Piglet birth weight and litter uniformity: Effects of weaning-to-pregnancy interval and body condition changes in sows of different parities and crossbred lines1

Abstract

Piglet birth weight and litter uniformity were studied in sows of different parities and crossbred lines in relation to: 1) weaning-to-pregnancy interval (WPI) and 2) sow body condition changes (in BW and backfat thickness) during lactation and gestation in sows with a short WPI (≤7d). At the Institute for Pig Genetics (IPG) research farm, individual piglet birth weights and sow body condition (BW and backfat thickness at farrowing and weaning) were measured for 949 TOPIGS20 and 889 TOPIGS40 sows with >4 total born piglets, inseminated between 2003 and 2011. In all analyses, mean piglet birth weight and birth weight SD and CV were corrected for total number born. Total number born was greater in sows with a WPI of 8 to 21 d (+1.2 piglets; n = 72) and >21 d (+0.7 piglets; n = 182), compared with sows with a WPI ≤7 d (P < 0.01; n = 1,584). Mean piglet birth weight was not affected by WPI. Birth weight SD (-23 g) and CV (-1.7%) were lower in sows with a WPI >21 d, compared with sows with a WPI ≤7 d (P < 0.01). Effects of WPI were independent of sow parity. Effects of body condition changes in sows with a WPI ≤7 d were studied separately in TOPIGS20 sows inseminated between 2006 and 2011 (n = 808), and in TOPIGS40 sows inseminated between 2003 and 2008 (n = 747). Sow body condition loss during lactation was not related with subsequent total number born or mean piglet birth weight. Only in TOPIGS20 sows, more BW loss during lactation was related with greater subsequent birth weight SD (β = 0.83 g/kg, P < 0.01; β = 1.62 g/%, P < 0.01). Additionally, more backfat loss during lactation was related with greater subsequent birth weight SD (β = 5.11 g/mm, P < 0.01) and CV (β = 0.36%/mm, P < 0.01), independent of sow parity. Sow BW increase during gestation was negatively related with total number born [TOPIGS20: β = -0.06 and -0.05 piglet/kg BW increase for parity 2 (P < 0.01), and 3 and 4 (P < 0.01), respectively; TOPIGS40: β = -0.04 piglet/kg BW increase (P < 0.01), independent of sow parity]. Sow BW increase during gestation was positively related with birth weight SD [TOPIGS20: β = 0.63 g/kg BW increase (P = 0.01), independent of sow parity]. Sow body condition increase during gestation was not related with mean piglet birth weight. To conclude, this study shows that litter uniformity is compromised by severe sow body condition loss during lactation and improved in sows with a prolonged WPI. These effects are likely related with (insufficient) restoration of follicle development.

Measurements of body composition during late gestation and lactation in first and second parity sows and its relationship to piglet production and post-weaning reproductive performance

“…And in a recent study in which primiparous sows nursing similar litter sizes were modestly feed restricted (7 kg feed/d versus recommended 8 kg feed/d) during lactation, high weight loss sows had greater loin muscle depth loss over lactation with subsequent reduced implantation sites and embryo viability at day 35 of gestation in comparison to low weight loss dams (Hoving et al, 2012). Wientjes et al (2013) reported that greater body weight and backfat thickness losses during lactation were associated with reduced litter uniformity in the subsequent farrowing as measured by piglet birth weight. Furthermore, sows with increased backfat gain during the subsequent gestation period were negatively associated with total number of piglets born.…”

Relationships between ovulation rate and embryonic and placental characteristics in multiparous sows at 35 days of pregnancy

“…Selection for litter size has been shown to disproportionally increase ovulation rate (OR) and prenatal mortality (Johnson et al, 1999;van der Waaij et al, 2010;Vallet et al, 2014) and OR of 25 to 30 are relatively common nowadays (Patterson et al, 2008;Wientjes et al, 2013). The increase in prenatal mortality with an increase in OR seems due to both an increase in pre-implantation and post-implantation mortality (van der Waaij et al, 2010).…”

Insulin-stimulating diets during the weaning-to-estrus interval do not improve fetal and placental development and uniformity in high-prolific multiparous sows

“…Quesnel, 2009). Insufficient restoration of follicle development at weaning may increase developmental variation within the pre-ovulatory follicle pool, as may be deduced from the recently found negative and linear relation between sow body condition loss during lactation and subsequent litter uniformity (Wientjes et al, 2013). In a previous study, in which sows lost 12.0% 6 0.5% of their BW during lactation, plasma insulin concentrations during WEI were positively related to LH, follicle development and subsequent luteal and embryo development at day 10 of pregnancy (Wientjes et al, 2012b and2012c).…”