• Journal of Life Science
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• v.19 no.8
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• pp.1170-1176
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• 2009

Porcine reproductive and respiratory syndrome virus (PRRSV) has plagued pig populations worldwide causing severe economical impacts. In order to establish effective strategies for prevention of PRRS, infection patterns on the herd level are primarily evaluated. In the present study, therefore, serological and virological analyses were conducted in 20 pig farms suffering from PRRS. Seroprevalence levels in each farm were grouped into 3 patterns: SN (Stable sow groups/Not infected piglet groups, SI (Stable sow groups and Infected piglet groups), and UI (Unstable sow groups and Infected piglet groups). The rates of each serological pattern were 15% (n=3), 10% (n=2), and 75% (n=15), respectively. In addition, the pattern analysis was extended to virological monitoring on the same farms that further included suckling pig groups. As a result, the infection pattern was classified into 4 categories: SNI (Stable sow groups/Not infected suckler groups/Infected piglet groups), SII (Stable sow groups/Infected suckler groups/Infected piglet groups), UNI (Unstable sow groups/Not infected suckler groups/Infected piglet groups), and UII (Unstable sow groups/Infected suckler groups/Infected piglet groups). The rates of each viroprevalence were estimated at 50% (n=10), 30% (n=6), 10% (n=2), and 10% (n=2), respectively. PRRSV viroprevalence results of suckling pig groups revealed that 8 farms were considered virus positive. In 2 farms among these farms, PRRSV appeared to be transmitted vertically to suckling piglets from their sows. In contrast, piglet-to-piglet horizontal transmission of PRRSV seemed to occur in sucking herds of the remaining farms. Thus, this virological analysis on suckling piglets will provide useful information to understand PRRSV transmission routes during the suckling period and to improve a PRRS control programs. Our seroprevalence and viroprevalence data found that infection patterns between sow and piglet groups are not always coincident in the same farm. Remarkably, 15 farms belonging to the UI seroprevalence pattern showed four distinct viroprevalence patterns (SNI; 7, SII; 4, UNI; 2 and UII; 2). Among these farms, 11 farms with unstable seroprevalence sow groups were further identified as the stable viroprevalence pattern. These results indicated that despite the absence of typical seroconversion, PRRSV infection was detected in several farms, implying the limitation of serological analysis. Taken together, our data strongly suggests that both seroprevalence and viroprevalence should be determined in parallel so that a PRRS control strategies can be efficiently developed on a farm level.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.7
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• pp.1019-1023
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• 2001

An on-farm trial was conducted in temperature-controlled lactation rooms at a commercial pig farm to investigate the efficacy of broadcasting sow suckling grunts from day 4 of lactation, on increasing piglet growth to weaning. In the Broadcast treatment, sows and litters were exposed to a 3-min broadcast from loud-speakers every 42 min. The Control treatment was not exposed to the broadcast. All sows and litters had similar husbandry and piglets were provided with creep feed on the floor twice daily. In each of the three replicates in time, the Broadcast and Control treatments were allocated to different lactation rooms at random and there were 12 sows and litters per treatment per replicate. A total of four identical lactation rooms were available for the trial, each containing 28 conventional sow and litter crates with piglet heater in the creep area. A non-trial room separated the two treatment rooms in each replicate to minimise the chance that the broadcast grunt stimulation was audible to the Control treatment litters. Five "normal and average-looking" piglets from the trial litters were weighed twice, 7 d apart. The cohort of five piglets was identified by ear-tags and formed the experimental unit for the statistical analysis. The average (${\pm}SD$) age of piglets at initial weighing was 7.7(${\pm}2.22$) days. For each litter, mean piglet live weight at day 14 of lactation was estimated by linear regression of the two weights recorded seven days apart, when on average, the Broadcast treatment had been exposed to the stimulation for 10 days. Piglets in the Broadcast treatment were heavier (p<0.01) at day 14 of lactation compared to Control treatment (4.24 and 3.92 kg, respectively) and tended to have a greater average daily weight gain over the 7-d period (245 and 228 g/day, respectively; p<0.08). The results suggest piglet growth was improved by about 8% in response to the regular, timed broadcast of sow suckling grunts in the lactation shed. The independent contributions of milk and creep feed to the improved growth remain to be determined.

• Journal of Animal Science and Technology
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• v.65 no.3
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• pp.562-578
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• 2023

The aim of the present study was to evaluate the effects of dietary supplementation of Ca-Mg complex on the longevity and reproductive performance of sows. In total, seventy-two gilts ([Yorkshire × Landrace] × Duroc, average body weight 181 kg) were randomly allocated to 1 of 3 treatments during 4 successive parity in a 4 × 3 factorial arrangement. Treatments consisted of CON (basal diet), CM1 (basal diet -MgO - 0.3% limestone + 0.4% Ca-Mg complex), and CM2 (basal diet - MgO - 0.7% limestone + 0.4% Ca-Mg complex). A higher (p < 0.05) number of totals born and live piglets, and sows increased feed intake during gestation and lactation, increased backfat thickness, and increased estrus interval were observed (p < 0.05) during their third and fourth parity than during their first and second parity. Ca-Mg complex supplementation improved (p < 0.05) the number of total piglets during the first and second parity as well as live-born piglets during the first to third parity, reduction (p < 0.05) in backfat thickness during the third and fourth parity, a higher (p < 0.05) initial and final number of suckling piglets as well as higher weaning weight compared with sows fed CON diet during the first, second, and third parity. The average daily gain (ADG) was higher (p < 0.05) in piglets born to CM1 and CM2 sows regardless of parity. The treatment diets fed to sows lowered (p < 0.05) the duration of first to last piglet birth and placenta expulsion time compared with CON sows. A significant interactive effect (p = 0.042) between parities and treatment diets was observed for the first to last piglet birth. Thus, Ca-Mg complex supplementation by partially replacing limestone in the basal diet enhanced sow performance, specifically during their third and fourth parity, thereby improving sow longevity.

• Korean Journal of Veterinary Service
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• v.35 no.4
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• pp.307-312
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• 2012

Iron deficiency anemia is also recognized as a serious disorder in many livestock, especially, piglets. We previously studied that the iron-fortified yeast (Saccharomyces cerevisiae) producing Sus scrofa ferritin heavy-chain (FER) was bioavailable to mice with iron deficiency. In this study, we determined whether FER could improve iron deficiency in piglets. The bioavailability of FER was examined by measuring body weight gain, hemoglobin concentration and hematocrit value in suckling and weaning piglets. We found that FER significantly increased hemoglobin value and the hematocrit ratio in suckling piglets (P<0.05). Furthermore, FER treatment significantly enhanced body weight gain in both groups of the suckling and weaning piglets (P<0.05). These results suggest that the iron-fortified recombinant yeast strain is helpful in iron absorption in piglets.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.11
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• pp.1601-1606
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• 2011

32 sows (Landrace${\times}$Yorkshire) and their litters were used to evaluate the effects of varying creep feed duration on pre-weaning, post-weaning performance of piglets and sows. Sows were randomly assigned with 1, 2 or 3+ parities into 1 of 4 treatments. Creep feeding was initiated at day 5, 10 and 15 from birth for treatment 1 (TRT1), 2 (TRT2) and (TRT3), respectively, with a control group provided no creep feed. In this study, TRT1 and TRT2 diets had reduced (p<0.05) the post-weaning diarrhea scores in piglets and the weaning-to-estrus interval and cortisol concentration in sows at weaning time compared with other treatments. Dietary TRT1 led to a higher (p<0.05) epinephrine and norepinephrine concentrations than other treatments. No differences (p>0.05) were noted in suckling, sleeping, fighting frequency and mortality in piglet and eating, standing times, backfat and body weight loss in sows. In conclusion, creep feed initiated from day 5 and 10 reduce diarrhea scores in piglets and benefit the estrus interval in sows compared with those initiated from day 15 and no-creep feeding diets, indicating creep feeding could improve the pigs and sows performance, especially those initiated from day 5 and 10.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.10
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• pp.1435-1439
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• 2011

This study was conducted to evaluate the effects of creep feed with different energy densities on litter performance. A total of 30 sows (Landrace${\times}$Yorkshire) and their litters were randomly assigned with 1, 2, or 3+parities into 1 of 3 treatments (10 sows). Dietary treatments were: i) CON (no creep feed), ii) LE (creep feed (DE 4,000 kcal/kg) from 5 d of age until weaning (21 d)), and iii) HE (creep feed (DE 5,000 kcal/kg) from 5 d of age until weaning). Each piglet was weighed at d 5, 10, 15, 21 (weaning), and d 7 postweaning to determine ADG. Creep feeding reduced concentrations of epinephrine, norepinephrine, and cortisol compared with those in CON group (p<0.05). Creep feeding reduced (p<0.05) the weaning-to-oestrus interval in sows. Piglets in the HE groups evidenced greater ADG (p = 0.024) and ADFI (p = 0.001) post-weaning than those in CON treatments. Creep feeding decreased (p<0.05) the suckling time of piglet in this study. In conclusion, creep feeding increased growth and feed intake of pigs after weaning. It can decrease the oestrus interval of sows. There was no difference between providing a high energy or a low energy creep fed diet to the piglets.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.8
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• pp.1065-1071
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• 2013

The swine leukocyte antigen class II molecules are possibly associated with the induction of protective immunity. The study described here was to investigate the relationship between polymorphisms in exon 2 of the swine DQA gene and piglet diarrhea. This study was carried out on 425 suckling piglets from three purebred pig strains (Large White, Landrace and Duroc). The genetic diversity of exon 2 in swine DQA was detected by PCR-SSCP and sequencing analysis, eight unique SSCP patterns (AB, BB, BC, CC, CD, BD, BE and DD) representing five specific allele (A to E) sequences were detected. Sequence analysis revealed 21 nucleotide variable sites and resulting in 12 amino acid substitutions in the populations. A moderate level polymorphism and significant deviations from Hardy-Weinberg equilibrium of the genotypes distribution were observed in the populations (p<0.01). The association analysis indicated that there was a statistically significant difference in the score of piglet diarrhea between different genotypes, individuals with genotype CC showed a lower diarrhea score than genotypes AB ($0.98{\pm}0.09$), BB ($0.85{\pm}0.77$) and BC ($1.25{\pm}0.23$) (p<0.05), and significantly low than genotype BE ($1.19{\pm}0.19$) (p<0.01), CC genotype may be a most resistance genotype for piglet diarrhea.

• Journal of Animal Science and Technology
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• v.63 no.1
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• pp.1-15
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• 2021

As a result of intensive breeding, litter size has considerably increased in pig production over the last three decades. This has resulted in an increase in farrowing complications. Prolonged farrowing will shorten the window for suckling colostrum and reduce the chances for high-quality colostrum intake. Studies also agree that increasing litter sizes concomitantly resulted in decreased piglet birth weight and increased within-litter birth weight variations. Birth weight, however, is one of the critical factors affecting the prognosis of colostrum intake, and piglet growth, welfare, and survival. Litters of uneven birth weight distribution will suffer and lead to increased piglet mortality before weaning. The proper management is key to handle the situation. Feeding strategies before farrowing, management routines during parturition (e.g., drying and moving piglets to the udder and cross-fostering) and feeding an energy source to piglets after birth may be beneficial management tools with large litters. Insulin-like growth factor 1 (IGF-1)-driven recovery from energy losses during lactation appears critical for supporting follicle development, the viability of oocytes and embryos, and, eventually, litter uniformity. This paper explores certain management routines for neonatal piglets that can lead to the optimization of their colostrum intake and thereby their survival in large litters. In addition, this paper reviews the evidence concerning nutritional factors, particularly lactation feeding that may reduce the loss of sow body reserves, affecting the growth of the next oocyte generation. In conclusion, decreasing birth weight and compromised immunity are subjects warranting investigation in the search for novel management tools. Furthermore, to increase litter uniformity, more focus should be placed on nutritional factors that affect IGF-1-driven follicle development before ovulation.

• Journal of Animal Science and Technology
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• v.45 no.4
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• pp.627-632
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• 2003

Piglets communicate with their sow by using special sounds and synchronize their suckling behavior with their mother’s grunting. This study sought to find an effective sound for controlling the nursing/suckling behavior of pigs. Eighteen crossbred Landrace${\times}$Yorkshire sows and their piglets were studied on days 1, 7, and 14 post-partum. The parity of the sows was three or four. The litter size ranged from 9 to 11, with a mean of 10.4 piglets. Thirty minutes after the end of the last suckling, either the nursing-suckling sound (NSS) or the nursing-suckling sound + click sound (NSSCS) was played for 90 s randomly, and this experiment was repeated three times. The behavior of the sows and their piglets was recorded using camcorders and observed each second. When comparing NSS and NSSCS, there was less lying and sleeping and more sitting, standing, walking, and massaging when NSSCS was played than when NSS was played. These results suggest that NSSCS may induce more nursing and suckling in pigs than NSS.

• Korean Journal of Veterinary Research
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• v.48 no.1
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• pp.67-73
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• 2008

Porcine reproductive and respiratory syndrome (PRRS) is the most economically important viral infectious disease in pig populations worldwide. This study was conducted to better understand the epidemic and dynamics of PRRS virus (PRRSV) on each farm and to evaluate the risk of PRRSV infection in Korea. Interviews with pig farmers were carried out to obtain PRRS vaccination programmes in 60 pig farms throughout Korea. Blood samples were also collected from the 59 pig farms to investigate outbreak patterns of each farm. Vaccination against PRRS was performed in 16.7% farms for breeding pigs and 8.3% of farms for nursery pigs. According to the seroepidemiological analysis, 56 (94.9%) out of 59 farms were considered to be affected by PRRSV infection. The results revealed that 68.9% of sows tested were seroconverted and interestingly, gilt herds had the highest seropositive rate (73%), suggesting that gilts may play a key role in PRRSV transmission in sow herds. Among the PRRS-affected piglet herds, 33 (55.9%), 14 (23.7%) and 6 (10.2%) farms were initially infected with PRRSV during the weaning, suckling and nursery period, respectively. It seems likely, therefore, that PRRSV infection predominantly occurs around the weaning period in piglet herds. Based on antibody seroprevalence levels in both sow and piglet groups, we were able to classify patterns of PRRSV infection per farm unit into 4 categories; category 1 (stable sow groups and non-infected piglet groups), category 2 (unstable sow groups and non-infected piglet groups), category 3 (stable sow groups and infected piglet groups), and category 4 (unstable sow groups and infected piglet groups). Our data suggested that 43 (72.9%) farms were analysed to belong to category 4, which is considered to be at high-risk for PRRS outbreak. Taken together, our information from this study will provide insight into the establishment of an effective control strategy for PRRS on the field.