Feeding Strategies Before and at Mixing: The Effect on Sow Aggression and Behavior

Abstract

Simple SummarySows in domestic settings are often mixed into new groups of animals, resulting in the need to form hierarchies, causing aggression and related stress. Restrictively fed gestating sows are unlikely to be sated, and are more likely to view food as a limited resource and to be frustrated and aggressive. Creating satiety in sows as they are mixed may be a simple method to reduce mixing aggression. This experiment assessed the provision of different diets; a standard diet (CON) or high (HI) volume of a “standard” diet, or a diet enhanced with lignocellulose (fiber source) fed before mixing (LC) and at mixing (LCM), was studied. There were treatment effects on fight duration, the number of fights, injuries, condition scores, and time spent eating and drinking. These results suggest that feeding a diet containing 2.5% lignocellulose and a standard diet at a high feeding level for four days post-mixing may affect overall aggression within groups and sow satiety levels. Our data found decreased fight numbers and increased fight duration in the LCM compared to the LC treatment, and therefore, feeding the fiber source before mixing affects aggression levels differently than when fed just after mixing. A further understanding of different fiber sources and how their properties affect digestion and sow satiety would enable critical evaluation and use of fiber sources for benefit in reducing aggression at mixing.AbstractHierarchy formation in domestic sows results in aggression and stress, which might be ameliorated through nutritional satiety. The effect on aggression in group housed, gestating sows provided a standard or high volume of a “standard” diet, or diet enhanced with lignocellulose before, at, and after mixing was studied. Ninety-six Large White cross Landrace weaned sows were allocated to: control diet (CON), high volume diet (HI), and lignocellulose-enhanced diet before and at mixing (LC), and after mixing (LCM) (24 sows per treatment). Sows were housed in stalls for 10 days before mixing, when the CON, HI, and LCM groups were fed a standard diet, and in the LC group, a diet enhanced with lignocellulose at 2.5% was given. At mixing, the CON group continued on a standard diet at 2.5 kg/sow per day, HI were fed the standard diet at 4 kg/sow per day for the first four days and 2.5 kg/sow per day thereafter, and LC and LCM were fed the lignocellulose-enhanced diet at 2.5 kg/sow per day. Behavior, salivary cortisol concentrations, lesion number, and condition were recorded on M0, M1, M6, and M14. Reproduction was assessed using pregnancy rate and progesterone measurements. There were several treatment effects on aggression in the sows following mixing. There were significantly lower fight numbers (CON = 0.34 ± 0.03 Log (1 + x) transformed mean and SEM (1.49 untransformed adjusted mean), LC = 0.31 ± 0.04 (1.14), LCM = 0.42 ± 0.04 (0.28), HI = 0.35 ± 0.04 (1.64); p = 0.001) and longer individual fight durations in the LCM group compared to the CON and LC group (CON = 0.88 s ± 0.07 Log transformed mean and S...

Inclusion of wheat aleurone in gestation diets improves postprandial satiety, stress status and stillbirth rate of sows

“…A growing number of studies have indicated that animal welfare is impaired in many conditions and should be improved ( Sapkota et al., 2016 ; Greenwood et al., 2019 ; Maes et al., 2019 ). Gestating sows tend to suffer insufficient satiety frequently due to feed restriction ( De Leeuw et al., 2005 ; Schneider et al., 2007 ; de Leeuw et al., 2008 ; Greenwood et al., 2019 ).…”

“…A growing number of studies have indicated that animal welfare is impaired in many conditions and should be improved ( Sapkota et al., 2016 ; Greenwood et al., 2019 ; Maes et al., 2019 ). Gestating sows tend to suffer insufficient satiety frequently due to feed restriction ( De Leeuw et al., 2005 ; Schneider et al., 2007 ; de Leeuw et al., 2008 ; Greenwood et al., 2019 ). The insufficient satiety of sows can be reflected by their stereotypical behaviors (often referred to as sham-chewing behavior, sniffing behavior and licking behavior) and physical activities (standing, lying, sitting, kneeling and position change) ( de Leeuw et al., 2008 ).…”

Feeding strategies to improve sow satiety in pen gestation housing

“…1 In response, sows may become increasingly frustrated, developing stereotypic behaviors that result in aggressive interactions towards pen mates. [2][3][4] Social hierarchy establishment elicits intense aggression that is generally resolved 2 days after initial mixing, whereas aggression related to pen resources is more chronic 5 and can occur throughout gestation, 1 particularly when sow satiety is not reached. Sow satiety is often measured by assessing self-directed or substratedirected stereotypic behavior.…”

“…Some also suggest that increasing feed allowance for up to 4 days after mixing is beneficial in reducing fights, although there is limited research available that supports this recommendation. 5…”

Animal Welfare and Production Challenges Associated with Pasture Pig Systems: A Review

“…Cinta Senese pigs and their crosses on pasture, preferred to conduct their activities in groups most of the time, particularly during morning hours [34]. In groups, dominance relationships between animals are established with subordinate animals having limited access to resources such as feed, water, preferred space, and receiving most of the aggressions [164].…”