Comparable cortisol, heart rate and milk let-down in nurse sows and non-nurse sows

Pinecone oil supplemented to multiparous sows from 107 days prenatal to 21 days postpartum improves reproductive performance and milk composition and affects serum parameters

Pinecone oil (PO) of Pinus koraiensis mainly contains α-pinene, β-pinene, and limonene that may ameliorate animal well-being and growth performance. This study evaluated its effects on feed intake, milk composition and yield, serum parameters, and litter growth of sows. Twenty-seven pregnant sows (parity 2-4) were distributed to three dietary treatments. The trial started on Day 107 of gestation and ended on Day 21 of lactation. Sows were given either a basal diet or the basal diet + 200 or 400 mg/kg PO. Each treatment contained nine sows and each sow was considered an experimental unit. Results showed that the average daily gain and weaned body weight of piglets from the sows fed 400 mg/kg PO supplements were higher (p < 0.05) than the piglets from the control sows. Lactose content in colostrum samples and fat content in milk samples were higher (p < 0.05) in 400 mg/kg PO-treated sows, respectively, than those from the sows fed basal diet. Additionally, cortisol concentration and aspartate aminotransferase concentration in sow serum was lowered (p < 0.05) by 400 mg/kg PO on Day 21 of lactation. In conclusion, supplementation of 400 mg/kg PO during late gestation and lactation contributed to greater offspring growth performance, possibly by enhanced milk quality and alleviated maternal stress.

Animal board invited review: The need to consider emissions, economics and pig welfare in the transition from farrowing crates to pens with loose lactating sows

In the development and implementation of housing systems for pigs, there has been a significant focus on pig welfare including loose housing of lactating sows either indoors or outdoors. However, it is equally important to consider the environmental and economic aspects of housing systems to ensure sustainability in livestock production. The aim of this work was to review the sustainability (societal and animal welfare, environmental and economic impact) of different approaches for housing farrowing and lactating sows in indoor environments. The review illustrates that like outdoor systems, indoor housing systems are challenged in meeting the three pillars of sustainability when changing the housing of lactating sows from conventional crates with permanent confinement to systems with temporary or zero-confinement. Increased space allowance increases sow welfare, but in addition, pen designs with increased space increase ammonia emission, investment and running costs. Furthermore, indoor loose lactation systems come with an increased risk for piglet mortality, which unless effectively managed, reduces animal welfare and the economic sustainability of the system. If farms retrofit existing buildings, the larger space per loose farrowing pen leads to a reduction in pen numbers and therefore herd size, reducing the farm profitability. If farmers choose to reduce herd size to meet requirements, welfare will be reduced while emissions will be increased as more sows are brought into production again in other countries, often in conventional systems with fully slatted flooring, to meet the demand for animal protein to feed the growing global population. The review indicates there are ways to house lactating sows loose indoors with increased opportunity to perform highly motivated species-specific behaviours compared to the conventional crates with continuous confinement. These systems can offer a lower risk for environmental impact and economic risk through reducing piglet mortality. Nevertheless, a trade-off for continual freedom of sow movement may be required as zero-confinement increases the risk of piglet mortality and increased emissions. It is important to raise awareness among citizens and policy makers that loose farrowing and lactating systems if applied today, come with a higher production cost and the risk of increased environmental impact. More research and development is needed in relation to the environmental and economic impact of these systems in order to give farmers the best information to invest in new and more sustainable production systems.

Selecting the optimal strategies when using nurse sows for supernumerous piglets

Hyper-prolific sows frequently do not have a sufficient number of functional teats for their piglets to nurse which has led to the use of nurse sows to manage these surplus piglets. This review discusses strategies for using nurse sows and factors that influence preweaning survival and weight gain of their litters, as well as those that affect their subsequent rebreeding performance. Rearing piglets using a nurse sow can be as successful as piglets reared with their biological mother and is thus a powerful management tool to decrease preweaning piglet mortality. Selecting a young sow as nurse sow is beneficial for piglet survival; however, piglets nursing first parity sows often have a lower daily weight gain than piglets nursing multiparous sows. A litter of uniform surplus piglets is preferably handled using the two-step nurse sow strategy. A consequence of nonuniform litters will most likely be an increased mortality and decreased weaning weight among the smallest piglets within a litter. The subsequent fertility of nurse sows is not compromised. There is an increased risk of lactational oestrus when using nurse sows leading to an increased weaning-to-oestrus interval; however, litter size in nurse sows is identical or even moderately higher in the subsequent parity compared with nonnurse sows.

The Effect of Different Feeding Systems on Salivary Cortisol Levels during Gestation in Sows on Herd Level

Simple Summary

Physiological stress increases the activity of the hypothalamic-pituitary-adrenal (HPA) axis and the secretion of cortisol, which might cross the placenta and affect foetal development. Stress in sows can be affected by management factors such as enrichment, different feed systems of the housing accommodation, and is reflected in the salivary cortisol concentration. It is unclear how stressed the sow must be before there is an impact on foetal growth, but higher levels of cortisol might affect the maturity of piglets at birth as well as their birth weight. Therefore, it could be beneficial to accommodate gestating sows in the least stressful manner, not only for piglet performance but also for sow welfare. Cortisol concentration in sows seems to be influenced by a combination of parity and feed systems, but its connection to those factors, as well as to foetal development, warrants further investigation.

Abstract

The aim of this study was to investigate herd cortisol levels as an indicator of stress during gestation in three different feeding systems. Twelve commercial Danish herds with 800 to 3050 sows were included, with either free-access feeding stall (Stall), floor feeding (Floor), or electronic sow feeding (ESF; n = 4 herds per system). Saliva samples were collected from 30 sows/herd in the gestation unit for cortisol analysis with an average of 67.2 gestation days for ESF, 72.4 days for Floor, and 68.6 days for Stall. Data on piglet birth weight (PBW) and the percentage of intrauterine growth restricted (IUGR) piglets from 452 litters (9652 piglets, 8677 liveborn) from all 12 herds were obtained on the saliva collection days. The cortisol levels in saliva increased throughout gestation (p < 0.01), and lower concentrations were observed among sows belonging to Stall (4.80 nmol/L), compared to Floor (7.03 nmol/L) and ESF (7.87 nmol/L), and that difference was significant as an independent effect in the case of ESF (p < 0.01). There was no difference between Floor and ESF or Stall and Floor (p > 0.05). An interaction was observed between parity and feeding system, with parities 4–5 in ESF herds having lower levels than other parities within the ESF system (p = 0.02).

Sow behaviour and piglet weight gain after late cross-fostering in farrowing crates and pens

Determining best practices for managing free farrowing systems is crucial for uptake. Cross-fostering, the exchange of piglets between litters, is routinely performed amongst crate-housed sows. However, cross-fostering can increase fighting amongst the litter and may be more challenging within free farrowing systems as sows have more freedom to respond to cross-fostered piglets. This study compared the effect of either cross-fostering (FOS), or a control of sham-fostering (CON), of four focal piglets per litter on Day 6 postpartum in crates (CRATE) and free farrowing pens (PEN). The post-treatment behavioural responses of sows were recorded (Day 6 = 60 min; Day 7 = 300 min; n = 48), as were the average daily gain (ADG; g/day), total weight gain (TWG; kg) and body lesion scores of focal piglets and their littermates throughout lactation (Day 6, Day 8, Day 11 and Day 26; n = 539) and the post-weaning period (Day 29, Day 32 and Day 60; n = 108). On Day 6, though post-reunion latency to nursing did not differ, latency to successful nursing was longer amongst FOS than CON litters (P < 0.001), more so amongst CRATE FOS than PEN FOS (P < 0.01). On Day 7, PEN FOS sows had fewer successful nursing bouts (P < 0.05) and exhibited decreased lateral (P < 0.01) and increased ventral lying frequencies (P < 0.01) compared to all other housing and treatment combinations. Focal piglet ADG was lower for FOS than CON in the CRATE during Day 6 to Day 8 (P < 0.01) and lower in the PEN during Day 6 to Day 8 (P < 0.001), Day 8 to Day 11 (P < 0.01) and Day 11 to Day 26 (P < 0.05). The TWG of pre-weaned focal piglets (Day 6 to Day 26) was higher amongst CON than FOS litters (P = 0.01). Post-weaning, piglet ADG was higher for PEN than CRATE during Day 26 to Day 29 (P < 0.01) and higher for FOS than CON during Day 26 to Day 29 (P < 0.05), Day 29 to Day 32 (P < 0.001) and Day 32 to Day 60 (P < 0.01); thus, TWG was higher for FOS than CON during the weaner (P = 0.001) and the combined lactation and weaner periods (P = 0.09). In conclusion, sow behaviour was disrupted by cross-fostering in the crates and pens and continued to be disturbed on the following day amongst penned sows. FOS piglets exhibited reduced ADG after cross-fostering, which extended throughout lactation in the pens. However, the increased post-weaning weight gain of FOS piglets meant that their TWG was higher than CON piglets, irrespective of the farrowing system used.

Effect of litter size, milk replacer and housing on production results of hyper-prolific sows

The modern hyper-prolific sow gives birth to more piglets than she has functional teats (in the following called supernumerary piglets). The aim of the present study was (1) to investigate the production consequences of hyper-prolific sows rearing supernumerary piglets equal to the mean live-born litter size, and (2) investigate whether potential negative effects on survival and growth could be alleviated by providing access to milk replacer and/or providing easier access to the udder (by loose housing). At day 1 (D1) postpartum (pp), 93 litters were standardised to 14 or 17 piglets (LS14/LS17) after which no piglets were moved between sows leading to decreased litter size if piglets died. Litters were provided with or without milk replacer in milk cups (+MILK/-MILK), and sows were either crated or loose housed (CRATE/LOOSE) in a 2 × 2 × 2 factorial design. Piglet mortality was higher in LS17 compared to LS14 (P < 0.01; OR = 2.0), higher in -MILK compared to +MILK (P = 0.01; OR = 1.2) and higher in LOOSE compared to CRATE (P = 0.02; OR = 1.8). This study showed that sow rearing of supernumerary piglets while supplying with milk replacer can increase piglet survival. It also showed that early mortality before piglets learned to drink milk replacer posed a challenge using this automatic milk replacer system. An interaction between access to milk replacer and the standardised litter size D1 affected litter weight (P < 0.01) and piglet weight day 28 (D28) (P = 0.03). The highest litter weight D28 was found in LS17 +MILK (P < 0.01) but with a lower individual piglet weight than in LS14 -MILK. Piglet weight D28 was higher in LS14 -MILK compared to LS17 regardless of access to milk replacer. Heterogeneity in piglet weight within litters D28 was larger in LS17 (P = 0.03) but could be reduced with +MILK in CRATE (P < 0.01). No effects were found on sow weight loss and feed intake (P > 0.05). In conclusion, the results showed that sows cannot rear the supernumerary piglets without further management interventions to reduce mortality. Supplying supernumerary piglets equal to the mean live-born litter size of hyper-prolific sows with milk replacer can from results of this study be an alternative strategy to the use of nurse sows.

Nurse sow strategies in the domestic pig: I. Consequences for selected measures of sow welfare

Management strategies are needed to optimise the number of piglets weaned from hyper-prolific sows. Nurse sow strategies involve transferring supernumerary new-born piglets onto a sow whose own piglets are either weaned or fostered onto another sow. Such 'nurse sows' have extended lactations spent in farrowing crates, which could have negative implications for their welfare. This study used 47 sows, 20 of which farrowed large litters and had their biggest piglets fostered onto nurse sows which were either 1 week (2STEP7, n=9) or 3 weeks into lactation (1STEP21, n=10). Sows from which piglets were removed (R) were either left with the remainder of the litter intact (I) (remain intact (RI) sows, n=10), or had their litters equalised (E) for birth weight using piglets of the same age from non-experimental sows (remain equalised (RE) sows, n=9). Piglets from 2STEP7 were fostered onto another nurse sow which was 3 weeks into lactation (2STEP21, n=9). Back-fat thickness was measured at entry to the farrowing house, at fostering (nurse sows only) and weaning. Sows were scored for ease of locomotion and skin and claw lesions at entry to the farrowing house and weaning. Salivary cortisol samples were collected and tear staining was scored at 0900 h weekly from entry until weaning. Saliva samples were also taken at fostering. Data were analysed using GLMs with appropriate random and repeated factors, or non-parametric tests were applied where appropriate. Back-fat thickness decreased between entry and weaning for all sows (F 1,42=26.59, P&lt;0.001) and tended to differ between treatments (F 4,16=2.91; P=0.06). At weaning RI sows had lower limb lesion scores than 2STEP7 and RE sows (χ 2 4=10.8, P0.05) and all nurse sows had a higher salivary cortisol concentration at fostering, compared with the other days (F 10,426=3.47; P&lt;0.05). Acute effects of fostering differed between nurse sow treatments (F 2,113=3.45, P0.05). In conclusion, no difference was detected between nurse sows and non-nurse sows in body condition or severity of lesions. Although some nurse sows experienced stress at fostering, no long-term effect of the nurse sow strategies was detected on stress levels compared with sows that raised their own litter.

A Review of Success Factors for Piglet Fostering in Lactation

Simple Summary

An understanding of behavioural and physiological mechanisms responsible for piglet survival and growth will assist in developing the best recommendations in which to manage piglet movements in the farrowing house. This review has identified six key principles that should underpin successful piglet fostering. These fostering principles will improve productivity and welfare of sows and piglets in commercial pig production.

Abstract

Piglet movement from one sow to another, or fostering, is required in modern pig farming but there is little available literature on the most effective strategy. In this review, we focus on the behavioural and physiological mechanisms responsible for piglet survival and growth, and have identified six key principles. (1) Colostrum provides piglets with warmth, energy and immunity. It is most accessible during the first 12 h from the birth sow, therefore no piglet should be moved before this; (2) To ensure even intake of birth sow colostrum, techniques such as split suckling prior to piglet movement should be implemented; (3) Udder assessment for functional teats should occur at farrowing, with number of fostered piglets not exceeding teat number; (4) Primiparous sows should receive as many piglets as the udder allows to maximise mammary stimulation, although older parities should be assessed for rearing ability; (5) Piglet fostering should occur between 12 and 24 h and movement kept to a minimum to prevent transfer of disease; Litter outliers should be moved and relocated to a litter of similar size; (6) Piglet movement after 24 h should be minimised. When required, strategies such as nurse usage should be employed. These principles will result in improved farrowing house performance by increasing the litter weight weaned per sow.

Animal Welfare and Economic Aspects of Using Nurse Sows in Swedish Pig Production

The number of born piglets per litter has increased in Swedish pig industry, and farmers are struggling to improve piglet survival. A common practice is to make litters more equally sized by moving piglets from large litters to smaller to make sure that all piglets get an own teat to suckle. Litter equalization is not always enough, as many sows have large litters and/or damaged teats, which results in an insufficient number of available teats. One way to solve this problem is to use nurse sows. A nurse sow raises, and weans, her own piglets before receiving a foster litter. The objectives of this study were to address how the use of nurse sows affects the welfare of sows and piglets and to explore how it impacts the contribution margin of pig production in Sweden. A literature search was made to investigate welfare aspects on sows and piglets. As there were few published studies on nurse sows, an expert group meeting was organized. In order to explore the impact on the contribution margin of pig production, a partial budgeting approach with stochastic elements was used for a fictive pig farm. Standard templates for calculating costs and benefits were supplemented with figures from existing literature and the gathered expert opinions. In Sweden, the minimum suckling period is 28 days while published studies involving nurse sows, all from outside of Sweden, weaned the piglets at 21 days. A Swedish nurse sow will thus get longer lactation period which might increase the risk of poor body condition, damaged teats, and shoulder ulcers. This indicates a reduced welfare of the sow and may lead to impaired fertility and increased culling risk. On the other hand, the piglet mortality could be reduced with the use of nurse sows, but the separation and mixing of piglets could be stressful. The partial budgeting suggested that the nurse sow system is slightly more profitable (+6,838 Swedish krona) per farrowing group during one dry and one lactation period compared to the conventional system. The result is, however, highly dependent on the input values, and welfare aspects were not considered in the calculations.