Agroscope, Tioleyre 4, 1725 Posieux, Switzerland.
ETH Zurich, Institute of Agricultural Sciences, Universitätsstrasse 2, 8092 Zurich, Switzerland.
Animal. 2019 Oct;13(10):2223-2231. doi: 10.1017/S1751731119000132. Epub 2019 Feb 26.
The optimized use of dietary nutrients and the accurate knowledge of the growth dynamics of body components is important for efficient pig production. This study aimed at evaluating the growth of carcass components and organs of Swiss Large White pigs from birth to 140 kg BW depending on the CP and amino acid (AA) supply. A total of 66 entire males (EM), 58 castrates (CA) and 66 female (FE) pigs were used. From 20 kg BW onwards, they had either ad libitum access to a control (C) or a diet (LP) with 20% lower CP, lysine, methionine + cystine, threonine and tryptophan content compared to C. The weight of organs, primal cuts and external fat were recorded in eight EM and eight FE; at 10 kg BW, on two EM, CA and FE each, and at 20 kg BW, on eight pigs from each sex. From 40 to 140 kg BW at 20 kg intervals, measurements were recorded on four pigs per sex and dietary treatment. The weight of each component was related to empty body (EB) using allometric regressions. Kidneys were heavier (P<0.05) in C- than LP-pigs and in EM than CA and FE. Above 21 kg EB weight, growth rate of LP-FE overpassed (P<0.05) the one of C-pigs. Consequently, LP-FE had heavier (P<0.05) lean cuts than C-pigs in the finisher period. However, LP-CA and LP-EM displayed lower (P<0.05) weights and growth rates of the lean cuts than C-CA and C-EM. Shoulder and loin weights and growth rates were reduced (P<0.05) in LP-pigs when compared to C-pigs. Growth rates of the ham were greater (P<0.05) in LP-FE than C-FE, whereas in LP-EM and LP-CA they were lower (P<0.05) than their C-counterparts. Total amounts of subcutaneous fat, backfat, ham fat and shoulder fat were lower (P<0.05) in C- than LP-pigs. The total amount of subcutaneous fat, backfat and shoulder fat of C-CA was, regardless of diet, greater (P<0.05) than of C-FE. In the LP group, this difference was even more pronounced. The amount of deposited ham fat was greater (P<0.05) in LP-CA than LP-FE, but not in C-CA v. C-FE. Differences in kidney weights suggested a greater nitrogen clearance required in C-pigs. Overall, dietary restriction and sex did not affect all body parts to the same extent. This study further suggests the possibility to reduce the CP and AA supply in FE without compromising the yield of primal lean cuts or increasing the amount of subcutaneous fat.
优化日粮养分的利用和准确了解体成分的生长动态对高效养猪生产至关重要。本研究旨在评估瑞士大白猪从出生到 140 公斤体重（BW）时胴体成分和器官的生长情况，具体取决于 CP 和氨基酸（AA）的供应情况。共有 66 头纯种公猪（EM）、58 头去势公猪（CA）和 66 头母猪（FE）参与本研究。从 20 公斤 BW 开始，它们可以自由采食对照（C）或日粮（LP），LP 日粮的 CP、赖氨酸、蛋氨酸+胱氨酸、苏氨酸和色氨酸含量比 C 日粮低 20%。在 8 头 EM 和 8 头 FE 中记录器官、胴体切块和外部脂肪的重量；在 20 公斤 BW 时，每头 EM、CA 和 FE 各有 2 头，在 40 公斤 BW 时，每头 EM 和 FE 各有 8 头。在 20 公斤 BW 的间隔内，每头公猪和母猪各记录 4 头。用异速回归法将各成分的重量与空腹体（EB）联系起来。C 日粮组的肾脏比 LP 日粮组和 EM 比 CA 和 FE 更重（P<0.05）。在 EB 体重超过 21 公斤后，LP-FE 的生长速度超过（P<0.05）C-pigs。因此，在育肥期，LP-FE 的瘦肉切块比 C-pigs 更重（P<0.05）。然而，LP-CA 和 LP-EM 的瘦肉切块重量和生长速度均低于（P<0.05）C-CA 和 C-EM。与 C-pigs 相比，LP-pigs 的肩部和腰部重量和生长速度降低（P<0.05）。LP-FE 的火腿生长速度大于（P<0.05）C-FE，而 LP-EM 和 LP-CA 的生长速度则低于（P<0.05）相应的 C 组。C-pigs 的皮下脂肪、背膘、火腿脂肪和肩部脂肪总量较低（P<0.05）。C-CA 的总皮下脂肪、背膘和肩部脂肪无论饮食如何都大于（P<0.05）C-FE。在 LP 组中，这种差异更为明显。LP-CA 的火腿脂肪沉积量大于（P<0.05）LP-FE，但在 C-CA 与 C-FE 之间不存在差异。肾脏重量的差异表明 C-pigs 需要更大的氮清除率。总的来说，日粮限制和性别对不同的身体部位的影响程度不同。本研究进一步表明，可以在不影响主要瘦肉切块产量或增加皮下脂肪量的情况下，降低母猪的 CP 和 AA 供应。
