• Journal of Life Science
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• v.25 no.10
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• pp.1148-1155
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• 2015

Commercial complete feeds contain enough nutrients to support animal growth and it is easy to be spoiled under proper temperature and humid conditions. The aim of this study was to investigate microbiological and chemical changes on complete feed for milking cow under open-air exposure with moisture 33% at 30℃ during 15 days. pH decreased 6.29 to 4.66 and water activity decreased gradually 0.99 to 0.95. Bacteria increased 6.2×10⁶~1.6×10⁷ to 2.1×10⁹ CFU/g at 5 days and showed 10⁸ CFU/g until 15 days. Fungi increased 10³ CFU/g to 8.0×10⁴ CFU/g. During the processing of spoilage, bacteria such as Acinetobacter oleivorans, Pediococcus acidilactici, Acinetobacter oleivorans, Weissella cibaria, and Methylobacterium komagatae were identified and fungi such as Fusarium sp. and Mucor sp. were also identified. Moisture content increased until 10 days (p<0.01). Crude protein was not changed so much whereas crude fat decreased 6.0% to 5.5% (p<0.01). Crude fiber and crude ash changed 2.0~ 3.0% and 4.5~ 4.8% levels with no significance, respectively. Gross energy was not almost changed at 4,400 kcal/g. During spoilage, lactate and propionate increased whereas acetate was not detected. Protease and lipase activities increased significantly during spoilage (p<0.01). Zearalenone content increased 59.2 μg/kg to 623.8 μg/kg, showing 10.5 times more production. During feed spoilage, pH decreased with microbial growth and various chemical changes were occurred.

• Journal of Food Hygiene and Safety
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• v.2 no.3
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• pp.109-119
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• 1987

This Study was conducted to provide fundamental data necessary for the improvement of milk quality. Milk quality was evaluated by 3 methods; milk fat percent measurement, methylene blue reduction test (MBRT), and somatic cell count measurement. At the same time, condition of hygienic management of dairy facilities and cows was investigated in each of 234 dairy farms located in Gyunggi area from May, 1986 to April, 1987. The results were as follows 1. Average milk fat percents among farms were 3.67%, 3.64%, 3.43%, 3.48% in January, April, July and October, respectively. The diUerences of milk fat percent from month to month were statistically significant (p<0.005). and the seasonal average was 3.56%. 2. Numbers of farms which produced bulk milk of first grade by MBRT were 153(65.4%), 157(67.1%), 76(32.5%) and 141(60.2%) in January, April, July and October, respectively. The diUerences among months were statistically significant (p<0.005). Also, significant diUerences of grade by milking quantity (p<0.05), presence of milk cooler (p<0.01), and collection means (p<0.05) were demonstrated. 3. Number8 of farms which produced bulk milk of fir8t grade in somatic cell count measurement were 227(97.0%), 226(96.6%), 218(93.2%) and 223(95.3%) in January, April, July and October, respectively. And diUerences of grade by the pratice of teat dipping, dry cow therapy and manner in which udder washing towel was used statisticaJJy 8ignificant (p<0.01).

• Korean Journal of Animal Reproduction
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• v.24 no.1
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• pp.19-33
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• 2000

Eighty dairy farms (38 farms responded) in Palmerston North area of New Zealand were questioned by mail questionnaire on: 1) general characteristics, 2) milk yield and feed supplementary, 3) reproductive efficiencies (12 questions) and 4) reproductive disorders (12 questions) from February to July, 1998. Among those 4 items, the reproductive efficiencies (3) and disorders (4), various diseases and culling rates were surveyed and analyzed for Korean dairy farmers (especially in Cheju island) and compared with New Zealand. The results are as follows: 1. Fifteen farms in 38 dairy farms relied entirely on artificial insemination, the rest of 23 dairy farms (60.5%) raised 5∼6 bulls to increase conception rate. The dairy farmers in Palmerston North used artificial insemination from Oct 4th to Dec 10th for 42.8 days, and then used bulls from that point to coming Jan 10th for 41.4 days. The submission rate within 3, 6 and 10 weeks following the initiation of AI season was 84.7, 93.9 and 97.9% respectively. 2. The average age of heifers at the first estrus, pregnancy and calving was 11.0, 18.0 and 24.7 months respectively, and an average 1.4 estrus cycles were required for conception. The intervals of estrus recurrence and the following conception after calving were 38 and 68 days respectively. 3. Among inseminated cows, calving, abortion and empty cow was 90.9, 1.6 and 7.4% respectively. Calving rate decreased according to increasing farm size, while the number of empty cows decreased. 4. Stillbirth, retained placenta and delivery abnormalities were 5.3, 3.7 and 5.5% respectively, not different depend on herd size. 5. The incidence of milk fever, grass tetany, and ketosis was 3.6, 3.0 and 1.0%, respectively. The delivery abnormality and mastitis treated with medicine were 3.1 and 6.7%, but decreased according to farm size. Lameness was 8.6% on average, but over 10% in farms which has more than 400 milking cows. 6. Among the culled cows (15.5% of the total), those culled due to an old age, lameness and other diseases were 2.9, 1.8 and 4.3% respectively and those culled due to low milk production, reproductive abnormality reduced with farm size. 7. Compared with the data collected in Korea, the reproductive efficiency was better, and lameness, metabolic problem and culling rate were higher in New Zealand