第5回 乳児期の発達:アタッチメントの形成

第5回 乳児期の発達:アタッチメントの形成






An HSUSReport:welface issues with Gestaion Crates for Pregnant Sows

An HSUS Report: Welfare Issues with
Gestation Crates for Pregnant Sows

HSUS レポート: 福祉問題 妊娠中の母豚のための妊娠クレート

Abstract 概要

Throughout nearly the entirety of their 112-115 day pregnancies, most breeding sows in the United States are
confined in gestation crates (also known as sow stalls)—individual metal enclosures so restrictive that the pigs
cannot turn around. Crated sows suffer a number of significant welfare problems, including elevated risk of
urinary tract infections, weakened bones, overgrown hooves, lameness, behavioral restriction, and stereotypies.
Due to concerns for the welfare of intensively confined sows, legislative, industry, and corporate policies are
increasingly phasing out the use of gestation crates.

112 日から 115 日の妊娠期間のほぼ全体を通じて、米国のほとんどの繁殖雌豚は、妊娠クレート(雌豚舎としても知られる)に閉じ込められた個々の金属製の囲いは非常に制限的であるため、豚は回りきれません。 クレート化された雌豚は、次のリスクの上昇を含む、多くの重大な福祉上の問題に苦しんでいます。

Introduction 序章

More than 5.8 million pigs are used for breeding in the U.S.
pork industry.1
In 1969, gestation crates were introduced
into production facilities, and became the most widely used
system for housing pregnant pigs in the 1980s and 90s.2
Gestation crates are individual, concrete-floored metal stalls
measuring 0.6-0.7 m (2.0-2.3 ft) by 2.0-2.1 m (6.6-6.9 ft),
only slightly larger than the animals themselves and so
severely restrictive that the sows are unable to turn around.3
The majority of breeding sows are now confined in these
crates for nearly the entirety of their approximately fourmonth (112-115 day)4
successive pregnancies. In typical
pig production facilities, the crates are placed side by side
in rows, often with more than 20 sows per row and 100 or
more sows per shed.5,6 The crate floors are customarily
constructed with slats to allow manure to fall into a lower pit to separate the sow from her excrement.
米国では 580 万頭以上の豚が繁殖に使用されています。
1980 年代と 90 年代の妊娠した豚を収容するためのシステム.2
0.6-0.7 m (2.0-2.3 フィート) × 2.0-2.1 m (6.6-6.9 フィート)、
約 4 か月 (112 ~ 115 日)4
相次ぐ妊娠。 典型的には
小屋あたりの母豚の数が増えます.5,6 木枠の床は通常

Economic pressure, rather than science or animal welfare, is the driving force behind the use of gestation crate
housing in the U.S. pork industry according to John J. McGlone, professor of Animal and Food Science and Cell
Biology and Anatomy at Texas Tech University and a director of the Pork Industry Institute: “[I]t is the
economic forces that drive pork producers to do things that hurt or stress their pigs.”8

Fortunately, public policy changes are beginning to occur around the globe. Gestation crates were first banned in
Sweden and the United Kingdom,9
but as of January 1, 2013 they are now illegal throughout the entire European
Union, although some countries are not yet compliant.10 In 2010, gestation crates were banned in Tasmania,11
and New Zealand.12 The pork industry has initiated a voluntary ban in the whole of Australia,13,14 and South
Africa is discussing a phase-out by 2020.15,16

Despite the clear international trend, gestation crates remain at present a common animal agribusiness practice
in the United States. In 2001, animal scientists estimated that 60-70% of breeding sows are confined to gestation
crates,17 but a 2012 survey conducted by a University of Missouri economist reportedly found that for pig
production operations with 1,000 or more sows, 82.7% are kept in gestation crates.18

動物および食品科学および細胞の教授であるジョン J. マクグローンによると、米国の豚肉産業における住宅

幸いなことに、公共政策の変更が世界中で起こり始めています。 妊娠クレートが最初に禁止されたのは
しかし、2013 年 1 月 1 日の時点で、それらはヨーロッパ全体で違法になりました。
10 2010 年、タスマニアでは妊娠クレートが禁止されました 11。
アフリカは 2020 年までに段階的に廃止することを検討しています.15,16

米国では。 2001 年、動物科学者は、繁殖雌豚の 60 ~ 70% が妊娠期間に限定されていると推定しました。
17 しかし、ミズーリ大学の経済学者が実施した 2012 年の調査では、豚の
1,000 頭以上の母豚を生産する場合、82.7% が妊娠クレートに保管されます.18

Recent policy changes in the United States have indicated a clear move away from gestation crate practices,
however, and nine U.S. states have now enacted legislative bans. In 2002, Florida voters legislated against the
use of gestation crates, with the ban going into effect in November 2008.19 In 2006, Arizonans passed the
Humane Treatment of Farm Animals Act, a voter proposition that disallows both gestation crates for pregnant
sows and crates for calves raised for veal beginning January 1, 2013.20 In 2007, Oregon became the first state to
ban the use of gestation crates through the state legislature, a ban effective on January 1, 2012.21 Colorado
followed suit in 2008, banning crates for both calves raised for veal and pregnant pigs with a ten year phase-out
period.22,23 A November 2008 ballot measure in California, which passed with 63.5% of the vote, bans gestation
crates, veal crates, and battery cages for egg-laying hens, effective January 1, 2015.24,25,26 In May 2009, the
Maine legislature passed a law banning gestation stalls for sows and veal crates for calves throughout the state,
effective January 1, 2011.27 Michigan followed in October 2009, with passage of state legislation that will phase
out veal crates and gestation crates within ten years.28 In 2010, an agreement in Ohio led to a comprehensive set
of rules banning the use of gestation crates for pregnant sows after 2025, among other animal welfare
improvements.29,30 In 2012, the state of Rhode Island enacted a legislative ban against gestation crates31 with a
one year phase-out.
Industry shifts have also pronounced movement away from the use of gestation crates. In 2007, Smithfield
Foods, the world’s and United States’ largest pig producer,32,33 and Maple Leaf, Canada’s largest pig producer,34
made corporate commitments to phase-out their use of gestation crates.35,36,37 Said Smithfield Foods CEO Larry
Pope, “Our own research has demonstrated that group pens are as good as individual gestation stalls in caring
for pregnant sows.”38 In 2013, Smithfield announced that nearly 40% of sows in its U.S. company-owned farms
were group housed, and their international hog-production operations in Poland and Romania are already using
group housing, while Granjas Carroll de Mexico and Norson joint ventures in Mexico are expected to complete
the transition by 2022.39 Cargill has reached 50% gestation crate-free production,40 and in January 2012 Hormel
announced that it would require all of its company-owned facilities to be converted to group housing by 2017. 41
Following the continued state legislation and shifts by major pork suppliers, progress in the retail sector has
come swiftly in the United States, at an increasing pace. In 2007, celebrity chef Wolfgang Puck committed to
purchasing pork from only gestation crate-free sources for all of his restaurants.42 Burger King was the first
major restaurant chain to announce that it would begin requiring gestation crate-free pork suppliers. 43,44 Since
the beginning of 2012, over 40 companies, including Hormel Foods (maker of SPAM),45,46 Denny’s
Corporation,47 McDonalds,48 Wendy’s,49 the Sonic drive-in chain,50 Cracker Barrel,51 CKE Restaurants (owner
of the Carl’s Jr. and Hardee’s chains),52 Oscar Mayer (owned by Kraft Foods),53,54 Heinz,55 Campbell Soup,56
Subway,57 Wienerschnitzel,58,59 Jack in the Box,60,61 Hillshire Brands,62,63 ConAgra,64,65 Dunkin’ Donuts,66,67
Brinker International (owner of Chili’s, Maggiano’s Little Italy brand, and Romano’s Macaroni Grill),68,69
Bruegger’s Bagels,70,71 The Cheesecake Factory,72,73 Arby’s,74,75 General Mills,76,77 and DineEquity Inc. (owner
of IHOP and Applebee’s restaurants)78 have all announced plans for moving away from gestation crates. In
2012, several grocery store giants, including Safeway,79 Kroger,80,81 Costco,82 Supervalu,83 and Harris Teeter
supermarkets84,85 also announced steps toward the elimination of gestation crates. Further, the largest
foodservice company in the world, Compass Group,86 the second largest foodservice company, Sodexo,87 as
well as the foodservice giant, Aramark,88,89 have all pledged to move away from gestation crates in their supply
chains as well.

しかし、現在、米国の 9 つの州が立法による禁止を制定しています。 2002 年、フロリダ州の有権者はこれに反対する法律を制定しました。
2008 年 11 月に禁止が発効されました.19 2006 年、アリゾナ人は
2013 年 1 月 1 日から子牛用に育てられた子豚用の母豚と木枠.20 2007 年、オレゴン州は
2012.21 コロラド
2008 年にこれに続き、子牛用に育てられた子牛と妊娠中の豚の両方のクレートを 10 年間で段階的に禁止しました。
period.22,23 2008 年 11 月にカリフォルニア州で行われた投票法案は、63.5% の得票率で可決され、妊娠を禁止しています。
2015 年 1 月 1 日から、産卵鶏用の木枠、子牛の木枠、バタリー ケージが適用されます 24,25,26。
2011 年 1 月 1 日発効。
28 2010 年、オハイオ州での合意により、包括的なセット
29,30 2012 年に、ロードアイランド州は妊娠クレートを法律で禁止する法律を制定しました。
1 年間の段階的廃止。
産業界の変化により、妊娠クレートの使用から遠ざかる動きも顕著になっています。 2007 年、スミスフィールド
世界および米国最大の養豚生産者である Foods 32,33 と、カナダ最大の養豚生産者である Maple Leaf 34
38 2013 年、スミスフィールドは、米国の自社所有農場の雌豚の 40% 近くが
メキシコのGranjas Carroll de MexicoとNorsonのジョイントベンチャーが完成する見込み
2022 年までの移行.39 カーギルは 50% の妊娠クレートフリー生産に達し、40 2012 年 1 月にはホーメル
は、2017 年までにすべての社有施設を集合住宅に転換することを義務付けることを発表した41。
米国では急速に、ペースが増しています。 2007 年、有名シェフのウルフギャング パックは、
彼のすべてのレストランで、妊娠クレートのないソースのみから豚肉を購入しました.42 バーガーキングは最初の
大手レストランチェーンは、妊娠クレートフリーの豚肉サプライヤーを要求し始めることを発表しました. 43,44 以降
2012 年の初めには、Hormel Foods (SPAM のメーカー)45,46、Denny’s など 40 以上の企業が
コーポレーション、47 マクドナルド、48 ウェンディーズ、49 ザ ソニック ドライブイン チェーン、50 クラッカー バレル、51 CKE レストラン (オーナー
Carl’s Jr. および Hardee’s チェーンの)、52 Oscar Mayer (Kraft Foods が所有)、53、54 Heinz、55 Campbell Soup、56
Subway、57 Wienerschnitzel、58、59 Jack in the Box、60、61 Hillshire Brands、62、63 ConAgra、64、65 Dunkin’ Donuts、66、67
Brinker International (Chili’s、Maggiano’s Little Italy ブランド、および Romano’s Macaroni Grill のオーナー),68,69
Bruegger’s Bagels、70、71 The Cheesecake Factory、72、73 Arby’s、74、75 General Mills、76、77、および DineEquity Inc. (所有者)
IHOP と Applebee のレストランの 78 はすべて、妊娠クレートから離れる計画を発表しました。 の
2012 年、Safeway、79 Kroger、80、81 Costco、82 Supervalu、83、Harris Teeter などの大手食料品店
スーパーマーケット 84,85 はまた、妊娠クレートの廃止に向けた措置を発表しました。 さらに、最大の
世界のフードサービス企業 Compass Group86、第 2 位のフードサービス企業 Sodexo87、

Crating Pregnant Sows
Within U.S. animal agriculture, breeding sows produce an average of 2.1-2.5 litters each year90 and are typically
first impregnated around seven months of age,91 often through artificial insemination.92,93 A week before
birthing, sows are customarily moved into farrowing crates to nurse their piglets. The piglets are weaned at 17-
21 days old,94 and the sows are re-impregnated a few days later.95 Breeding sows are typically culled after an
average of 3.5 parities.96 Although in decreasing percentages given legislative and industry shifts away from
individually confining pregnant sows, at present, the majority spend nearly their entire approximately fourmonth pregnancies in gestation crates, which prevent the animals from satisfying basic psychological needs and
An HSUS Report: Welfare Issues with Gestation Crates for Pregnant Sows 3
engaging in most of their social and natural behavior,97 including rooting, foraging, nest-building, grazing, and

米国の畜産業では、繁殖雌豚は毎年平均 2.1 ~ 2.5 腹を産みます90。
最初の受胎は生後 7 か月頃91で、多くの場合、人工授精によって行われます92,93。
出産後、母豚は子豚を育てるために分娩用の木枠に移されるのが通例です。 子豚は 17 歳で離乳します。
生後 21 日 94 で、母豚は数日後に再妊娠します 95。
平均 3.5 パリティ.96
現在、妊娠中の母豚を個別に監禁しているが、現在、大部分の母豚は約 4 か月の妊娠期間のほぼすべてを妊娠クレートで過ごしている。
HSUS レポート: 妊娠中の母豚のための妊娠クレートに関する福祉の問題 3

As a result of the intensive confinement, crated sows suffer a number of welfare problems, including poor
hygiene, risk of urinary infections, weakened bones, overgrown hooves, poor social interaction, lameness,
behavioral restriction, and stereotypies. The European Union Scientific Veterinary Committee (SVC) criticized
gestation crates in its 1997 report, “The Welfare of Intensively Kept Pigs,” and concluded: “No individual pen
should be used which does not allow the sow to turn around easily.”100
Crated gestating sows have difficulty moving due to the spatial restriction, lack of exercise, and flooring type,101
whereas group-housed sows have a greater range of movement and show fewer abnormities of bone and muscle
development.102 As well, several factors relating to the construction of gestation crates and the unsanitary
conditions prevalent in pig production facilities may predispose crated sows to disease and/or injury, including:
confinement, slatted floors with sharp corners, rough concrete flooring, lack of bedding, and endemic

行動制限、ステレオタイプ。 欧州連合の科学獣医委員会 (SVC) は次のように批判しました。
1997 年の報告書「集中的に飼育された豚の福祉」の中で、妊娠クレートは次のように結論付けています。
102 同様に、妊娠クレートの建設と不衛生に関連するいくつかの要因

Physical Health Concerns
Virtually immobilized in barren, restrictive gestation crates, the welfare of breeding sows is severely
compromised. Jeremy Marchant-Forde, now a research animal scientist with the U.S. Department of Agriculture
(USDA), and Donald Broom, professor of Animal Welfare at the University of Cambridge, have posited that
difficulty performing the simple movements of standing and lying is indicative of poor sow welfare.105 They
describe that commercial stalls were not designed with the understanding of these movements and note: “With
these dynamic space requirements taken into account, the vast majority of gestation stalls and farrowing crates
are too small in width and length, to allow standing and lying to be carried out without spatial restriction.”106
Other animal scientists have made similar determinations and also suggest that crated sows experience
increasingly severe discomfort as pregnancy advances.107
Indeed, welfare concerns were not the primary consideration in the design of many current housing systems.108
A survey of manufacturers revealed that engineers never used sow measurements during the design of the first
gestation crates.109
Discomfort can be compounded by problems associated with barren crates. Without any bedding materials, sows
have no thermal protection, which can cause systemic and local cold stress, and may contribute to or exacerbate
injuries to skin and limbs.110 Since gestation crates are barely larger than the sow’s body, the animals must
urinate and defecate where they stand. As such, the concrete floors of the crates are often partially or fully
slatted to allow waste to fall into a pit below. Housing the sows directly above their own excrement has been
shown to expose the animals to aversively high levels of ammonia,111 and respiratory disease has been found to
be a significant health issue for pigs kept in confinement.112 Foot and leg disorders, urinary tract infections, and
cardiovascular problems are also of concern for crated sows, who additionally suffer traumatic injuries and body
sores often caused by being forced to stand and lie on unnatural flooring or in residual feces and urine. Research
led by Broom found 33% of crated sows required removal from production as a result of health problems,
compared with less than 4% of group-housed sows.113
Injury Due to Gestation Crate Design
Space restriction in gestation crates is a significant cause of injuries to pregnant sows. Intensively confined,
crated sows experience soreness and injuries from rubbing against the bars of their enclosures and from standing
or lying on barren flooring.114 As gestation crates are narrow and typically placed side by side within pig
production facilities, when lying down, sows must extend their limbs into adjacent stalls where they may be
stepped on.115 The slatted floors often have sharp corners that can injure exposed limbs and sows who slip in the
crates.116 Food-deprived sows can also suffer head and snout injuries from attempting to access an adjacent
stall’s feeder.117 Research has shown that rates of injury increase with time spent in the gestation stall.118 Despite
An HSUS Report: Welfare Issues with Gestation Crates for Pregnant Sows 4
concerns regarding injuries and research showing that providing extra stall space can considerably reduce
injuries and improve breeding sow welfare,119 industry observers believe the trend may be towards even
narrower stalls.120 Though stalls have not yet become physically smaller, over time, they have become
effectively smaller compared to the size of the sow. Industry journal National Hog Farmer reported that in
1989, the sow stall was of adequate size to hold the average gestating sow,121 but research from 2004 found that
more than 60% of sows could not fit in conventional stalls without being compressed against the crate’s sides.122

妥協した。 Jeremy Marchant-Forde、現在は米国農務省の研究動物科学者
不快感は、不毛の木枠に関連する問題によって悪化する可能性があります。 敷料なし、雌豚
110 妊娠クレートは母豚の体よりかろうじて大きいので、動物は
立ったまま排尿、排便。 そのため、クレートのコンクリート床は、部分的または完全に覆われていることがよくあります。
廃棄物が下の穴に落ちるようにすのこを付けました。 自分の排泄物の真上に母豚を収容することは、
112 足と脚の障害、尿路感染症、
多くの場合、不自然な床の上に立ったり横になったりすることを余儀なくされたり、残留糞便や尿の中に傷ができたりします. リサーチ
Broom が率いる研究では、クレート化された雌豚の 33% が健康上の問題の結果として生産から除外される必要があったことがわかりました。
集団飼育された母豚の 4% 未満と比較して.113
妊娠クレートのスペースの制限は、妊娠中の雌豚の損傷の重大な原因です。 極度に閉じ込められた、
114 妊娠中のクレートは狭く、通常は豚の体内に並べて配置されます。
115 すのこ床にはしばしば鋭利な角があり、露出した手足や雌豚が滑り落ちて怪我をする可能性があります。
116 食物を奪われた母豚は、隣接する家畜小屋に近づこうとして頭や鼻を負傷することもあります。
ストールのフィーダー.117 調査によると、妊娠ストールで過ごす時間とともに損傷率が増加することが示されています.118
HSUS レポート: 妊娠中の母豚のための妊娠クレートに関する福祉の問題 4
繁殖雌豚のウェルフェアを改善するため、119 業界のオブザーバーは、この傾向は偶数に向かう可能性があると考えています。
120 屋台は物理的にはまだ小さくなっていませんが、時間の経過とともに小さくなりました。
雌豚のサイズに比べて事実上小さい。 業界誌 National Hog Farmer は次のように報告しています。
1989 年当時、母豚舎は平均的な妊娠中の母豚を収容するのに十分な大きさでしたが 121、2004 年からの調査では、
母豚の 60% 以上は、クレートの側面に押しつけられなければ、従来のストールに収まりませんでした.122

Foot and Leg Problems
In their natural habitat, pigs evolved to walk in woodlands and scrub. Putting sows in gestation crates with
unnatural flooring changes the stresses on sows’ feet123 and is considered to significantly contribute to toe
lesions,124 with some reports finding up to 80% of stall-housed sows suffering from this condition.125 Gestationcrate confinement has also been found to excessively
126 cause damage to joints127 and lameness.128,129 Erosion of
the cement floor from water and feed may leave rocks and sharp edges that can contribute to foot, leg, and
shoulder sores,130 and bolts which fix the crates in place can also contribute to similar injuries.13