Comb size, shape complexity and laterality of laying hens reared in environments varying in resource choice.

The comb is an ornament involved in signalling condition in domestic fowl. We hypothesised that comb size, comb shape complexity (i.e., rugosity, the comb perimeter jaggedness), and comb laterality of laying hens would be influenced by the degree of environmental enrichment experienced during juvenile development in the form of resource choice. We conducted a 2 × 2 factorial crossover experiment with pullets reared in pens containing four perches of equal length and four litter areas of equal size. Pullets were exposed to a single choice vs multiple choices of perch and litter types (i.e., all the same vs all different) during Weeks 1-4 (Period 1) and/or Weeks 5-15 (Period 2) of rearing (n = 4 pens/treatment combination) prior to transfer to standard adult laying pens for Weeks 16-27 (Period 3). In Week 27, combs were photographed, and comb laterality (hanging on left or right side) was noted. Using a custom-made image analysis programme, we captured comb area (mm2), perimeter length (mm), and rugosity ((perimeter length - horizontal length) / horizontal length) from comb photographs of 6-7 randomly selected hens/pen. We predicted that hens reared in the multi-choice environment during Periods 1 and 2 would have larger, more complex, and left-side-biased combs than those in the other treatment groups, reflecting lower allostatic load. The predicted comb side bias was based on a possible bias in head posture/movements associated with greater right eye/ear use and left-brain hemispheric dominance. Contrary to our predictions, we detected an overall right-side bias in comb laterality, and no associations between resource choice treatment in Period 1 or Period 2 and comb area, perimeter length, rugosity, or laterality of the adult hens. Thus, variation in allostatic load resulting from the rearing treatments was insufficient to modify the trajectory of comb morphological development, possibly due to a ceiling effect when comparing environmental treatments on the positive end of the welfare spectrum. We found that left-lopping combs had shorter perimeters than right-lopping combs. However, among hens with left-lopping combs, those with larger combs were heavier and had less feather damage, while among hens with right-lopping combs, those with longer-perimeter combs were heavier and tended to have less comb damage. In conclusion, comb characteristics were related to physical condition at the individual level but did not serve as sensitive integrated indicators of hen welfare in response to basic vs enhanced resource choice during rearing.

Can we improve maternal care in sows? Maternal behavioral traits important for piglet survival in loose-housed sow herds.

The primary objective of this survey was to investigate the relationship between qualitative maternal behavioral scores (nest building activities, sow communication, and sow carefulness), piglet mortality, and the number of weaned piglets on commercial farms with loose-housed lactating (Norsvin Landrace × Yorkshire) sows. Second, the impact of these scores on productivity compared with the physical condition of sows (movement disorders, body condition, and shoulder lesions) was assessed. Data on maternal care behaviors and physical condition were collected on 895 sows from 45 commercial farms. Farmers scored sows on their physical condition (movement disorders [MD], BCS, and shoulder lesions [SL]) and qualitative maternal care behaviors (nest building activities [NEST] prior to farrowing and sow communication [COM] and sow carefulness [CARE] after farrowing, while sows were standing and moving and just before lying down). There was a low positive correlation between NEST and COM ( = 0.10, = 0.026) and between NEST and CARE ( = 0.15, = 0.010) but a high positive correlation between COM and CARE ( = 0.57, < 0.001). Higher COM and CARE were associated with lower piglet mortality ( ˂ 0.001 and = 0.013, respectively), and a greater number of weaned piglets was associated with higher scores for NEST ( = 0.009), COM ( < 0.001), and CARE ( = 0.009). Maternal care behavior had a greater impact on piglet mortality and the number of weaned piglets than sow physical condition (MD, BCS, and SL). We tested 7 different models (combinations of behavioral scores) and compared their relative predictive accuracies using Akaike information criteria. The model including COM and CARE had the best predictive accuracy for piglet mortality/weaned piglets. There was between-sow variation in maternal care behaviors (COM and CARE), and both were unaffected by litter size. Because these behaviors were also easy to score for the farmers, combining COM and CARE has the greatest potential to be tested in nucleus herds for calculation of genetic variation and heritability and should be taken into account in future breeding programs for sows.

Can a super sow be a robust sow? Consequences of litter investment in purebred and crossbred sows of different parities.

The aim of this project was to study the consequences of litter investment on physical characteristics in primiparous and multiparous sows in 3 Norwegian breeds (Norsvin Duroc [ = 12], Norsvin Landrace [ = 12], and crossbreeds [Norsvin Landrace and Swedish Yorkshire { = 15}]). We predicted that the maternal sow line (Norsvin Landrace) would invest more in their litter in term of higher weight at birth, resulting in a higher litter weight of weaned piglets but with the consequence of greater loss in body condition and a higher prevalence of shoulder lesions. It was predicted that this should be more pronounced in primiparous sows than in multiparous sows. As predicted, the maternal pure line (Norsvin Landrace) had higher litter investment in terms of litter weight at birth ( = 0.003) and litter weight at weaning ( = 0.050) as well as higher total litter investment (litter weight at weaning plus weight of dead piglets [stillborn and mummified piglets and weight of piglets that died after farrowing but before weaning]; = 0.050) and suffered larger losses of body condition ( = 0.016) and had a higher prevalence of shoulder lesions ( = 0.008) during lactation than other breeds. Moreover, only in Norsvin Landrace was development of shoulder lesions related to inadequate feed consumption ( = 0.006). This has become a major welfare concern of modern pig breeding. Although primiparous and multiparous sows had similar litter sizes, primiparous sows had lower litter investment in terms of litter weight at birth ( = 0.032) and litter weight at weaning ( = 0.007) as well as total litter investment ( = 0.008). Primiparous sows suffered greater losses in body condition ( = 0.012) and developed more shoulder lesions ( = 0.026) due to lower total feed consumption ( < 0.001) during lactation than multiparous sows. Especially in the highly productive maternal line (Norsvin Landrace), development of shoulder lesions during the lactation period was more pronounced in primiparous sows than in multiparous sows ( < 0.001). The selection program has shifted the balance to greater investments in earlier life, when sows still need resources for their own growth and development. This has resulted in a larger number of weaned piglets but at a higher sow welfare cost in terms of higher losses in body condition and a higher prevalence of shoulder lesions. Our results pinpoint the importance of improving the balance between economic traits and traits that improve welfare and longevity of the sows.

Udder characteristics of importance for teat use in purebred and crossbred pigs.

Possible side effects of the current sow selection criteria on udder characteristics and their influence on teat use and functionality have not yet been investigated. The first aim of the present study was to investigate differences in udder morphology characteristics (distance between teats in a pair, teat length, and teat diameter) in 2 different pure breeds (Norsvin Duroc [ND; = 12] and Norsvin Landrace [NL; = 12]) and 1 crossbreed (Norsvin Landrace × Yorkshire [NL×Y; = 14]) at 3 different time periods (Days 1, 21, and 35) during lactation. Second, we also investigated the association between udder morphology and teat use on d 1 and if some of these characteristics influence whether teats become nonfunctional (from d 1 to 35) during lactation. During lactation, udder morphology (teat pair distance, teat length, and diameter of functional teats) and teat use (from 6 consecutive nursings: functional teats being used/not being used and which teat row [left or right] was uppermost) were documented. The NL had shorter distance between teat pairs than ND ( = 0.030). Teat pair distance increased with sows' parity ( = 0.010) and was affected by teat position ( < 0.001). The ND had shorter teats than NL and NL×Y ( < 0.001). Teat length and diameter increased with parity ( = 0.027 and = 0.043, respectively) and were affected by teat position ( < 0.001 and < 0.001, respectively). Functional teats were less used on d 1 postpartum (21.4%) than at 2 later time periods (10.4% on Day 21 and 4.7% on Day 35; < 0.001) during lactation. On d 1, the greater the distance between teat pairs in the middle and posterior position, the higher was the proportion of not-used functional teats ( = 0.003), with a larger decline in the lower teat row ( < 0.001), where approximately half of middle and posterior teats were not used. Proportion of not-used functional teats in the lower middle position increased when the teat pair distance exceeded 16 cm, whereas in the lower posterior position, this limit was 14 cm. Furthermore, the proportion of not-used teats on d 1 influenced teats becoming nonfunctional during lactation ( < 0.001). The greater the distance between pairs, the more teats became nonfunctional irrespective of teat position ( < 0.001). The present results suggest that teat pair distance is of importance for teat use in all breeds and should be included in the breeding program to ensure colostrum intake and maintain teat functionality during lactation.

Invited review: piglet mortality: management solutions.

Preweaning mortality varies greatly among herds and this is partly attributed to differences in farrowing house management. In this review, we describe the various management strategies than can be adopted to decrease mortality and critically examine the evidence that exists to support their use. First, we consider which management procedures are effective against specific causes of death: intrapartum stillbirth, hypothermia, starvation, disease, crushing, and savaging. The most effective techniques include intervention to assist dystocic sows, measures to prevent and treat sow hypogalactia, good farrowing house hygiene, providing newborn piglets with a warm microenvironment, early fostering of supernumerary piglets, methods that assist small and weak piglets to breathe and obtain colostrum, and intervention to prevent deaths from crushing and savaging. The provision of nest-building material and modifications to the pen to assist the sow when lying down may also be beneficial, but the evidence is less clear. Because most deaths occur around the time of farrowing and during the first few days of life, the periparturient period is a particularly important time for management interventions intended to reduce piglet mortality. A number of procedures require a stockperson to be present during and immediately after farrowing. Second, we consider the benefits of farrowing supervision for preweaning mortality in general, focusing particularly on methods for the treatment of dystocia and programs of piglet care that combine multiple procedures. Third, we discuss the need for good stockmanship if farrowing supervision is to be effective. Stockmanship refers not only to technical skills but also to the manner in which sows are handled because this influences their fearfulness of humans. We conclude that piglet survival can be improved by a range of management procedures, many of which occur in the perinatal period and require the supervision of farrowing by trained staff. Although this incurs additional labor costs, there is some evidence that this can be economically offset by improved piglet survival.

Piglet mortality: the impact of induction of farrowing using prostaglandins and oxytocin.

Induction is usually carried out by administering prostaglandins (prostaglandin F2α or a synthetic analogue). Other hormones, most commonly oxytocin, may also be given. The primary objective is to increase the synchrony of farrowing. This facilitates farrowing supervision, early fostering and 'all in, all out' management of the farrowing house, all of which have the potential to decrease piglet mortality. However, there are also risks, including decreased piglet viability when farrowing is induced too early and an increased probability of dystocia associated with oxytocin use. What are the effects of induction procedures on mortality in pigs? With respect to prostaglandins, studies show that the date of induction and the level of supervision provided are important factors affecting piglet mortality. We recommend administering prostaglandins no earlier than 2d before the expected farrowing date for the herd. Some studies have reported that prostaglandin induction decreases stillbirth and live-born mortality and this is probably due to increased farrowing supervision. The incidence of postpartum dysgalactia syndrome is also decreased in herds with a high prevalence of this condition. Inconsistent effects on the progress of farrowing are reported following the routine administration of oxytocin 20-24h after prostaglandin. Although there is generally no effect on stillbirth rate, dystocia may increase. Earlier administration of low doses may decrease stillbirths, but this requires further research. Carbetocin, a long-acting analogue of oxytocin, is a possible alternative. We recommend that prostaglandin induction be used in conjunction with skilled farrowing supervision to decrease piglet mortality.

Feed intake and competition in ewes on ad libitum or semi-restricted feeding of grass silage and hay.

The aim of the present experiment was to investigate the effect of feeding level and type of roughage on feed intake, feeding behavior and competition of ewes. A 2 × 2 factorial experiment was conducted with amount of roughage available (ad libitum or semi restricted) and type of roughage (grass silage or hay) as main factors. Forty-eight ewes were randomly assigned to 8 groups of 6 ewes. All groups were subjected to all 4 treatments, each treatment period lasted 7 d, and the order of treatments was rotated systematically. The ewes were video recorded for the 2 last days of each treatment period and feeding and general activity were scored every 10 min. All aggressive interactions and displacement at the feed barrier were scored continuously the first 3 h after feeding. Daily feed intake (P < 0.0001) and DMI (P < 0.0001) were both greater in the silage than in the hay treatment. Ewes in the semi-restricted treatment spent less time feeding (P < 0.0001), had a greater individual variation in feeding time (P < 0.05) and spent more time queuing for feed (standing maximum 1.5 m from the feeding barrier with the head towards the feed; P < 0.0001). Individual data showed that 5 ewes fed hay and 3 ewes fed silage reduced their time spent feeding more than 50% when the feeding level was reduced. When fed hay, the level of feeding did not affect number of aggressive interactions or displacements, but when fed silage the number of aggressive interactions (P < 0.01) and the number of displacements (P < 0.05) were much greater in the semi-restricted than in the ad libitum treatment. We conclude that even a minor restriction in the level of feeding will decrease time spent feeding and increase queuing and number of aggressive interactions when feeding space is also restricted, and that the increase in aggressive interactions is mainly for ewes fed grass silage.

Gentle vs. aversive handling of pregnant ewes: I. Maternal cortisol and behavior.

The aim of the experiment was to study the effects of aversive vs. gentle handling in late pregnancy on maternal behavior of ewes. Sixteen Norwegian Dala ewes bearing twins were subjected to 10 min of either gentle (GEN--soft talking and calm behavior) or aversive (AVS--swift movements and shouting) handling twice a day during the last 5 weeks of pregnancy. Salivary cortisol was recorded before and after treatments. The following behaviors were recorded post-partum in the ewes: grooming duration, number of vocalizations and in the lambs: number of vocalizations, latency and duration of standing, latency and duration in udder-directed position. The ability of the ewe to follow her lamb carried away by a human was scored on day 1 and 7. After the treatment sessions, cortisol levels tended to increase in AVS ewes but not GEN ewes. At parturition, AVS ewes groomed their offspring for a longer duration than GEN ewes. AVS lambs tended to be heavier than GEN lambs at 24 h of age. Follow Scores from GEN ewes were higher than for the AVS ewes at day one, but no difference between treatment groups was detected after one week. These results show that aversively treated ewes increased their grooming behavior towards their offspring, but that fear of humans disrupted their ability to follow their lambs closely when carried away by a human. We conclude that the type of handling of ewes during pregnancy may have some impact on important maternal behaviors.

Neonatal piglet traits of importance for survival in crates and indoor pens.

The primary aim of the present study was to investigate whether the same piglet traits contributed to the same causes of neonatal piglet mortality in crates (CT) and pens (PN). Gilts originating from 2 distinct genetic groups that differed in breeding value for piglet survival rate at d 5 (SR5) were used. These were distributed to farrow in either PN or CT as follows: high-SR5 and CT (n = 30); low-SR5 and CT (n = 27); high-SR5 and PN (n = 22); and low-SR5 and PN (n = 24). Data on individual piglets were collected at birth, including interbirth interval; birth order; birth weight; rectal temperature at birth, 2 h after birth, and 24 h after birth; cordal plasma lactate; and latency to first suckle. Based on autopsy, causes of mortality were divided into stillborn, bitten to death, starvation, crushed, disease, and other causes. Potential risk factors of dying were estimated using a GLM with a logit link function. No significant effect (NS) of housing was observed on the odds of a piglet being stillborn (F(1,73) = 0.1, NS), being crushed (F(1,53) = 1.4, NS), or dying of starvation (F(1,53) = 0.3, NS). No significant differences were observed between the 2 genetic groups for any category of mortality. Piglet traits for pre- and postnatal survival were the same for CT and PN. The odds of being stillborn were increased in piglets born late in the birth order (F(1,1061) = 33.5, P < 0.0001), after a long interbirth interval (F(1,1061) = 19.2, P < 0.0001), and with a lighter birth weight (F(1,1061) = 9.2, P = 0.003). The lighter the birth weight of the piglets, the greater were the odds of being crushed (F(1,1050) = 18, P < 0.0001) and dying of starvation (F(1,1050) = 19, P < 0.0001). The lower the rectal temperature 2 h after birth, the greater were the odds of being crushed (F(1,1050) = 4.6, P = 0.03), starving (F(1,1050) = 16.6, P < 0.0001), or dying of diseases (F(1,1050) = 4.9, P = 0.03). Increased cordal plasma lactate increased the odds of dying from starvation (F(1,1050) = 18, P < 0.0001). In both CT and PN, the birth weight, body temperature 2 h after birth, and birth process were important traits related to crushing, starvation, and disease. Neither housing nor breeding value influenced mortality or traits of importance for the inborn viability of piglets. The results emphasize that the microclimate in the PN for newborn piglets and its heat-preserving properties are more important for survival than whether the sow is crated or penned.

Drying and warming immediately after birth may reduce piglet mortality in loose-housed sows.

The aim of the present experiment was to investigate the effects of placing newborn piglets under the heat lamp or both drying and placing them under the heat lamp on piglet mortality. Sixty-seven healthy (Landrace × Yorkshire) sows were divided equally into three different experimental groups: a control group where the farrowings occurred without supervision from the farmer (C; n = 23 litters), another group where the piglets were placed under the heat lamp in the creep area immediately after birth (HL; n = 22 litters) and a third group where the piglets were dried with straw and paper towels followed by placing them under the heat lamp in the creep area immediately after birth (DHL; n = 22 litters). The sows were individually loose-housed in farrowing pens during farrowing and lactation. The piglets were not closed inside the creep area, but were free to move around in the pen. The routines in the experimental groups required the stock person to attend the farrowings from the onset of birth of the first piglet until the last piglet was born. All the dead piglets were weighed and subjected to a post mortem examination at the farm to ascertain the causes of death. Postnatal mortality (% of live born) was significantly lower in the HL and DHL groups than in the control group (P < 0.0001). This was significant concerning all causes of mortality. Compared to the control group, crushing occurred in significantly fewer litters when the piglets were both dried and placed under the heat lamp (P < 0.05). In the DHL treatment, crushing of one or more piglets by the sow occurred in only 13.6% of the litters, whereas this was increased to 34.8% in the HL and to 47.9% in the control group, respectively. All causes of death, except the proportion of stillborn piglets, increased significantly with increasing litter size. Because of the relatively large potential that these rather simple routines may have to improve piglet survival, different types of management or human interference around the time of farrowing should be compared on a larger scale, both experimentally and on commercial farms.

Cytogenetic and molecular analysis of a family with three brothers afflicted with germ-cell cancer.

A thorough cytogenetic investigation and an analysis of detailed questionnaires were performed in a family with three brothers afflicted with germ-cell tumors (GCTs), in an attempt to detect a congenital factor related either to a hereditary genetic background or an environmental/lifestyle influence. One brother had an intracranial tumor in the pineal region and the two others had testicular tumors. Peripheral blood was studied by traditional karyotyping, multicolor-FISH, high-resolution comparative genomic hybridization (HR-CGH), and molecular analysis of selected loci on sex chromosomes (Yq11 region, TSPY, and the androgen receptor gene); however, no abnormalities were detected. The HR-CGH analysis of microdissected histological components of the overt tumors and the adjacent carcinoma in situ demonstrated a pattern of genomic imbalances characteristic for sporadic GCTs, including gain of 12p. The questionnaire and interview revealed a history of different cancers in the extended family, and a possible in utero and/or infantile exposure of the three brothers with GCTs to compounds suspected of endocrine-disrupting properties. Although no genetic aberration was detected in this family, we suspect the presence of a recessive hereditary factor pre-disposing to cancer, which probably was manifested as GCTs in the three brothers because of an adverse effect of an environmental factor on the early germ-cell differentiation.