All pens were 4.12 m long so pen widths for respective treatments were 1) 1.62 m, 2) 2.80 m, and 3) 3.98 m.
Behaviors was registered using a 5-min scan over six 4-h periods on d 95 ± 5 of gestation (only used for this comparison). All sows in each pen or stall were observed. Data were divided into six 4-h time periods across 24 h: periods 1 (0300 to 0700 h), 2 (0700 to 1100 h), 3 (1100 to 1500 h), 4 (1500 to 1900 h), 5 (1900 to 2300 h), and 6 (2300 to 0300 h). These time periods were chosen to reflect daily activity cycles of the sows. For comparison among sows kept in pens at 3 different floor space allowances a more detailed behavioral analysis was obtained. Behavioral frequencies and durations were registered using continuous sampling over a 24-h period on d 90 ± 5 of gestation using video records using a time-lapse video recorder from a subsample of sows (n = 15 sows/gestation space treatment).Three focal animals per pen of equal parity distribution were identified via unique paint markings and assessed over 2 consecutive parities. Both duration and frequencyof behaviors were analyzed from behavioral ethogram for these sows, which included drinking, eating, standing, sitting, lying, ONF on either pen floor or bars, sham-chewing,and aggressive behaviors.
Mean frequencies of behaviors are presented in Table 2. Lying, sitting, and ONF behavior were all affected by gestation space treatment (P < 0.05). Lying was greater (P < 0.05) among sows in pens at 3.3 m2 than among sows in stalls (Table 2). Sows in stalls had more frequent sitting bouts (P < 0.001) than did sows in pens at 1.4, 2.3, or 3.3 m2. Sows housed in pens at 2.3 m2 performed more (P = 0.01) ONF behavior compared with sows in pens at 3.3 m2 (1.3 ± 0.2 occurrences/h). All other behaviors were similar among sows across all space treatments. Sows housed in stalls were observed sitting and drinking more (P ≤ 0.001) and lying less (P = 0.01) than sows housed in pens, regardless of floor space treatment (Table 2).
The control group (sow-pen) was a typical sow group as usually observed in a commercial setting, consisting of first-parity and multiparous sows. Each penconsisted of 4 first-parity and 11 multiparous (parity 2 to 10) sows. The treatment group (gilt-pen) consisted of 4 first-parity sows and 11 gilts. Because familiarity to each other affects aggression among sows and gilts at mixing (Strawford et al., 2008), each pen had approximately two-thirds unfamiliar dyads (unfamiliar pairs of animals), and the proportion of unfamiliar dyads was similar between control and treatment pens. Unfamiliar is defined as sows and gilts that had not been housed in the same group at least during the last 4 wk
No differences in wean-to-mating intervals, gestation length, and litter performance were observed in first-parity sows between treatment and control pens (Table 3). First-parity sows in treatment pens had similar BW at mixing, were heavier (P < 0.01) before the subsequent farrowing, and gained greater weight (P < 0.01) during gestation than first-parity sows in control pens. The BCS and backfat thicknessat mixing and before farrowing were not different for first-parity sows between treatment and control pens.
No differences in injury scores were observed in first-parity sows between treatment and control pens before mixing (Table 3). After mixing, injury score for the body (P < 0.001) and total injury score for an individual animal (P = 0.03) were less for first-parity sows in treatment pens compared with their counterparts in control pens. No differences were observed in injury scores for head and shoulders after mixing in first-parity sows between treatment and control pens.
Frequency, duration, and outcomes (winner, loser, and unsolved) of fights were registered. The winner was defined as the sow that pursued a retreating pig followed by any form of submissive behavior performed by the opponent, and the winner did not receive renewed aggression from the loser for 5 s or more. The loser was defined as the sow that first stopped fighting, turned away from an attack, and tried to flee, and the loser did not show renewed aggression toward the winner for 5 s or more. An unsolved fight was defined as a standoff fight without a clear winner or loser. The intensity of aggression was assessed by parallel pressing, head-to-head knocking, and head to-body knocking. Parallel pressing was defined as sows that stand side-by-side and push hard with the shoulders against each other, generally performed with frequent bites. Head-to-head knocking was defined as a sow delivering rapid knocks with the snout against the head, neck, or ears of the receiver, generally performed with bites as accessory features. Head-to-body knocking was defined as a sow delivering rapid knocks with the snout against any parts of the body behind the ears of the receiver, generally performed with bites as accessory features. The intensity of aggression is greatest in parallel pressing, least in head-to-body knocking, and intermediate in head-to-head knocking. Total duration and frequency of pressing and knocking and outcomes of each fight during each period were calculated for all first-parity sows in each pen.The total duration (Figure 1) and frequency (Figure 2) of all agonistic interactions involving first-parity sows were greater during the first 6 h compared with other periods during the 72-h observation period (all P < 0.001).
Because no interactions between treatment and time after mixing for any aggressive interactions (both duration and frequency) were observed, treatment effect was tested for total duration and frequency of each agonistic interaction during the entire 72 h of the observation period (Table 4). Compared with control pens, first-parity sows in treatment pens fought more frequently (P = 0.01) and tended to fight for a greater period of time (P = 0.08). First-parity sows had more head-to-body fights (P = 0.03) in treatment pens than their counterparts in control pens. In addition, first-parity sows had more parallel pressing (P = 0.04), tended to engage in parallel pressing for a longer period of time (P = 0.08), and won more fights of parallel pressing (P = 0.04) in treatment pens compared with control pens. No differences were observed in the total duration of head-to-body and head to-head knocking, frequency of head-to-head knocking, or wins for knockings or defeats for all agonistic interactions between first-parity sows in treatment pens compared with first-parity sows in control pens.
Johnson - Discussion Panel - Evaluating Sow Housing Decisions
Recent published research on gestation sow housing A. K. Johnson Associate Professor Animal Behavior and Well-being Department of Animal Science, Iowa State University, Ames, IA E-mail: email@example.comIOWA STATE UNIVERSITYDepartment of Animal Science
Search terms for the talk Journal Journal of Animal Science Terms Sow + gestation + housing Time January to December 2012 Search conclusion; n = 4 peer review papers Salak-Johnson et al., 2012 – pen space and effects on behavior and immunity Li et al., 2012 – managing groups Kirchner et al., 2012 – individual feeding in groups Canaday et al., 2012 – lighting and temperatures for stalled sowsIOWA STATE UNIVERSITYDepartment of Animal Science
IOWA STATE UNIVERSITYDepartment of Animal Science
Study objective The primary objective of this study was to determine the impacts of floor space allowance for dry sows in pens (group size constant) and floor feeding on behavior and immune traits. Differential effects of keeping sows in individual stalls vs. pens on traits were evaluatedIOWA STATE UNIVERSITYDepartment of Animal Science
Animals and housing Cross-bred (PIC) sows (n = 217) Pens vs. stalls Pens, flooring was Parity breakdown partially slatted concrete, with a section of solid Parity 1 n = 69 concrete for feeding Parity 2 = 62 Parity 3 = 44 Individual stalls had fully Parity ≥ 4 = 42 slatted floors equipped with concrete feeding troughsIOWA STATE UNIVERSITYDepartment of Animal Science
Treatments 5 sows were randomly allocated to one of four treatments: TRT ONE: 1.4 m2/sow PEN (15.07 ft2) TRT TWO: 2.3 m2/sow PEN (24 ft2) TRT THREE: 3.3 m2/sow PEN (35.54 ft2) TRT FOUR: STALL (2.12 m long x 0.61 m wide) 1.34 m2/sow (14.42 ft2) The EU standard of space requirement in group- gestation housing is 2.23 m2 (24 ft2) for a mature sow, and 1.67 m2 (18 ft2) for a giltIOWA STATE UNIVERSITYDepartment of Animal Science
BehaviorIOWA STATE UNIVERSITYDepartment of Animal Science
Behavior measures When comparing sows in stalls to all pen groups regardless of space allowance; sows in stalls sat and drank more and laid lessIOWA STATE UNIVERSITYDepartment of Animal Science
Take home from this study Behavior serves as an interface between the sow and its environment Relationship is affected by internal and external factors Chief behavioral restraint of stalls is restriction of movement Laid less and sat more ONF occurred most often when sows were housed at 2.3 m2/sow Energetically consumingIOWA STATE UNIVERSITYDepartment of Animal Science
Take home from this study Sows were able to initiate an appropriate and adequate biological response to the environment that enable them to adapt without deleterious effects on health and well-being No one system compared in this study excelled by improving or compromising the sows health and well-being in production agricultureIOWA STATE UNIVERSITYDepartment of Animal Science
IOWA STATE UNIVERSITYDepartment of Animal Science
Study objective Investigated effects of sorting by parity on aggression, associated stress, and performance of young sows in a group-housed gestation systemIOWA STATE UNIVERSITYDepartment of Animal Science
Animals and housing Gestating sows and gilts (Yorkshire × Landrace) were group housed in a straw- bedded hoop barn Barn had 4 pens, which accommodated 15 animals/pen Equipped with individual feeding stalls and a bowl drinker with 2 drinking spaces Space allowance in each pen was 3.7 m2 excluding the area occupied by feeding stalls and the water drinkerIOWA STATE UNIVERSITYDepartment of Animal Science
Treatments Control (sow-pen): observed in a commercial setting (1st parity [n=4] and multiparous sows [n=11]) Treatment (gilt-pen) (1st parity [n=4] and gilts [n=11])IOWA STATE UNIVERSITYDepartment of Animal Science
ReproductionIOWA STATE UNIVERSITYDepartment of Animal Science
Injury Scores; 48-h after mixingIOWA STATE UNIVERSITYDepartment of Animal Science
Aggression; First 72-h Total duration s/h Frequency number/h These numbers are for first parity sowsIOWA STATE UNIVERSITYDepartment of Animal Science
Aggression: First 72-h Gilt-pen vs. Sow-pen Fought more frequently 9 vs. 5.7 fight/h; P = 0.01 Tended to fight for a greater period of time 67 vs. 29.9 s/h; P = 0.08 More head-to-body fights 6.6 vs. 4.5 fight/h; P = 0.03 More parallel pressing 0.8 vs. 0.3 fight/h; P = 0.04 Tended to parallel press longer 43.9 vs. 14 s/h; P = 0.08 Won more parallel pressing fights 46.4 vs. 18.3 %; P = 0.04IOWA STATE UNIVERSITYDepartment of Animal Science
Take home from this study Most fighting involving first parity sows occurred within the 6-h of mixing First parity sows in gilt-pens at mixing (72-h) Fought more frequently Tended to fight longer Won more fights parallel pressing First parity sows in gilt-pens had fewer injuries First parity sows in gilt-pens gained more BW during gestationIOWA STATE UNIVERSITYDepartment of Animal Science
Take home from this study Suggest that farmers should consider dividing their herd into gilt and first parity groups and multiparous (2nd parity+) and house the groups in separate pens to improve well-being and performance of first parity sowsIOWA STATE UNIVERSITYDepartment of Animal Science
Heads up Checkoff funded work – contact 1-800-PORK or Sherrie Niekamp Director Animal WelfareIOWA STATE UNIVERSITYDepartment of Animal Science
THANK YOU FOR YOUR ATTENTIONIOWA STATE UNIVERSITYDepartment of Animal Science