Least-cost Ration Formulation Research Articles

328 Comparison of Predicted Nutritional Requirements of Two Feeding Systems for Dairy Cattle Implemented in a Monte-Carlo Simulation Model of Herd Dynamics

Abstract There is increased interest in precision-feeding systems that account for individual-animal variation and temporal dairy herd dynamics to increase feed-efficiency and reduce environmental footprints. The Ruminant Farm Systems (RuFaS; Hansen et al., 2021) model simulates individual animals on a daily timestep using a stochastic, Monte Carlo framework to represent the phenotypic diversity and population dynamics expected in a dairy herd. Within RuFaS, individual animal nutrient requirements are used to inform pen-level diet formulations and feed delivery. However, nutritional requirements for feeding dairy cattle were recently updated via consideration of both animal and diet-related factors. Our aim was to calculate individual animal predictions for dry matter intake (DMI), as well as energy and metabolizable protein requirements, and compare the methods described in the 7th (NRC, 2001) and 8th (NASEM, 2021) editions of the Nutrient Requirements for Dairy Cattle. For that purpose, we simulated dairy herds (ca. 6,000 individual Holstein animals per simulation, mean adult body weight = 671 kg, standard deviation = 79, mean daily milk production = 39.8 kg·day-1·cow-1 , standard deviation = 7.5) for 10+ year time periods with an updated version of RuFaS. The simulated herds provided a wide range of values with which to test the nutrient requirement models, and their implications. The NASEM DMI estimates were less across the board but began to converge towards NRC calculated values at the larger simulated animal body weights. The principal differences in energy requirements between the two models (NRC vs. NASEM) were: 1) predicted requirements for pregnancy were significantly greater for NASEM than NRC across all life history stages; 2) NASEM displayed slightly greater energy requirements for growth in first and second lactation cows, and; 3) NASEM predicted decreased maintenance requirements for all heifer stages but the opposite was true for mature cows. Metabolizable protein requirements were greater following NASEM calculations in heifers over 300 kg, but strikingly similar to NRC-computed values for lactating cows. Overall, results from this modeling study align with our expectations and demonstrate successful implementation of the two nutrition models within the RuFaS model. These outputs confirm the usefulness of data obtained to explore applications of the two nutrient requirement models under different precision feeding management practices and, to some extent, to quantitatively evaluate their viability of the models in edge cases that can occur within the expected variation of a herd’s population. Future work will explore downstream consequences of the nutrient requirement models within the automated, least-cost ration formulation framework using nonlinear programming and metrics related to manure output and storage. These data will guide further developments of RuFaS as whole farm simulation model and provide insights into expected variation in nutritional requirements within a dynamic set of animals.

An Insight on Feed Formulation for Livestock

Animal diets now a days contain a wide range of plant-based materials, as well as rendered animals and animal waste, antibiotics, and vitamins. Various feed components are utilised in the meal, depending on the animal. Animals will need to be supplemented during late pregnancy, early lactation, or rapid growth to ensure that requirements are satisfied. The required nutrients by each animal differs according on body weight, milk output, milk fat, and other factors. As an outcome, the feed formulation tool can now be developed using a variety of unique ration formulation methods, such as linear programming, stochastic programming, and goal programming. Many programmes exist that create rations for various livestock species using the most cost-effective feeds available. It will also help the farmer choose feeds that fulfil the ration’s nutritional needs. ICAR-NIANP Smart Tools, Dairy cattle nutrition and feed calculator, Application for Least-Cost Ration Formulation, and Feed Chart are only a few examples.

Nutrient requirement equations for Indian goat by multiple regression analysis and least cost ration formulation using a linear and non-linear stochastic model.

An elaborate multiple regression analysis was done to arrive a nutrient requirement equation for goat including dry matter intake, DMI (kg/day), total digestible nutrient, TDN (g/day) and crude protein, CP (g/day) based on animal body weight (BW) (kg) and average daily gain (ADG)(g/day). The derived equations were highly significant (p<0.001) and had high R2 (0.99) values. The estimated values of TDN, CP and DMI are compared with NRC (1981), Kearl (Nutrient Requirements of Ruminants in Developing Countries, All Graduate Theses and Dissertations, 1982), as well as ICAR (Livestock Management, 2013). The estimated total TDN and CP requirements at different body weights and ADG are close to the values of recommended feeding standards of Mandal et al. (Small Ruminant Res., 58, 2005, 201). The estimated DMI values are close to the values of ICAR (Livestock Management, 2013) but lower (26.5%-43.8%) as compared to NRC (1981). Regressed values are used to develop a linear programming (LP) model and a stochastic model (SM) for least-cost ration formulation for the Indian goat breed, whose average BW is about 45kg and ADG is 130 (g/day), and which is solved using LP simplex and Generalised Reduced Gradient (GRG) nonlinear of Microsoft Excel. The models satisfy the nutrient requirement calculated by regression equations with minimum specified level of variation (usually 5%-10%) in CP and TDN. Both methods adequately meet the nutritional requirements. Therefore, an electronic sheet is developed in Excel to calculate DMI, TDN and CP for different body weights, ADG and formulate the ration by LP and stochastic model.

Performance and income over feed costs when feeding alfalfa or grass hays and corn or wheat grains to high-producing dairy cows

The objective of this study was to evaluate the production performance, nutrient digestibility, and income over feed cost (IOFC) of high-producing dairy cows consuming diets containing alfalfa or grass hays with either corn or wheat grain. Twenty-four Holstein cows were randomly assigned to 1 of 4 diets in a replicated 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments (hay and grain types) and 21-d periods. Diets were formulated using a least-cost approach. To determine revenues from milk produced, the amount of ECM (kg·d −1 ) was multiplied by $0.303·kg −1 (i.e., class III milk price; US Federal Milk Marketing Order 5). The cost of the ration provided by the formulation software ($·cow −1 ·d −1 ) was divided by the predicted DMI (kg·cow −1 ·d −1 ) to obtain the cost of feed ($·kg −1 ), which was then multiplied by DMI (kg·cow −1 ·d −1 ) to provide the actual daily feed cost ($·cow −1 ·d −1 ). Cows consuming diets containing alfalfa hay consumed more DM than cows consuming diets with grass hay (27.1 vs. 24.4 kg·d −1 ). Cows consuming diets containing alfalfa hay produced more milk than cows consuming diets containing grass hay (47.5 vs. 44.7 kg·d −1 ). Milk from cows consuming diets containing grass hay had greater fat concentrations than milk from cows consuming diets containing alfalfa hay (4.22 vs. 3.89%). Using hay prices of $418 and $154∙t −1 , respectively, for alfalfa and grass hays, diets containing grass hay resulted in greater IOFC than diets containing alfalfa hay ($8.39·d −1 vs. $7.68·d −1 , respectively). Results of this study showed that IOFC can be supported when feeding grass hay using a least-cost ration formulation approach.

Nitrous oxide, ammonia and methane from Australian meat chicken houses measured under commercial operating conditions and with mitigation strategies applied

Greenhouse gas (GHG) and ammonia emissions are important environmental impacts from meat chicken houses. This study measured ammonia (NH3), nitrous oxide (N2O) and methane (CH4) in two trials from paired, commercial meat chicken houses using standard (control) and mitigation strategies. In Trial 1, emissions from houses with standard litter depth of 47 mm (LD47) or increased litter depth of 67 mm (LD67) were compared. When standardised to a 42-day-old bird, emissions were 11.9 g NH3/bird, 0.30 g N2O/bird and 0.16 g CH4/bird from the LD47 and 11.7 g NH3/bird, 0.69 g N2O/bird and 0.12 g CH4/bird from the LD67. Emissions per kilogram of manure N were 0.14 and 0.11 for NH3-N, 0.003 and 0.005 N2O-N and CH4 conversion factors were 0.08% and 0.05%. Total direct and indirect GHG emissions reported in carbon dioxide equivalents were found to be higher in LD67 in response to the elevated direct N2O emissions. Trial 2 compared the impact of reduced crude protein (CP19.8) and a standard diet (CP21.3) developed using least-cost ration formulation, on emissions. Emissions per bird for the CP19.8 diet were 7.7 g NH3/bird, 0.39 g N2O/bird and 0.14 g CH4/bird, while emissions from birds fed the CP21.3 diet were 10.6 g NH3/bird, 0.42 g N2O/bird and 0.19 g CH4/bird. Significant differences were observed only in the NH3 results, where emissions were reduced by 27% for the low-CP diet. Because of the low emission levels, total mitigation potential from indirect GHG emissions was relatively small in Trial 2, corresponding to 11 t carbon dioxide equivalents/year per million birds.

Synchronous Least-Cost Ration Formulation for Lactating Barki Ewes using Nonlinear Programming

Least-cost procedures do not always produce the most practical rations for ruminants. The aim of this work was to incorporate the concept of synchronizing ruminal energy and protein digestion in the traditional leastcost procedure, in order to produce more appropriate and practical rations for lactating Barki ewes. The degree of dietary nutrient synchrony is measured using the synchrony index (SI) reported by Sinclair et al., (1993). In a preliminary study, degradation kinetics of seven commonly used feedstuffs were estimated using nylon bag technique. The observed patterns of crude protein (CP) and organic matter (OM) degradability of feedstuffs were largely varied and greatly depend on the rumen outflow rate (fraction/h). We developed a new userfriendly software application ‘Lacto-sheep’ based on the C# language and the. NET Framework 4.0 to facilitate the processes of ration formulation. Simplex and Hybrid local search solvers in Microsoft Solver Foundation 3.1 have been used to solve both linear and nonlinear programming models, respectively. Example synchronous least-cost ration (SLCR) and least-cost ration (LCR) formulations of 35.46 kg (body weight) lactating ewe based on the NRC recommendation is presented. SLCR and LCR showed two different patterns of N/OM release within a day. The calculated SI was about 0.87 and 0.60, respectively. As cost is often a limiting factor in the traditional least cost ration formulation therefore, LCR did not contain any source of protein-rich sources. We conclude this synchronous least-cost procedure is more appropriate to produce practical rations.

Escherichia coli O157:H7 populations in ruminants can be reduced by orange peel product feeding.

Foodborne pathogenic bacteria such as Escherichia coli O157:H7 are threats to the safety of beef. Citrus peel and dried orange pulp are by-products from citrus juice production that have natural antimicrobial effects and are often incorporated into least-cost ration formulations for beef and dairy cattle. This study was designed to determine if orange peel and pulp affected E. coli O157:H7 populations in vivo. Sheep (n = 24) were fed a cracked corn grain-based diet that was supplemented with a 50-50 mixture of dried orange pellet and fresh orange peel to achieve a final concentration (dry matter basis, wt/wt) of 0, 5, or 10% pelleted orange peel (OP) for 10 days. Sheep were artificially inoculated with 10(10) CFU of E. coli O157:H7 by oral dosing. Fecal shedding of E. coli O157:H7 was measured daily for 5 days after inoculation, after which all animals were humanely euthanized. At 96 h postinoculation, E. coli O157:H7 shedding was reduced (P < 0.05) in sheep fed 10% OP. Populations of inoculated E. coli O157:H7 were reduced by OP treatment throughout the gastrointestinal tract; however, this reduction reached significant levels in the rumen (P < 0.05) of sheep fed 10% OP diets. Cecal and rectal populations of E. coli O157:H7 were reduced (P < 0.05) by inclusion of both 5 and 10% OP diets. Our results demonstrate that orange peel products can be used as a preharvest intervention strategy as part of an integrated pathogen reduction scheme.

Application of Linear Programming Technique in Least-cost Ration Formulation for African Catfish (Clarias gariepinus) in Semi-intensive Culture System in Nigeria

Application of Linear Programming Technique in Least-cost Ration Formulation for African Catfish (Clarias gariepinus) in Semi-intensive Culture System in Nigeria

Nutritional Evaluation of Some Locally Available Ingredients use for Least-cost Ration Formulation for African Catfish (Clarias gariepinus) in Nigeria

Nutritional Evaluation of Some Locally Available Ingredients use for Least-cost Ration Formulation for African Catfish (Clarias gariepinus) in Nigeria

Dairy farm nutrient management model: 2. Evaluation of different strategies to mitigate phosphorus surplus

To reduce (P) surpluses on dairy farms and thereby the risk of P losses to natural waters we studied different management alternatives by a nutrient balance model described in the companion paper. The strategies evaluated mitigating the P surpluses were: mineral P fertilisation, dietary mineral P supplementation, replacement rate, animal density, production level, feeding intensity, dietary P concentration and nutrient efficiency in crop production. Responses to several interventions (e.g. mineral P fertilisation, purchased feed P, replacement rate) were similar to those observed in Finnish field studies. Reducing or completely giving up the use of purchased mineral P fertilisers was the most efficient measure to reduce P surplus. The slope between the amount of mineral fertilisers and P surplus was 0.98–0.99 (in the field data 1.0). Increased animal density resulted in a greater P surplus, but the slope between P input from purchased feed and surplus was considerably smaller (0.65) than that of P fertilisation. Increasing milk yield with improved genetic potential of the cows would have minimal effects on P surplus per unit of product, but it would increase P surplus per hectare. When the intensity of energy and protein feeding was increased, P surplus rose markedly both per unit of product and hectare. This is (1) due to increased dietary P concentration and (2) due to smaller marginal production responses than those calculated from feeding standards. Reducing dietary P concentration by constraining P excess per kg milk in least-cost ration formulation improved P efficiency in milk production and dairy farming system. However, feed cost increased as low P energy (sugar-beet pulp) and protein (soybean meal) supplements are more expensive than cereal grains or rapeseed feeds. Improving the nutrient use efficiency in crop production had a strong influence in the whole-farm efficiency and P surplus. The modelling results showed that Finnish dairy farms have a great potential to improve P efficiency and reduce P losses to the environment, even by increasing production intensity (milk/ha). It is concluded that the most cost-effective scenario to mitigate P surpluses at a dairy farm would be to reduce or give up the use of mineral P as fertilisers and supplements, and to improve the use of present soil P reserves.

Multi-step beef ration optimisation: application of linear and weighted goal programming with a penalty function

The aim of this paper is to present the method and tool for optimisation of beef-fattening diets. Changes in policy environment and changes in costs of feed pose challenges for farm efficiency. We construct a spreadsheet from two modules based on mathematical deterministic programming techniques. In order to obtain an estimate of the magnitude of costs that may be incurred, the first module utilizes a linear program for least-cost ration formulation. The resulting value is then targeted as a cost goal in the second module. This is supported by weighted goal programming with a penalty function system. The approach presented here is an example of how a combination of mathematical programming techniques might be applied to prepare a user-friendly tool for ‘optimal’ ration formulations. We report results that confirm this approach as useful, since one is able to formulate a least-cost ration without risking a decrease in the ration’s nutritive value or affecting the balance between nutrients.;

Incorporating Environmentally Compliant Manure Nutrient Disposal Costs into Least-Cost Livestock Ration Formulation

Livestock rations are formulated to minimize feed cost subject to nutritional requirements for a target performance level, which ignores the potentially substantial cost of disposing of nutrients fed in excess of nutritional requirements. We incorporate nutrient disposal costs into a modified least-cost ration formulation model to arrive at a joint least-cost decision that minimizes the sum of feed and net nutrient disposal costs. The method is demonstrated with phosphorus disposal costs on a representative dairy farm. Herd size, land availability and proximity, crop rotation, and initial soil phosphorus content are shown to be important in determining phosphorus disposal costs.

Incorporating Environmentally Compliant Manure Nutrient Disposal Costs into Least-Cost Livestock Ration Formulation

Livestock rations are formulated to minimize feed cost subject to nutritional requirements for a target performance level, which ignores the potentially substantial cost of disposing of nutrients fed in excess of nutritional requirements. We incorporate nutrient disposal costs into a modified least-cost ration formulation model to arrive at a joint least-cost decision that minimizes the sum of feed and net nutrient disposal costs. The method is demonstrated with phosphorus disposal costs on a representative dairy farm. Herd size, land availability and proximity, crop rotation, and initial soil phosphorus content are shown to be important in determining phosphorus disposal costs.

Linear Programming Approach to Least-cost Ration Formulation for Poults

Linear Programming Approach to Least-cost Ration Formulation for Poults

Linear Programming Application to Utilization of Duckweed (Lemna paucicostata) in Least-cost Ration Formulation for Broiler Finisher

Linear Programming Application to Utilization of Duckweed (Lemna paucicostata) in Least-cost Ration Formulation for Broiler Finisher

Effects of Phytase Supplementation of Diets with Two Tiers of Nutrient Specifications on Growth Performance and Protein Efficiency Ratios of Broiler Chickens

In two feeding experiments male and mixed-sex broiler chicks were offered diets based on sorghum and a wheat-sorghum blend with two tiers of nutrient specifications, without and with microbial phytase (600 and 800 FTU/kg), from 7-25 and 1-42 days post-hatch, respectively. The nutrient specifications for protein, amino acids, energy density and phosphorus (P) of standard diets were reduced to formulate the modified diets on a least-cost basis. Calculated differences in nutrient specifications between standard and modified diets ranged from 14.3 to 17.1 g/kg crude protein, 0.24 to 0.40 MJ/kg apparent metabolisable energy (AME) and 1.06 to 1.20 g/kg available P. In both experiments, reduced nutrient specifications had a negative impact on growth rates and feed efficiency and phytase supplementation had a positive influence on growth performance and protein efficiency ratios (PER). Phytase addition to the less expensive, modified diets either partially or entirely compensated for reduced growth performance and, consequently, feed costs per kg of live weight gain were reduced. In Experiment 1, phytase increased (p<0.001) nitrogen-corrected AME (AMEn) from 15.39 to 15.89 MJ/kg dry matter. For nitrogen (N) retention there was an interaction (p<0.05) between diet type and phytase as the effects of phytase on N retention were more pronounced in the modified diets, with an increase from 0.512 to 0.561. These results demonstrate the positive effects of phytase on protein and energy utilisation, in addition to its established liberation of phytate-bound P and illustrate the feasibility of assigning nutrient replacement values to the feed enzyme for consideration in least-cost ration formulations. Further work is, however, required to define the most appropriate reductions in nutrient specifications in association with phytase supplementation.

Least-Cost Ration Formulations for Holstein Dairy Heifers By Using Linear and Stochastic Programming

Four mathematical programming models were developed to formulate rations for large breed replacement dairy heifers in each of 11 different weight classes from 50 to 550kg and daily growth rates of 600, 700, and 800g, with the objective of achieving a final calving weight of 600kg. First, a base linear programming model was developed; then, to account for variability in the crude protein content of ration ingredients three other methods were used: right-hand side adjustment, incorporation of a safety margin, and stochastic programming. The average daily cost to calving, given a daily gain of 600, 700, and 800g, was $0.62, $0.64, and $0.68, respectively. The total feed cost to 600kg was $89.87 more for a growth rate of 600 over 800 g/d. The stochastic programming model performed better, on the bases of cost and protein-feeding, than did the right-hand side adjustment or the safety margin methods. The stochastic programming model over-adjusted crude protein by 5% and cost an average of 3.5% more than the linear programming solution for a dairy heifer growing at 800 g/d with a desired probability of 80% of crude protein intake achieving the NRC minimum. The other two methods over-adjusted crude protein by 10 and 13% and cost an extra 5.5 and 7.6%, respectively, for the right-hand side adjustment and the safety margin methods.

Feeding urea ammonia treated rice straw in the tropics. II. Assumptions on nutritive value and their validity for least cost ration formulation

Field application of new feeding methods, such as urea ammonia treatment of straws requires an ex-ante assessment of their economic feasibility. Animal experiments are expensive for such an analysis, therefore cheaper and quicker methods are required. One such method is least cost ration formulation (LCRF), which extrapolates from a restricted number of feeding trials to a large number of feed combinations. The assumptions underlying LCRF can, however, be challenged and this paper discusses their validity in nutritional terms. The first part reviews literature on nutritive quality of rice straw, in relation to nutrient requirements and animal performance on rice straw based diets. The second part calculates the expected performances ( P calc) on straw based rations, using measured dry matter intake (DMI) and estimated total digestible nitrogen (TDN) and crude protein (CP) values. It then compares P calc with real performance ( P real) as found in the literature. Most dose response trials indicate a rather linear response to supplementation, with exceptions particularly at low levels of supplementation. The pooled values of P calc relate linearly with P real in several feeding trials. The P calc only comes close to P real when calculated on a TDN basis, when energy requirements for liveweight gain of light tropical animals are taken to be higher than those of NRC and when digestibility of energy in straws is assumed to be low. This suggests a low utilisation of digestible energy from either treated or untreated straw for reasons that cannot easily be established. Total CP supply cannot be limiting because the P calc on the basis of CP also considerably overestimates P real. The available literature values do not allow specification of CP into fractions according to rumen degradability. At production levels around maintenance, the correlation between P real and P calc decreases, possibly because at those levels the variability of maintenance requirements exerts a bigger effect on the total performance. Also, at those levels, straw constitutes a larger part of the ration, and associative effects are more likely. The sparse literature values for milk production also indicate differences between P real and P calc. The conclusions are that, in the absence of better methods, LCRF can be useful for ranking purposes but absolute values need to be interpreted with care, and P calc tends to overestimate P real. Future performance trials should measure digestible organic matter intake, substitution rates and maintenance requirements by dose response curves in order to improve their predictive value, and to allow interpretation of differences between P real and P calc. Differences between P real and P calc can then be investigated and weighed against accuracy and cost of performance trials.

Factors affecting the nutritional value of canola meal: A review

In this review canola meal (CM), its nutritionally significant components and the availability of its nutrients to poultry, pigs and cattle were discussed. Avenues for possible improvement in available energy, protein and lysine were identified. Recent findings on glucosinolates were also discussed with the conclusion that a further reduction of glucosinolates through plant breeding is both possible and desirable. The role of the anti-nutrients sinapine, tannins and phytic acid were also considered. The potential impact of improvements to CM on its economic value was examined using linear program least-cost ration formulations applied to typical market situations. Key words: Canola meal, energy, protein, carbohydrates, anti-nutritional factors, economics

Feeding of urea treated straw in the tropics. I. A review of its technical principles and economics

Urea treatment is a method in which straw is treated by ammonia released from urea. The process is similar to ammonia treatment, and it is a technically feasible method to improve the nutritive value of straw. Application in the field depends on economic and practical considerations. Local prices of feed and produce as well as type and level of animal production determine whether there is any economic advantage in feeding treated (TS) over untreated straw (US). Two approaches are used to assess the economics of straw treatment: (a) comparison of the cost of a unit of energy (TDN) and crude protein (CP); (b) the use of least cost ration formulation (LCRF). The first approach is convenient but can be misleading because of its simplifications. The use of LCRF with linear programming can account for more factors, such as dry matter intake limitations. The calculations show that straw treatment is economically attractive (a) when treated straw is cheap compared with other supplements for cows of medium production, and (b) when animal products can be sold at a remunerative price. Secondary effects of treatment on health, calf rearing or composition of produce are reviewed and no negative effects are known. Aspects of ammonia economy and savings of concentrate as well as the use of straw for other purposes are discussed. The emphasis of this article is on urea treatment of rice straw for the tropical smallholder's farming system, especially in south and southeast Asia, with reference to work elsewhere.