Performance of gestating sows in bedded hoop barns and confinement stalls1

Providing periodic exercise to stall-housed gestating sows influences only the total number of live-born piglets in older parity sows

The 2014 Canadian Pig Code of Practice includes a recommendation to provide stall-housed gestating pigs with periodic exercise. The objective of this study was to evaluate the effects of periodic exercise on sow performance and placental and piglet characteristics. Sows ( n = 180) were assigned to one of three gestation treatments: stall-housed sows (Control: C), stall-housed sows given weekly exercise (Exercise: E—10 min of walking per week), and group-housed sows (Group: G). Sows were distributed among three parity groups: young (parity 0–1), mid (parity 2–4), and old (parity 5–7). Old C sows had a higher number of total born than G sows, and E sows were intermediate; mid G sows had a higher total born than E and C sows ( P = 0.023). Old E and G sows had similar numbers of total live-born piglets, which were higher than in old C sows ( P = 0.033). Periodic exercise did not influence placental and piglet characteristics in the current study. In conclusion, periodic exercise benefited only the reproductive performance of older parity sows, increasing the number of live-born piglets in E and G sows compared to C sows.

Life cycle assessment of alternative swine management practices

Life cycle assessment of various alternative management strategies in the swine industry was performed to evaluate their impact on greenhouse gas (GHG) emissions, cumulative energy use, and cumulative water use. The management strategies included the use of immunocastration (IC), production without ractopamine (NoRAC), production without antimicrobials used for either growth promotion (NoAGP) or disease prevention (NoPREV), production of entire males (boars) (EM), and use of gestation pens (PENS). A common baseline scenario representing standard management practices in the swine industry was created against which all alternative management practices were compared pairwise. The study scope was from cradle-to-farm gate with a functional unit of 1 kg live weight at the farm gate. The baseline and each alternative management scenario was simulated in Pig Production Environmental Footprint Calculator (PPEC) model by varying key variables to populate life cycle inventory inputs for SimaPro V7.3 (Pre' Consultant, the Netherlands), a life cycle assessment modeling program. Increase in GHG emissions, energy use, and water use were observed for NoAGP (1.56, 1.75, and 1.03%, respectively), NoPREV (17.32, 18.40, and 15.58%, respectively), and NoRAC (6.52, 4.87, and 7.52%, respectively) scenarios. For EM scenario, GHG emissions and energy use increased by 2.09 and 3.75%, respectively but water use decreased by 2.29%. Lower GHG emissions, energy use, and water use were observed for PENS (0.97, 1.50, and 0.97%, respectively) and IC (2.39, 2.57, and 2.96%, respectively) scenarios. These changes in the impact categories were statistically significant (P < 0.05) for all scenarios except for changes to GHG emissions for EM and changes to water consumption for PENS and NoAGP. However, the uncertainty analysis showed that the tails of distribution for baseline and alternative management scenario pair overlapped. The impact of management practices on sustainability metrics resulted from differences in pig performance parameters, manure production, feed consumption, etc. between various management practices and the baseline scenario. Due to uncertainties in input parameters, the results should be interpreted as general trends which specifically highlight trade-offs that may result from shifts in production practices. The study identified some of the hot spots in pig production and can be useful in determining best management practices to make swine production more environmentally sustainable.

Social status and housing factors affect reproductive performance of pregnant sows in groups

Group-housing systems for pregnant sows are considered a welfare-promoting alternative to the individual stall. A major concern associated with pregnant sows housed in group pens is increased aggression at mixing and at feeding, which may cause chronic stress among some of the sows in the group due to low feed intake and social stress. Prolonged activation of the stress axis, based on elevated cortisol levels, may inhibit or impair reproductive success via disruption of the reproductive axis. Mixing sows into groups shortly after insemination evokes a stress response, which may affect fertilization and implantation due to sustained, elevated cortisol levels that disrupt reproductive processes. Yet, most studies reported minimal effects of group housing sows during pregnancy on reproduction or cortisol-related stress response. Differences between housing systems-in terms of group size, floor-space allowance, feeding system, and genetics-could account for these unexpected results. Indeed, interrupted feed intake, especially in early pregnancy, and sustained aggression in late pregnancy are two unfavorable social stresses that deserve special attention in order to achieve good reproductive performance. Unfortunately, most studies do not consider other factors, such as social rank and parity, which may interactively affect reproductive success and aggressive behavior of sows, especially in group-pen systems.

Sow housing associated with reproductive performance in breeding herds

Female pigs in breeding herds can be managed through four phases-gilt development, breeding, gestation, and lactation-during which they may be housed in group or individual pens, stalls, or on pasture. In this review, we focus on housing environments that optimize outcomes during gestation and lactation. Appropriate housing is important during early gestation, to protect embryos and to confirm pregnancy, and from mid-to-late gestation, to ensure sufficient nutrition to increase placental and fetal growth. No difference in the number of pigs born alive were reported between group housing and individual stall housing, although more risk factors for reproductive performance are associated with group housing than stall housing including genetics, bedding, floor space allowance, group size, social ranking, and parity. Furthermore, lameness in pregnant pigs is more frequent in group housing than in stall housing. Housing during lactation helps protect piglets from being crushed or from contracting disease, and can foster the transfer of enough colostrum from mother to piglets. Indeed, lactating sows in pen housing tend to have higher pre-weaning mortality and lighter litter weights than those in crated housing.

Programming the offspring through altered uteroplacental hemodynamics: how maternal environment impacts uterine and umbilical blood flow in cattle, sheep and pigs

As placental growth and vascularity precedes exponential fetal growth, not only is proper establishment of the placenta important, but also a continual plasticity of placental function throughout gestation. Inadequate maternal environment, such as nutritional plane, has been documented to alter fetal organogenesis and growth, thus leading to improper postnatal growth and performance in many livestock species. The timing and duration of maternal nutritional restriction appears to influence the capillary vascularity, angiogenic profile and vascular function of the placenta in cattle and sheep. In environments where fetal growth and/or fetal organogenesis are compromised, potential therapeutics may augment placental nutrient transport capacity and improve offspring performance. Supplementation of specific nutrients, including protein, as well as hormone supplements, such as indolamines, during times of nutrient restriction may assist placental function. Current use of Doppler ultrasonography has allowed for repeated measurements of uterine and umbilical blood flow including assessment of uteroplacental hemodynamics in cattle, sheep and swine. Moreover, these variables can be monitored in conjugation with placental capacity and fetal growth at specific time points of gestation. Elucidating the consequences of inadequate maternal intake on the continual plasticity of placental function will allow us to determine the proper timing and duration for intervention.

Performance and carcass characteristics of finishing beef cattle managed in a bedded hoop-barn system

The use of bedded hoop barns in finishing systems for beef cattle has not been widely researched. In this management system, beef cattle are confined to hoop barns throughout finishing, and bedding is used to absorb animal waste, which results in minimal effluent. The objective of this study was to compare the performance and carcass characteristics of finishing beef steers (n = 1,428) managed in a bedded hoop-barn management system vs. an open-feedlot system with shelter. Six feeding trials were conducted over a 3-yr period. Three trials were conducted during summer-fall and 3 trials were conducted during winter-spring. Crossbred steers were allotted to 3 pens in the hoop-barn system and to 3 pens in the open-lot system (approximately 40 steers per pen in both facility systems). Stocking densities for the steers were 4.65 m(2) per steer in the hoop-barn system and 14.7 m(2) per steer in the open-lot system. The steers were begun on trial weighing 410 and 411 kg (SD = 21), were fed for 102.3 and 103.0 d (SD = 3.8), and were weighed off test at 595 and 602 kg (SD = 21) for the hoop-barn and open-lot systems, respectively. Steer performance measures consisted of ADG, DMI, and G:F. Carcass characteristics were HCW, fat thickness, LM area, KPH percentage, marbling score, USDA yield grade, and USDA quality grade. No year, season, or pen (management system) main effects, or season x management system and year x management system interactions were observed for any of the items measured related to cattle performance or carcass characteristics (P > 0.05). Final mud scores (a subjective evaluation of the amount of soil and manure adhering to the hair coat of the animals) were greater for the steers from the open-lot system compared with those from the hoop-barn system (P < 0.02), suggesting steers in the hoop-barn system carried less mud than steers from the open-lot system. Average daily cornstalk bedding use in the hoop-barn system was 2.3 kg/steer during summer-fall and 2.6 kg/steer during winter-spring. The performance of finishing cattle managed in a hoop-barn system was not different from the performance of cattle managed in an open-feedlot system with shelter during summer and winter. Managing beef cattle in hoop barns required more bedding but resulted in decreased mud scores compared with cattle managed in an open-lot system with shelter. Hoop barns are a viable alternative housing management system for finishing beef cattle.

Strengthening US organic standards on animal health and welfare

Organic livestock production has been increasing in the US, although it still merely constitutes a small fraction of total production. Its success will require detailed standards supported by scientific knowledge and consistent with organic farming principles. However, such standards, mandated under the Organic Foods Production Act of 1990, are yet to be fully developed. Regulations issued by the USDA's National Organic Program identify livestock health and welfare concerns that must be addressed in a farmer's organic farm plan (eg that there be appropriate housing). However, specifics regarding achievement of these goals are not provided in the form of clear standards for organic livestock production. This paper provides a new starting point to further the development of such standards. First, we outline a rationale based upon the legal context and state of the organic livestock industry detailing the reasons why development of these standards is timely. Second, using a review of existing organic and nonorganic national and international animal health and welfare standards, a search of available scientific research, and a consensus of key stakeholders, we identify areas in which organic standards should be readily adopted. We conclude by presenting one example of a plausible organic standard for each of four major US livestock categories: minimum space for feedlot beef cattle; prohibition of routine tail-docking in dairy cows; provision of perches for laying hens and prohibition of gestation crates for sows.