its capacity to identify factors that define or limit growth and production provides scope to use the model for yield gap analysis. [ABSTRACT FROM AUTHOR]

The model LiGAPS-Beef (Livestock simulator for Generic analysis of Animal Production Systems – Beef cattle) has been developed to assess potential and feed-limited growth and production of beef cattle in different areas of the world and to identify the processes responsible for the yield gap. Sensitivity analysis and evaluation of model results with experimental data are important steps after model development. The first aim of this paper, therefore, is to identify which parameters affect the output of LiGAPS-Beef most by conducting sensitivity analyses. The second aim is to evaluate the accuracy of the thermoregulation sub-model and the feed intake and digestion sub-model with experimental data. Sensitivity analysis was conducted using a one-at-a-time approach. The upper critical temperature (UCT) simulated with the thermoregulation sub-model was most affected by the body core temperature and parameters affecting latent heat release from the skin. The lower critical temperature (LCT) and UCT were considerably affected by weather variables, especially ambient temperature and wind speed. Sensitivity analysis for the feed intake and digestion sub-model showed that the digested protein per kg feed intake was affected to a larger extent than the metabolisable energy (ME) content. Sensitivity analysis for LiGAPS-Beef was conducted for ¾ Brahman×¼ Shorthorn cattle in Australia and Hereford cattle in Uruguay. Body core temperature, conversion of digestible energy to ME, net energy requirements for maintenance, and several parameters associated with heat release affected feed efficiency at the herd level most. Sensitivity analyses have contributed, therefore, to insight which parameters are to be investigated in more detail when applying LiGAPS-Beef. Model evaluation was conducted by comparing model simulations with independent data from experiments. Measured heat production in experiments corresponded fairly well to the heat production simulated with the thermoregulation sub-model. Measured ME contents from two data sets corresponded well to the ME contents simulated with the feed intake and digestion sub-model. The relative mean absolute errors were 9.3% and 6.4% of the measured ME contents for the two data sets. In conclusion, model evaluation indicates the thermoregulation sub-model can deal with a wide range of weather conditions, and the feed intake and digestion sub-model with a variety of feeds, which corresponds to the aim of LiGAPS-Beef to simulate cattle in different beef production systems across the world. [ABSTRACT FROM AUTHOR]

The expected increase in the global demand for livestock products calls for insight in the scope to increase actual production levels across the world. This insight can be obtained by using theoretical concepts of production ecology. These concepts distinguish three production levels for livestock: potential (i.e. theoretical maximum) production, which is defined by genotype and climate only; feed-limited production, which is limited by feed quantity and quality; and actual production. The difference between the potential or limited production and the actual production is the yield gap. The objective of this paper, the first in a series of three, is to present a mechanistic, dynamic model simulating potential and feed-limited production for beef cattle, which can be used to assess yield gaps. A novelty of this model, named LiGAPS-Beef (Livestock simulator for Generic analysis of Animal Production Systems – Beef cattle), is the identification of the defining factors (genotype and climate) and limiting factors (feed quality and available feed quantity) for cattle growth by integrating sub-models on thermoregulation, feed intake and digestion, and energy and protein utilisation. Growth of beef cattle is simulated at the animal and herd level. The model is designed to be applicable to different beef production systems across the world. Main model inputs are breed-specific parameters, daily weather data, information about housing, and data on feed quality and quantity. Main model outputs are live weight gain, feed intake and feed efficiency (FE) at the animal and herd level. Here, the model is presented, and its use is illustrated for Charolais and Brahman × Shorthorn cattle in France and Australia. Potential and feed-limited production were assessed successfully, and we show that FE of herds is highest for breeds most adapted to the local climate conditions. LiGAPS-Beef also identified the factors that define and limit growth and production of cattle. Hence, we argue the model has scope to be used as a tool for the assessment and analysis of yield gaps in beef production systems. [ABSTRACT FROM AUTHOR]

Mineral phosphorus (P) used to fertilise crops is derived from phosphate rock, which is a finite resource. Preventing and recycling mineral P waste in the food system, therefore, are essential to sustain future food security and long-term availability of mineral P. The aim of our modelling exercise was to assess the potential of preventing and recycling P waste in a food system, in order to reduce the dependency on phosphate rock. To this end, we modelled a hypothetical food system designed to produce sufficient food for a fixed population with a minimum input requirement of mineral P. This model included representative crop and animal production systems, and was parameterised using data from the Netherlands. We assumed no import or export of feed and food. We furthermore assumed small P soil losses and no net P accumulation in soils, which is typical for northwest European conditions. We first assessed the minimum P requirement in a baseline situation, that is 42% of crop waste is recycled, and humans derived 60% of their dietary protein from animals (PA). Results showed that about 60% of the P waste in this food system resulted from wasting P in human excreta. We subsequently evaluated P input for alternative situations to assess the (combined) effect of: (1) preventing waste of crop and animal products, (2) fully recycling waste of crop products, (3) fully recycling waste of animal products and (4) fully recycling human excreta and industrial processing water. Recycling of human excreta showed most potential to reduce P waste from the food system, followed by prevention and finally recycling of agricultural waste. Fully recycling P could reduce mineral P input by 90%. Finally, for each situation, we studied the impact of consumption of PA in the human diet from 0% to 80%. The optimal amount of animal protein in the diet depended on whether P waste from animal products was prevented or fully recycled: if it was, then a small amount of animal protein in the human diet resulted in the most sustainable use of P; but if it was not, then the most sustainable use of P would result from a complete absence of animal protein in the human diet. Our results apply to our hypothetical situation. The principles included in our model however, also hold for food systems with, for example, different climatic and soil conditions, farming practices, representative types of crops and animals and population densities. [ABSTRACT FROM AUTHOR]

Pastoralists have traditional ecological knowledge (TEK), which is important for their livelihoods and for policies and interventions. Pastoralism is under pressure, however, which may result in a decline of pastoral lifestyle and its related TEK. We, therefore, addressed the following objectives (i) to inventorise and assess how pastoralists characterise and value soils and forages in their environment, (ii) to analyse how soil, forage and livestock (i.e. cattle) characteristics relate to herding decisions and (iii) to determine whether TEK underlying herding decisions differs across generations. Data were collected through focus groups and individual interviews with 72 pastoralists, belonging to three generations and to three agro-ecological zones. Using a three-point scale (high, medium, low), four grasses and three tree forages were assessed in terms of nutritional quality for milk, meat, health and strength. Using their own visual criteria, pastoralists identified five different soils, which they selected for herding at different times of the year. Pastoralists stated that Pokuri was the best soil because of its low moisture content, whereas Karaal was the worst because forage hardly grows on it. They stated that perennials, such as Andropogon gayanus and Loxoderra ledermannii, were of high nutritional quality, whereas annuals such as Andropogon pseudapricus and Hyparrhenia involucrata were of low nutritional quality. Afzelia africana was perceived of high quality for milk production, whereas Khaya senegalensis had the highest quality for meat, health and strength. Pastoralists first used soil, then forage and finally livestock characteristics in their herding decisions. Pastoralists’ TEK was not associated with their generations, but with their agro-ecological zones. This study suggests that pastoralists had common and detailed TEK about soils, forages and livestock characteristics, underlying their herding decisions. To conclude, pastoralists use a holistic approach, combining soil, vegetation and livestock TEK in herding decisions. Such TEK can guide restoration or improvement of grazing lands, and land use planning. [ABSTRACT FROM PUBLISHER]

Livestock production is a major consumer of fresh water, and the influence of livestock production on global fresh water resources is increasing because of the growing demand for livestock products. Increasing water use efficiency of livestock production, therefore, can contribute to the overall water use efficiency of agriculture. Previous studies have reported significant variation in livestock water productivity (LWP) within and among farming systems. Underlying causes of this variation in LWP require further investigation. The objective of this paper was to identify the factors that explain the variation in LWP within and among farming systems in Ethiopia. We quantified LWP for various farms in mixed-crop livestock systems and explored the effect of household demographic characteristics and farm assets on LWP using ANOVA and multilevel mixed-effect linear regression. We focused on water used to cultivate feeds on privately owned agricultural lands. There was a difference in LWP among farming systems and wealth categories. Better-off households followed by medium households had the highest LWP, whereas poor households had the lowest LWP. The variation in LWP among wealth categories could be explained by the differences in the ownership of livestock and availability of family labor. Regression results showed that the age of the household head, the size of the livestock holding and availability of family labor affected LWP positively. The results suggest that water use efficiency could be improved by alleviating resource constraints such as access to farm labor and livestock assets, oxen in particular. [ABSTRACT FROM PUBLISHER]

Because of an increasing demand for animal-source foods, an increasing desire to reduce poverty and an increasing need to reduce the environmental impact of livestock production, tropical farming systems with livestock must increase their productivity. An important share of the global human and livestock populations are found within smallholder mixed-crop–livestock systems, which should, therefore, contribute significantly towards this increase in livestock production. The present paper argues that increased livestock production in smallholder mixed-crop–livestock systems faces many constraints at the level of the farm and the value chain. The present paper aims to describe and explain the impact of increased production from the farm and farmers’ perspective, in order to understand the constraints for increased livestock production. A framework is presented that links farming systems to livestock value chains. It is concluded that farming systems that pass from subsistence to commercial livestock production will: (1) shift from rural to urban markets; (2) become part of a different value chain (with lower prices, higher demands for product quality and increased competition from peri-urban producers and imports); and (3) have to face changes in within-farm mechanisms and crop–livestock relationships. A model study showed that feed limitation, which is common in tropical farming systems with livestock, implies that maximum herd output is achieved with small herd sizes, leaving low-quality feeds unutilised. Maximal herd output is not achieved at maximal individual animal output. Having more animals than required for optimal production – which is often the case as a larger herd size supports non-production functions of livestock, such as manure production, draught, traction and capital storage – goes at the expense of animal-source food output. Improving low-quality feeds by treatment allows keeping more animals while maintaining the same level of production. Ruminant methane emission per kg of milk produced is mainly determined by the level of milk production per cow. Part of the methane emissions, however, should be attributed to the non-production functions of ruminants. It was concluded that understanding the farm and farmers’ perceptions of increased production helps with the understanding of productivity increase constraints and adds information to that reported in the literature at the level of technology, markets and institutions. [ABSTRACT FROM PUBLISHER]

The article focuses on the mitigation of enteric methane emissions from ruminant animals. It reveals that inclusion of digestible and legume forage in animals' diet helps lowering of methane emissions level. It further reveals that some yeast-based products which can be directly fed to animals lower methane emission, increases animal productivity and feed efficiency.

Most citizens in modern societies have little personal knowledge or experience of animal farming. This study explores the social construction of animal farming by studying how citizens perceive and evaluate modern farming after visiting a farm in real life. We wanted to understand how (non-farming) citizens develop an opinion of modern dairy farming when experiencing dairy farming in real life and practice, and how they translate what they see, smell and feel into an evaluative perception and mental image. We therefore conducted dairy farm visits with citizen panels in Norway and the Netherlands and asked the panel members to register what they saw, heard, smelled and felt and what they appreciated (or not) on the farm. The aspects that respondents registered could be grouped into four themes: the animals and their products, the rural landscape, farm practices and the farmer. When respondents described their experiences of these aspects on a specific farm, they appeared to look at them from three angles: modernity, tradition and naturality. Most respondents wanted farms to be modern, traditional as well as natural, but they were ready to negotiate and to accept compromises. Many respondents considered the farmer to be responsible for reconciling modernity, tradition and naturality. By taking different topics and issues into account and looking at animal farms from multiple angles, the respondents' developed a balanced and nuanced opinion of animal farming. The image that they constructed was not dualistic (arcadia versus factory) but pluralistic, thus at the same time more complex but also more flexible than expected. We expect that the development of a pluralistic image and balanced opinion was facilitated through the direct experience of dairy farming and farm life. The article starts with a theoretical analysis and aims to contribute to recent debates in rural sociology in two ways: 1) it studies how material experience and mental perception interact in the construction of an evaluative image of animal farming; and 2) it explores the social construction of animal farming as embedded into to the construction of nature, rurality and human-animal relationships. It concludes by discussing the contribution of the findings to the ongoing theoretical debate in this field. [ABSTRACT FROM AUTHOR]

The effects of ammoniation of wheat straw with or without supplementation of protein sources of either high (casein) or relatively low (potato protein) rumen degradability on intake and digestion were studied with four sheep in a 4 × 4 Latin square design. Rations offered were: (1) untreated wheat straw (UWS), (2) ammoniated wheat straw (AWS), (3) AWS supplemented with 3·2 g casein/kg live weight (W)0·75 per d (AWSC) and (4) AWS supplemented with 3·9 g potato protein/kg W0·75per d (AWSP). Straw was offered ad lib. and all rations were supplemented with sugarbeet pulp and a mineral mixture. NH3 treatment increased intake and digestion. Supplementation of AWS with potato protein increased total digestible organic matter intake (DOMI) compared with AWS whereas supplementation with casein did not affect total DOMI. Protein supplementation of AWS significantly reduced rumen digestion of cellulose, and when the supplementation was with casein it reduced rumen digestion of neutral-detergent fibre and hemicellulose also. This lower rumen digestion was compensated by a higher proportion of digestion occurring in the hindgut for hemicellulose (P<0·05 for AWSC, P>0·05 for AWSP), but not for cellulose. Across all rations, rumen fluid volume increased with increasing cell-wall intake. The efficiencies of microbial protein synthesis were (average of three different methods of estimation) 23·3, 26·2, 34·8 and 31·7gN/kg apparently-rumen-degraded organic matter for UWS, AWS, AWSC and AWSP respectively. The difference between UWS and AWS was not significant, but values for AWSC and AWSP were significantly higher than that for AWS. The rumen digestion of feed aimno acid-N (AA-N) was significantly higher for AWSC than for the other rations. The apparent small-intestinal digestion of AA-N and N was significantly higher for AWSP than for the other rations. The true small-intestinal digestion values were 0·86, 0·84 and 0·68 for AA-N, N and non-protein-N respectively. Heal endogenous losses of AA-N were approximately 6 mg/g duodenal non-protein dry-matter flow. Linear relationships were observed between DOMI and N balance and truly absorbed AA-N, indicating that DOMI could have been limited by small-intestinal amino acid availability. Regression of N balance v. truly absorbed AA-N resulted in an estimate of net efficiency of utilization of truly absorbed AA-N of 0·54. [ABSTRACT FROM PUBLISHER]

Untreated wheat straw (UWS) or ammoniated wheat straw without (AWS) or with (AWSP) a supplement of potato protein of a low rumen degradability was fed to three steers according to a 3 ?? 3 Latin square design. All rations were supplemented with sugar-beet pulp and minerals. Voluntary organic matter intake (OMI, g/kg0.75 per d) was 67.8, 76.0 and 80.1 for whole rations (51.1, 59.7 and 59.2 for straw) for UWS, AWS and AWSP respectively, which was significantly higher for AWS and AWSP than for UWS. Organic matter digestibility (OMD, g/kg) was 561, 596 and 625 for the respective rations UWS, AWS and AWSP, also significantly higher for AWS and AWSP than for UWS. The increased voluntary intake and digestion of ammoniated wheat-straw-based rations were associated with a significantly higher potentially degradable fraction (D) of neutral detergent fibre (NDF) in offered straw (556 and 661 g/kg for untreated and ammoniated wheat straw respectively) and in the rumen pool (469, 555 and 554 g/kg for UWS, AWS and AWSP respectively). Isolated small rumen particles (retained on sieves with a pore size < 1.25 and > 0.041 mm) had a significantly lower D of NDF (average 588 g/kg) than isolated large rumen particles (average 663 g/kg). Fractional rates of degradation of NDF did not differ significantly either between untreated and ammonia-treated wheat straw offered (2.9 and 2.6%/h respectively) or between rumen pools (1.8, 1.7 and 2.1 %/h for UWS, AWS and AWSP respectively). Rations based on ammoniated wheat straw had a significantly higher rumen NH3-N concentration than UWS. Although the rumen pool size of total contents differed significantly between treatments, those of dry and organic matter and of cell wall constituents were not significantly different. The proportion of rumen dry matter passing through a sieve with a pore size of 1.25 mm averaged 0.684 over rations (not significantly different between rations). Daily rumination (96 min) and eating (52 min) times/kg NDF ingested did not differ between rations. The rate of comminution of large particles estimated from the disappearance of indigestible NDF in large rumen particles from the rumen of animals without access to feed was 4.1, 6.3 and 7.1 %/h for UWS, AWS and AWSP respectively. These values were not significantly different. The fractional rate of passage estimated from the faecal excretion of Cr-NDF was 5.4, 6.1 and 6.3%/h for UWS, AWS and AWSP respectively (significantly higher for AWS and AWSP than for UWS) but the turnover rate of indigestible NDF did not differ between treatments. [ABSTRACT FROM PUBLISHER]

The objective of the present study was to determine the effects of the combination of a lactoperoxidase system (LP-s) and lactoferrin (LF) added to a milk replacer diet on severity of diarrhoea, the morphology of the small intestinal mucosa, and the microbiology of digesta and faeces in young calves, in comparison with a control diet. The experiment was conducted with 30 young calves, 15 per treatment, during the period of 7–21 days of age. During this period, calves are sensitive to gastrointestinal disturbances that can cause diarrhoea. The results showed a significantly (p < 0.05) reduced severity of diarrhoea in the LP-s/LF group compared to the control group as assessed by faecal consistency scores. Numbers of CFU (colony forming units) of Escherichia coli in jejunal and colonic digesta and in faeces were lower in the LP-s/LF group compared with the control group. The differences were significant in both colonic digesta (p < 0.1) and in faeces (p < 0.05). Examination of the small intestinal mucosa, using a dissecting microscope, indicated more finger shaped villi in the distal jejunum of LP-s/LF-treated calves compared with the control group (p < 0.05). Histometrical measurements showed that these villi were significantly (p < 0.05) longer. [ABSTRACT FROM AUTHOR]