Early weaning to reduce tissue mobilization in lactating sows and milk supplementation to enhance pig weaning weight during extreme heat stress1,2

Abstract

This study was conducted to determine the effect of reduced lactation length and supplemental milk replacer (MR) during high ambient temperatures. Thirty nine primiparous and 100 multiparous sows (PIC, Franklin, KY, C-22) were used in a 2 x 2 x 2 factorial arrangement of treatments. Treatments consisted of two lactation room temperatures (21 degrees C [TN] and 32 degrees C [HOT]), two lactation lengths (14 or 19 d), and two parity groups (primiparous, multiparous). Pigs were either: 1) sow-reared to 19 d or 2) sow-reared to 14 d, and then reared to 19 d with MR after sow removal. All sows were fed the same diet (1.07% lysine, 3,366 kcal of ME/kg). Sows were weighed and ultrasound for backfat thickness (BF) and longissimus muscle area (LMA) within 6 h after farrowing and at the time of sow removal (d 14 or 19). Pigs were individually weighed at weaning (d 19) and after a 47-d nursery period (d 66). Heat stress increased sow weight loss (-13.35 kg, P < 0.01) and decreased sow feed intake (4.63 kg/d, P < 0.01) during lactation compared with sows in TN (+4.5 kg and 7.5 kg/d, respectively). Early weaning (d 14) during heat stress decreased maternal weight loss (-10.1 vs. -16.6 kg, P < 0.01). Primiparous sows lost more BF in both environments (-2.60 vs. -1.56 mm, P < 0.05), and both parity groups lost more BF (-3.35 vs. -2.3 mm, P < 0.10) and LMA (-1.82 vs. -0.77 cm2, P < 0.05) when lactating for 19 d in the HOT environment than those lactating for 14 d. Pigs nursing primiparous and multiparous sows in the HOT environment and provided MR had heavier individual 19-d weights (7.37 and 8.12 kg/ pig, respectively) than those nursing to 19 d (5.57 and 6.04 kg/pig, P < 0.01). Milk replacer decreased the difference normally observed in 19-d weights between primiparous and multiparous sow-reared pigs in TN. Pigs fed MR in both environments and nursing multiparous sows had improved weight gains in the nursery compared with pigs nursing sows to 19 d (428 vs. 406 g/d, respectively; P < 0.01), or reared by primiparous sows (444 vs. 390 g/d , respectively; P < 0.01). Sow weaning on d 14 in the HOT environment decreased the wean-to-estrus interval in primiparous sows (22.8 vs. 9.2 d, P < 0.10). This study shows the benefit of early weaning in combination with milk replacer to preserve the sow and to restore pig weaning weights and nursery end weights under heat stress.

The dynamics of changes in selected parameters in relation to different air temperature in the farrowing house for sows

“…This finding is not in compliance with that reported by Spencer et al (2003), i.e. high room temperatures during lactation decrease milk production, piglet growth rate and reproductive performance of the sow.…”

Do nurse sows and foster litters have impaired animal welfare? Results from a cross-sectional study in sow herds

“…Jarvis et al (2006) and Cronin et al (1991) have demonstrated that extended confinement may lead to chronic stress responses. In general, the body reserves of lactating sows are depleted throughout lactation (Spencer et al, 2003) and, it is known that poor body condition may increase the risk of shoulder Animal welfare of nurse sows lesions (Zurbrigg, 2006;Knauer et al, 2007). Thus, we expected a higher incidence of shoulder lesions in nurse sows due to a longer lactation length and thus a higher risk of poor body condition.…”

Effect of feeding liquid milk supplement on litter performances and on sow back-fat thickness change during the suckling period

“…For example, supplementing diets with L-carnitine during lactation sows resulted in higher milk yields than the controls for days 11 and 18 of lactation. Highly significant breed difference was found in the amount of milk produced and in the average size of the litter suckled, whereas a significant difference was found in the average litter weight at the end of the suckling period (Allen and Lasley, 1960;King et al, 1997;Ramanau et al, 2004;Spencer et al, 2003).…”