Departamento de Medicina Animal/Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
Departamento de Zootecnia/Faculdade de Agronomia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
J Anim Sci. 2020 Mar 1;98(3). doi: 10.1093/jas/skaa075.
The effect of increasing the feed level (1.8, 2.5, and 3.2 kg/d) during early gestation in parity 1 (PO1) and parity 2 (PO2) sows on maternal growth and litter size was evaluated. A total of 361 sows were group-housed and fed a diet based on a corn-soybean meal (3.15 Mcal Metabolizable Energy (ME) per kg and 0.68% standardized ileal digestible lysine) from day 6 of gestation until day 30. Sows were weighed at weaning and on day 30 of gestation. Farrowing rate, number of total piglets born, piglets born alive, stillborn piglets, and mummified fetuses were recorded at farrowing. The effect of feed level on the total number of piglets born was also evaluated according to classes of body weight (BW), body condition score (BCS), backfat (BF), and caliper unit at weaning for each parity order. There was no evidence for significant effect of the interaction between feed level × parity on the variables related to maternal growth and reproductive performance (P ≥ 0.128). Greater feed levels linearly increased the gains in body condition (i.e., BW, BCS, BF, and caliper unit) between weaning and day 30 of gestation (P < 0.001). Farrowing rate was not influenced by the feed level (P ≥ 0.200) and parity (P ≥ 0.209). The number of total piglets born decreased linearly as the feed level increased (P = 0.041), whereas no evidences for differences were observed on piglets born alive among treatments (P ≥ 0.317), neither between parities (P ≥ 0.904). For PO1 sows, the total piglets born on BW classes (≤183 vs. >183 kg) and on classes of BF (≤11.5 vs. > 11.5 mm) were quadratically affected by the feed levels (P ≤ 0.041). In contrast, the number of total piglets born was marginally affected (linear; P ≤ 0.094) by the feed level in the different classes of BW, BCS, and caliper unit in PO2 sows. There was no evidence for differences for the interaction of feed level and classes of body condition (P ≥ 0.199) for PO2 sows. Similarly, no interactions between feed level and classes of BW, BCS, and BF at weaning were observed (P ≥ 0.233) for PO1 sows; however, the total piglets born were affected by an interaction between feed level and caliper unit class (P = 0.042). In conclusion, increased feed intake from day 6 of gestation until day 30 resulted in increased maternal BW gain but reduced the number of total piglets born. Furthermore, lighter and in a poor BCS PO1 sows at weaning produced fewer total born piglets with no benefits from greater amounts of feed.
在第 1 胎（PO1）和第 2 胎（PO2）母猪妊娠早期分别提高 1.8、2.5 和 3.2kg/d 的采食量，评估其对母体生长和窝产仔数的影响。361 头母猪采用基于玉米-豆粕（代谢能 3.15 Mcal，可消化赖氨酸 0.68%）的日粮，在妊娠第 6 天至第 30 天进行群养。母猪在断奶和妊娠第 30 天进行称重。分娩时记录产仔率、总产仔数、活产仔数、死产仔数和木乃伊化胎儿数。还根据每个胎次的体重（BW）、体况评分（BCS）、背膘（BF）和断奶卡尺单位类别，评估采食量对总产仔数的影响。采食量×胎次对母体生长和繁殖性能相关变量无显著互作效应（P≥0.128）。较高的采食量线性增加了断奶至妊娠第 30 天之间的体况（即 BW、BCS、BF 和卡尺单位）增益（P＜0.001）。产仔率不受采食量（P≥0.200）和胎次（P≥0.209）的影响。随着采食量的增加，总产仔数线性减少（P=0.041），但处理组之间的活产仔数没有差异（P≥0.317），胎次之间也没有差异（P≥0.904）。对于 PO1 母猪，BW 类别（≤183 与＞183kg）和 BF 类别（≤11.5 与＞11.5mm）的总产仔数受采食量的二次影响（P≤0.041）。相比之下，PO2 母猪 BW、BCS 和卡尺单位的不同类别中，总产仔数仅受采食量的线性影响（P≤0.094）。PO2 母猪的采食量和体况类别之间没有交互作用的证据（P≥0.199）。同样，PO1 母猪 BW、BCS 和 BF 断奶时采食量和类别之间没有观察到互作（P≥0.233），但总产仔数受采食量和卡尺单位类别互作的影响（P=0.042）。总之，妊娠第 6 天至第 30 天增加采食量会增加母体 BW 增益，但会减少总产仔数。此外，断奶时体重较轻且体况评分较差的 PO1 母猪产仔数较少，而增加采食量并不能带来益处。
