地域に根ざした総合的乳牛管理技術の確立

• 資料種別: 博士論文
• タイトル: 地域に根ざした総合的乳牛管理技術の確立
• 著者・編者: 久保田, 学
• 出版年月日等: 2014-03-25
• 出版年（W3CDTF）: 2014-03-25
• 並列タイトル等: Establishment of comprehensive dairy herd management and support techniques for the area based on regional characteristics in northern Japan
• 授与機関名: 酪農学園大学
• 授与年月日: 2014-03-25
• 授与年月日（W3CDTF）: 2014-03-25
• 報告番号: 乙第127号
• 学位: 博士（農学）
• 博論授与番号: 乙第127号
• 本文の言語コード: jpn
• 一般注記: The recent dairy farms in Hokkaido have been increasing the amount of production milk yield by the scale expansion of production facilities and increase in the number of cows. A new machine and a new technology were adopted, and dependence on concentrate feeds became higher in the nourishment of the cow. Furthermore, the production system in dairy farms changed from grazing to housing to maintain stable milk production and stable milk quality. A figure of grazing style in dairy farms disappeared in Hokkaido day by day. It is raised as one of the main factors that it created such situation to have evaluated a production system in dairy farms focused attention an economic aspect. In such a background, it was suggested that we have to evaluate a dairy farming system totally. The evaluation by 5 indexes of economic balance, energy balance, environmental load, animal health and human satisfaction was carried out in Hamanaka Town. The results were suggested the possibility that a large amount of concentrate feeds leads to aggravation of animal health, and then a long-term plan in the town has been promoting from intensive to grazing dairy farming. Therefore, the aim of this study was to clarify checkpoints about the direction of grazing practical use and the fall of the feed cost to milk receipt ratio (F/M ratio), and to establish comprehensive dairy herd management and support techniques for the area based on regional characteristics. Total 53 dairy farms were chosen in Anebetsu district, Hamanaka Town, as eastern Hokkaido, Japan. Those farms have joined Japan Agricultural Cooperation (JA) of Hamanaka-cho since 1996. In chapter II, I compared the situation of the farm, which included productivity, economy, cow health and reproductive performance, between grazing and housing system. Furthermore, I divided into three groups by the levels of F/M ratio and analyzed the situation of the farm as described above. As a characteristic of grazing, the number of cows decreased, the rate of the agriculture income was high, and the rate of death and abolished cows to the number of farm cows decreased. As a characteristic of the falls of F/M ratio in the farm, the productivity was no change, the rate of the agriculture income was high, the rate of death and abolished cows decreased and the number of the somatic cell counts in bulk tank milk decreased. In chapter III, I studied the influence of the type of dairy farm from 1996 through 2010 on productivity, economy, or cow health. The type of farm was divided into four groups based on grazing or housing, which groups were 1) continued grazing, 2) continued housing, 3) switched from housing to grazing and 4) switched from grazing to hosing from 1996 through 2010. By the analysis, in the type of dairy farm which continued grazing and which switched from housing to grazing, the number of cows decreased, amount of production was maintained, the stocking density in the land area (the number of cows /ha) was appropriate, the economy was high or stable management, and the health condition of the cow was good. In chapter VI, I investigated a typical farm which changed from housing style with high F/M ratio and high milk production to grazing style with low F/M ratio. The farm had been more than 30% F/M ratio to keep the cow with high-yield milk production. Productivity and economy in the farm had not changed, but production disease had increased and the animal health had been worse. The farm has switched from hosing to grazing and decreased the amount of concentrate feeds since 1993. As the result, the number of cows, the milk yield in an individual cow and the amount of milk production in the farm decreased, nevertheless, the production cost was reduced and an agriculture net income was maintained. In addition, the reproductive performance decreased a little nevertheless, the number of production disease decreased, the average of parity number in cows increased, and longevity characteristics increased clearly. I conducted the metabolic profile test(MPT）4 times a year, May 1995 – February 1996, to understand the change in cows around grazing. First, there was low dry matter intake (DMI), high protein and low energy during grazing period. Secondly, there was low energy during housing period. In addition, it was revealed that during grazing period it became strained the liver. I summarized these results focused on about directionality of grazing and the fall of F/M ratio. The number of heifers decreased, the productivity decreased, and the reproductive performance decreased a little, nevertheless, cow health condition became better, longevity characteristics increased clearly, and the economy was maintained and stable. It is necessary for dairy farmers to have stable dairy herd to aim at the stabilization of productivity and economy. I propose the following checkpoints for the establishment of the comprehensive dairy herd management and support techniques as directionality of grazing and the fall of F/M ratio from this study. Checkpoint 1 about the health condition of cows. ① Low energy during both grazing period and housing period ② Low DMI during both grazing period and housing period ③ High protein during grazing period ④ Stress to liver during grazing period Number ①, ②, and ③ were monitored by milk protein, milk fat and milk urea nitrogen, respectively, which were milk ingredients in the bulk tank. We should use it for monitoring cow health as much as possible. Checkpoint 2 about the stability of dairy herd. ① Decrease in reproductive efficiency ② Decrease in the number of production disease ③ Decrease in the number of death and abolished cows ④ Increase in the number of parity of cows ⑤ Decrease in the number of cows (as an appropriate range of stocking density) If we cannot confirm these checkpoints in the switching farm, it is necessary to confirm directionality of grazing and the fall of F/M ratio once again. In this case, firstly we should check checkpoint 1, because it is thought that a problem of cow health condition happens, To a future problem, we have to enlighten an effective grazing method while watching a monitor of bulk tank milk ingredients. One more, we have to suggest a reduction method for directionality of the fall of F/M ratio. In conclusion, the dairy farm is run in various environment including land condition and climate condition. The recycling dairy farm of the self-conclusion type is necessary so that the dairy farm system in grass land continues. To that end, the viewpoint of the stocking density as the environmental problem is important. The global cereals supply and demand is tight more and more. We never forget to produce milk and meat from the cow which is a grazing animal. Whenever we stat to design every study of livestock agriculture, we have to globally recognize what is our on-site background, and then we build up the general dairy farm system adapted to the local conditions. Therefore, it is necessary to keep thinking about switching over from housing style to grazing style as utilization of grass resources and reduction of concentrate feeds derived from cereals.; 開始ページ : 1; 終了ページ : 126
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• 収集根拠: 博士論文（自動収集）
• 受理日（W3CDTF）: 2016-06-03T01:05:16+09:00
• 作成日（W3CDTF）: 2017-09-19
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• 掲載誌（URI）: http://hdl.handle.net/10659/3400
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