Dry Sows Research Articles

Intensive (commercial) systems for breeding sows and piglets to weaning

This chapter describes and discusses some of the present day housing systems in the breeding section, dry sow unit and farrowing and lactation units in commercial pig production. These are ‘intensive systems’, wherein an attempt is made to have an efficient use of the available resources in the northern temperate zone. The recent and the future developments are briefly considered. The biological requirements of the animals at the different production stages and the problems encountered are also explained, especially with respect to welfare and commercial requirements. In addition the role of the stockperson for the success of these systems is noted.

The effect of dietary inclusion of sugar-beet pulp on the feeding behaviour of dry sows

AbstractFeeding behaviour of six sows receiving a diet with a high inclusion (500 g/kg) of sugar-beet pulp (SBP) was compared with that of six sows receiving a conventional cereal-based diet (control). The feeding rate was determined for both the rate of consumption of the daily food allowance (SBP or control diet) and of a test portion (of control diet) offered at different intervals after the daily food allowance. SBP sows consumed their daily food allowance more slowly than control sows, SBP sows also consumed the test portion more slowly than control sows, when this was offered immediately after the daily food allowance. Prolonging the time taken to eat the control diet, by presenting it in meal form, did not change the feeding rate of the test diet. Offering the test portion 2 h after the daily food allowance, increased the feeding rate of the test portion for both control and SBP sows, with a smaller but still significant treatment difference. Gastric distension appeared to be a major factor in regulating intake when feeding a diet containing SBP. The extent to which feeding rate could be used as an index of feeding motivation and the welfare consequences of using bulky diets for sows are discussed.

Reproductive performance and aggression between sows re-mixed into small stable groups at different stages during the embryo implantation period following initial mixing at weaning

With the advent of the stall and tether ban in the UK it is now a requirement to house dry sows in groups throughout their pregnancy which necessitates their being mixed with other sows at some point after service. It is generally recommended that mixing sows during the embryo implantation period should be avoided as this is thought to effect embryo survival rates. The object of this experiment was to demonstrate the aggression that occurs between sows after mixing and determine the effect on reproductive performance when mixing sows at different times during the 42 days post-service.294 sows were mixed at six different times during early pregnancy: 0 to 7(T1), 8 to 14,(T2) 15 to 21(T3), 22 to 28(T4), 29 to 35(T5) and 36 to 42(T6) days post service. Six groups of sows from six consecutive weeks weanings were served at the first post-weaning oestrus and kept in stable weekly treatment groups until the sixth group was served.

Factors affecting posture-changing in loose-housed and confined gestating sows

AbstractThe time taken to lie down and stand up was determined for dry sows from different housing systems and related to physical and genetic parameters. In experiment 1, the times taken to lie down by 32 sows in two dry-sow housing conditions were measured. Sows housed long-term in stalls took longer to lie down than group-housed sows (20·42 v. 9·28 s, P < 0·001). Group-housed sows took longer to lie down in the open than to lie down against a wall (11·07 v. 7·48 s, P = 0·004). The length of time taken for stall-housed sows to lie down had strongest association with body length (P = 0·033, R2 = 0·718). The length of time taken for group-housed sows to lie down in the open had strongest association with the proportional weight of the extensor carpi radialis, (P = 0·001, R2 = 0·915). In experiment 2, the times taken for 30 sows in stalls to lie down and stand up were measured and genotype differences investigated. There were no differences between genotypes in total times taken to stand up or lie down, but total times taken to stand up quickly and lie down had strongest association with body length (P = 0·032, R2 = 0·185, and P < 0·001, R2 = 0·574 respectively). The results indicate that sows housed long-term in gestation stalls experience difficulty of movement when standing up quickly and lying down. Although the chronic effects of lack of exercise and the acute effects offloor type may contribute to this difficulty, the major factor is likely to be space restriction as the times taken to lie down and stand up quickly both increase as body length, and hence dynamic space requirement, increases. Lying down in an unrestricted environment is under muscular control and the degree of control depends on the proportion of muscle weight to total body weight. The factors affecting lying down and standing up should be considered when designing dry-sow and farrowing accommodation.

Effects of dry sow housing conditions on muscle weight and bone strength

AbstractConfinement has been shown to affect bone strenth in poultry but this weakness has not been documented in other species housed in confinement. The objectives of this experiment were to compare muscle weight and bone strength in non-pregnant sows, of similar age and parity, housed throughout eight or nine pregnancies in two different dry sow systems: (1) individually in stalls and (2) communally in a large group. Following slaughter, the left thoracic and pelvic limbs were dissected and 14 locomotor muscles removed and c. ???lied. A proportional muscle weight was then calculated by dividing individual muscle weight (g) by total body weight (kg). Where there were significant differences, stall-housed sows had lower absolute and proportional muscle weights than group-housed sows. The left humerus and femur were also removed. The bones were broken by a three-point bend test using an Instron Universal Tester. Both bones from stall-housed sows had breaking strengths that were about two-thirds those of group-housed sows. The results indicate that confinement of sows, with a consequent lack of exercise, results in reduction of muscle weight and considerable reduction of bone strength.

Housing of Pregnant Sows in Loose and Confined Systems–a Field Study. 2. Claw Lesions: Morphology, Prevalence, Location and Relation to Age

A field study of 36 Norwegian sow herds was conducted over a 12 month period, 18 herds had loose housing of pregnant sows and 18 herds had confined (stalled or tethered) dry sows. Fifteen of the loose housing herds had partly slatted concrete floors while 3 herds had other kinds of flooring. The types of claw lesions that were observed in these herds are described. The most prevalent lesions on both loose sows and confined sows were side wall cracks, heel lesions, cracks in the white line and overgrown heels. The lateral hind claws were the most frequent location for lesions and they were more severe than at other sites. These lesions tended to show a bilateral occurrence. More than 96% of slaughtered loose sows and 80% of slaughtered confined sows had at least 1 lesion on the lateral hind claws. The prevalence of claw lesions showed no obvious age pattern. However the prevalence seemed to be lower for the first litter sows and increased slightly thereafter, especially in the confined herds.

Effects of gentling at early weaning or later on goats' reactions to humans

The easy attachment of goats to humans has not been well studied. We compared the effects of gentling at two ages. Norwegian dairy kids were weaned at 1 week, put together, fed artificially, and allocated into three groups: HO animals (n = 8) received no additional contact; Hl animals (n = 9) were individually gentled 5 min twice a day for 10 days after weaning; H6 animals (n = 9) were gentled similarly at 6 weeks of age. Kids were tested at 5 and 7.5 months successively in social isolation ( 1 min), in the presence of a seated person ( 1.5 min) and with a standing person trying to touch the kid ( 1.5 min). At 5 months, HO kids moved more and kept further from the human than Hl and H6 animals (P < 0.05). Hl kids vocalised less when alone and stayed closer to the moving human (P < 0.05) than either H6 or HO animals (time in the human square (mean f SE) HO, 24 f 16%, Hl, 67 & 38%; H6,35 f 34%). At 7.5 months, Hl, but not H6 kids, were closer to the human (P < 0.05) than HO. Kids only sought human contact if they had been previously gentled. Gentling at weaning seems more effective for the establishment of a durable friendly human-goat relationship than gentling at a later age. Dry sow welfare throughout life in one of three housing conditions D.M. Broom, M.T. Mendl, J.N. Marchant Department of Clinical Veterinary Medicine, Cambridge University, Madingley Road Cambridge, CB3 OES, UK

Dry sow welfare throughout life in one of three housing conditions

Dry sow welfare throughout life in one of three housing conditions

Influence of fibrous feed ingredients on voluntary intake of dry sows

The low feeding level for pregnant sows, common in commercial practice, has been linked to the occurrence of stereotypies and, in group-feeding systems, with aggressive competition for feed. Whilst the high intake capacity of dry sows limits any attempts to feed a conventional diet at a higher level without concomitant problems of excessive growth and obesity of the sow, it might be possible to control intake by the use of high fibre diets. The suitability of several fibrous ingredients in diets to be offered ad libitum was investigated in the first experiment. Six diets with a high inclusion level of either unmolassed sugar-beet pulp (SBP), barley straw (BS), oat husks (OH), malt culms (MC), rice bran (RB) or wheat bran (WB) were formulated. A total of 36 sows received one of the diets during a 3-week period. Voluntary feed intake of the SBP diet was significantly lower than that of the other five diets (2.3 kg, 6.4 kg, 7.7 kg, 6.8 kg, 7.6 kg and 7.1 kg day −1 for diet SBP, BS, OH, MC, RB, and WB respectively, SED 0.65, P < 0.001). Apparent neutral detergent fibre and acid detergent fibre digestibilities were highest with diet SBP (0.84 and 0.80 respectively for SBP vs. 0.33–0.51 and 0.13–0.37 for other diets). Sows receiving diet SBP gained only 2.2 kg in weight, while the sows receiving other diets gained between 39.2 and 47.7 kg (SED 6.3, P < 0.001). In the second experiment, four diets with increasing inclusion level of SBP were formulated. A fifth diet was formulated with both a high SBP inclusion level and high energy density. Each diet was offered ad libitum to eight pregnant sows during a 3-week period. Voluntary feed intake decreased from 5.0 to 3.0 kg day −1 (SED 0.30, P < 0.001) when the inclusion level of SBP increased from 400 to 650 g kg −1). The intake of the SBP fraction was 2.0 kg day −1 for all diets (SED 0.20, not significant). Apparent nutrient digestibility increased with increasing inclusion level of SBP. It is concluded that a diet containing a high inclusion level of SBP could give an acceptable level of energy intake if used in an ad libitum feeding system for dry sows.

A Field Study on Group Housing of Lactating Sows with Special Reference to Sow Health at Weaning

Four farms that group-housed sows from 2 weeks of lactation until weaning (G-farms) and 3 farms that kept the sows individually penned throughout the 5 to 6-week-long lactation period (C-farms), were compared in terms of sow health. All sows were crossbred Swedish Yorkshire x Swedish Landrace. The daily food ration was similar on all farms except during the group-housing period, when G-farm sows were fed ad libitum. Sows were grouped in the breeding section and kept grouped on deep litter in the dry sow section on all farms. Individual health examinations were performed at the time of weaning (+/- 4 days) on 179 G-farm sows and on 167 C-farm sows. Teat- and udder skin wounds occurred less frequently (p < 0.001) in G-farm sows than in C-farm sows. In addition, preweaning atrophy of all mammary glands occurred in 6.6% of the G-farm-sows but not in a single C-farm sow (p < 0.001). This indicates that sow-piglet interactions decrease when sows are group housed. However, these differences did not occur in primiparous sows, suggesting that the relation between the primiparous sow and her litter is not affected. Mastitis frequency was the same in the 2 systems. Moreover, the frequency of locomotor disorders was the same in the 2 groups, and hoof overgrowth was common in both systems. These similarities could be due to the fact that all farms group housed dry sows on deep litter. A strong relation (p < 0.001) between hoof overgrowth and locomotor disorders was evident. Low access to food due to low rank among primiparous group-housed sows was indicated by a lower (p < 0.05) backfat thickness compared with multiparous sows, and a higher (p < 0.001) frequency of skin wounds compared with individually housed primiparous sows.

The effects of food level on general activity and aggression in dynamic groups of 30 sows

Aggression in group housed sows is often related to competition over food. Sequential feeding avoids the confrontations at the trough, but puts them at the feeder entrance. Studies of large groups of dry sows using computerised feeding systems showed that vulva biting was most frequent after visits when only a small amount of food had been dispensed (Buré, 1991). This suggests that frustrated feeding motivation may cause increased aggression. A Swedish survey into group housed sows found a link between sow condition and mean injury scores: farms averaging a high injury score had a larger proportion of thin sows (Svendsen et al., 1990). The present study aimed to investigate the hypothesis that in large dynamic groups of sows a high food level results in lower levels of aggression and associated skin lesions.

The effects of food level on general activity and aggression in dynamic groups of 30 sows

Aggression in group housed sows is often related to competition over food. Sequential feeding avoids the confrontations at the trough, but puts them at the feeder entrance. Studies of large groups of dry sows using computerised feeding systems showed that vulva biting was most frequent after visits when only a small amount of food had been dispensed (Buré, 1991). This suggests that frustrated feeding motivation may cause increased aggression. A Swedish survey into group housed sows found a link between sow condition and mean injury scores: farms averaging a high injury score had a larger proportion of thin sows (Svendsen et al., 1990). The present study aimed to investigate the hypothesis that in large dynamic groups of sows a high food level results in lower levels of aggression and associated skin lesions.

Social rank and feeding success in outdoor sows and the influence of feed level and composition

Six groups of six dry sows were subject to three feeding treatments in a repeated Latin square design, with 2 week periods on each treatment. Sows were group fed outdoors once daily receiving one of the following: ( 1 ) a conventional dry sow diet ( 13 MJ DE kg1, 4.1% CF) at 1.1 maintenance; (2) a high-fibre diet ( l l .5 MJ DE kg -1, 7.6% CF) at 1.1 maintenance; (3) the same conventional diet as Treatment ( 1 ) but fed at the same daily quantity as treatment (2) (giving an energy intake 13% greater than Treatment (1)). Total feeding period and time food was present were both longer for groups on the highfibre diet. They spent a significantly greater proportion of the total period feeding and a smaller proportion of the time rooting, suggesting that this diet caused a higher degree of satiety. Dominant animals, determined in pair testing, were more likely to 'win' interactions and lower-ranking sows to 'lose' interactions during feeding. The proportion of time spent feeding was found to be positively correlated, and the frequency of time spent moving along the feed line and rooting negatively correlated with dominance rank. Dominant sows were of high liveweight and spent more time feeding. However, lower-ranking animals were able to achieve comparable liveweight gain. Outdoor sows, owing to more space for retreat and avoidance, do not have high levels of aggression during feeding. Low-ranking sows did not seem to be disadvantaged in an outdoor feeding situation to the same extent as indoor sows. Environmental stress and parturition in the sow K.A. Mclean a, A.B. Lawrence a, J.C. Petherick b, C.L. Gi lbe r t c aGenetics and Behavioural Sciences, Scottish Agricultural College, West Mains Road, Edinburgh EH9 3JG, UK bBBSRC's Roslin Institute, Roslin, Midlothian EH25 9PS, UK cBBSRC's Babraham Institute, Babraham, Cambridge CB2 4AT, UK

Agonistic behaviour amongst newly mixed sows and the effects of pen design and feeding method

With adoption of legislation to prohibit individual confinement of dry sows, methods to minimise aggression when unfamiliar sows are grouped must be developed. Sixteen groups of six multiparous sows, half newly weaned and half in mid-pregnancy, were used in an experiment of factorial design to investigate the influence of pen size (6.1 vs. 3.7 m 2 per sow), pen design (presence or absence of a central barrier) and feeding method (once daily floor feeding or ad libitum feeding). The number of interactions decreased with time after mixing, with a resurgence each feeding time for floor fed groups. Pregnant sow groups spent less time active in the first 12 h after mixing than newly weaned sows (26.0 vs. 50.0%, SED 3.77, P<0.001 ), and had fewer contact interactions in first t2 h (47.3 vs. 123.6, SED 26.94, P< 0.05). In the subsequent 24 h they were less active and had fewer prolonged agonistic interactions. Provision of ad libitum feed reduced the number of contact interactions in the first 12 h (37.8 vs. 133.1, SED 26.94, P<0.01 ), reduced level of activity and number of contact interactions in the subsequent 24 h, and reduced skin lesion score after 48 h (4.8 vs. 9.0, SED 0.25, P<0.01 ). There were no overall effects of pen design, but when only groups without food were considered there was a tendency (P< 0.10) for the number of interactions in the first 12 h to be greater in the larger pen, and in the absence of a barrier. Social rank index (based on number of penmates dominated) and the proportion of total encounters won were highly (P< 0.001 ) correlated with relative weight and size. How does social behaviour of dairy cows affect the occurrence of lameness? F. Galindo, D.M. Broom University of Cambridge, Department of Clinical Veterinary Medicine, Madingley Road, Cambridge CB30ES, UK

The Effects of Dry Sow Housing Conditions on Bone Strength and Muscle Conformation

Lameness is the second commonest cause of culling in breeding sows after reproductive failure and can occur as a result of physical injury, infection or inherent leg weakness. Lameness incidence may be affected by both genetic and environmental factors, and is especially prevalent in confined systems such as stalls and tethers, which restrict the amount of exercise that the sows can perform. Confinement, with a corresponding lack of exercise, has been shown to affect bone strength in poultry but this weakness has not been documented in other species housed in confinement. The objectives of this experiment were to compare bone strength and muscle conformation in sows housed in two different dry sow systems.A total of 18 non-pregnant Large White X Landrace sows of similar age, parity and genetic stock, were studied in two different dry sows systems: 1) permanent stalls (n=8) and 2) a large group with Electronic Sow Feeder system (n=10). All sows were weighed and following slaughter by pentabarbitone injection, the left thoracic and pelvic limbs were dissected and five forelimb and nine hindlimb locomotory muscles were removed and weighed. The muscles were chosen partly on the basis of perceived importance for locomotion and partly on the basis of ease of identification and removal. A proportional muscle weight was then calculated by dividing individual muscle weight (in grams) by total body weight (in kilograms). This removed any differences in muscle weight due purely to differences in total body weight between systems. The left humerus and femur were also removed, and were broken by a three-point bend test using an Instron Universal Tester.

Lying behaviour of dry sows in relation to housing conditions

Most sows in the European pig industry are kept in confinement, and are restricted in the amount of locomotory exercise they can perform. Any difficulty in carrying out the movements necessary for standing up and lying down, due to a lack of muscular and cardiovascular fitness, can indicate poor welfare for the sow. Also, because a large proportion of piglet mortality is attributable to over-lying by the sow when she lies down or stands up clumsily, there are welfare implications for her litter. The objectives of these studies were to investigate the time taken for sows to lie down in different dry sow housing systems, and to determine any relationships between the time taken and body dimensions of the sow.

A review of sow group-housing systems in germany and holland with respect to animals welfare - braude scholarship 1993

As a result of welfare legislation introduced in recent years, systems in which dry sows are confined are no longer considered acceptable practice and will be phased out entirely in Europe by 2005. Consequently, there is a need to research and develop alternative housing systems before this deadline is reached.To review the present day developments in this area and to observe different approaches to solving the question of how to improve the welfare of the group-housed sow without compromising productivity, a number of farms and research institutes were visited in Germany andHolland. The aims of the trip were as follows:

Effect of Diet on Behaviour of Individually Penned Sheep

A number of abnormal activities had been observed in a group of 30 lambs (R lambs; 10 Shetland (SH),10 Scottish Blackface (SB) and 10 Welsh Mountain (WM), half females and half entire males), on a restricted allowance (about mature maintenance intake and 0.5 of ad libitum intake), of a high quality pelleted diet (Diet A; 200g/kg crude protein, HMJ/kg ME). The lambs had been individually housed since 8 weeks of age, in pens (2m x lm), made up of metal barred gates with wooden slatted floors. Abnormal oral activities included some that caused obvious husbandry problems, such as wool-biting and slat chewing, and others which caused no overt damage, but may nevertheless be associated with impaired welfare (Cooper and Nicol 1993), such as bar-biting and repetitive licking. In a preliminary observation at 22 weeks of age, lambs only ate in the hour following food presentation (Fig 1), after which all of the allowance had been eaten, and abnormal oral activities were recorded in 30% of scans. Similar repetitive activities, described as “stereotypies” have been associated with food restriction in dry sows (Appleby and Lawrence 1987). In a series of observations, we investigated the effect of increasing weight and nutrient value of the lamb's diet on the incidence of oral stereotypies, whilst minimising any influence on the ongoing feed trial.

Dry sow housing-induced anatomical differences and the effects on lying behaviour

Over the last few decades, the modern domestic pig has been genetically selected to maximise weight and length of back for meat production. Consequently, its body shape has changed and the physical acts of standing up and lying down have become difficult and relatively uncontrolled, even without any modification that housing systems may impose. Confined housing systems restrict the amount of exercise that locomotory muscles perform, and may affect muscular conformation and strength. It is possible, therefore, that confinement will decrease any element of muscular control during standing and lying, even further. The objective of this study was to determine any relationship between muscular conformation and time taken to lie down in sows housed in different dry sow systems.

The effect of liquid feeding in a deep straw system on sow behaviour and welfare

A survey of dry sow housing across England (Baynes and Hunter, 1993) was conducted to assess farmers' future plans and opinions regarding the onset of the 1999 ban relating to stall and tether housing systems. Results from this survey showed that approximately one third of English pig producers currently with these types of systems were undecided as to which system to choose. A number of case studies are currently being conducted on existing group-housed systems to contribute to a data base on group housing options.Sows were housed in a general purpose barn which had been divided into 12 pens, each housing ten sows. Sows were liquid fed once a day in a common trough with partial barriers. Total space allowance was 2.96m2/sow, of which 1.23m2was kennelled.