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ISSN : 2287-5824(Print)
ISSN : 2287-5832(Online)
Journal of The Korean Society of Grassland and Forage Science Vol.46 No.3 pp.213-219
DOI : https://doi.org/10.5333/KGFS.2026.46.3.213

Effects of Replacing Alfalfa Hay with Hot-air Dry System on the Production Performance and Economic Efficiency of Lactating Holstein Dairy Cows

Young-Lae Kim, Dong-Hyun Lim, Seoung-Min Park, Ji-Hoo Park, Ji-Hwan Lee, Chang-Gwon Dang, Dong-Hyeon Kim*
Dairy Science Division, National Institute of Animal Science, RDA, Cheonan 31000, Republic of Korea
*Corresponding author: Dong-Hyeon Kim, Dairy Science Division, National Institute of Animal Science, RDA, Cheonan 31000, Republic of Korea. Tel: +82-41-580-3402, Fax: +82-41-580-3419, E-mail: kimdh3465@korea.kr
September 18, 2026 September 28, 2026 September 28, 2026

Abstract


This study was conducted to investigate the effects of feeding domestic hot-air dried alfalfa hay on the productivity and farm economics of Holstein dairy cows compared to imported alfalfa hay. The experimental animals consisted of 221 Holstein dairy cows (milk yield: 31.01 ± 0.58 kg/d; milk fat: 4.12 ± 0.45%; milk protein: 3.28 ± 0.84%), with 114 cows assigned to the control group (CON, total mixed ration [TMR] using imported alfalfa) and 107 cows to the treatment group (TRT, TMR using domestic hot-air dried alfalfa hay). Milk yield tended to be higher in the TRT group than in the CON group throughout the entire experimental period (p = 0.055). Regarding milk protein, lactose, and solid not fat were higher in the TRT group than in the CON group at week 3 (p<0.05). However, these differences were not observed at weeks 1, 2, and 4. In addition, no significant differences were found in the overall means across the experimental period. Economic analysis results showed that daily feed cost per cow was lower in the TRT group compared to the CON group, and all other economic indicators—including feed cost per kg of milk yield, milk price, income over feed cost, and feed cost ratio—showed improvement in the TRT group compared to the CON group. The results of this study indicate that when domestic hot-air dried alfalfa hay is fed as a substitute for imported alfalfa hay, there was no difference in productivity parameters such as milk yield and milk composition of Holstein dairy cows, while it had a positive effect on reducing production costs through decreased feed expenses. Therefore, it is concluded that feeding domestic hot-air-dried alfalfa hay can maintain the productivity of Holstein dairy cows compared to imported alfalfa hay while improving farm economics.


Lactating Holstein Dairy Cows , Hot-Air Dry System , Alfalfa , Total Mixed Ration , Feed Cost

초록

    Ⅰ. INTRODUCTION

    Feed cost accounts for the largest proportion of production costs in dairy farming (Buza et al., 2014), and fluctuations in feed ingredient prices directly affect farm profitability. Korean dairy farms procure a substantial portion of their forage and grain ingredients from overseas (Chang et al., 2024)), making them structurally vulnerable to fluctuations in international raw material and oil prices. The recent sustained rise in international crude oil prices has led to increased prices of imported feed ingredients, thereby aggravating the financial burden on dairy farmers. Indeed, the prices of major forages used in Korea have recently increased sharply by 30–55%, including those of Italian ryegrass, rice straw, timothy, and alfalfa (Chang et al., 2024). Among these, the proportion of alfalfa hay in imported forages expanded from 16.5% (164 thousand tons) in 2013 to 21.3% (191 thousand tons) in 2020, and its demand is expected to continue increasing (Kim et al., 2021;Kim et al., 2023); consequently, the burden on farms resulting from price fluctuations is anticipated to grow further.

    Alfalfa (Medicago sativa L.) is the most widely used legume forage worldwide owing to its high protein and calcium contents and excellent palatability (Kamalak et al., 2005;Radović et al., 2009), and it serves as a key forage source in total mixed ration (TMR) for lactating cows, supplying both protein and fiber. In Korea, however, the alfalfa harvest season coincides with a period of frequent rainfall and persistently high humidity, which makes it difficult to produce high-quality hay by natural drying; as a result, most of the domestic demand for alfalfa hay has been met by imports. To overcome this limitation, a hot-air drying method that artificially dries alfalfa within a short time immediately after harvest has been introduced in Korea. Hot-air drying enables drying regardless of weather conditions and reduces the leaf and nutrient losses that occur during natural drying, thereby allowing the stable production of hay with uniform quality (Zheng et al., 2007).

    Recently, several studies have compared the feed value of domestically produced alfalfa with that of imported alfalfa. Moon et al. (2024) reported that the growth performance of Hanwoo calves and growing cattle fed domestic alfalfa was comparable to that of animals fed imported alfalfa. Similarly, Kim et al. (2026) replaced imported alfalfa hay with domestic hot-air dried alfalfa hay in the TMR of 20 Holstein dairy cows and observed no differences in feed intake, milk yield, milk composition, or rumination time between treatments. However, because the previous study on dairy cows was conducted as a feeding trial with a limited number of animals, it remains to be verified whether the same results can be reproduced at the scale of commercial farms with a large number of lactating cows, and how changes in feed cost resulting from ingredient replacement actually affect farm economics. Considering that farmers' uncertainty about domestic forages is a major factor sustaining their dependence on imported forages (Chang et al., 2024), verification of productivity and economic analysis at the farm scale would provide important evidence for the on-farm adoption of domestic hot-air dried alfalfa hay.

    Therefore, this study was conducted to examine the effects of replacing imported alfalfa hay with domestic hot-air dried alfalfa hay on the productivity of Holstein dairy cows, including milk yield and milk composition, and to evaluate farm-level economics by analyzing economic indicators such as feed cost, milk income, and income over feed cost (IOFC).

    Ⅱ. MATERIALS AND METHODS

    This study was conducted at the Livestock Resources Development Division of the National Institute of Animal Science (NIAS). All experimental procedures were performed in accordance with the Animal Protection Act and the protocols reviewed and approved by the Institutional Animal Care and Use Committee (IACUC) of the National Institute of Animal Science (Approval No. NIAS2024-0019).

    1. Animals, Experimental Design, and Management

    A total of 221 Holstein dairy cows (milk yield: 31.01 ± 0.58 kg/d; milk fat: 4.12 ± 0.45%; milk protein: 3.28 ± 0.84%) were used in this study. The experiment was conducted on five commercial dairy farms, two of which were assigned to the control group (CON, TMR with imported alfalfa hay; n = 114) and three to the treatment group (TRT, TMR with domestic hot-air-dried alfalfa hay; n = 107). Within each group, all farms fed TMR with the same ingredient composition. Milk yield and milk composition were similar among the farms before the start of the experiment. The nutrient requirements for the experimental diets were formulated to satisfy the requirements for lactating cows as specified by the Korean Feeding Standards for Dairy Cattle (2022). The ingredient composition of the experimental TMR is presented in Table 1, and the chemical compositions of the imported alfalfa hay, domestic hot-air dried alfalfa hay, and experimental TMR are shown in Table 2. The TMR was offered twice daily at 08:00 and 15:00. The cows were adapted to the experimental diets for one week, and then the feeding trial was conducted for four weeks. All cows had ad libitum access to water and sodium bicarbonate throughout the experimental period.

    2. Measurements

    1) Chemical Composition of Experimental Diets

    To analyze the nutrient content of the experimental TMR, samples were collected and dried in a forced-air oven (OF-22W, Jeio Tech, Daejeon, Korea) at 65°C for 48 hours. The dried samples were then ground to pass through a 1 mm screen using a cutting mill (Shinmyung Electric Co. Ltd., Gimpo, Korea) to pass through a 1 mm screen and used as analytical samples. The moisture content was determined by drying the samples in a forced-air oven (OF-22W, Jeio Tech, Daejeon, Korea) at 105°C for 24 hours. Crude protein and ether extract were analyzed according to the AOAC (2005) methods using a Kjeldahl apparatus (B-324, 412, 435, and 719 Titrino, BUCHI, Essen, Germany) and a Soxhlet extractor (OB-25E, Jeio Tech, Daejeon, Korea), respectively. The neutral detergent fiber and acid detergent fiber contents were determined according to the methods of Van Soest et al. (1991) using a fiber analyzer (ANKOM 2000 Fiber Analyzer, Ankom Technology, Macedon, NY, USA).

    2) Milk Yield and Composition Analysis

    Cows were milked twice daily at 07:00 and 17:00. The average daily milk yield per cow was calculated by dividing the total daily milk production of each group by the number of cows milked. Milk samples were collected daily from the bulk milk tank for composition analysis. The contents of milk fat, protein, lactose, somatic cell count (SCC), and solids not fat (SNF) were determined using a Milkoscan (Automatic IR 4000/5000 Milk Analyzer, Foss, Hillerod, Denmark).

    3) Economic Analysis

    In this study, the economic efficiency of replacing imported alfalfa hay with domestic hot-air dried alfalfa at a 1:1 ratio was analyzed. The unit cost of the TMR was calculated based on the market prices of individual ingredients and their inclusion rates in the formulation. The daily feed cost per cow was then determined by applying this unit cost to the daily feed intake. Gross income was estimated based on the average milk yield and composition results during the experimental period, applying a base milk price of 1,263 won/L (Grade 1 and 1A quality) according to the standard raw milk payment system. Finally, the economic viability was evaluated by comparing the income over feed cost (IOFC) between the groups.

    3. Statistical Analysis

    Statistical analyses were performed using IBM SPSS Statistics ver. 29.0 (SPSS Inc., Chicago, IL, USA). All data were analyzed using the t-test, and statistical significance was declared at p<0.05.

    Ⅲ. RESULTS AND DISCUSSION

    1. Milk Yield and Composition

    The effects of replacing imported alfalfa hay with domestic hot-air dried alfalfa hay on the milk yield and composition of lactating Holstein cows are shown in Table 3.

    In the present study, milk yield over the entire experimental period tended to be higher in the TRT group than in the CON group (p = 0.055). Milk composition did not differ markedly between the CON and TRT groups throughout the experimental period; however, at week 3, milk protein, lactose, and SNF were higher in the TRT group than in the CON group (p<0.05).

    In the present study, milk yield tended to be higher in the TRT group fed domestic hot-air dried alfalfa hay than in the CON group fed imported alfalfa hay, although the difference was not statistically significant. This suggests that replacing imported alfalfa hay with domestic hot-air dried alfalfa hay had no negative effect on the productivity of Holstein dairy cows. Moon et al. (2024) reported no differences in growth performance, including feed intake and average daily gain, when Hanwoo calves and growing cattle were fed domestic or imported alfalfa. In addition, Kim et al. (2026) reported that milk yield and milk composition did not differ between the CON and TRT groups when Holstein dairy cows were fed imported alfalfa hay or domestic hot-air dried alfalfa hay. Taken together with the findings of these previous studies, the results of the present study indicate that feeding domestic hot-air dried alfalfa hay has no negative effect on the productivity of cattle compared with feeding imported alfalfa hay.

    In the present study, the contents of milk protein, lactose, and SNF were higher in the TRT group than in the CON group at week 3 (p<0.05). These differences were not observed at weeks 1, 2, or 4. In addition, the average milk composition over the entire experimental period did not differ between the CON and TRT groups. The transient increase in milk components observed at week 3 may have occurred during the adaptation of rumen microorganisms to the experimental diets, as changes in the ruminal fermentation pattern during this period can affect the synthesis of milk components (Tajima et al., 2001;Fernando et al., 2010). In general, it has been reported that 3–4 weeks may be required for rumen microorganisms to fully stabilize after a change in the forage source of the diet (Tajima et al., 2001). Furthermore, the differences in milk composition observed at week 3 were not detected at week 4, and no significant differences between groups were found in the average milk composition over the entire experimental period. This suggests that replacing imported alfalfa hay with domestic hot-air dried alfalfa hay has no negative effect on the milk quality of Holstein dairy cows. Consequently, when imported alfalfa hay was replaced with domestic hot-air dried alfalfa hay, milk yield did not differ, and milk composition showed only a transient difference. However, this difference is considered to be a change during the dietary adaptation process, and the values were higher in the TRT group than in the CON group. Therefore, these results support that domestic hot-air dried alfalfa hay has sufficient feed value to replace imported alfalfa hay in dairy farms.

    The chemical composition of the imported alfalfa hay and domestic hot-air dried alfalfa hay used in this study was similar, and the chemical composition of the TMR in which imported alfalfa hay was replaced with domestic hot-air dried alfalfa hay at a 1:1 ratio also did not differ markedly between the CON and TRT groups (Table 2). This suggests that the lack of differences in nutrient composition between imported alfalfa hay and domestic hot-air dried alfalfa hay resulted in comparable productivity between the two groups. Therefore, replacing imported alfalfa hay with domestic hot-air dried alfalfa hay at the farm level is considered to have no negative effect on the productivity of Holstein dairy cows.

    2. Economic Analysis

    The results of the economic analysis on replacing imported alfalfa hay with domestic hot-air dried alfalfa hay for lactating Holstein cows are shown in Tables 4 and 5.

    The economic analysis of feeding imported alfalfa hay versus domestic hot-air dried alfalfa hay showed that the daily TMR feed cost was reduced by approximately 3.2% in the TRT group (9,794.3 won) compared with the CON group (10,121.3 won). Feed cost per kg of milk was also 3.9% significantly lower in the TRT group (314.9 won/kg milk) than in the CON group (327.6 won/kg milk) (p<0.001). Milk income tended to be 0.63% higher in the TRT group (39,294.2 won/cow/d) than in the CON group (39,046.6 won/cow/d) (p = 0.056), and income over feed cost (IOFC) was 28,917.2 won/cow/d in the CON group and 29,497.0 won/cow/d in the TRT group, representing a 2.01% increase in the TRT group (p<0.001). The feed cost to milk income ratio was also improved by 3.89% in the TRT group (24.93%) compared with the CON group (25.94%) (p<0.001).

    The economic analysis in the present study showed that all economic indicators, including feed cost, milk income, IOFC, and the feed cost to milk income ratio, were improved in the TRT group fed domestic hot-air dried alfalfa hay compared with the CON group fed imported alfalfa hay. This result may be attributed to the lower unit price of domestic hot-air dried alfalfa hay (507 won/kg) compared with imported alfalfa hay (616 won/kg) as of 2024, a difference of approximately 110 won/kg, together with the tendency toward higher milk yield in the TRT group than in the CON group (p = 0.055) and the absence of differences in milk composition between the groups (Table 3).

    Therefore, feeding domestic hot-air dried alfalfa hay instead of imported alfalfa hay at the dairy farm level is considered to maintain the productivity of Holstein dairy cows while having a positive effect on reducing farm production costs owing to the lower unit price of domestic hot-air dried alfalfa hay.

    Ⅳ. CONCLUSIONS

    This study was conducted to investigate the effects of feeding imported alfalfa hay or domestic hot-air dried alfalfa hay on the productivity of Holstein dairy cows and farm economics. Overall milk yield tended to be higher in the TRT group than in the CON group, and milk composition showed only a transient difference at week 3. This difference is considered to be a temporary change that occurred during the adaptation of rumen microorganisms to the experimental diets (Tajima et al., 2001).

    The economic analysis showed that all economic indicators, including feed cost, milk income, IOFC, and the feed cost to milk income ratio, were improved in the TRT group fed domestic hot-air dried alfalfa hay. Therefore, when domestic hot-air dried alfalfa hay is fed to dairy cows as a replacement for imported alfalfa hay, the productivity of Holstein dairy cows, including milk yield and milk composition, is maintained, and the lower unit price of domestic hot-air dried alfalfa hay is considered to be more advantageous for reducing farm production costs.

    Ⅴ. ACKNOWLEDGMENT

    This work was carried out with the support of “Research Program for Agriculture Science and Technology Development (Project No. PJ01739503)”, Rural Development Administration, and was supported by 2026 the RDA Fellowship Program of National Institute of Animal Science, Rural Development Administration, Republic of Korea.

    Figure

    Table

    Ingredient of total mixed ration
    1Concentrate 1: dairy cow concentrate, 2Concentrate 2: top dressing concentrate, 3Effective microorganisms were contained Lactobacillus acidophilus (1×106 cfu/ml), Saccharomyces cerevisiae (1×105 cfu/ml), Bacillus subtillis (1×105 cfu/ml).
    *The CON and TRT diets had the same ingredient composition, differing only in the source of alfalfa hay.
    Chemical composition of alfalfa and total mixed ration
    1TMR: total mixed ration, 2CON: imported alfalfa hay; 3TRT: domestic hot-air dried alfalfa hay.
    Effect of hot-air dried alfalfa supplementation on milk yield and composition in lactating Holstein cows
    1CON: imported alfalfa hay; 2TRT: domestic hot-air dried alfalfa hay; 3SCC: somatic cell count; 4SNF: solid not fat.
    *Data are presented as means ± standard error (n = CON: 114 and TRT: 107). **Data were analyzed using t-test.
    Comparison of total feed costs and cost reduction by replacing imported alfalfa with domestic hot-air dried alfalfa hay
    1CON: imported alfalfa hay; 2TRT: domestic hot-air dried alfalfa hay; 3Concentrate 1: dairy cow concentrate, 4Concentrate 2: top dressing concentrate.
    *Feed prices were calculated based on the procurement prices from the Dairy Science Division, National Institute of Animal Science, combined with field average prices derived from the 2024 Nonghyup Agribusiness Group price list; the price of domestic alfalfa hay was determined by applying the estimated supply price from the forage production system.
    Economic analysis of feeding imported alfalfa hay and domestic hot-air dried alfalfa hay to lactating Holstein cows in whole period
    1CON: imported alfalfa hay; 2TRT: domestic hot-air dried alfalfa hay; 3IOFC: income over feed cost.
    *Data are presented as means ± standard error (n = CON: 114 and TRT: 107). **Data were analyzed using t-test.

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