A method of economic comparisons for aquaculture diet development

A feeding trial was conducted for 28 d to evaluate the effects of feeding albino rats with processed Senna obtusifolia leaf meal (SOLM) based diets. Five experimental diets were compounded to contain 0% and 20% each of the sun-dried, boiled, fresh fermented, boiled fermented SOLM-based diets designated as T1, T2, T3, T4, and T5, respectively. A total of 90 young albino rats with initial weight of 13.52–14.48 g were randomly allocated to the dietary treatments in a completely randomized design with three replicates of six rats each. The result of the productive performance was not significantly (P > 0.05) different, except feed intake, which indicated significant (P < 0.05) variation. The highest total feed intake (365.40 g) was recorded in albino rats fed the control diet (0% SOLM) and 20% boiled and fermented SOLM (334.32 g). The overall weight gain among the albino rats fed the processed SOLM-based diets were not significantly (P > 0.05) different. Results on cost benefits revealed a reduction in feed cost per kilogram, cost of feed intake, and feed cost per kilogram body weight gain recorded in SOLM-based diets (T2–T5). Feed cost per kilogram was observed to reduce by 21.86, 20.79, 21.80, and 18.79 in T2–T5, respectively. It was concluded that the processed SOLM-based diets had enhanced the productive performance of albino rats. However, albino rats fed the boiled and fermented SOLM-based diet indicated better feed intake compared with the other groups of rats fed the other processed SOLM-based diets. On economic grounds, the use of processed SOLM as a feed ingredient for albino rats is cost effective because of the reduction in feed cost per kilogram of the SOLM-based diets and feed cost per kilogram body weight gain observed in albino rats fed SOLM-based diets and is, therefore, recommended for feeding albino rats.

A five-week study was conducted to determine the effect of feed type on performance of pullet chicks in Nsukka Local Government Area of Enugu State, Nigeria. One hundred and twenty 4-week old pullet chicks (ISA Brown strain) averaging 100.03g body weight were randomly divided into 4 groups of 30 birds each. Each group was randomly assigned to one of four experimental diets (self-compounded starter diet (C) and three commercial starter diets-A, B and D, respectively), using a completely randomized design (CRD). Each diet constituted a treatment. Each treatment was replicated 2 times with 15 birds per replicate. Feed and water were supplied ad libitum. There were significant (P&lt;0.05) differences among treatments in average daily weight gain, average daily feed intake, feed conversion ratio, protein intake, protein efficiency ratio and final body weight. Birds on treatment C (self-compounded feed) had significantly (P&lt;0.05) higher final body weight and average daily weight gain than those on treatments A, B and D (commercial feeds), while birds on treatment A had significantly (P&lt;0.05) higher average daily feed intake than birds on other treatments. Birds on treatment C had the least FCR value and higher (P&lt;0.05) protein efficiency ratio (PER) value. Birds on treatment C had the least (P&lt;0.05) cost of daily feed intake and total feed intake and cost of feed per kg weight gain. It was concluded that diet C (self-compounded feed) was superior to the commercial feeds because it supported the highest growth rate of chicks and its use resulted in drastic reduction in feed cost per kg weight gain.Keywords: Feed type, growth performance, pullet chicks, Nsukka Local Government Area, Enugu State, Nigeria

The research aimed to examine the effectiveness of using fermented water-soluble lipid complex (ELC – essential lipid complex) in the amount of 0.4–1.0 % instead of soybean oil in the amount of 0.5–0.6 % on the growth and development of replacement young laying hens of the Loman LSL-classic cross. The studies were conducted in the conditions of the farm (FG) “Zahid-Ptytsia”. The control and experimental groups received balanced crude protein, metabolizable energy, amino acids, minerals, and vitamins. The control group received 0.6 % soybean oil from one day to 27 days and 0.5 % from 28 to 56 days. Experimental groups II, III, and IV received 0.5–0.4 %, 0.7–0.6 %, and 1.0–0.9 %, respectively. As a result of the research, it was found that adding a fermented water-soluble lipid complex had a positive effect on the growth and development of replacement young laying hens. In particular, the live weight at 112 days of age was within the recommended standard but was highest in the control group. However, all experimental groups had an advantage in developing reproductive organs. Ovarian weight was greater by 4.19, 11.24, and 5.14 % in groups II, III, and IV, respectively. The oviduct length was higher by 6.24, 14.20, and 4.31 %, respectively, in groups II, III, and IV. In terms of the development of secondary sexual characteristics, particularly the height of the comb, 112-day-old chickens of groups III and IV had an advantage by 2.94 %. Regarding the number of flight feathers, group III had an advantage of 4.88 %. An essential element of the technology of raising chickens is the cost of feed, which is about 70 % of the cost structure. In the II experimental group, feed costs were lower by 6.56 %, III by 8.92 %, and IV by 14.24 %. During the growing period, the cost of compound feed for growing one head decreased by 113.44 grams or 14.20 %. An essential element of the technology of raising chickens is the cost of feed, which is about 70 % of the cost structure. Feed consumption in the II experimental group was lower by 6.56 %, in the III – by 8.92 %, and in the IV – by 14.24 %. During the growing period, the cost of compound feed for growing one head decreased by 96–170 g or 1,81–3,20 %. If feed costs account for 70 % of the cost structure, then the cost of rearing was reduced due to the reduction in feed costs. The rearing efficiency will ultimately be known from the egg production results.

Development of efficient cost‐effective diets is a critical component in the refinement of production technologies for the largemouth bass, Micropterus salmoides (LMB). One of the first steps in reducing feed costs can be to decrease the amount of fish meal in the diet. The objective of this study was to evaluate reduced levels of fish meal, and a least‐cost formulation diet, for second year growout of LMB under practical pond conditions. Twelve 0.04‐ha ponds were stocked with juvenile LMB (210.1±3.3 g) at a stocking density of 8650 fish/ha (350 fish/pond). Each pond was randomly assigned one of the four dietary treatments with three replicate ponds per treatment. The three experimental diets contained varying levels of fish meal. Diets FM‐45, FM‐24, and FM‐8 contained 45, 23.5, and 8% fish meal, respectively. In diets FM‐24 and FM‐8, fish meal was replaced by varying levels of poultry by‐product meal, soybean meal, and blood meal. The fourth diet was a commercial salmonid diet widely used as a LMB growout feed (Nelson and Sons, Inc., SilvercupTM, Steelhead, Murray, UT, USA). This diet served as a commercial control (CC) and contained 46% crude protein. The experimental diets were formulated to be isonitrogenous and isocaloric with the CC diet and were fed once daily to apparent satiation for 180 d. At harvest, there were no significant differences between treatments (P &gt; 0.05) in terms of survival, which averaged 95% overall. Mean weights of fish fed the three experimental diets FM‐45, FM‐24 and FM‐8 were not significantly different (P &gt; 0.05) and averaged 518, 546, and 529 g, respectively, but were all significantly greater (P≤ 0.05) than those fed the CC (488 g). Feed conversion ratio (FCR) of fish fed the FM‐45 and FM‐8 diets (1.43 and 1.46, respectively) was significantly greater (P≤ 0.05) than those fed the FM‐24 diet (1.34). The FCR of fish fed the CC diet (1.39) was not significantly different (P &gt; 0.05) from fish fed other diets. Feed cost per unit of weight gain ($US/kg) was significantly lower (P≤ 0.05) in fish fed the FM‐24 and FM‐8 diets ($0.73 and $0.72/kg, respectively) than in fish fed other diets. Feed cost per unit gain of fish fed the FM‐45 diet ($0.83/kg) was significantly lower (P≤ 0.05) than those fed the CC diet ($1.04/kg). There were no significant differences (P &gt; 0.05) in dress‐out percentages or proximate composition among fish fed the four diets. This study indicates that fish meal levels in feeds used for the second year growout of LMB can be reduced to≥8% of the formulation without reducing survival or growth and without negatively impacting body composition.

Nile tilapia, Oreochromis niloticus (4.12 ± 0.05 g initial weight), and red seaweed, Gracilaria tenuistipitata, were co-cultured in 250-L tanks for 8 weeks. Six feeding treatments were conducted, with the control group (monoculture) being fed a commercial pellet (30% protein, 6% lipid) at 100% feed ration (4% of biomass per day), while fish in the five other groups were co-cultured with red seaweed (1 kg m−3) and received pellet at 80%, 60%, 40%, 20%, and 0% of the feeding ration of the control. The results indicated that the concentrations of TAN, NO2−, NO3−, and PO43− in the co-culture tanks were much lower than those in the monoculture. Moreover, the growth rate and productivity of fish in the 80% feeding ration treatment were comparable to those in the control group (p > 0.05). However, fish performance gradually reduced with a decrease in feeding rates from 60% downwards and all were significantly inferior to the control group (p < 0.05). Feed conversion ratio and feed cost were lower at the lower feeding rates. The results also proved that the co-culture of tilapia–red seaweed supplied at 80% feed ration, which could reduce feed cost by 28.9% compared with the control, still sustained normal growth while also maintaining better water quality. The proximate composition of fish fillet (moisture, protein, lipid, and ash) is also discussed.

The effects of raw and local processing methods on the nutritive value of Mucuna utilis seeds fed in diets to broiler performance were investigated. The processing methods were: seeds were soaked for 24 h in plain water, cooking of 24-h pre-soaked seeds for 60 min and cooking in a solution of potash (kanwa, trona) for 60 min. Five experimental diets were formulated such that diet 1 contained no mucuna (control), while raw, soaked, pre-soaked and cooked and cooked-in-potash mucuna seed meal were included at 20% dietary levels respectively. One hundred and fifty (150) 0ne-week old (Anak, 2000) broiler chicks were randomly assigned to the experimental diets in a completely randomized design. There were 3 replicates of the 5 treatme nts and 10 birds per replicate. 22% Crude Protein (CP) diets were fed during the starter phase and 20%CP diets during the finisher phase. Feed and water were supplied ad libitum throughout the 8-week trial period. At the end of the feeding trial, 3 birds were selected from replicates and slaughtered for carcass and blood evaluation. The different processing methods caused percentage reductions in Crud e Protein (CP) and ether extract but increased the gross energy and ash content of the seeds. Cooking of pre- soaked beans and cooking in potash solution significantly (p<0.05) reduced most of the antinutrient factor contents of the seeds. During the starter phase, average fed intake and feed conversion efficiency f birds on cooked mucuna seed diets were similar to the control group. At the finisher phase better performance in terms of weight gain, feed conversion efficiency, protein efficiency ratio were significantly (p<0.05) achieved with a 25% reduction in cost of feed per kilogram gain in the group fed seeds cooked for 60 minutes diet. Birds on cooked mucuna seed diets had comparable dressing percentage, empty gizzard, liver, pancreas spleen and lungs weights with the birds fed the control diet. The packed cell volume, haemoglobin and white blood cell count values of the birds on the cooked mucuna diets were significantly similar to the control group.

This study aimed to evaluate the use of banana peel (BP) and sweet potato vines (SPV) as a replacement for maize and alfalfa hay in diets for rabbits. Animal performance, economic analyses, meat composition, and color were evaluated for 49 days in a total 50 New Zealand White rabbits weaned at 35 days with an average body mass of ± 614 g. The animals were allotted, in a completely randomized design, having five dietary groups: control diet (0), without banana peels and sweet potato vines, or experimental diets, 25, 50, 75, and 100-with 25%, 50%, 75%, and 100% of banana peels and sweet potato vines in substitution to maize and alfalfa hay, respectively. The data were analyzed using ANOVA, while the means were compared by Tukey test (p < 0.05). The results indicate that daily feed intake, mass gain, and feed conversion were not statistically different from one another in the test groups compared to the control group treatment. In addition, the study shows no differences were observed in centesimal compositions and muscle color. The replacement of maize and alfalfa hay by the combination of BP and SPV resulted in reduction in feed costs, reaching 50% in the experimental diet with 100% of substitution the ingredients. It can be concluded, based on the results on animal performance, meat/color composition, and economic analyses, that BP and SPV may be used as a substitute for maize and alfalfa hay up to 100% in diets for growing rabbits.

Effects of the extrusion process on the physical properties of micro pellets and the growth performance of juvenile Nile tilapia

Feeding trial was conducted for 90 days using 20 Bunaji bulls with a live weight range of 210-249kg and aged 2-3 years to evaluate the feeding value of raw or parboiled rice offal as energy source for bull fattening. Four bulls per treatment were allotted to 5 dietary treatments in a 2x2 factorial arrangement with a common control. A concentrate and basal diets of Digitaria smutsii were offered at 2% body weight. The CP contents of the experimental diets varied between 19.69 and 20.44% while the ME ranged from 10.86 to 11.16MJ/kg DM. The crude fibre varied from 14.59 to 17.84%. The intake of concentrate, hay, total feed and daily live weight gain of the bulls were similar (P&gt;0.05) with type and inclusion levels of rice offal. All the bulls in experiment attained an average weight gain of between 1.11Kg to 1.29Kg. Economic parameters like cost per Kg gain, net benefit (NB) and return to naira invested on feed (RIF) were similar (P&gt;0.05) for bulls on both RRO and PRO. There was no significant (P&gt;0.05) differences in the Value of weight gain (VWG), NB, RIF, Cost of feed and Cost per Kg gain for bulls on varying levels of inclusion of RRO or PRO. The inclusion of raw rice offal or parboiled rice offal lead to reduction in feed cost from N25,001.10 to a range of N22,115.50-N23,639.6 (about 5.45%-11.54% reduction in feed cost). It was concluded from this trial that rice offal can replace up to 30% of maize offal as source of energy.

A study was conducted using 20 Bunaji bulls with a live weight range of 210-249kg and age range of 2-3 years to evaluate the feeding value of raw or parboiled rice offal as energy source for bull fattening. Four bulls per treatment were allotted to five dietary treatments in a 2x2 factorial arrangement with a common control. Feeding trials was conducted for 90 days. A concentrate and basal diets of Digitaria smutsii were offered at 2% body weight. The proximate and mineral composition of the feed ingredients showed that raw rice offal (RRO) had 7.69% CP, 6.64% hemicellulose and 24.86% silica while parboiled rice offal had (PRO) 4.38% CP, 6.10% hemicellulose and 36.91% silica. The CP contents of the experimental diets vary between 19.69 and 20.44% while the ME ranged from 10.86 to 11.16MJ/kg DM. The crude fibre varies from 14.59 to 17.84%. The result of the fattening trial showed that there was no significant (P&gt;0.05) difference in concentrate, hay, total dry matter intakes and daily weight gain of bulls fed the control diet (NRO) and diets containing RRO and PRO. Inclusion level of rice offal had no significant effect (P&gt;0.05) on intake of concentrate, hay and total feed intake. However, live weight gain of the bulls on the control diet was significantly (P&lt;0.05) higher than bulls on 20 and 30% rice offal inclusion The intake of concentrate, hay, total feed and daily live weight gain of the bulls were similar (P&gt;0.05) irrespective of type and inclusion levels of the rice offal. All the bulls experimented attained an average weight gain of between 1.11Kg to 1.29Kg which was above 1Kg. Economic parameters such as cost per Kg gain, net benefit (NB) and return to naira invested on feed (RIF) were similar (P&gt;0.05) for bulls on both RRO and PRO. There was no significant (P&gt;0.05) differences in the Value of weight gain (VWG), NB, RIF, Cost of feed and Cost per Kg gain for bulls on varying levels of inclusion of RRO or PRO. The inclusion of raw rice offal or parboiled rice offal lead to reduction in feed cost from N25,001.10 to a range of N22,115.50-N23,639.6 (about 5.45%-11.54% reduction in feed cost). It was concluded from this trial that rice offal of all kind (raw or parboiled) may be used to replace up to 30% of maize offal as source of energy in the fattening diet of Bunaji bulls without any detrimental effect on live weight. Hence it can be adopted by farmers.

In most commercial abalone nurseries worldwide, algal biomass grown on vertical plates becomes inadequate once juvenile abalone reach about 5 mm in shell length. At that stage animals need to be moved into a different tank system and weaned onto a formulated feed or alternative algal diets consisting of diatoms or macroalgae that can provide more biomass for the growing juveniles. Two trials were conducted to compare the growth and survival of juvenile greenlip abalone (5.9 ± 0.6 and 7.1 ± 0.1 mm in initial shell length) in two rearing systems: (1) shallower tanks with or without horizontal shelter, feeding a commercial formulated feed on horizontal surfaces; (2) deeper tanks with plate system feeding algal diets. The second experiment included two algal diets and two abalone stocking densities for one of the algal diets. The first experiment revealed that the algal diet consisting of Ulvella lens produced the best growth rates during the first 4 wk of the experiment, when juveniles reached about 9 mm in shell length and seawater temperatures averaged 20.1°C. Growth rates on the Ulvella diet declined rapidly thereafter, whereas growth rates on formulated feeds increased, coinciding with a decrease in seawater temperature to 15.2°C at the end of the experiment. The formulated feed produced high growth rates (over 75 μm day−1) once juveniles reached 7 mm in shell length. In the second experiment, the algal diet that included germlings of the green alga Ulva sp. produced the highest growth rates (105 μm day−1), indicating that Ulva sp. germlings are a suitable additional food source for juvenile greenlip abalone. Growth rates were particularly high towards the end of the experiment when seawater temperatures were above 19°C. Juveniles stocked at higher density (80 juveniles per plate) feeding on one of the algal diets showed reduced growth rates and overall lower average weight gain per individual compared with the juveniles stocked at low density and juveniles in the tank system feeding on formulated diet. In both experiments the survival was higher on the algal diets (77% to 82%) than on the formulated feed (62% to 65%). Culturing and maintaining algae for larger juveniles in the nursery system involved more labor, compared with the tank systems feeding formulated feed, suggesting that in higher labor cost countries, juveniles should be weaned onto a formulated feed as early as possible. We recommend moving animals into a tank system to feed formulated feed once they reach 7 mm in shell length. The weaning process can be delayed (e.g., to 17 mm shell length) by supplementing with macroalgal germlings if the seawater temperature is high and high mortality is expected when weaning onto formulated diets. The algal diet including Ulva sp. germlings produced particularly high growth rates when seawater temperature was above 19°C.

Phytase is commonly used in pig feed to improve the availability of phosphorus (P) and other minerals such as calcium (Ca) and sodium (Na). However, a phytase that can break down phytate quickly and completely in the early gut, can also reduce the anti-nutritional effect of phytate, resulting in an improved amino acid (AA) and energy digestibility. Recent studies demonstrated that a consensus bacterial 6-phytase variant (PhyG) consistently improved apparent ileal AA digestibility (meta-analysis of 8 datasets) and ileal energy digestibility in pigs (meta-analysis of 4 datasets). Application of digestible AA and energy matrix for phytase alone, or in combination with other enzymes, can reduce the feed cost and improve pig production benefits. This concept has been tested in 3 studies including one study in piglets and two studies from weaning to slaughter. In Exp. 1, three treatments were tested including a nutritionally adequate positive control (PC) and 2 PhyG-supplemented diets, reduced in digestible P, Ca, Na, net energy and digestible AA vs. PC, based on the contribution of PhyG added at 1,000 or 2,000 FTU/kg, respectively. The data showed that the application of full matrix could maintain or improve piglet performance and lead to up to 5.5% reduction in feed cost per kg body weight gain. In 2nd Exp., weaned pigs were randomized to 4 treatments and fed test diets in 5 phases, from weaning until market weight. Treatments included: a nutritionally sufficient positive control (PC) and 3 test diets with PhyG alone at low or high dose (phased dosing in different phases), or PhyG at low dose in combination with xylanase–β-glucanase (XB). All test diets were formulated with application of full energy and nutrient matrix. Overall growth performance (from weaning to slaughter) in all enzymes supplemented diets with full matrix application, was maintained or improved compared to PC, and there was a reduction in feed cost per kg body weight gain by up to 5.8%. In the third experiment, weaning pigs were randomly distributed to 3 treatments corresponding to a control diet, a PhyG treatment with diets supplemented with 1500 FTU/kg of PhyG, and a third treatment supplemented with the same PhyG dose and a multi-enzyme (Xylanase, β-glucanase, Amylase, and Protease). The enzyme supplemented diets were formulated with corresponding matrix values. Application of full energy and nutrient matrix for phytase alone or in combination with a multi-enzyme maintained the performance and carcass yield and quality of pigs from weaning to slaughter, leading to feed cost savings. In summary, the application of digestible AA and energy matrix, in addition to mineral matrix, can reduce feed cost and improve pig production benefits.

Feed cost is the highest cost item to the total costs of dairy farming all over the world including India, Pakistan and Bangladesh. Reducing feed costs and increasing feed efficiency-are two promising ways to decrease the cost of milk production and increase the competitiveness nationally and internationally(Hemme et al. 2014). Feed price in Bangladesh dairy farm is 51%higher than global feed price which has increased further due to the sudden infection of Coronavirus (Covid-19) (IDRN, 2020).Therefore, the objective of this paper is to estimate the impact of pandemic novel Coronavirus (COVID-19) prevalence on feed costs and feed efficiency in order to find a suitable feed supporting policy to the dairy farmers. The International Farm Comparison Network (IFCN) Feed Simulation Approach and Technology Impact Policy Impact Calculations (TIPICAL) model was used for estimating feed costs and feed efficiency of the dairy farm with and without Corona situation (This model is highly relevant to this study due to the fact that this model can produce result seven with the scarcity of the data and it is highly scientific and produce the results that are simultaneously used both Academia(University and Research organization) and Industry (for business strategic decisions). The Integrated Dairy Research Network (IDRN) dairy sector and dairy farm database (January2019 to March 2020) was used where 2019 is considered as without Corona (WOC) and March 2020 is considered as with Corona(WC). Two typical farms:2cow farm (BD-2) which is representative of 42% household farm (Household Farm (HF) is defined as one the income source for livelihoods, mainly consumed at household level and sells the surplus milk. The average size of the household farm (1-3 cows/farm) as per the International Farm Comparison Network (IFCN) methodology) and fourteen cow (BD-14) which is representative of 48% family farms in Bangladesh were selected. The share of feed cost to the total costs of milk production is increased by 9.5% and 8.9% for BD-2/19-WC and BD-14/20-WC,respectively. The purchased feed costs before corona was 22.1USD/100 kg milk for BD-2/19-WOC and 32.2 USD/100 kg milk forBD-14/19-WOC which is increased to 23.8 USD/100 kg and 35.0USD/100 kg for BD-2/20-WC and BD-14/20-WC, respectively(Author’s own results). The purchased feed costs increased by7.6% and 8.7% for BD-2/20-WC and BD-14/20-WC, respectively while for the homegrown feed, it is increased even higher which is 14.1% and 9.7%, respectively. The results revealed that decreasing milk price and increasing feed price has direct impact on increasing feed costs of 8.6% and decreasing margin over compound feed costs by 4.5% due to Coronavirus. As a result, an increase in feed cost, decrease in the margin over total feed cost and the feed efficiency (total, energy, and protein efficiency)was observed due to coronavirus (Covid-19) infection. The finding of this study revealed that for short-term and medium-term, farmers might need feed incentives either in the form of reduced feed price or liberalized concentrate feed input market. The outcome of this study is expected to be beneficial for policymakers, feed suppliers and farmers in Bangladesh and similar other countries like India, Pakistan, Sri Lanka and Nepal.

This study was conducted to investigate effect of changes in target fat and protein contents in milk on feed cost using a simulation modeling approach based on the 2001 dairy NRC. Two simulations were done; simulation I had a limitation (up to 20%), but simulation II had no limitation for the use of cottonseed hull in a diet. Using commonly used feed ingredients in Korea, we formulated least cost diets that meet nutrient requirement of a lactating dairy cow producing 36 ㎏ of milk with combinations of 0.1% decrease or 0.1% increase in target milk fat or protein, respectively, from the national average milk fat (4.0%) and milk protein (3.1%). The contents of alfalfa and corn in a least-cost diet were decreased and those of tall fescue, whole cottonseed and rapeseed meal were increased with decreasing fat and/or increasing protein in milk. Scenarios that decreased target milk fat percentage from 4.0% to 3.9% reduced feed cost by 2 won per ㎏. Due to decrease in feed intake, daily feed cost was even more reduced (136 won per head) by decreasing target milk fat percentage. Increase in target milk protein percentage from 3.1% to 3.2% reduced feed cost by 6 won per ㎏. Among scenarios simulated, the least feed cost was obtained in scenario aimed for 3.9% fat and 3.2% of protein in milk. We conclude that a feeding practice for increasing milk protein percentage does not directly increase feed cost. In addition, feeding practices that increase protein content in milk is expected to improve economic life-span and reproductive performance of dairy cows.

Nutritional grouping (NG), where cows are fed in groups based on similar nutrient requirements, has been used as a strategy to improve the precision of nutrition delivery and thus economic returns. Enteric methane, one of the largest on-farm sources of greenhouse gas emissions, is strongly influenced by diet formulation. With growing concerns about climate change, it is important to evaluate whether NG can also help reduce enteric methane emissions. To address this, we developed an open-source linear optimization model to assess the impact of NG on both feed cost and enteric methane emissions. We conducted a case study with 675 cows from the University of Wisconsin's Arlington Agricultural Research Station. Diets were formulated using the farm's actual feed ingredients and prices and were constrained according to current dairy cattle feeding guidelines. Without NG, optimization alone reduced feed cost by $2.52/cow per day (32%) under the cost-minimization objective, and reduced methane emissions by 57 g/cow per day (12%) under the methane-minimization objective, relative to the on-farm diet used during the study period. Under a dual-objective approach that simultaneously considered feed cost and enteric methane emissions, the model identified a pragmatic compromise solution. By placing greater emphasis on economic performance to reflect the current US production context, methane emissions decreased by 55 g/cow per day compared with the cost-minimization scenario while maintaining similarly low feed costs. Nutritional grouping did not consistently outperform the optimized single-group diet, but it modestly improved the nontarget outcome (lower methane when minimizing cost and lower cost when minimizing methane). These findings indicate that well-optimized rations using existing feeds can deliver meaningful economic and environmental benefits, and NG offers an additional layer of management refinement that may not only reduce the feed cost as suggested by literature, but also offer complementary benefits when methane is considered as a secondary performance dimension.