Anna Valros

Environmental and sow-related factors affecting the duration of farrowing

A short duration of farrowing is important for piglet survival as a delay can increase the number of stillborn. Many factors may affect the duration of farrowing, including breed, age of the sow, length of gestation, number of piglets born, housing (CRATE vs. PEN), body condition of the sow and state of constipation. The aim of the present study was to investigate these factors and how they interact with each other and thus increasing the risk of prolonged farrowing. The total duration of farrowing and average piglet birth interval were recorded in 172 sows from two herds (HERD-1, n = 76; HERD-2, n = 96). Back-fat measurements and intestinal activity (based on the mean of a constipation index) were measured in all 172 sows. The total duration of farrowing was 272 +/- 152 min (mean +/- SD, n = 172): 301 +/- 165 min (n = 115) in the CRATE group and 212 +/- 95 min (n = 57; P < 0.05) in the PEN group. The average piglet birth interval was 26 +/- 25 min (mean +/- SD, n = 172): 29 +/- 29 min (n = 115) in the CRATE group and 19 +/- 10 min (n = 57; P < 0.05) in the PEN group. Housing (P < 0.05), stillborn (P < 0.001), back-fat average (P < 0.001) and constipation index (P < 0.05) significantly correlated with the duration of farrowing. In conclusion, allowing the sow to move freely before farrowing, reducing the constipation state and avoid excessive fattening during late pregnancy all appear to be key factors in shortening farrowing time and reducing perinatal mortality.

Nursing behaviour of sows during 5 weeks lactation and effects on piglet growth

Abstract The main goal of this study was to investigate the effect of sow nursing behaviour on piglet weight gain and within-litter variation (WLV) in piglet weight gain under as naturalistic conditions as possible. In order to achieve this, patterns of sow nursing behaviour and piglet weight gain were recorded during 5 weeks lactation. In addition, to be able to assess importance of sow behaviour on piglet growth more definitely, individual within-lactation repeatability of sow behaviour was also evaluated. Average piglet daily weight gain (ADG) and within-litter variation in weight gain during lactation were recorded by weighing the piglets of 21 individually penned, unrestrained Yorkshire sows on days 1, 4, 8, 15, 22 postpartum (PP) and at weaning (day 35±2). Nursing behaviour and sternal recumbency from five 24h periods (days 3, 6, 13, 20 and 30 postpartum) were described as frequency of successful nursings (SFREQ), frequency of unsuccessful nursings (USFREQ), total duration of all nursings (TOTDUR), percentage of nursings terminated by the sow (%SOW), average duration of sow-terminated nursings (SOWDUR) and percentage of observations when the sow was lying sternally (%STERN). With proceeding lactation, the only significant change in SFREQ was an increase on day 6. USFREQ increased to day 13, and then decreased towards the end of lactation. TOTDUR began decreasing after day 13, while SOWDUR decreased already after day 3. %SOW and %STERN both increased with proceeding lactation. All behavioural measures showed within-sow repeatability (first-order autoregression coefficient (AR(1))=0.39–0.73). Average piglet weight gain (ADG) was influenced positively by SFREQ ( P =0.02), while none of the other behavioural variables affected ADG. The effect of SFREQ on ADG was similar throughout lactation, the model estimated a 5.12g increase in ADG with one more successful nursing per 24h. Within-litter variation was not influenced by any of the selected variables. The results indicate that (i) nursing behaviour changes during lactation, according to a pattern suggesting an ongoing weaning process; (ii) sow behaviour is repeatable within-sow and within-lactation; (iii) a high frequency of successful nursings affects piglet growth positively also in sows that are not experimentally manipulated, and throughout the full course of lactation.

Metabolic state of the sow, nursing behaviour and milk production

Twenty-one sows were studied to investigate if lactating sow metabolism relates to behaviour and piglet performance. Blood samples from days 7 and 21 were analysed for NEFA, urea, glucose, insulin, somatostatin and prolactin. The behaviour parameters obtained from 24-h video recordings (days 6 and 20) included: successful and unsuccessful nursing frequency, total nursing duration, percentage and average duration of nursings terminated by the sow, and percentage of observations of sow sternal recumbency. Weight loss and catabolic state of the sows increased from day 7 to day 21; NEFA and post-feeding urea were higher and pre-feeding glucose and insulin lower on day 21. NEFA correlated strongly with sow weight loss during week 1. Prolactin correlated positively with the amount of udder stimulation in week 1 and insulin positively (week 1) or negatively (week 3) with a high incidence of massage-avoiding behaviour. High sow weight loss and NEFA during week 1 were associated with low piglet mortality. High piglet growth correlated positively with sow weight loss during week 3. We conclude that (i) catabolism increases during the first 3 weeks of lactation, (ii) there is some association between sow metabolism and behaviour and (iii) the ability of a sow to turn catabolic soon after parturition decreases piglet mortality risk.

The prevalence of tail damage in slaughter pigs in Finland and associations to carcass condemnations

Tail biting is a serious and common welfare problem in modern pig production. The aims of this study were to evaluate the prevalence of tail damage in Finland and to study relationships between tail damage and carcass condemnations. Information on a total of 10,852 pigs from 479 farms was collected at a Finnish abattoir. The prevalence of total tail damage was 34.6%, but the majority of this was healed tail damage. The prevalence of fresh versus severe tail biting was 11.7% and 1.3%, respectively. All forms of tail damage caused an increased risk of carcass condemnation, especially due to abscesses (RR: 4.9 for all tail damage). Severe tail biting caused a highly increased risk for condemnation (RR: 5.2 for condemnations in general, RR: 17.6 for condemnations due to abscesses). Of carcasses with severely bitten tails, 26.8% were partly or fully condemned. Between-farm variation in prevalence of tail damage was large, stressing the importance of on-farm factors. Tail biting appears to be a common problem in Finland and measures should be taken to improve the situation. Tail damage, in all its forms, needs to be taken seriously, as it has, in addition to causing lowered welfare to the animals, large economic implications for production.

Sow activity level, frequency of standing-to-lying posture changes and anti-crushing behaviour—within sow-repeatability and interactions with nursing behaviour and piglet performance

Abstract Starvation and crushing by the sow are the two main causes of piglet mortality prior to weaning, thus it is obvious that the behaviour of the sow influences piglet survival. In order to increase the understanding of the behavioural mechanisms influencing piglet performance, we recorded undisturbed general activity (standing or walking), frequency of standing-to-lying posture changes (standing-to-lying) and carefulness at standing-to-lying during a 5-week lactation for 24 Yorkshire sows. Carefulness was estimated using four components of sow anti-crushing behaviour (rooting or sniffing piglet prior to standing-to-lying, careful standing-to-lying and no piglets in danger zone at standing-to-lying). We investigated the changes in and consistency of these behaviours throughout lactation, as well as the associations between different aspects of behaviour. Secondly, we examined whether sow activity level and frequency of standing-to-lying were related to nursing behaviour, sow body resource mobilisation (measured as blood concentration of non-esterified fatty-acids (NEFA)) and piglet growth. In addition, we grouped the sows according to litter mortality and according to whether they had crushed any piglets or not and determined if these groups differed in the above mentioned behaviour patterns. Both the activity level and frequency of standing-to-lying of sows increased and had high within-sow repeatability throughout the 5-week period. Carefulness at standing-to-lying did not change significantly over lactation. The variable showed very low within-sow repeatability and only one aspect of carefulness (rooting of the floor) decreased in the later stages of lactation. No significant associations were found between activity level and frequency of standing-to-lying on the one hand, and nursing behaviour or growth of the piglets on the other, except for a positive correlation between frequency of standing-to-lying and observations of the sow lying on her udder. Sows with low mortality (less than two dead piglets) in their litters were more active on day 3 postpartum (pp) than sows with high mortality. The difference was especially clear when comparing sows with or without any crushed piglets in their litters. Sows with no crushed piglets also showed a higher incidence of rooting the floor on day 3 than sows with at least one crushed piglet. Activity level of the sow seems to be an individual characteristic that has possibly been decreased by selection for large and docile animals, suited to intensive production systems. Activity level and amount of rooting performed at standing-to-lying appear to be important aspects of good maternal characteristics. Our results encourage studies of selection for enhanced piglet survival via improved maternal abilities.

Tail biting induces a strong acute phase response and tail-end inflammation in finishing pigs.

The extent of inflammation associated with tail biting in finishing pigs was evaluated. Tail histopathology, carcass condemnation and the concentration of three acute phase proteins (APPs), C-reactive protein (CRP), serum amyloid-A (SAA) and haptoglobin (Hp), were examined in 12 tail-bitten and 13 control pigs. The median concentrations of APPs were higher (P<0.01) in bitten (CRP 617.5mg/L, range 80.5-969.9; SAA 128.0mg/L, 6.2-774.4; Hp 2.8g/L, 1.6-3.5) than in control pigs (CRP 65.7mg/L, 28.4-180.4; SAA 6.2mg/L, 6.2-21.4; Hp 1.2g/L, 0.9-1.5). There was a tendency for APP concentrations to rise with the histopathological score but the differences were only statistically significant between some of the scores. Five (42%) bitten cases and one (8%) control pig had partial carcass condemnations owing to abscesses (P=0.07). The results show that tail biting induces an inflammatory response in the tail end leading to an acute phase response and formation of carcass abscesses.

Milk yield affects time budget of dairy cows in tie-stalls

Effective selection in breeding programs and improved management has increased the milk production per cow. However, the effects of the increased yield on behavior have not yet been clarified. We investigated the effect of milk yield on the time budget of 29 Finnish Ayrshire cows in the same stage of lactation kept in tie-stalls. The time spent lying, eating, ruminating, lying inactive without ruminating, and lying with the neck muscles relaxed, as well as the milk yield of primiparous and multiparous cows were recorded for 2d. The effects of milk yield and parity on behavior were analyzed with mixed models. The mean milk yield was 38.3 kg (SD 7.8) per day. Higher-yielding cows spent more time ruminating while standing and less time lying than lower-yielding cows. The latency to lie inactive without ruminating after lying down decreased as milk yield increased and it was shorter in primiparous compared with multiparous cows. Multiparous cows ruminated more while lying than primiparous cows. High milk yield cows spent a shorter time lying and they fell asleep (lay with neck relaxed) sooner. The degree of daily milk yield was associated with modifications in behavior and cows with high milk production had less lying time even with free access to lie down in the tie-stall.

Housing During Early Pregnancy Affects Fertility and Behaviour of Sows

From 1.1.2013 EU legislation will permit stall-housing of dry sows for only 4 weeks post-service. Stalls are associated with compromised animal welfare, but group housing comes with risks from social confrontations. Studies on housing effects on fertility have produced contradictory results as systems are inconsistently defined. Effects of housing on pregnancy rate 28 days post-service (P28), early disruption of pregnancy (EDP) and behaviour were investigated in 12 replicates of 40 sows. Half of the animals were stalled (treatment S, mean parity 2.4) and half group-housed adjacent on 5.1 m(2) deep litter per sow (treatment G, mean parity 2.3). Pregnancy was detected using real-time ultrasound. An EDP-diagnosis required a drop of salivary progesterone concentration from >15.9 to <15.9 mmol/l in a series of samples taken on days 17, 20, 24 and 27 post-service. Behaviour was scan sampled on day 27 for 120 min with 10-min intervals. Data was analysed using mixed regression models in MLwiN. Treatment S increased the odds for P28 with 2.3 and the pregnancy rate of a treatment group with 0.1 compared with G. G increased the odds for EDP with 4.6. Treatment did not affect total exploratory or total passive behaviour. S sows explored floor and fixtures (not bedding) more and performed more passive sitting than G sows. Social stress may have caused the impaired reproductive performance in G sows. S sows showed behavioural signs of decreased welfare, but no corresponding reproductive effects. An interdisciplinary approach is needed when evaluating the appropriateness of housing systems.

Health parameters in tail biters and bitten pigs in a case-control study.

Health in relation to tail-biting behaviour was investigated on a problem farm. Quartets (n = 16) of age- and gender-matched fattening pigs including a tail biter (TB, n = 16), a victim (V, n = 16), a control in the same pen (Ctb, n = 10) and a control in a pen where no tail biting was observed (Cno, n = 14) were chosen by direct behavioural observation. Haematological and clinicochemical analyses, autopsy and histological examination of 16 different tissues were carried out. Tail lesion severity was evaluated both macroscopically, on the basis of inspection, and histologically, in the sagittally cut tail. Category effects were tested using Friedmans ANOVA by Ranks, Cochrans Q or a repeated-measure GLM and, if significant, pair-wise tests were conducted using Wilcoxon Signed Ranks or McNemars Test. The number of received tail bites correlated better with histological than with macroscopic tail lesion scoring because of deep inflammation beneath healthy skin in some cases. Most individuals had mild inflammatory lesions in internal organs suggestive of generalized activation of the immune system, and 30% of the animals were anaemic, possibly because of systemic spread of infectious agents. V had more severe respiratory organ lesions and higher serum protein concentrations than all other categories of pigs. Liver- and muscle-specific enzymes (alanine aminotransferase, alkaline phosphatase and creatine kinase) differed between categories. In conclusion, most animals had signs of generalized activation of the immune system, possibly because of systemic spread of infectious agents. V pigs suffered from more severe inflammatory lesions than TB, Ctb or Cno. Deep infections may exist under healthy skin in the tail of bitten pigs.

Stress measures in tail biters and bitten pigs in a matched case-control study

This study aimed to identify differences in stress measures in pigs (Sus scrofa) with different roles during a tail-biting outbreak. Quartets (n = 16) of ageand gender-matched fattening pigs including a tail biter (TB; n = 16), a victim (V; n = 16), a control in the same pen (Ctb; n = 10), and one in a pen without tail biting (Cno; n = 14) were chosen by direct behavioural observation. Stress measures used were behaviour (dog-sitting, sniffing of pen-mates and aggression), thyroid hormone concentration, morphology of adrenal and thyroid glands and salivary cortisol concentration sampled at 0700, 1000, 1600 and 1900h. Category (TB, V, Ctb, Cno) effects were investigated using a mixed model with replicate as subject and category as repeated effect. Category had a significant effect on adrenal total (cortex + medulla) and cortical area, salivary cortisol at 1900h, serum triiodothyronine (T3) and the behaviours performing and receiving sniffing. Victims suffered from a triad of chronic stress, pathology and suppressed T3 secretion. Evidence for stress in tail biters, a possible cause of the behaviour, consisted of a slightly flattened day-time cortisol pattern and more performed sniffing than all other categories. Differences in evening cortisol concentration and T3 levels between the categories in the pen with ongoing tail biting emphasise the qualities of the control animal. It supports the view that neutral pigs represent a phenotype that adopts a coping strategy leading to lower stress levels than in tail biters and victims, despite being housed in the same pen.