Identification of Genomic Regions Associated With Lactation Performance in Yorkshire Sows

본 연구는 혈장의 insulin-like growth factor (IGF)-I과 IGF-II 농도와 산자수 및 비유성적과의 관계를 구명하고자 착수되었다. 분만주가 비슷한 미경산 및 경산 임신돈 중에서 선발한 총 60두의 순종 Landrace와 Yorkshire 공시돈을 저산자수 (low; <<TEX>${\mu}$</TEX>­0.5 SD)와 고산자수 (high; ><TEX>${\mu}$</TEX> + 0.5 SD)-lines로 구분하여 2 (품종) <TEX>${\times}$</TEX> 2 (line) 요인분석 실험설계 하에 본 실험을 진행하였다. 공시돈은 분만시 모돈당 포유자돈수를 9두로 고정시키고, 3주령 이유시 비유량의 척도로서 총 이유자돈 체중을 측정하였다. 혈액 시료는 임신 90일과 분만 후 15일에 경정맥으로부터 채취하였다. 본 실험기간 중 산자수 및 본 실험기간까지의 평균 산자수는 high-line이 low-line보다 각각 3.7두와 2.4두 많았고 (P< 0.01), 두 품종간 산자수 차이는 없었다. 임신 90일 혈장의 IGF-II 농도는 low-line보다 high-line에서 높았다. 산자수는 임신 90일 IGF-I 농도와 Landrace에서는 부의 상관관계를 나타냈고 (r=－0.46; P<0.05), Yorkshire에서는 부의 상관관계 경향을 나타내어 (r=－0.31; P=0.09) 전체 공시돈에서는 이들 두 변수간 유의적인 부의 상관관계를 보였다 (r=－0.35; P< 0.01). 이유시 모돈당 총 이유자돈 체중은 두 품종간 혹은 두 lines간 차이가 없었다. 이유자돈 체중과 IGF 농도와의 관계는 품종 <TEX>${\times}$</TEX> 생리적인 생태 조합들간 일정한 경향을 나타내지 않았다. 이상의 결과는 임신 90일 IGF 농도가 임박한 분만시 산자수의 지표가 될 수 있는 가능성을 시사한다. The present study was undertaken to find relationships of plasma insulin-like growth factor (IGF)-I and IGF-II concentrations to litter size and lactation performance. Sixty pure-bred Landrace and Yorkshire pigs having similar farrowing weeks which had been selected from a large number of pregnant gilts and sows were divided into low- (<<TEX>${\mu}$</TEX>－0.5SD) and high-litter size (><TEX>${\mu}$</TEX>+0.5 SD) lines under a 2 (breed)<TEX>${\times}$</TEX>2 (line) factorial arrange of treatments. After adjusting the litter size to nine piglets per sow at farrowing, total litter weight was measured at three weeks postpartum at weaning as an index of milk yield. Blood samples were obtained from the jugular vein at day (d)-90 pregnancy (Px) and at d-15 postpartum. The litter size or the number of piglets born during the present experiment and the average litter size during the entire parities up to the present one were greater in the high-line than in the low-line by 3.7 and 2.4 piglets, respectively (P<0.01); effect of the breed on litter size was not significant. Plasma IGF-II concentration at d-90 Px was greater in the high-line than in the low-line. Litter size and d-90 Px IGF-I concentration were negatively correlated in Landrace (r=－0.46; P<0.05) and tended to be negatively correlated in Yorkshire (r=－0.31; P=0.09), which resulted in a significant negative correlation between these two variables in total animals (r=－0.35; P<0.01). Litter weight at weaning was not different between the two breeds or lines. Relationships between the litter weight and IGF concentration were not consistent across the breed <TEX>${\times}$</TEX> physiological stage combinations. Results suggest that d-90 Px IGF concentrations may be indicative of the litter size at impending farrowing.

This study is a portion from the validation process of an objective methodology to measure feet and leg joint angles and to evaluate their relationship with sow longevity. Joint angle measurements from five feet and leg conformation traits (knee, hock, front and rear pasterns and rear stance) that have been previously described in the literature as being related with sow longevity were obtained from maternal gilts at selection and during their second gestation and compared with those obtained from 45 crossbred sows parity 5 and above. Significant differences (P < 0.05) between parities were identified in the knee, both pasterns, hock and rear stance joint angle measurements. These results suggest that as pigs age, structural changes occur. The range of which these changes occur could carry implications for the use of objective feet and leg angles towards future selection programs and protocols.

Creep feeding strategies in piglets are designed to ease the transition from sow’s milk to dry feed. Essential oils have gained attention due to their antimicrobial and immunomodulatory effects as well as improved growth performance and feed palatability in pigs. This study evaluated the effects of supplementation of a blend of microencapsulated essential oils and a prebiotic (EOP) in creep feed and two levels during the nursery. Seven days before weaning, litters were allotted by sow parity (avg. 2.8), genetics, weaning age (avg. 20.3 d), number of pigs per litter (avg. 11.9), and litter weight (avg. 50.2 kg) and assigned to one of two creep feeding treatments: 1) Basal Diet (NC, n=35) or 2) Basal Diet+0.10% EOP (A, n=17). Post-weaning, pigs were blocked by weaning weight within creep feed group and randomly allotted to a nursery treatment. Pigs from the NC creep feed were allotted to one of four nursery dietary treatments: 1) Basal diet (NC-NC), 2) Basal diet+55 ppm Carbadox (NC-PC), 3) Basal diet+0.10% EOP (NC-A), or 4) Basal diet+0.16% EOP (NC-B). Pigs from the A creep feed group were allotted to one of two treatments: 5) Basal diet+0.10% EOP (A-A), or 6) Basal diet+0.16% EOP (A-B). Each treatment had 10 pens/treatment with 8 or 9 pigs/pen evenly distributed within block. Fecal samples were collected from a subset of piglets and sows during lactation and pigs post-weaning for future microbiome analysis. Creep feed treatment had no effect on intake or growth performance of piglets during lactation. During week 1 of the nursery, NC creep feed groups had greater G:F than A creep feed groups (P=0.031). There were interactions between creep feed and nursery feed EOP with pigs fed treatments NC-B and A-A having higher ADFI week 2 (P=0.029) and week 4 (P=0.094) and ADG week 2 (P=0.029) than NC-A and A-B, respectively. Pigs fed NC-PC had greater ADG week 4 (P=0.029), week 5 (P=0.030), and overall, d0-34, (P=0.071) with greater G:F week 3 (P=0.034) and d0-34 (P=0.040) than pigs fed NC-NC. For the overall 34-day nursery period, there was no effect of treatment on ADFI. ADG was greater for NC-PC than NC-A, A-A, and A-B, with NC-NC and NC-B being intermediate but not different (P&amp;lt; 0.05). Overall, NC-PC had greater ADG (P=0.003) than the average of all nursery EOP-supplemented groups, however, the EOP treatments had similar G:F to NC-PC and numerically higher G:F than the NC-NC fed pigs. While NC-PC had the best growth performance, pigs receiving NC creep feed followed by high EOP or low creep feed dose of EOP followed by a low dose of EOP performed best of the EOP supplementations. Future research should explore varying EOP levels and durations to optimize piglet performance.

IL28B single nucleotide polymorphisms in the treatment of hepatitis C

The inclusion of β-hydroxy β-methyl butyrate (HMB) in sow diets can improve sow and piglet pre-weaning performance. The aim of this study was to determine whether there was a dose-dependent effect of HMB supplementation of sows in gestation on litter and piglet performance to weaning and on colostrum production. A total of 140 (Large White × Landrace [JSR Genepacker 90, JSR, UK]) multiparous sows were allocated to one of four treatments. There was a control treatment (CT) which was supplemented with HMB at the following doses to create four treatments: 0 (CT + 0), 5 (CT + 5), 15 (CT + 15) or 45 (CT + 45) mg/kg of the sow’s body weight. Sows were fed their treatments from d 100 of gestation until parturition. Feeding sows increasing doses of HMB increased total live born litter weight and average piglet 24-h weight in a quadratic manner (P < 0.001 and P = 0.004, respectively). This quadratic pattern remained significant for litter and piglet weights at week one (P = 0.021 and P = 0.021, respectively) and a trend for litter weights at weaning (P = 0.056). There were quadratic increases in colostrum intake (P = 0.005) and yield (P = 0.004) in response to increased doses of HMB. Additionally, the IgG concentration of colostrum increased linearly up to the highest dose tested (P = 0.002). Mortality within the first 24-h of farrowing was reduced in a quadratic manner (P = 0.045) and this remained a trend at weaning (P = 0.055). Overall, increasing the dose of HMB fed to sows for the last 15 days of gestation increased litter and piglet weights and colostrum yield quadratically and increased colostrum IgG level linearly which in turn contributed towards reduced mortality to weaning.

Various multiple regression models were used primarily to examine the regression of swine litter traits from farrowing through 154 days of age on differences in inbreeding and in age of dam. The records included were for 7,075 litters from eight cooperating agricultural experiment stations in the Regional Swine Breeding Laboratory. Only first parity litters, from gilts aged 10 to 19 mo., were studied. An initial study indicated that the inbreeding of the sire of the litter had little or no effect on litter size at farrowing. The inbreeding of the dam significantly depressed litter size, total litter weight, and average weight per live pig at farrowing. Nonlinearity was apparent with the traits involving weight. Each of the litter traits at farrowing increased curvilinearly as age of dam at first parity increased. The predicted peak performance was by gilts of age 15 to 17 mo. at farrowing. The inbreeding of the litter showed practically no influence on litter size but evidenced a significant effect on pig weights at farrowing. The inbreeding and age of dam had practically no effect on number weaned over their indirect effects on litter traits at farrowing. However, the inbreeding of the dam continued to exert a significant direct influence on both pig and litter weights at weaning, while age of dam retained a significant effect on average weaning weight per pig. The quadratic equation provided a significantly closer fit than the linear equation in relating the inbreeding of the dam to the total weight of the litter at weaning. The inbreeding of the litter showed an increased influence on weaning traits over that shown at farrowing. Significant curvilinear relationships were noted for each trait. The inbreeding of the dam retained a significant direct effect on total litter weight at 154 days, in addition to its indirect influence through the litter traits at farrowing. No such direct effect was noted for the inbreeding of the dam on litter size or average pig weight at 154 days. However, the inbreeding of the litter exerted a significant influence on the 154-day litter traits even when litter farrowing or weaning traits were considered as covariables. The significant curvilinear effects of the inbreeding of the dam and litter suggest that complex inter-locus genetic interactions may be involved. Differential opportunities for selection also may have modified the apparent effects of the inbreeding of the dam. Average pig weight at weaning was heaviest in litters in which about nine live pigs had been farrowed and six to seven pigs weaned. The birth weight of the pig showed a highly significant influence on the litter traits at weaning and at 154 days.

The litter weights and number of live pigs per litter for 371 litters of Duroc swine at birth, 21, 56, and 180 days of age were studied. The same items were studied on 73 additional litters at birth and 56 days. All litters were farrowed at the Oklahoma Agricultural Experiment Station during the period from 1939 to 1949 inclusive. The study included inbred litters from seven different lines, as well as two-line-cross, three-line-cross, and outbred Duroc litters. Intra-season weighted mean differences were obtained for number of pigs per litter and litter weights at birth, 21, 56, and 180 days for five different comparisons. The comparisons made were: I, two-line-cross litters with inbred litters within line of dam; II, two-line-cross litters with the average of the two parental inbred lines; III, three-line-cross litters with two-line-cross litters; IV, three-line-cross litters with outbred Duroc litters; V, two-line crosses with outbred Durocs. The data on litters produced by sows over one year of age were corrected to a gilt-equivalent age. Hybrid vigor was evident both in number of pigs per litter and litter weights at birth, and increased as the litters became less dependent upon the direct mothering ability of the dams. This vigor was expressed to a greater extent in the increased viability of the pigs and productivity of two-line-cross gilts than in the increased growth rate of the individual pigs. There was no significant difference in the performance of two-line-cross litters raised by inbred sows and the performance of outbred Duroc litters which were produced in the same season. Three-line-cross litters, raised by two-line-cross dams and sired by inbred boars of a third line, were superior to both two-line-cross and outbred Duroc litters with which they were compared. The differences were not statistically significant for all items. Increased number of pigs per litter in most cases was sufficient to account for a large percentage of the increase in total litter weight. When initial weights of the pigs were the same, advantages of two-line-cross pigs over inbreds with the same line of dam in post-weaning rate of gain and efficiency of gain were relatively small and inconsistent. Because heterosis was expressed in both number of pigs which survived and the growth rate of the individual, total weight of the litter seems to be the one best over all measure of performance for comparison of lines or crosses.

Several authors have noted that a sow’s parity has a significant impact not only on her own productivity but also on the performance of her piglets. Analyzing all the factors related to sows and their neonates at each birth event is an effective tool for improving management and reproductive performance on production units. Multiparous sows exhibit cortisol levels up to 38% higher than those of primiparous sows at peripartum, but the latter have prolactin levels 54-70% lower that reduce colostrum production. In addition, the weaning-to-estrous period is 3 days longer in primiparous sows, and their farrowing intervals up to 8 days longer. Farrowing performance is significantly affected, as litter size tends to increase in multiparous sows, thus extending duration. Piglets are also influenced by parity: those born to multiparous sows have higher weights, up to 2.21 kg more in total litter weight (up to 200 g/piglet). Their thermoregulation capacity is better as they show temperatures up to 1.6°C higher, greater overall vitality, and higher growth rates than the neonates of primiparous sows, which also suffer higher mortality rates. Given the obvious performance differences among sows of different parity and their offspring, swine breeders must determine the precise effects of this factor. This review details the key differences related to parity in the events surrounding farrowing in sows and the early lives of their offspring.

Heat stress (HS) exacerbates the body weight loss of lactating sows and reduces litter weight gain. Selenium (Se), vitamin E (VE), chromium (Cr) and betaine have been shown to ameliorate symptoms of HS, and yeast nucleotides and mannan oligosaccharides have been reported to improve lactational performance and immune response in pigs. Therefore, a combination of these nutrients may improve lactational performance of sows in summer. The effects of two nutritionally enhanced diets on lactational performance of sows in summer were investigated in two experiments. In experiment 1, we compared the effects of a nutritionally fortified diet (0.4ppm Se, 95IU/kg VE, 0.4ppm Cr and 0.2% betaine; named as SVCB diet) with the NRC 2012 standard diet (0.15ppm Se, 44IU/kg VE) on lactational performance of sows in summer. Results showed that the SVCB diet reduced body weight loss (P=0.039) and tended to reduce backfat loss (P=0.075) of sows without affecting feed intake, while litter weight gain was not influenced. In experiment 2, we further enhanced the nutrients in the SVCB diet (0.8ppm Se, 1% yeast nucleotides, and 0.1% mannan oligosaccharides; named as SNM diet). Results showed that the SNM diet did not improve feed intake of sows, farrowing performance, or litter weight gain compared with the SVCB diet, but increased body weight loss of the third parity sows (P=0.037). Overall, a combined supplementation of Se, VE, Cr, and betaine above the NRC recommended levels can reduce mobilisation of body reserve of lactating sows in summer.

The objective of this retrospective study was to investigate the effect of mating type [natural mating (NM) versus artificial insemination (AI)], weaning-to-first-service interval (WSI) and lactation length on some reproductive traits of purebred Swedish Landrace (L) and Swedish Yorkshire (Y) sows. Data analysed comprised farrowings during the period 1994-1997 from 19 Swedish nucleus herds and included 20 275 litters from 6989 purebred sows (3598 L and 3391 Y). Analysis of variance was used for the statistical analysis of quantitative data. Logistic regression analysis was applied for binary data using the GLIMMIX macro in the SAS program. The response variables analysed were litter size, WSI, farrowing rate and remating rate. Explanatory variables included in the analyses were mating type, lactation length, sow breed, boar breed, parity, herd-year combination within breed and month of the year. The effect of WSI on subsequent fertility performance (i.e. litter size, farrowing rate and remating rate) was also analysed. Compared with AI, NM resulted in significantly larger litters (0.2 total born per litter; P<0.001; 0.3 born alive per litter; P<0.001), and lower remating rate (1.6%-units; P<0.01). The difference between NM and AI varied according to sow breed, parity number and month of the year. Subsequent litter sizes decreased by about one piglet when WSI increased from 4 to 10 days. Thereafter, litter size increased as the WSI increased from 10 to 20 days. Farrowing rate decreased gradually when WSI increased from 4 to 7 days, but an increase in WSI from day 9 to day 20 resulted in an increase in farrowing rate. A longer lactation period led to a shorter WSI and a larger subsequent litter size for both breeds.

Estimation of genetic parameters for reproductive traits in Lori-Bakhtiari sheep

To analyze the association of lameness and performance variables on sow longevity by use of time-to-event analysis. Cohort study. 674 sows from a commercial breeding herd. A lameness assessment was performed on each sow. Data on farrowing performance and longevity were collected for the sows during 3 or fewer parities from the database of the herd during 2005 and 2006. The association of risk factors with sow longevity within 350 days after lameness assessment was analyzed via Cox regression analysis. Pigs per day, total production days, and survival at 350 days after lameness evaluation were compared between lame and nonlame sows. Numbers of preweaning baby pig deaths, stillborn pigs, and mummified pigs were negatively associated with sow longevity within 350 days after lameness assessment. A higher number of pigs born alive and younger parity of sows were protective. Lame sows had a higher risk (1.710 times as high) of removal from the herd within 350 days after lameness assessment. The number of pigs born alive per day, survival of sows at 350 days, and total number of days in the herd were lower in lame sows. Results of this study indicated significant differences in the survivability of lame and nonlame sows in a commercial herd. Parity and farrowing performance variables were factors influencing sow longevity in this herd. Producers need to minimize sow lameness and remove lame sows from a herd early (when treatment is not an option) to minimize economic loss.

Factors affecting standardized milk and fat yields in Alpine goats

The objective of this research was to evaluate the effect of two doses of hCG (100 and 300 IU) administered at two different times after fixed-time artificial insemination (FTAI) on some response variables related to early fetal loss and total litter weight in goats during the reproductive transition period. Crossbred multiparous goats (n = 40) were subjected to an estrus induction protocol, subsequently inseminated, and randomly distributed into five experimental groups (n = 8): (1). G100-7, 100 IU hCG, 7 d post FTAI; (2). G100-14, 100 IU hCG, 14 days post FTAI; (3). G300-7, 300 IU hCG, 7 d post FTAI; (4). G300-14, 300 IU hCG, 14 days post FTAI; and (5). CONT, 0.5 mL of saline solution, 7 and 14 days post FTAI. The variables of corpus luteum area, embryonic implantation rate, embryonic efficiency index 1 and 2, conception rate, fertility rate, fecundity rate, fetal losses at days 30 and 45, total fetal losses, and the total weight of the litter favored G300-14. The use of hCG (300 IU) in the reproductive transition period is an effective reproductive strategy, reducing early fetal losses, improving embryonic efficiency, and increasing total litter weight, all of which are fundamental to the reproductive success of marginal goat production systems.

IntroductionDietary fibre in late gestation may affect sow physiology, colostrum quality, gut microbiota, and piglet performance. This study examined whether increasing fibre levels enhances sow health and reproductive outcomes.MethodsForty pregnant Landrace × Yorkshire sows (parity 2 or 4) were allocated to either a low-fibre (LF, 5.2%) or high-fibre (HF, 7.7%) diet from day 85 of gestation until parturition, after which all sows received a common lactation diet. Sow performance, constipation, nutrient digestibility, colostrum quality, cord blood parameters, and gut microbiota profiles were assessed. Piglet growth performance was recorded until weaning. Correlation analyses were conducted to examine associations between bacterial taxa and physiological indicators.ResultsHF sows showed improved piglet vitality (p < 0.05), higher faecal scores, and lower constipation rates (p < 0.05). Colostrum protein, total solids, IgA, and IgM concentrations were increased in HF sows (p < 0.05). Cord blood glucose and IL-10 were reduced, whereas eNOS was elevated (p < 0.05). Digestibility of crude fibre, ADF, and NDF increased, while protein digestibility decreased (p < 0.05). Gut microbiota analysis indicated increased abundances of Lactobacillus, Lachnospiraceae_XPB1014_group, and Methanobrevibacter, and decreased Treponema, Prevotellaceae_UCG-001, and Escherichia-Shigella. Piglets from HF sows exhibited greater average daily gain and weaning weight (p < 0.05). Beneficial associations were observed for Lactobacillus, Terrisporobacter, and Lachnospiraceae_XPB1014_group with reproductive traits; Phascolarctobacterium and X-Eubacterium_ruminantium_group correlated with piglet growth; while Treponema and Rikenellaceae_RC9_gut_group were negatively associated with constipation.DiscussionHigher dietary fibre in late gestation improved gastrointestinal function, colostrum quality, and piglet growth, likely through enhanced fibre digestibility and favourable modulation of gut microbiota. These findings support increased fibre supplementation to optimise sow and piglet health.