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前期，我们在这一版块讨论了农场跛足发病率、分类、起因及达到可能因为其而被淘汰母猪从而影响生产数据的程度。这种影响是非常明显地，已有研究者对此进行了多次介绍。但是，农场中归类为一种或划分为“不明原因”，或“其它原因”，或仅命名为“繁殖困难”的生产损失到底是怎样呢？ 1、因为这些原因而被屠宰淘汰的母猪到底发现了什么？真实原因是什么？ 2、非特殊化生产损失如不规则返情、后备母猪重复性低热等等到底是指什么？ 大多数时候农场主在淘汰母猪时，并不能清晰地鉴别这些问题、判断这些原因、做好正确地记录，这样导致不同类型地非特殊化记录数据增加，生产管理者并不能从中获得任何有用的信息。 我们调查了超过33000白种母猪的淘汰数据记录，其中不明原因淘汰率非常高。 上图1所示，年龄因素占据了淘汰率的一半，剩余的55%则与年龄无关。例如，2015年数据中68000头淘汰母猪中，超过20%的母猪是不明原因的被淘汰，超过25%的母猪是因为特殊繁殖阻碍（如繁殖力低、体力不足、分娩时才发现空怀、低热症等）而被淘汰。 从表面来看，跛足问题仅占据5%的淘汰率。鉴别跛足时一般都是不可治愈，母猪已经不能正常行走、不进食、流产等症状。但实际上，并没有哪个农场对母猪的蹄部损伤或不正常流产母猪作定期检查，或将还没有出现上述明显症状的母猪单独处理。 在过去的10个月里，我们参观了许多农场，调查这些农场是否对跛足问题产生怀疑，客观地收集了蹄部疾病发生率，以确定本地区的真实情况。并最终尝试找出这些数据与可用地非特殊原因淘汰率（每年超过30000头）数据间的相关性。 从首先的550头母猪的记录数据发现蹄部问题数据与繁殖问题数据并没有联系。 为了尽可能地避免主观性，我们只收集有数值的数据。 为了统一标准，由同一个人负责在线兽医培训，且作第一次评估。之后，这些兽医将各自农场的实地数据传送至数据库。 所有的病变均是在封闭的形式发现，根据受损程度划分为1-3级。如果母猪没有任何损害，那不作计录。
1、踵过度生长和腐蚀 2、底部或侧部裂开 3、白线 4、蹄壁水平裂开 5、蹄壁垂直裂开 6、大足趾的过度生长 7、次足趾的过度生长
对每个农场10%的母猪再次观察，确定是否存在跛足问题。记录是完全随机，遵守母猪群结构。例如，如果母猪群中后备母猪占23%，那么将会随机选择23%的初产母猪进行调查。
Lameness blindness （1/2） On previous occasions, we discussed?in this section the prevalence of lameness on farms, its classification and original causes, and to what extent it may affect production data under the heading “lameness” as the registered reason for the removal of sows. This effect is clear and has been repeatedly demonstrated （Anil et al. 2009; Ehlorsson et al. 2009; Pluym et al. 2013）。 But… what about data from production losses of one kind or another classified as “unknown”, “other” or some vague names such as “reproductive problems”?
Most of the time the farmer, which is the person diagnosing the reasons and recording them when sending the sow for slaughter, is unable to clearly identify the source of the problem, which results in a large number of different types of unspecific records from which it is impossible to draw any useful information for the production manager. The database available to us （over 330,000 white sows） contains many, even too many, unspecific causes listed as the reason for selling sows for slaughter. As shown in Figure 1, age accounts for almost half of reasons to slaughter a sow, the other 55% not being related to it. For example, in 2015 the reason listed for sending almost 68,000 sows to slaughter —more than 20% of the sow census—， was “other” or “unknown”. More than 25% of sows are slaughtered due to more or less specific reproductive reasons, such as “low productivity”, “lack of heat”, “found empty at farrowing”, “weak heat” and so on. Apparently, lameness problems amount to just 5% of the causes for sending pigs to slaughter. Lameness are usually diagnosed when healing is unlikely; as a general rule, the sow is already recumbent, not eating, has miscarried, or its gait is greatly affected. However, virtually no farm routinely examines sows with hoof injuries or a slightly abnormal gait, let alone sows that show none of these problems. For the last 10 months, we have visited different farms —where lameness problems were or were not suspected—， objectively collecting data on the incidence of hoof injuries in order to draw a map of the real situation in our country, and finally link these data to the records available of shippings to slaughter due non-specific causes （more than 30,000 per year）。 This article describes the first trends extracted from the data of the first 550 sows investigated, data related not yet linked to reproductive data. Methodology for data collection is numerical, in order to avoid subjectivity as much as possible. To unify the criterion, the same person is responsible for training veterinarians on line and making the first assessments with them. Subsequently, these veterinarians send data from their farms to add to the database. All the lesions are captured in a closed form, and rated from grade 1 to grade 3. If the sow does not have any injuries, an injury is recorded with no value. The revised injuries are:
Other data captured for the sows are: farrowing number, physiological state （lactation, nulliparous, pregnant…）， location and additional remarks such as: does not eat, bad farrowing… or any other significant incident. 10% of sows are reviewed on each farm, whether hoof lesions are suspected or not. Recording is completely random and always distributed according to the existent census structure: i.e., if there the holding has a 23% of gilts, 23% of the sows inspected will be on their first farrowing （Figure 2）， but randomly selected. |
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