This study was conducted for SNPs in the 5'-regions of estrogen receptor-α(ESR-α), and association with calving interval (CI), service per conception (SPC) and 305 days milk yield in Hanwoo and Holstein dairy cattle. The genet-ic improvement was incurred low reproduction performance. The objective of this study was to investigate connec-tions between single nucleotide polymorphisms (SNP) of Estrogen receptor-α (ESR-α) with reproduction performance (calving interval, service per conception, and 305 d milk yield) in Hanwoo and Holstein dairy cattle. Hanwoo and Holstein blood samples were collected from 183 and 124 dam of breeding farms and DNA was extracted. Primer design was based on NCBI GenBank (Accession No. AY340579). The PCR-RFLP method with Bgl I was used to ge-notype the cattle. The result showed two variants of the ESR-α gene. The Bgl I cut the 492 bp amplification pro- duct into 322 bp and 170 bp fragments for allele G, while allele A remained uncut, resulting in two restriction frag-ments for homozygote G/G and three fragments for heterozygote A/G. We found two of different genotypes in the-se breeds, A/G and G/G. In Hanwoo, the A/G genotype frequency was 0.13, and G/G was 0.87. The CI of A/G was 382.18±10.03 days, and G/G was 381.69±5.22 days. The SPC of A/G was 1.62±0.16, and G/G was 1.32±0.04. While CI showed no significance difference, SPC exhibited significant difference (p<0.05). In Holstein cattle, the frequency of genotype A/G was 0.02 and G/G was 0.98. The 305 days milk yield of A/G was 7,253.00±936.00 kg and of G/G was 8,747.51±204.88 kg, showing no significant difference.

The purpose of this study was to investigate the effect of calcium (Ca) and vitamin D (vit. D) levels on metabolism of various minerals such as Ca, P, Mg, Fe, Zn, Cu, and Cr. The comparison was made on the rats that were placed on diet containing powdered skim milk with different Ca and vit. D levels for 5 weeks. A total of 42 5-week-old Sprague- Dawley rats were divided into 7 groups as follows: Control group consisted of normal Ca and normal vit. D (0.5% Ca, 1,000 IU vit. D); Experimental groups were divided into low (0.25%) and high (1.0%) calcium levels; and vit. D group was divided into low (10 IU), normal (1,000 IU), and high (5,000 IU) subgroups. The weight gain and food efficiency ratios of the rats were not significantly different with increasing dietary Ca levels. The absorption rates of 7 minerals (Ca, P, Mg, Fe, Zn, Cu, and Cr) were significantly decreased with increasing dietary Ca levels. Also, fecal excretion of P significantly increased with increasing dietary vit. D levels (p<0.05), and urine excretion of Fe was significantly increased with increasing dietary vit. D levels (p<0.001). The result indicated that higher Ca intake affected on bioavailability of other minerals, due to interactions among minerals in the process of intestinal absorption. However, vitamin D intake had no effect on bioavailability of several minerals. Therefore, it could be suggested that adequate Ca intake is important for balance of the minerals.

This study was conducted to determine the efficacy of anthelmintics against gastrointestinal parasitic infestation in periparturient dairy cows and its effect on milk yield and quality. Sixty pregnant cows of 1st & 2nd parity were divided into four groups. The efficacy of anthelmintic treatment was evaluated by counting faecal egg per gram (EPG) compared with pre-treatment values. The milk yield of each cow was recorded in pre and post treatment lactations. Cows of group A were treated with Nitroxynil 10 mg/kg body weight subcutaneously 30 days before parturition, group B were treated with combination of triclabendazole and levamisole 19.5 mg/kg body weight orally at calving and group C treated with Endex® at calving and 42 days after. The mean change in EPG 14 days after treatment was significantly higher (p<0.05) in treated (79.1%) cows than control. Average milk yield of group C (2.8 ± 0.8) was significantly higher (p<0.01) than group A (2.6 ± 0.7). Similarly, the average milk yield in all the treated cows was significantly (p<0.01) higher in treated lactation (2.5 ± 0.7) than in the previous lactation (2.2 ± 0.7). The average milk yield in all treated cows was significantly (p<0.01) higher than the control cows. Although, milk yields were higher in second parity than the first, there was no significant difference (p>0.05). The milk protein percentage was significantly higher (p<0.05) in treated group than the control group. Therefore, it may be concluded that periparturient anthelmintic treatment effectively reduced the gastrointestinal parasitic load and improved milk yield.

본 연구는 사료 내 총NDF 수준과 조사료에서 기인된 NDF 수준(fNDF)이 착유우에서의 영양소 섭취량과 유생산 성에 미치는 영향을 평가하기 위하여 실시하였다. 분만우 36두를 대상으로 6개의 처리구를 나누어 2×3 요인실험으로 설계를 하였고, 각 처리구별 사료는 건물기준 NDF 38%에 1) fNDF 18%, 2) fNDF 15%, 3) fNDF 12% 와 건물기준 NDF 34%에 4) fNDF 18%, 5) fNDF 15%, 6) fNDF 12%로 구분하여 분만 후 3주부터 20주까지 급여하였으며 결과의 처리는 분만 4주부터 영양소 섭취량 및 산유성적을 분석하 였다. 사료 내 총 NDF 함량과 fNDF 함량이 감소함에 따라 건물섭취량, NEl 섭취량 그리고 비구조탄수화물 섭취량이 유의적으로(p<0.01) 증가하였고, 통계적인 유의성은 없었으 나 유생산량 또한 다소 증가하는 경향이었으며 유지방율은 감소하였다(p<0.01). 건물섭취량의 증가에 따른 NEl 섭취 량의 증가가 유발되었고, NDF 섭취량은 감소하였음에도 불구하고 NDF 함량이 낮은 처리구와 높은 처리구간의 비 교에서 유지방율에 대한 유의적인 차이를 나타내지는 않았 다. 총 NDF와 조사료유래 NDF의 사료 내 함량변화는 유 단백질율과 무지유고형분 함량에는 영향을 미치지 않았지 만, 유단백질 함량과 무지유고형분 생산량에 있어서는 유 량 증가에 의한 영향으로 증가하는 경향을 나타내었다. 조 사료유래 NDF 섭취량과 유지방율 간의 상관관계는 저수준 NDF 함량에서 고수준 NDF 함량보다 높게 나타났으며 유 량과 영양소 섭취량간의 상관관계 또한 저수준의 NDF 처 리구에서 고수준 처리구보다 높게 나타났다.

지구 온난화에 따른 외기온도의 지속적인 상승은 젖소의 유질저하를 초래하는 것으로 알려져 있다. 현재 우리나라에서는 원유의 유지방함량, 체세포수 및 세균수를 기준으로 유대가격을 산정하고 있어 궁극적으로 여름철 온도의 상승은 젖소농가의 수익성에 악영향을 미치게 된다. 본 연구에서는 경북지역을 중심으로 외기온도와 상대습도을 조사하고 외기온도와 상대습도에 따른 온습도지수 (THI)를 도출하여 유질에 미치는 영향을 상관관계와 회귀분석 방법을 이용하여 분석하였다. 유지방 함량은 겨울철 4.0-4.1%에서 여름철로 접어들면서 3.6-3.7%로 저하하였고 동시에 온도와 THI가 상승하였다. 체세포수 1등급 출현율은 4-9월이 다른 달에 비해 낮은 것으로 나타났다. THI는 유지방 함량과는 r=-0.8914, 체세포수 1등급 출현율과는 r=-0.6067의 상관관계를 보였으나, 세균수 1등급 출현율과는 통계적으로 유의한 상관관계을 보이지 않았다. THI에 따른 유지방함량 및 체세포수 1등급 출현율을 예측할 수 있는 공식을 단순회귀분석법을 이용하여 도출하였다. 본 연구의 결과을 종합하면, 온도 및 상대습도를 이용하여 도출한 THI는 젖소의 고온스트레스를 분석하는 지표로 사용될 수 있을 것으로 사료된다.

The Lactobacillus brevis 340G strain isolated from traditional Korean fermented food (kimchi) produced 15.50mMof γ-aminobutyric acid (GABA) after 48 h of cultivation in MRS media containing 1% L-monosodium glutamate(MSG). The culture conditions of Lb. brevis 340G were optimized for GABA production. Lb. brevis 340G was cul-tivated at 30oC in optimized MRS media containing 3% sucrose and 2% yeast extract with 3% MSG, resulting inmaximum GABA production (68.77mM) after 54 h of cultivation. Skim milk fermented with Lb. brevis 340G pro-duced 4.64mM of GABA in the presence of 1% MSG. These results suggest that Lb. brevis 340G could be usedas a starter for functional fermented foods and skim milk fermented with Lb. brevis 340G could be further devel-oped to become functional dairy food fortified with GABA.

Melamine has been reported to be responsible for kidney stones and renal failure among infants and children. Con-ventional detection methods, High-Performance Liquid Chromatography (HPLC) and Gas Chromatography (GC), aresensitive enough to detect trace amounts of the contaminant, but they are time consuming, expensive, and labor-intensive. Hyperspectral imaging methods, which combine spectroscopy and imaging, can provide rapid and non-destructive means to assess the quality and safety of agricultural products. In this study, near-infrared hyperspectralreflectance imaging combined with partial least square regression analysis was used to predict melamine particleconcentration in dry milk powder. Melamine particles, with concentration levels ranging from 0.02% to 1% byweight ratio (g/g), were mixed with dry milk powder and used for the experiment. Hyperspectral reflectance imagesin the wavelength range from 992.0nm to 1682.1nm were acquired for the mixtures. Then PLSR models weredeveloped with several preprocessing methods. Optimal wavelength bands were selected from 1454.5nm to 1555.6nm using beta-coefficients from the PLSR model. The best PLSR result for predicting melamine concentration inmilk powder was obtained using a 1st order derivative pretreatment with Rv=0.974, SEP=±0.055%, and F=6.

For this research, prepared water soluble milk casein resin and waterborne polyurethane-acrylic resin. Use these resin, this article has been analyzed about change of mechanical properties by increasing amount of casein resin in polyurethane-acrylic resin on coated leather. According to measure data for solvent resistance, WPA(waterborne polyurethane-acrylic resin) resin and WPA-C1, C2, C3(samples of polyurethane-acrylic resin with milk casein resin) had good property. As known in the results, increase of casein constant did not influence to big change of hybrid resin properties. As test of tensile strength, WPA had lowest tensile characteristic(1.598 kgf/㎟) and WPA-C3 had highest tensile characteristic(1.718 kgf/㎟). Also best properties of abrasion was WPA-C3(06.021 ㎎.loss). In elongation case, WPA had best properties(754 %) in this experiment.

To investigate the adhesion effect of sodium bisulfite content in making blocked isocyanate, wood adhesive PB-1, PB-2, PB-3 and PB-4 containing sodium bisulfite content of 15%, 22.5%, 30% and 37.5% were synthesized respectively. As a result, when the amount of sodium bisulfite increased in adhesives, the tensile strength was found to be proportionally increased. The final adhesive mixtures were manufactured using a two-components system which are prepared by mixing two separate protein and BI solutions due to the precipitate in the adhesives. As PVA was added to adhesives to increase tenacity, the plywood dehiscence phenomenon after cold pressing process was declined. By addition of PVA, the tensile strength was improved up to 6.5~7kgf/cm2 with BI/protein ratio from 1:6 up to 1:8. Phase separation between milk fat and aqueous layer was disappeared after addition of emulsifier, Tween 20. Additon of Tween 20 showed tensile strength up to 5 ~ 6.5 kgf/cm2 at NCO/protein ratio of 1:12 ~ 1:14 without phase separation.

This study was conducted to investigate the effects of supplementing additional sucrose, in the form of black sugar (BS), into the diet of Holstein dairy cows on dry matter intake (DMI), milk yield, and milk composition. Eight Holstein dairy cows (741 ± 65.8 kg body weight) were divided into two groups, including the control and BS groups. Animals in the control group were offered a total mixed ration (TMR) ad libitum, and the BS group was offered TMR with 300 g of BS/head/d. After two weeks of adaptation period, the animal performance, including DMI, milk yield and milk composition, was measured. Cows supplemented with BS appeared to consume more feed than that by the controls (i.e., 17.08 and 18.28 kg/d for the control and BS groups, respectively). However, there were no significant differences between treatments. Milk yield or milk composition, such as milk fat, milk protein, lactose, solids-non-fat, total solids and pH, did not differ between treatments. However, there was a significant difference (p<0.05) in the concentration of milk urea nitrogen (MUN). The MUN concentration of the BS group was approximately 15% lower than that of the control group (i.e., 18.75 vs. 16.05 mg/dL for the control and BS groups, respectively), which suggests improved nitrogen metabolism in the animals. The somatic cell count was numerically lower in the cows of the BS group compared to those in the control group. However, a significant difference was not noted due to the substantial amount of variation among cows. In terms of the trace mineral composition for milk, the concentration of Cu from BS animals was higher (p<0.05) than that of the control animals. In summary, supplementing the diets of dairy cows with BS marginally affected animal performance and improved nitrogen metabolism. The level of supplementation and other factors, such as animal variation were discussed.

During January-November 2012, a total of 2,041 quarter milk samples were collected from dairy cattle of 82 dairy farms nationwide. About 42% (870/2,041) of the samples that had somatic cell counts (SCC) of ≥ 200,000 cells/ml were subjected to microbiological examination. No bacteria was isolated from 95 of 870 (10.9%) samples. Among 1,237 bacteria isolated from the rest 775 samples, 1,085 were identified with VITEK: more than half (52.1%, 645/1,237) of the isolates were gram negative bacillus. Gram positive cocci including Staphylococcus accounted for 35% of the isolates and almost none of gram positive bacilli isolated. Excluding Coagulase-negative Staphylococcus (CNS), the most frequently isolated bacterial species was Escherichia coli (11.2%, 138/1, 237), followed by Klebsiella pneumoniae (8.1%,100/1,237), Staphylococcus aureus (7.1%, 88/1, 237), Enterobacter cloacae (6.0%, 74/1, 237), and Serratia marcescens (3.5%, 43/1, 237). The most common resistance of S. aureus was to penicillin (77.4%) and ampicillin (73.0%), while no resistance was observed against gentamicin and cephalothin. Although CNS presented resistance to all antimicrobials tested but the most prevalent resistance was to penicillin (35.6%) and ampicillin (37.0%). The pattern of antimicrobial resistance observed in CNS was similar to that of S. aureus, but the rates were much lower than those of S. aureus. E. coli also showed resistance to all the antimicrobials tested, although the rates were not very high. The highest resistance of E. coli was to cephalothin (39.4%) and ampicillin (36.2%), while most of the strains (98.0%) showed sensitivity to amikacin. The results of this study provide information on current situation of bovine mastitis in Korea.

This study was conducted to evaluate the effect of various types of functional brown rice milk porridge, which has been popular as a fast yet nutritional food, to promote rice consumption and to examine the best ratio and recipe. Each sample contained 10, 20, 30, and 40% brown rice compared to non-glutinous rice and sweet rice and were applied to mechanical and sensory tests. The moisture content of both non-glutinous rice and sweet rice porridges increased with increasing brown rice content. The viscosity of non-glutinous rice milk porridge decreased as with increasing brown rice content, whereas the viscosity of sweet rice milk porridge increased with increasing brown rice content. The pH was highest for BRT0 at 6.74 and lowest for BGT0, which is sweet rice porridge with brown rice, at 6.27. The sweetness decreased significantly for both sweet rice and non-glutinous rice porridges with the increase in brown rice content. The brightness of weet rice and non-glutinous rice porridges with brown rice increased significantly (p<0.001) with the increase in brown rice content, while the redness and yellowness of the color increased significantly (p<0.001) with increasing in brown rice content. As a result of analyzing the preference in the milk porridge containing brown rice, BRT30, which is non-glutinous rice milk porridge with brown rice, was most preferred at 5.8 in terms of color, while BRT30 was most preferred at 6.2 in terms of fragrance. All samples containing brown rice powder were highly preferred in terms of taste and the overall preference of sweet rice milk porridge was highest for BRT30 (5.8). The overall preference was highest for BGT30 at 6.1 and the preference was generally higher for the experiment groups prepared with sweet rice as opposed to those prepared with non-glutinous rice. Also, the scores for the sensory test were higher when brown rice was added. Therefore, it was concluded that the milk porridge could quickly and easily be prepared with brown rice instead of non-glutinous rice or sweet rice.

This study aimed to improve the reproductive efficiency of dairy herds by comparison and analyzing estrous appearance rate, conception and non-conception rate according to the stage of lactation using the lactation and reproductive records of average (less than 10,000 liters milk in 305 days) and high yielding (more than 10,000 liters milk in 305 days) Holstein cows (n=102). Milk production and reproduction data were collected between January 2010 and December 2012 from Holstein cows kept in the commercial dairy farms. Average (n=32) and high yielding (n=24) Holstein cows used to analyze the relationship between milk yield and reproductive performance. Our results showed that estrous appearance rate according to the stage of lactation was 25.0% (30∼59d), 40.6% (60∼ 89d), 25% (90∼110d) and 9.4% (>111d) in average yielding cows and 16.7% (30∼59d), 20.8% (60∼89d), 12.5% (90 ∼110d) and 50.0% (>111d) in high yielding cows, respectively. Conception rate according to the stage of lactation was 87.5% (30∼59d), 61.5% (60∼ 89d), 75.0% (90∼110d) and 66.7% (>111d) in average yielding cows and 25.0% (30∼59d), 0% (60∼89d), 33.3% (90∼ 110d) and 50.0% (>111d) in high yielding cows, respectively. Days between parturition and conception was 23.7% (<149d), 0% (150∼209d) and 0% (>210 d) in average yielding cows and 69.0% (<149 d), 77.8% (150∼209d) and 38.9% (>210d) in high yielding cows, respectively. Conception rate from 110 days postpartum in high yielding cows was 41.7% (110∼150d), 50.0% (151∼180d) and 50.0% (>181d). Body condition score (BCS) in 120 days postpartum was 2.64±0.1 in average yielding cows and 2.28±0.1 in high yielding cows, respectively.

An experiment was conducted to study effects of abomasal infusions of casein, glucose or starch on milk production and blood metabolites in dairy cows. Four lactating cows (559±41.9kg) fitted with 100 mm ruminal cannulas were used in a 4 × 4 Latin square experiment. The cows were given access ad libitum to grass silage and received 6.2 kg dry matter (DM) of a mixture of rapeseed meal (5.3kg/d DM) and barley grain (0.9kg/d DM) as a basal diet (CON), the basal diet plus intra-abomasal infusions of 270 g sodium caseinate (CAS), 300 g of glucose (GLU) or 243 g of starch (STA) starting at 09:00 h each day. Abomasal infusion of different nutrients did not affect (p>0.05) grass silage intake and rumen fermentation parameters (rumen pH, ammonia N and volatile fatty acids). As unexpected, milk yield and composition data did not differ between CON and the treated groups (p>0.05). Most of plasma amino acids were not significantly (p>0.05) affected by the abomasal infusions of CAS, GLU or STA except for histidine, tryptophan and glycine. Although histidine, known as the first limiting amino acid in dairy cows fed grass silage based diets, was significantly (p=0.003) increased by CAS, we failed to result in a clear increase in milk yield and protein yield. This discrepancy between plasma AA profiles and milk production could be presumably explained by relatively high concentration of total amino acids in the present study (2,039μmol/l).

Pulsed electronic field(PEF) 처리에 의한 우유 단백질과 물리화학적 특성의 변화를 확인하기 위하여 원유, 탈지유, HTST, LTLT, UHT 우유를 PEF 처리하였다. 시료 중의 단백질을 SDS-PAGE로 확인하였을 때, PEF 처리에 의한 우유 단백질의 변성은 관찰할 수 없었다. Differential scanning calorimetry(DSC)로 우유 단백질의 열변성 정점 온도(Td)를 분석한 결과, 탈지유를 65oC에서 PEF 처리하였을 때 Td가 87.66oC에서 97.18oC로 증가하여 PEF 처리가 우유 단백질의 변성에 영향을 미치는 것을 확인하였다. PEF 처리에 의한 alkaline phosphatase, protease, lactoperoxidase의 잔존효소활성을 측정한 결과, 원유와 탈지유에서 alkalinephosphatase는 PEF 처리에 의해 효소활성이 감소하였다. 또한 protease와 lactoperoxidase의 활성은 PEF 처리에 의해 영향을 받지 않았다. 65oC에서 PEF 처리한 원유는 처리하지 않은 원유보다 높은 갈색도를 나타내었으나, 기타 우유는 PEF에 의한 유의적인 차이가 없었다. 우유를 PEF 처리하였을 경우 산도의 변화는 관찰되지 않았고 pH의 경우에도 PEF 처리 여부에 따라 유의적인 차이는 있었으나 크게 변화하지는 않았다.

Jersey 종은 다른 품종에 비해 총 건물사료 섭취량당 우유 고형분 생산량이 매우 높은 품종이다. 특히 유지방과 유단백질 함량이 높아 시유 뿐 아니라 아이스크림, 요구르트와 같은 다양한 유제품을 제조할 경우 영양적 우수성은 물론 뛰어난 풍미를 제공한다. 또한, Jersey 우유는 소비량이 점차 증가하는 치즈와 같이 고형분 함량에 따라 수율이 결정되는 유제품에 높은 경제성을 부여할 수 있다. 비록 우유 성분들은 같은 품종이라도 사육 조건, 지역 등에 따라 다소 차이를 보이지만 일반적인 Jersey 우유의 주요 특성은 타 품종에 비해 유단백질내 A1/A2 β-케이신 변이체 비율이 낮고 유지방내중쇄지방산의 비율이 높다. 또한 중성 올리고당 함량이 상대적으로 높아 bifidobacteria와 같은 유익한 세균의 성장을 촉진시키는 프리바이오틱 효과를 발휘한다. 그 밖에 칼슘, 인, 마그네슘의 함량과 α-토코페롤 함량이 높아 고품질의 프리미엄 유제품 생산에 바람직한 특성을 가지고 있어 향후 특성화된 제품 개발에 사용 가능하다.

This study was performed to identify the effect of lactic-fermentation of peanut milk on n-hexanal content. Changes in viable cell populations, pH and titratable acidity indicated that there was a synergistic interaction between Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus during fermentation. The analysis of headspace volatiles revealed that n-hexanal nearly disappeared due to fermentation. S. salivarius subsp. thermophilus was more effective than L. delbrueckii subsp. bulgaricus in reducing the n-hexanal content.

본 실험은 조사료와 농후사료비율(조:농비)에 따라 low forage (LF)구 및 high forage (HF)구로 나누어 Holstein 착유소(초산) 10두를 각 5두씩 배치하여 실시하였다. LF구는조:농비가 37:63로 BIRG 사일리지와 혼합건초를 포함한조사료의 급여량을 줄인 반면 농후사료를 다량 급여하였다.HF구는 조:농비가 62:38로 농후사료 급여량을 줄인 반면BIRG 사일리지와 혼합건초를 포함한 조사료를 다량 급여하였다. 평균 조사료섭취량은 LF구 7.1및 HF구 13.0 kg으로 HF구에서, 평균 농후사료 섭취량은 LF구 12.3 및 HF구7.9 kg으로 LF구에서 유의적으로 높았다(p<0.05). 총 사료섭취량은 LF구 19.4 및 HF구 20.9 kg으로 HF구에서 높은경향을 보였으나 유의적인 차이는 없었다(p>0.05). CP,TDN 및 NEL 섭취량은 두 처리구간에 유의적인 차이는없었다(p>0.05). 실제 산유량은 LF구 26 및 HF구 23.9 kg/d으로 처리 간에 유의적인 차이는 없었으나(p>0.05) LF구에서 높은 경향을 보였다. 4% FCM은 LF구 22.8 및 HF구22.3 kg/d 으로 유의적인 차이는 없었다(p>0.05). HF구에서유지방 함량은 높고 MUN 함량은 낮았다. 우유의 C14:0,C16:0 및 C16:1n7 함량은 HF구가 LF구 보다 유의적으로높았으나(p<0.05), 그 외의 우유지방산은 두 처리구간에 차이는 없었다. 이상의 결과로부터 본 연구에서와 같이 급여사료 중 BIRG 사일리지와 수입건초와 같은 조사료를 적절하게 배합하여 다량급여 하여도 착유소(초산우)에 필요한영양소 충족이 가능하여 산유량의 감소가 없는 것으로 사료된다.

본 연구에서는 발효유 제품의 특성과 앞으로의 발효유 시장 동향을 이해하기 위해 국내 유통중인 발효유 제품에 사용된 유산균을 분리·동정하고 그 함량을 조사하였다. 국내 5개 회사의 농후발효유 5종과 호상발효유 5종, 총 10종을 구입하였으며, 유산균 표시함량은 대부분 1×10⁸ CFU/mL이었다. BCP 첨가 평판측정용배지와 BS 한천배지를 이용해 생균수를 측정한 결과, 발효유 10종 모두 1×10⁸ CFU/mL 이상의 유산균을 포함하고 있었다. 본 연구에서 모니터링 검사에 사용된 발효유는 모두 표시함량 및 법적 기준(1×10⁸ CFU/mL 이상)을 만족하고 있음을 알 수 있었다.
균 동정을 위해 분리된 유산균에 대해 Gram 염색을 실시하였다. Gram 양성 연쇄상구균, 간균, 다형성 간균 형태를 관찰할 수 있었으며, Gram양성 간균은 유일하게 sample2에서만 관찰되었다. API CHL, API 20A kit를 이용하여 균동정을 실시한 결과, 발효유 10종 모두에서 관찰되었던 Gram 양성 연쇄상구균은 S. thermophilus(99.2%)였으며, 다형성 간균은 Bifidobacterium spp.(96.2%)였다. 그리고 유일하게 sample 2에서 관찰되었던 Gram 양성 간균은 L. rhamnosus(99.8%)였다. 유산균 초기 접종량, 생장 적온, 필요 영양분, 내산성의 차이로 S. thermophilus, Bifidobacterium spp. 이외의 유산균을 동정할 수 없었지만 국내 발효유 회사는 배양시간의 단축, 잡균의 오염 방지, 그리고 독특한 향미와 맛을 부여하기 위해 2가지 이상의 혼합균주를 사용하고 있다. 현재 소비자들은 맛과 함께 기능성이 강화된 발효유를 선호하고 있다. 이러한 기능성은 유산균주의 생리 및 발효 특성으로 기능성 유산균주를 활용한 다양한 컨셉의 제품이 지속적으로 시판될 것으로 기대된다. 향후 발효유 시장은 고유의 기능성 유산균주 발굴 및 연구를 위해 많은 투자가 이루어질 것으로 사료된다.