Mixed Sows Research Articles

PSIII-4 Effect of Housing System and Supplementation of 25-hydroxicholecalciferol (25-OH-D3) on Performance and 25(OH)D3 Serum Levels of Sows during Gestation and Lactation

Abstract Vitamin D is an essential key modulator of metabolism in pigs. Improvements in sow productivity have raised questions regarding dietary vitamin recommendations. In this sense, vitamin D serum levels could be limiting to attend high demanding phases. The present study aimed to study the impact of housing system with access to sunlight exposure and supplementation of 25(OH)D3 (Hy-D®) on performance and serum levels of 25(OH)D3 in sows during gestation and lactation. A total of 48 mixed parity sows were distributed in a factorial 2 x 2 experimental design (2 housing systems: gestation crates or free-range system with external area for sunlight exposure; and 2 diets: 0 or 50µg of Hy-D® per kg of diet). Sows remained in treatments from insemination until weaning. The housing systems did not influence (P >0.10) performance traits during gestation nor lactation. The use of Hy-D® tended (P=0.052) to improve total born (17.5 vs. 15.4, respectively 50 and 0 µg Hy-D®) and influenced (P=0.046) on number of born alive (13.4 vs. 12.2, respectively 50 and 0 µg Hy-D®). Litter weight at birth was influenced (P=0.01) by Hy-D® supplementation (20.8 vs. 17.5 kg, respectively 50 and 0 µg Hy-D®). Hy-D® supplementation and housing system (free-range with sunlight exposure) tended to increase weaning weight (P=0.07) and litter daily gain (P=0.051) during lactation. Exposure to sunlight and Hy-D® influenced (P=0.008) 25(OH)D3 serum levels when compared to control (without sunlight and 0 µg of Hy-D®) during gestation (132.3 vs. 116.6 ng mL-1, respectively) and lactation (120.3 vs. 92.2 ng mL-1, respectively). In conclusion, our findings showed that the supplementation of Hy-D® during gestation and lactation has a significant impact on performance of sows and their litters. Also, the association of Hy-D® supplementation with exposure to sunlight during gestation improved significantly 25(OH)D3 serum levels and consequently performance traits in gestation and lactation.

ВЛИЯНИЕ МИНЕРАЛЬНЫХ УДОБРЕНИЙ НА ИЗМЕНЕНИЕ БИОХИМИЧЕСКОГО СОСТАВА ГЕТЕРОГЕННЫХ ПОСЕВОВ ЛЮЦЕРНЫ ИЗМЕНЧИВОЙ С МЯТЛИКОВЫМИ ТРАВАМИ НА СЕРЫХ ЛЕСНЫХ ПОЧВАХ ЦЕНТРАЛЬНОГО РЕГИОНА РОССИИ

Sustainable development of animal husbandry and feed production now can be characterized by a complex approach to the introduction of elements of intensive agricultural technologies, the main direction of which should be the rise of natural resource potential of agrocenoses and, as a result, achievement of the necessary amount of balanced carbohydrate-protein complex of highly nutritious feed. Until now, the structure of seeds of perennial grasses has been dominated mainly by bluegrass species. In the future, agricultural producers plan to expand the area of perennial grasses with an increase in the share of legume species in herbage mixtures. Perennial legumes in single and mixed sows are the main components in solving the problem of protein deficiency in the production of highly nutritious feeds. It is known that mixed (heterogeneous) sows of perennial legumes and bluegrass grasses have a clear advantage in productivity over single-species agrocenosis due to the fact that they are much more efficient in using nutrients from the soil and fertilizers, moisture, solar insolation due to the different structure of bush and root system of perennial grasses. When carrying out experiments in the fields of Bryansk SAU, a modern assortment of variable alfalfa and bluegrass perennial grasses was used. In herbage mixtures, the bean component varied from 40 to 50%. Seeding was carried out under the cover of annual ryegrass westerwold (Lolium westerwoldicum Wittm.), diploid variety Izorsky. As a legume component, we used variable alfalfa (Medicago varia Mart.). The bluegrass component is represented by the meadow Timothy (phlum pratense L.),meadow fescue (Festuca pratensis Huds.), cocksfoot(Dactylis glomerata L.), smooth brome (Bromopsis inermis Leyss.). at the present time, the introduction of modern science-based fertilizer systems and technologies for the cultivation of heterogeneous seeds based on the inclusion of crops with productive longevity in their composition will solve the problem of increasing production highly nutritious feed.

Effects of repeated social mixing on behavior and blood immune cells of group-housed pregnant sows (Sus scrofa domestica)

Commercial housing of sows often involves frequent regrouping (“mixing”) of animals that poses a potential welfare problem due to social stress. Although mixing is a common management practice worldwide, immunological consequences are poorly investigated in pregnant sows. This study combines both behavioral and endocrine data with detailed analyses of blood cellular immunity to examine whether repeated social mixing affects the immune system in pregnant sows, which none of the studies conducted so far could confirm. Pregnant multiparous sows (German Landrace, n = 40) were housed in groups of five animals. Sows were either assigned to a repeated social mixing treatment with a mutual exchange of two randomly selected sows of two specific groups (2 × 2) twice a week over a period of eight weeks, or remained undisturbed in their original group. Blood samples of all sows were collected at five time points before, during, and after the mixing period to evaluate the distribution of blood lymphocyte subpopulations, mitogen-induced lymphocyte proliferation and plasma cortisol concentrations. Mixing caused higher levels of aggressive behavior (p ≤ 0.05) during the entire mixing period. Compared to pre mixing baseline values, lymphocyte numbers were lower in mixed sows (p ≤ 0.05), which was primarily caused by lower antigen-experienced T helper cells, cytotoxic T cells and natural killer cells. Mixed sows showed a higher proliferative response of lymphocytes while granulocytes and cortisol concentrations were not affected (p > 0.05). Repeated social mixing thus not only resulted in an increase of aggressive behavior, but also in altered immune cell numbers of the adaptive immune system, even though sows became eventually familiar with each other. These findings suggest, in contrast to previous studies, an adverse influence of frequent mixing on the immune system of pregnant sows.

Longitudinal study of Senecavirus a shedding in sows and piglets on a single United States farm during an outbreak of vesicular disease

BackgroundThe study highlights the shedding pattern of Senecavirus A (SVA) during an outbreak of vesicular disease in a sow farm from the South-central Minnesota, USA. In this study, 34 individual, mixed parity sows with clinical signs of vesicular lesions and 30 individual piglets from 15 individual litters from sows with vesicular lesions were conveniently selected for individual, longitudinal sampling. Serum, tonsil, rectal, and vesicular swabs were collected on day1 post outbreak, and then again at 1, 2, 3, 4, 6, and 9 weeks post outbreak. Samples were tested at the University of Minnesota Veterinary Diagnostic Laboratory for SVA via Real Time Polymerase Chain Reaction (RT-PCR)ResultsIn sows, vesicular lesions had the highest concentration of SVA, but had the shortest duration of detection lasting only 2 weeks. Viremia was detected for 1 week post outbreak, and quickly declined thereafter. SVA was detected at approximately the same frequency for both tonsil and rectal swabs with the highest percentage of SVA positive samples detected in the first 6 weeks post outbreak. In suckling piglets, viremia quickly declined 1 week post outbreak and was prevalent in low levels during the first week after weaning (4 weeks post outbreak) and was also detected in piglets that were co-mingled from a SVA negative sow farm. Similar to sows, SVA detection on rectal and tonsil swabs in piglets lasted approximately 6 weeks post outbreak.ConclusionThe study illustrates the variation of SVA shedding patterns in different sample types over a 9 week period in sows and piglets, and suggests the potential for viral spread between piglets at weaning.

Evaluation of Different Calcium Sources on the Performance of Highly Prolific Lactating Sows

Improvements in sow productivity have raised questions regarding dietary mineral recommendations. Current calcium (Ca) levels and/or Ca sources might not support milk requirements of the larger litter in the modern sow. Therefore, four hundred and eighty mixed parity sows of a high prolificacy genetic line were used to evaluate the impact of the calcium source on the performance of highly prolific lactating sows. Sows were distributed in a completely randomized experimental design among six treatments containing different levels of inorganic Ca (INO) and organic calcium carbon-amino-phospho-chelate (CQT) inclusion. The sows were allocated to one of the six treatments represented by increased replacement ratios between sources of calcium: 100% INO; 100% CQT; 80% INO and 20% CQT; 60% INO and 40% CQT; 40% INO and 60% CQT; 20% INO and 80% CQT. Farrowing duration was not influenced (P>0.10) by the treatments, and averaged 185 minutes. Average daily voluntary feed intake did not differ (P>0.10) between treatments (5.54 kg d-1 on average). The lactation BW, backfat losses and chemical composition of body weight loss was not influenced (P>0.10) by the treatments. Litter size and average piglet weight at birth were not influenced (P>0.10) by the treatments (13.7 and 1.26 kg, on average). Litter weight gain, litter size and average piglet weight at weaning were also not influenced (P>0.10) by the treatments. The Treatments did not influence (P>0.10) estimated daily milk yield; which averaged 11.41 kg d-1. The treatments tended to influence (P 0.10) by treatments during lactation and averaged 1.38 mmol/L and 14.62 pg/ml, respectively. In conclusion, this experiment demonstrated that in diets for lactating sows an inorganic Ca source can be fully replaced by a more available Ca source (i.e., calcium carbon-amino-phospho-chelate), without negatively impacting the productive and reproductive performance of these animals or the performance of their litters.

Effect of day of mixing gestating sows on measures of reproductive performance and animal welfare1

Effects of day of mixing sows after breeding were measured for reproduction and welfare on a commercial research farm. Sows (n = 1,436) were weaned into stalls for breeding, and groups of sows were assigned to 1) no mixing and housed in individual stalls (STL), 2) mixed on d 3 to 7 after breeding (D3), 3) mixed on d 13 to 17 after breeding (D14), or 4) mixed 35 d after breeding (D35). Mixed sows were moved into pens (n = 58 sows/pen) with an electronic sow feeding station and maintained as a static group. In the first 12 d after mixing or movement into STL (period 1), sows were assessed for lameness and lesions every 3 d and then every 2 wk until farrowing (period 2). Cortisol and fights were measured in period 1. Conception rates were reduced (P < 0.005) in D3 (87.1%) and D14 (89.2%) compared to D35 (92.2%) and STL (96.2%). Farrowing rates were lower (P < 0.0001) in D3 (82.8%) compared to D35 (90.5%) and STL (96.2%), but litter size was not (P ≥ 0.20) affected by mixing. The proportion of sows bred within 10 d of weaning was reduced (P < 0.05) for D14 compared to STL, but D3 and D35 did not differ among treatments. Number of fights 24 h after mixing was less (P < 0.0001) for D14 compared to D3 and D35 groups, and serum cortisol was greater (P < 0.05) for D35 compared to STL and D3. From period 1 to 2, lameness increased in D3 and decreased in D35 but did not change for D14 and STL (treatment × period, P < 0.05), whereas leg inflammation did not differ (P > 0.10) among treatments. Head and body lesion scores declined from period 1 to 2 in all mix groups, whereas vulva lesions increased in the D3 and D35 but did not change in D14 and STL (treatment × period, P < 0.0001). These results suggest STL can improve most measures of welfare compared to mixing in groups. However, when mixing sows, assessments for reproductive performance and welfare may change from gestation to farrowing. The poorest reproductive performance and welfare was observed when sows were mixed 3 to 7 d after breeding. There were few differences between the D14 and D35 treatments in reproduction or welfare, but D14--not D35--differed from STL in weaned sows rebred. Overall, results of this trial suggest that, even though any of the mixing days can result in acceptable measures of reproduction, there are clear effects of day of mixing on fertility and welfare, and special attention should be focused on the long-term reproductive and welfare consequences.

Growth and reproductive development of male piglets are more vulnerable to midgestation maternal stress than that of female piglets12

In many mammalian species, prenatal stress masculinizes female and feminizes male offspring impairing their reproductive capacity. Regrouping gestating sows is a common, stressful production practice, but its impact on the developing pigs of the sow is not fully known. This study examined the effects of regrouping gestating sows and the administration of exogenous glucocorticoids on the growth and external reproductive morphology of pigs. At 37.2 ± 0.26 d of gestation, 6 cohorts of 18 sows (N = 108) were placed in 1 of 3 treatments: socially stable (Stable), hydrocortisone acetate (HCA), or mixed (Mixed). The HCA sows were administered 70 mg HCA, a synthetic glucocorticoid, twice daily during the 21 d experimental period. Each Mixed sow was penned with 2 companion sows (Companion) and regrouped on d 7 and 14 with 2 different Companion sows in a new pen. Stable and HCA sows were penned in treatment groups of 3 sows. Sow social rank was assessed weekly during feeding. After the 21 d experimental period, all sows were housed in gestation stalls for the duration of pregnancy. During the 21 d, Companion sows gained more weight than HCA and Mixed sows (P < 0.05) with Stable sows intermediate. High ranked sows gained more weight than middle and low ranked sows (P < 0.05). Mixed sows had greater head lesion scores than Stable and HCA sows (P < 0.05) with Companion sows intermediate. Head lesions increased with lower social rank (P < 0.001). Sow treatment did not affect farrowing rate, litter size, or sex ratio (P > 0.10). Social rank also had no effect on farrowing rate (P > 0.10), but affected total litter size (P = 0.03). High ranked sows bore and weaned more live females than low ranked sows (P < 0.05), in part due to differential preweaning mortality among female pigs (P = 0.01). Only male pigs were affected by sow treatment. Preweaning mortality was higher among male pigs from HCA than from Mixed sows (P = 0.04) with other treatments intermediate. Despite no weight differences in the preweaning period, at 160 d of age males from HCA sows weighed more than males from Stable sows (P = 0.01) with other treatments intermediate. Males born to Companion sows had longer relative anogenital distances, a marker of fetal testosterone exposure, than males from Mixed sows (P = 0.03) with other treatments intermediate. The prenatal environment affected the pigs in a sex-specific manner altering the growth and reproductive morphology of the males more than that of the females.

Effects of Buserelin on day of service or 12 days post service on farrowing rate and litter size to first service in outdoor sows and gilts

The problem of seasonal infertility in pigs has been recognised for many years. The infertility complex can may be manifested by increased returns to service, prolonged weaning to oestrus intervals and decreased litter size. The purpose of this trial was to evaluate the effects of Buserelin treatment on fertility in sows and gilts during the seasonally infertile period.A total of 1231 mixed parity sows and gilts from five outdoor herds in East Anglia were randomly assigned to one of three treatment groups. Any sows not presented for service at first post weaning oestrus were excluded. All sows and gilts judged to be in adequate health and condition to be kept in a commercial breeding herd were included. Group C sows and gilts were given no treatment. Group R1 sows and gilts were injected i.m. with 8μg Buserelin (2.0ml Receptal; Hoechst Roussel Vet UK Ltd) on the day of service.

Agonistic and mating behaviour in two loose-housing systems for sows

The mixing of unfamiliar sows usually results in fighting which can have adverse consequences for both welfare and production. It has been suggested that aggression may be moderated by both the presence of a boar and by allowing sows access to feeding stalls (Arey and Edwards, 1998). The objective of this experiment was to investigate these effects on the behaviour of newly weaned sows mixed into two loose-housing systems.In the first system (dynamic), 24 Large White x Landrace mixed parity sows were introduced 4 days post weaning to a dynamic group of 22 sows and 2 boars with a replacement rate of 2 sows per week. Observations were carried out on the 2 newly introduced sows each week. The straw-bedded pen provided 4.5 m2 space per animal. The sows were floor fed 3 kg/sow at 08.00 each day.

Efficacy of Guardian 10% Swine Ear Tags for Control of Hog Lice, 1985

Abstract Guardian 10% swine ear tags were evaluated for hog lice control when applied to brood sows and gilts in Page Co, VA. The following treatment groups were established on 3 Mar: A) untreated control, consisting of 6 mixed breed gilts; each gilt received 2 Allflex identification tags; B) Guardian 10% ear tags, attached to the inside of ears (one per ear), consisting of 12 mixed breed gilts; C) Guardian 10% ear tags, attached to the outside of ears (one per ear), consisting of 7 mixed breed sows. Six animals from each group were individually identified and used for evaluation. Each group was confined separately in pens in a breeding and gestation barn. However, each group had access to a common self-feeder, which they used on a rotational basis. Each group was allowed to feed for a 24-h period, and then return to their holding pen for a 48-h period. An alternate untreated control group (D), consisting of 8 mixed-breed sows with Allflex identification tags, was established in the same location on 2 May. This group, of which 6 were used for evaluation, had no access to the self-feeder. This alternate control group was established because there was a concern that the original control animals were subject to contamination with insecticide from the treated animals through the rotational use of the self-feeder.