Effect of the valine-to-lysine ratio on the performance of sows and piglets in a hot, humid environment.

To determine the effect of the valine-to-lysine (Val: Lys) ratio on the performance of sows and piglets in a hot, humid environment, eleven Large White × Landrace sows (parity 2 or 3) were selected and randomly assigned to 3 groups. The diets contained total dietary Val: Lys ratios of 0.72, 0.87, or 1.01:1. Sows were fed from d 29 prepartum to d 21 postpartum in a hot, humid environment (temperature: 22-31 ℃, relative humidity: 69-96%). The results showed that dietary valine improved the average daily feed intake (ADFI) of the sows in wk3 of the lactation and the average daily gain (ADG) of the piglets from day 7-14 after farrowing. Dietary valine increased the concentrations of lactose in colostrum and immunoglobulin M (IgM) in piglet serum. Additionally, dietary valine affected metabolite and metabolic hormone concentrations. The increase in the ratio of dietary Val: Lys decreased the blood urea nitrogen and increased serum glucose in the sows and increased serum albumin in the piglets. In addition, increasing dietary Val: Lys increased the serum concentration of estradiol-17ß in the sows. In conclusion, in a hot, humid environment, dietary valine could improve the performance of sows and piglets by increasing colostrum lactose and serum immunoglobulin concentration in piglets and by influencing serum glucose in sows.

Genetic parameters for litter size, piglet growth and sow's early growth and body composition in the Chinese-European line Tai Zumu.

Genetics of piglet growth in association with sow's early growth and body composition were estimated in the Tai Zumu line. Piglet and sow's litter growth traits were calculated from individual weights collected at birth and at 3 weeks of age. Sow's litter traits included the number of piglets born alive (NBA), the mean piglet weight (MW) and the standard deviation of weights within the litter (SDW). Sow's early growth was measured by the age at 100 kg (A100), and body composition included backfat thickness (BF100). A main objective of this study was to estimate separately the direct genetic effect (d) and the maternal genetic effect (m) on piglet weight and daily weight gain during lactation. Variance components were estimated using the restricted maximum likelihood methodology based on animal models. The heritability estimates were 0.19 for NBA, 0.15 and 0.26 for SDW and MW at 3 weeks and 0.42 and 0.70 for A100 and BF100. The NBA was almost independent from SDW. Conversely, the A100 and BF100 were correlated unfavourably with SDW (rg <-0.24, SE<0.12). A stronger selection for litter size should have little effect on litter homogeneity in weights. Selection for lean growth rate tends to favour heterogeneity in weights. The direct effect on piglet weight at birth and daily weight gain accounted for 12% (h(²) (d) = 0.02) and 50% (h(²) (d) = 0.11) of the genetic variance, respectively. The association between d and m for piglet weight was not different from zero at birth (rg = 0.19, SE = 0.27), but a strong antagonism between d and m for daily weight gain from birth to 3 weeks was found (rg = -0.41, SE = 0.17). Substantial direct and maternal genetic effects influenced piglet growth until weaning in opposite way.

Ad libitum feeding systems for lactating sows: effects on productivity and welfare of sows and piglets.

The nutritional requirements of sows change during lactation and thus require adapted and dynamic feeding regimes that consider the sows' behavioral needs and production traits. The present study evaluated the effect of four different feeding systems on productivity and aspects of the welfare of 61 sows and their piglets during lactation. A non-ad libitum system (CON) was compared with two computer-monitored (COMP, COMP + ) ad libitum feeding systems, that allowed sows to access feed via displacement of an electronic sensor, as well as a third purely mechanical ad libitum feeding system (MECH). Daily feed disappearance, piglet growth, piglet growth per feed disappearance as well as sows' weight and conception rate were recorded. Health indicators of sows and piglets were scored as well as sow behavior analyzed for a total of 96 hours/sow from video recordings taken on days 2-4 and 23 postfarrowing (n = 35 sows). Sows from all three ad libitum systems (COMP, COMP+, MECH) showed a lower feed disappearance than CON (P < 0.01). Additionally, average daily piglet growth tended to be higher (P = 0.05) and piglet growth per sow feed disappearance was significantly higher in all three ad libitum systems than in CON (P < 0.01). Piglet mortality, sow weight loss and subsequent conception rates did not differ between treatment groups. Piglets in COMP and COMP + had fewer head lesions (P = 0.01). Sows in all three ad libitum systems spent more time with their head in the trough than in the non-ad libitum system (P < 0.01). Occurrence of sow stereotypies (vacuum chewing, biting fixtures) was rare (typically < 2% of scans) and did not differ between treatments. Our data suggest that sows fed ad libitum eat what they need and can convert feed more efficiently into the piglets' growth without additional weight loss. Furthermore, the increased time sows spent in ad libitum systems with their head in the trough points toward longer feeding times, which might be beneficial in terms of meeting pigs' behavioral need to forage. Taken together, our initial studies on sow feeding behavior and feed efficiency will benefit the development of new lactation feeding systems that promise to improve animal welfare and productivity while reducing feed costs.

Investigation of supplementation with a combination of fermented bean dregs and wheat bran for improving the growth performance of the sow.

To investigate the effect of dietary supplementation with a fermented mixture of bean dregs and wheat bran (FBW) on sow performance. FBW was given to sows during late gestation and lactation; in total, 24 sows were randomly assigned to 4 groups (control diet; 3% FBW diet; 6% FBW diet; 9% FBW diet, n = 6). The weight ratio of bean dregs (wet) to wheat bran was 4:6. Sows were fed different diets from 85 d of gestation until weaning. The results showed that supplementation with FBW increased average daily feed intake (ADFI) during lactation (p < 0.05). FBW supplementation also increased litter weight and milk yield (p < 0.05). The contents of Escherichia coli in the feces of the treatment groups were significantly reduced by FBW supplementation (p < 0.01). FBW supplementation significantly improved the fecal morphology (p < 0.05), alleviating sows' constipation. In conclusion, FBW could increase the ADFI, improve lactation and piglet litter weight in sows and reduce the pathogenic bacterial content in sow feces and constipation.

Evaluation of oxidized beta-carotene on sow and piglet immune systems, sow reproductive performance, and piglet growth.

This study aimed to determine if supplementation of oxidized-beta carotene (OxC-Beta) improved sow reproductive performance, litter growth performance, vitamin A status, and ability to alter immune cells abundance in sows and piglets, subsequent litter performance, and nursery growth performance. On approximately day 60 of gestation and through the lactation period, 194 sows (blocked by parity) were assigned to a common gestation diet or the common diet supplemented with 80 ppm oxidized beta-carotene (OxC-Beta, Aviagen, Ottawa, ON, Canada). A subset of sows (N = 54 per treatment) were sampled for blood and body weight recorded at the beginning of the study, farrowing, and weaning. A blood sample was taken from a subset of piglets at birth and weaning, and all piglet weights were recorded. Blood was analyzed for vitamin A as retinol concentrations and immunoglobulin G (IgG) and immunoglobulin M (IgG) levels were assessed from the sow's blood. Twelve pigs (N = 6 per treatment) were euthanized at birth and weaning. The livers were collected and analyzed for the Kupffer cell phagocytic activity through flow cytometry. Whole blood was analyzed via flow cytometry for cluster of differentiation (CD335, CD8, and CD4). Colostrum during farrowing and milk at weaning were analyzed for IgG and IgA concentrations. Data were analyzed via SAS 9.4 using MIXED and frequency procedures where appropriate. No differences (P > 0.05) between dietary treatments were observed in sow reproductive performance, feed intake, wean to estrus interval, or piglet growth performance. No differences (P > 0.05) were observed in the plasma or liver for vitamin A. No differences (P > 0.05) were observed in the composition of the colostrum or milk. No immunological differences (P > 0.05) were observed in the piglets' liver and blood or sow antibodies in colostrum and milk. The supplementation of OxC-Beta did (P < 0.05) decrease IgM and tended (P < 0.10) to decrease IgG in sow plasma. No differences (P > 0.05) were observed in the reproductive performance of subsequent litter information from the sows. Gilt litter weaning weight and feed intake were reduced (P < 0.05) compared to sow performance. In conclusion, the supplementation of OxC-Beta at 80 ppm from day 60 of gestation through lactation does not affect the reproductive performance of sows, litter growth performance, vitamin A status, piglet immune status, and antibodies or composition in colostrum and milk.

Beta-carotene is a known antioxidant found in most red and orange-pigmented vegetables and has been documented to have health benefits. However, beta-carotene has been reported to gain oxygen molecules spontaneously, thus oxidizing it. Oxidized beta-carotene has been recognized to provide potential health benefits to animals, although its functions are independent of beta-carotene. Sows in this study were supplemented with an oxidized beta-carotene product to evaluate whether the product could improve reproductive performance, including the number of piglets born alive, piglet birth weight, weaning weight, sow milk quality, and immune function of both the sow and piglets. There were no significant findings between the reproductive performance or difference in colostrum and milk composition of the control sows and the sows supplemented with the product. There was also no difference in piglet growth between the two groups. The product did not affect the measured immune functions of the piglets. However, immunoglobulin G tended to decrease with the use of the product, and there was a decrease in immunoglobulin M. Overall, supplementing the oxidized beta-carotene product did not affect the reproductive performance of sows or the growth performance of piglets.

Feeding level during the last week of gestation can influence performance of sows and their litters in the subsequent lactation.

This study investigated the impact of feeding level during the last week of gestation on performance of sows and their litters in the subsequent lactation. A total of 48 sows were assigned to one of six feeding levels (1.8, 2.4, 3.1, 3.7, 4.3, or 5.0 kg/d) from day 108 of gestation until farrowing. Post-farrowing, all sows were fed similarly during lactation with a gradual increase in feed allowance in accordance with Danish recommendation until it reached the maximum allowance of 9 kg/d on day 17 of lactation. Plasma samples were collected from the sows during farrowing and lactation, and sow's body weight and backfat thickness, and milk samples were taken during lactation. Litters were standardized to have 13 to 15 piglets each and weighed once weekly during lactation. Plasma concentrations of urea, acetate, and butyrate in sows linearly increased (P < 0.001), while non-esterified fatty acids linearly decreased (P < 0.001) during farrowing with increasing feeding level. Moreover, concentrations of triglycerides (P < 0.001), acetate (P = 0.007), and succinate (P < 0.001) were greater in plasma collected at the onset of farrowing compared to the end of farrowing. Conversely, concentrations of glucose, urea, and butyrate (P < 0.001) were lower in plasma collected at the onset of farrowing than at the end. Sows fed 2.4 and 3.1 kg/d exhibited greater triglyceride concentrations than those fed 3.7 (P = 0.03) and 5.0 (P = 0.02) kg/d. Sows fed 1.8 kg/d during the last week of gestation had lower milk yield in wk 1 (P < 0.001) and wk 2 (P = 0.001) of lactation compared to the other groups. Additionally, litter weight gain (P = 0.04) and litter weaning weight (P = 0.007) were lower in sows fed 1.8 kg/d compared to the other groups. The greatest milk yield, litter growth, and litter size were observed in sows fed 3.7 kg/d during the last week of gestation, whereas the estimate generated by the regression model revealed that sows should have been provided with 4.0 to 4.1 kg/d as an adequate feeding level to maximize these performances in the subsequent lactation. Interestingly, feeding level during the last week of gestation did not influence feed intake during lactation. In conclusion, this study highlights the significance of adequate feed supply (4.0 to 4.1 kg/d) during the last week of gestation in order to maximize performance of sows in the subsequent lactation.

Feeding sows at high or ad libitum level during an extended gestation period has been found to have a negative impact on the subsequent lactation performance. Conversely, in some European countries, it has been a common practice to reduce the feed allowance during the last 2 to 3 d before expected farrowing to mitigate issues like constipation and postpartum health problems such as mastitis, metritis, and agalactia. However, recent studies suggest that sows should be fed approximately 4 kg/d during transition period to improve farrowing performance. In the present study, we investigated the carry-over effects of feeding level (dose­response design) during the last week of gestation on lactation performance of sows and their litters in the subsequent lactation. The findings revealed that a lower feeding level during the last week of gestation reduced milk yield and litter size at weaning. Milk yield, litter growth, and litter size at weaning were greater in sows supplied with 3.7 kg/d during the last week of gestation. However, the estimate generated by the regression model indicates that sows should be provided with 4.0 to 4.1 kg/d during the final week of gestation to enhance their performance in the subsequent lactation. Therefore, the present results emphasize the benefits of maintaining an adequate feeding level during the last week of gestation to improve sows' lactation performance in the subsequent lactation.

Different Effect of Vitamin E or Hydroxytyrosol Supplementation to Sow's Diet on Oxidative Status and Performances of Weaned Piglets.

Different feeding strategies are being applied to sows in order to obtain homogeneous piglets' weights and improved health status. This study evaluated how the dietary supplementation of vitamin E (VE) (100 mg/kg), hydroxytyrosol (HXT) (1.5 mg/kg) or the combined administration (VE + HXT) given to Iberian sows from day 85 of gestation affected the growth pattern of the piglets and their oxidative status; and quantified what these effects were due to. Dietary VE and HXT improved the oxidative status of sows and piglets. Both VE and HXT modified the growth pattern at birth and performances of the piglets in a different way according to the growing period. Piglets' performances were positively correlated with plasma VE and negatively with plasma malondialdehyde (MDA) of the sow. However, the highest variation in growth patterns was explained by the colostrum composition. Significant linear equations were observed between piglets' performances and colostrum saturated (SAT), n-7 monounsaturated fatty acids (C16:1n-7 and C18:1n-7) and different desaturases indices. This study would confirm that VE supplementation to the sow diet could be more adequate than HXT for the improved development during the first weeks of a piglet's life. The combined administration of both antioxidants would not produce additional positive effects compared to the individual supplementation.

The Effect of Sow Maternal Behavior on the Growth of Piglets and a Genome-Wide Association Study.

Sows' maternal behavior is important for improving piglet survival and growth; thus, breeding for good mothering sows is necessary for pig production. However, there is little research on the genetic mechanism of maternal behavior. In this study, a comparative analysis of piglets' growth traits between good and bad maternal behavior groups and a genome-wide association study (GWAS) was performed to elucidate the impact of sows' maternal behavior on piglet growth and identify candidate genes and markers of sow's maternal behaviors. Comparing the growth traits of piglets between good and bad sows' maternal behavior groups, the results showed that the growth traits of piglets from sows with good maternal behavior were better than those from sows with bad maternal behavior and especially for the multiparous sows group, this comparative difference was significant. For the intensive study of the genetic mechanisms of sows' maternal behavior, a total of 452 sows were genotyped using the Illumina Porcine 50K SNP Chip, and 4 traits, including biting piglets (BP), crushing piglets (CP), trampling piglets (TP) and screaming test (ST), were examined. Using a GWAS, 20 single nucleotide polymorphisms (SNPs) were found to be associated with these traits. Within 1 Mb upstream and downstream of the significant SNPs screened, 138 genes were obtained. After pathway enrichment and gene annotation, HIP1, FZD9 and HTR7 were identified as important candidate genes affecting sows' maternal behaviors. These findings preliminarily elucidate the genetic basis of sows' maternal behavior traits and provide candidate genes and markers for molecular breeding in pigs.

Effects of ß-glucan with vitamin E supplementation on the physiological response, litter performance, blood profiles, immune response, and milk composition of lactating sows.

OBJECTIVE: This study was conducted to evaluate the effects of ß-glucan with vitamin E supplementation on the physiological response, litter performance, blood profiles, immune response, and milk composition of lactating sows. METHODS: A total of 50 multiparous F1 sows (Yorkshire×Landrace) with an average body weight (BW) of 233.6±4.30 kg and an average parity of 4.00±0.307 and their litters were used in this experiment. All sows were allotted to one of five treatments, taking into consideration BW, backfat thickness, and parity in a completely randomized design with 10 replicates. The experimental diets included a corn-soybean meal-based basal diet with or without 0.1% or 0.2% ß-glucan and 110 IU vitamin E/kg diet. RESULTS: All treatments added with ß-glucan or vitamin E were statistically higher in the average daily feed intake (ADFI) of lactating sows compared to those of the control (Diet, p<0.01). Additionally, the ADFI of lactating sows was significantly higher in the groups supplemented with 0.1% ß-glucan compared to 0.2% ß-glucan (BG, p<0.01). There was an increasing trend in piglet weight at weaning (BG, p = 0.07), litter weight at the 21st day of lactation (BG, p = 0.07) and litter weight gain (BG, p = 0.08) in groups supplemented with 0.1% ß-glucan. The addition of 110 IU vitamin E/kg diet increased vitamin E concentration significantly in lactating sows (VE, p<0.01) and exhibited a trend for higher concentrations of vitamin E (VE, p = 0.09) in piglets. Adding 0.1% ß-glucan compared to 0.2% ß-glucan induced a decrease in the concentration of tumor necrosis factor-α in lactating sows (BG, p = 0.06) and in piglets (BG, p = 0.09) on the 21st day of lactation. There were no significant differences in the milk composition of sows. CONCLUSION: Adding 0.1% ß-glucan and 110 IU vitamin E/kg to a lactating sow's diet was beneficial to the growth performance of piglets by leading to an increase in the feed intake of sows and efficiently supplying vitamin E to both the sows and piglets.

Characteristics of sows' milk and piglet nutrient utilization during a 28-d lactation period.

The present study aimed to characterize the performance of suckling piglets from high prolific sows and investigate the impact of milk composition on piglet growth during a 4-wk lactation period. Piglet performance included weight gain (WG), milk intake, nutrients and energy in milk, and piglet energy metabolism in weeks 1 to 4 of lactation. Data from six previous experiments were used with a total of 2,047 piglets and 604 milk samples collected from 151 sows. Piglet body weight linearly increased (P < 0.001) as lactation progressed, with the piglet WG being low in week 1 (132 g/d) and relatively constant from weeks 2 to 4 (248 g/d; P < 0.001). The metabolizable energy (ME) intake of the piglets increased (P < 0.001) from weeks 1 to 3; however, with lower values in week 4 than for week 3. The heat energy production and energy required for maintenance (MEm) linearly increased (P < 0.001) from weeks 1 to 4. In addition, the retained energy and ME to MEm ratio only increased from weeks 1 to 2 (P < 0.001) and then declined through week 4. Pearson correlation coefficients were used to examine the relations between the milk nutrient composition and the WG in weeks 1 to 4. The results showed that WG was negatively correlated with the milk protein concentration at all stages of lactation (P < 0.001). In contrast, the WG was positively correlated with milk fat and lactose concentrations in weeks 2 and 4, respectively (P < 0.001). In conclusion, the stage of lactation influenced WG, milk intake, nutrients in milk, energy in milk, and the energy metabolism of the suckling piglets. Moreover, maximizing milk protein concentration does not optimize piglet growth.

The manuscript reviews the results of six experiments with high-performing lactating sows. Different variables in sow's milk, which influence the performance of suckling piglets during lactation, have been examined.

Are Growth Performance and Fecal Score in Weaning Pigs Affected by the Inclusion Level of Potato Protein Concentrate and the Enclosed Glycoalkaloids in Iso-Nitrogenous Diets?

Glycoalkaloids (GA) are anti-nutritional factors in standard potato protein concentrate (PPC) fed to piglets. Increasing levels of standard PPC was expected to affect growth performance and fecal score negatively. Seven-hundred-and-twenty pigs (7-30 kg) were fed one of the following four diets within three feeding phases (days 0-13, 13-24, and 24-45): control (CTRL), PPC standard inclusion (PPC-S; 4%, 2%, and 0%), high PPC inclusion (PPC-H; 8%, 3.5%, and 2%), and extremely high PPC inclusion (PPC-EH; 12%, 5%, and 3.5%). During days 0-13, CTRL displayed no difference in growth performance compared with the three experimental groups (PPC-S, PPC-H, and PPC-EH). During days 13-24, PPC-H achieved greater (p < 0.001) average daily feed intake (ADFI) compared to CTRL. During days 24-45, no differences between groups were observed. For the overall experimental period (0-45 days), PPC-H displayed greater average daily gain (ADG) (p = 0.010) and ADFI (p = 0.024) compared to CTRL. The feed conversion ratio (FCR) remained unaffected between the groups for all experimental periods. Increasing levels of PPC and hence GA did not affect the probability of diarrhea. In conclusion, increased standard PPC and hence increased levels of GA in isonitrogenous diets did not negatively affect growth performance nor fecal score in piglets (7-30 kg).

Impact of dietary fat levels and fatty acid composition on milk fat synthesis in sows at peak lactation.

BACKGROUND: Dietary fat is important for energy provision and immune function of lactating sows and their progeny. However, knowledge on the impact of fat on mammary transcription of lipogenic genes, de novo fat synthesis, and milk fatty acid (FA) output is sparse in sows. This study aimed to evaluate impacts of dietary fat levels and FA composition on these traits in sows. Forty second-parity sows (Danish Landrace × Yorkshire) were assigned to 1 of 5 dietary treatments from d 108 of gestation until weaning (d 28 of lactation): low-fat control diet (3% added animal fat); or 1 of 4 high-fat diets with 8% added fat: coconut oil (CO), fish oil (FO), sunflower oil (SO), or 4% octanoic acid plus 4% FO (OFO). Three approaches were taken to estimate de novo milk fat synthesis from glucose and body fat. RESULTS: Daily intake of FA was lowest in low-fat sows within fat levels (P < 0.01) and in OFO and FO sows within high-fat diets (P < 0.01). Daily milk outputs of fat, FA, energy, and FA-derived carbon reflected to a large extent the intake of those. On average, estimates for de novo fat synthesis were 82 or 194 g/d from glucose according to method 1 or 2 and 255 g de novo + mobilized FA/d according to method 3. The low-fat diet increased mammary FAS expression (P < 0.05) and de novo fat synthesis (method 1; P = 0.13) within fat levels. The OFO diet increased de novo fat synthesis (method 1; P < 0.05) and numerically upregulated mammary FAS expression compared to the other high-fat diets. Across diets, a daily intake of 440 g digestible FA minimized milk fat originating from glucose and mobilized body fat. CONCLUSIONS: Sows fed diets with low-fat or octanoic acid, through upregulating FAS expression, increased mammary de novo fat synthesis whereas the milk FA output remained low in sows fed the low-fat diet or high-fat OFO or FO diets, indicating that dietary FA intake, dietary fat level, and body fat mobilization in concert determine de novo fat synthesis, amount and profiles of FA in milk.

Identification of mutations in porcine STAT5A that contributes to the transcription of CISH.

Identification of causative genes or genetic variants associated with phenotype traits benefits the genetic improvement of animals. CISH plays a role in immunity and growth, however, the upstream transcriptional factors of porcine CISH and the genetic variations in these factors remain unclear. In this study, we firstly identified the minimal core promoter of porcine CISH and confirmed the existence of STATx binding sites. Overexpression and RT-qPCR demonstrated STAT5A increased CISH transcriptional activity (P < 0.01) and mRNA expression (P < 0.01), while GATA1 inhibited CISH transcriptional activity (P < 0.01) and the following mRNA expression (P < 0.05 or P < 0.01). Then, the putative functional genetic variations of porcine STAT5A were screened and a PCR-SSCP was established for genotype g.508A>C and g.566C>T. Population genetic analysis showed the A allele frequency of g.508A>C and C allele frequency of g.566C>T was 0.61 and 0.94 in Min pigs, respectively, while these two alleles were fixed in the Landrace population. Statistical analysis showed that Min piglets with CC genotype at g.566C>T or Hap1: AC had higher 28-day body weight, 35-day body weight, and ADG than TC or Hap3: CT animals (P < 0.05, P < 0.05). Further luciferase activity assay demonstrated that the activity of g.508A>C in the C allele was lower than the A allele (P < 0.05). Collectively, the present study demonstrated that STAT5A positively regulated porcine CISH transcription, and SNP g.566C>T in the STAT5A was associated with the Min piglet growth trait.

Gruel Creep Feeding Accelerates Growth and Alters Intestinal Health of Young Pigs.

To combat the stress of weaning, we utilized novel gruel creep feeders to supplement suckling pigs with divergent soluble (n = 6 litters) versus insoluble (n = 6) diets compared with un-supplemented controls (n = 6). Post-weaning, pigs were fed a common phase 1 diet. Average daily weight gains of pigs fed soluble and insoluble creep diets were 53% and 17% greater than control pigs, respectively (p < 0.01). Creep intake was higher (82%) for pigs fed the soluble diet, and the accompanying weight increase was sustained post-weaning (p < 0.02). Villus measures were prematurely altered in soluble-creep-fed pigs (p < 0.01), with decreases in villi length, crypt depth, and villus area pre-weaning. No effects of treatment were detected for VFA concentrations and pH in the cecum. There was an interaction between treatment and age for several pro- and anti-inflammatory cytokines (p < 0.01), where soluble-creep-fed pigs had increased cytokine levels with age, whereas cytokine levels in the insoluble and control groups decreased over time. We conclude that a soluble creep diet fed in a gruel state during the pre-weaning period has a positive impact on weaning weight that is sustained post-weaning, and is accompanied by alterations in the intestinal health of young pigs.

Analysis of image-based sow activity patterns reveals several associations with piglet survival and early growth.

An activity pattern describes variations in activities over time. The objectives of this study are to automatically predict sow activity from computer vision over 11 days peripartum and estimate how sow behavior influences piglet's performance during early lactation. The analysis of video images used the convolutional neural network (CNN) YOLO for sow detection and posture classification of 21 Large White and 22 Meishan primiparous sows housed in individual farrowing pens. A longitudinal analysis and a clustering method were combined to identify groups of sows with a similar activity pattern. Traits under study are as follows: (i) the distribution of time spent daily in different postures and (ii) different activities while standing. Six postures were included along with three classes of standing activities, i.e., eating, drinking, and other, which can be in motion or not and root-pawing or not. They correspond to a postural budget and a standing-activity budget. Groups of sows with similar changes in their budget over the period (D-3 to D-1; D0 and D1-D7) were identified with the k-means clustering method. Next, behavioral traits (time spent daily in each posture, frequency of postural changes) were used as explanatory variables in the Cox proportional hazards model for survival and in the linear model for growth. Piglet survival was influenced by sow behavior on D-1 and during the period D1-D7. Piglets born from sows that were standing and doing an activity other than drinking and eating on D-1 had a 26% lower risk of dying than other piglets. Those born from sows that changed posture more frequently on D1-D7 had a 44% lower risk of dying. The number of postural changes, which illustrate sow restlessness, influenced piglet growth in the three periods. The average daily gain of piglets born from sows that were more restless on D1-D7 and that changed posture more frequently to hide their udder on D0 decreased by 22 and 45 g/d, respectively. Conversely, those born from sows that changed posture more frequently to hide their udder during the period of D1-D7 grew faster (+71 g/d) than the other piglets. Sow restlessness at different time periods influenced piglet performance.

Effects of dietary valine supplementation during late gestation on the reproductive performance and mammary gland development of gilts.

BACKGROUND: Mammary gland development during late gestation in gilts is a major factor that alters the composition of colostrum and growth performance of piglets. Plasma valine is taken up and metabolized extensively by the mammary gland; however, the effects of valine on mammary gland development during late gestation are still unclear. Thirty primiparous gilts were divided into three treatment groups (n = 10) and received one of the three diets starting on day 75 of gestation until the day of farrowing. The total dietary valine to lysine ratio of the three diets was 0.63 (LV), 0.73 (MV), and 0.93 (HV), respectively. RESULTS: Dietary valine supplementation during late gestation did not affect (P > 0.05) the litter size and weight at farrowing; however, the piglet weight and average daily gain at weaning were linearly increased (P < 0.05) as the dietary valine increased. The highest piglet weight at weaning was observed when the gilts were provided the HV diet. Dietary valine supplementation linearly elevated (P < 0.05) protein, fat and solids-not-fat and some free amino acids content in colostrum. The concentration of prolactin in plasma of gilts was linearly increased in response to valine supplementation at days 1 and 10 of lactation (P < 0.05). Furthermore, with increasing dietary valine allowance, a linear increase (P < 0.05) was observed in the area of the lumen of alveolus and the content of DNA, RNA, and total protein in the mammary tissues at day 1 of lactation. Moreover, the protein expression of cyclin D1, p-mTOR, p-S6, and p-4EBP1 was also linearly increased (P < 0.05) in the mammary tissue at day 1 of lactation. However, no difference (P > 0.05) was observed in the indices related to mammary development and the mTOR signaling pathway at day 21 of lactation. CONCLUSION: The results revealed that increasing the total dietary valine to lysine ratio to 0.93 during late gestation significantly enhances the piglet weight and average daily gain at weaning probably due to improved development of mammary gland.

Impact of milk and nutrient intake of piglets and sow milk composition on piglet growth and body composition at weaning.

The main objective of this study was to evaluate the impact of milk intake, milk composition, and nutrient intake on piglet growth in lactation and body composition at weaning. To evaluate the body composition of piglets, data from one experiment (44 Danish Landrace × Yorkshire × Duroc piglets) were used to develop prediction equations for body pools of fat, protein, ash, and water based on live weight and deuterium dilution space (exp. 1). Furthermore, a total of 294 piglets (Danish Landrace × Yorkshire × Duroc) from 21 sows of second parity were included in a second experiment (exp. 2). In exp. 2, piglet live weight was recorded on days 3, 10, 17, and 25 of lactation. On the same days, the milk intake and body composition were measured, using the deuterium oxide (D2O) dilution technique. Piglet weight gain was highly positively correlated with the intake of milk and the intake of milk constituents each week and on an overall basis having r values ranging from 0.65 to 0.93 (P < 0.001). When evaluating regressions for piglet growth, the milk intake in combination with the milk protein concentration explained 85% and 87% of the total variation in piglet gain in the second and third week of lactation, respectively, whereas milk intake was the only predictor of piglet gain in the first week of lactation explaining 81% of the variation. Fat, protein, and energy retention rates were all highly positively correlated with the daily intake of milk and intake of milk nutrients with r values ranging from 0.76 to 0.94 (P < 0.001). Piglet gain and retention rates were rather weakly correlated with the milk composition with r values ranging from 0.01 to 0.50 (being either negative or positive). Curvilinear response curves were fitted for live weight gain and body fat content at weaning in response to milk protein concentration, showing that live weight gain was slightly greater and body fat content was slightly lower at 4.9% milk protein, but it should be emphasized that the quadratic effects did not reach significance. Body fat content at weaning was positively related with the intake of milk (R2 = 0.44, P < 0.001) and milk fat (R2 = 0.46, P < 0.01). In conclusion, milk intake had a major impact on the piglet growth rate, and milk fat intake greatly influenced the body fat percentage at weaning, whereas milk composition per se only played a minor role for these traits.

The Effect of Dietary Oil Type and Energy Intake in Lactating Sows on the Fatty Acid Profile of Colostrum and Milk, and Piglet Growth to Weaning.

This study investigated the effect of salmon oil in lactating sow diets and offering these diets in a phased dietary regimen to increase the energy density of the diet in late lactation. Sow and piglet productivity to weaning, the fatty acid profile of milk, piglet blood and tissues at weaning were the main parameters measured. Multiparous sows (n = 100) (Landrace × Large White) were offered dietary treatments from day 105 of gestation until weaning. Dietary treatments (2 × 2 factorial) included oil type (soya or salmon oil) and dietary regimen (Flat 14.5 MJ/kg DE diet offered until weaning or Phased 14.5 MJ/kg DE diet offered to day 14 of lactation then a second diet containing 15.5 MJ/kg DE offered from day 15 until weaning). Salmon oil inclusion increased the total proportion of n-3 fatty acids in colostrum (p < 0.001), milk (p < 0.001), piglet plasma (p < 0.01), adipose (p < 0.001), liver (p < 0.001) and muscle (p < 0.001). Increasing sow dietary energy level in late lactation increased the total n-3 fatty acids in milk (p < 0.001), piglet adipose (p < 0.01) and piglet muscle (p < 0.05). However, piglet growth to weaning did not improve.

Different dietary methionine to lysine ratios in the lactation diet: effects on the performance of sows and their offspring and methionine metabolism in lactating sows.

BACKGROUND: Over the last decade, the nutritional requirements of lactating modern genotype sows have increased. The current nutritional recommendations might be unable to meet the needs of increased litter size and milk production, and thus the nutritional requirements need to be re-evaluated. The current study was conducted to investigate the effects of dietary methionine to lysine (Met:Lys) ratios on the performance of and methionine metabolism in lactating sows. RESULTS: During the 1st week of lactation, piglets reared on sows in the 0.37 to 0.57 Met:Lys ratio groups grew faster than those reared on sows in the control group (0.27) (P < 0.01). The 0.37-ratio group showed increased levels of GSH-Px in plasma during lactation (P < 0.01) and decreased concentrations of urea nitrogen in the plasma of sows (P < 0.05). Compared with the 0.27-ratio group, the levels of T-AOC and GSH-Px in the plasma and homocysteine in the milk of lactating sows were significantly increased in sows in the 0.47-ratio group (P < 0.01). In sows fed a 0.57-ratio diet, the levels of glutathione and taurine in the plasma and milk were improved significantly during lactation. However, the content of TBARS in the blood (P < 0.05 at day 7 and P = 0.06 at weaning day) was increased (P < 0.01). Moreover, there were linear increases in the levels of homocysteine in the blood and milk of sows during the lactation period (P < 0.01) with increased dietary Met:Lys ratios in the lactation diet. CONCLUSIONS: The current study indicated that increasing the dietary Met:Lys ratio (0.37~0.57) in the lactation diet had no significant effect on the overall performance of sows or the colostrum and milk composition, but it increased piglet mean BW and piglet ADG during the first week of lactation. Increasing dietary methionine levels had no significant effect on antioxidant function in lactation sows, even though it increased levels of GSH and GSH-Px in the plasma of sows during lactation. However, the content of homocysteine in the plasma and milk increased during lactation due to a high level of dietary methionine.

Effects of supplementing processed straw during late gestation on sow physiology, lactation feed intake, and offspring body weight and carcass quality1.

This study investigated the effects of supplementing late gestation sow diets with processed or unprocessed oat or wheat straw on physiology, early lactation feed intake, and offspring performance. One hundred fifty gestating sows were randomly assigned to 1 of 5 dietary treatments (30 sows per diet) from day 86 of gestation until farrowing. Treatments, arranged as a 2 × 2 factorial plus a control, were a standard gestation diet (control) or control supplemented with 10% wheat or oat straw, processed or unprocessed. Sows were fed a standard lactation diet postfarrowing. The processed straws were produced by high-pressure compaction at 80 °C. On day 101 of gestation (day 15 of the trial), blood samples were collected from a subset of sows (n = 8 per treatment) through ear vein catheters and analyzed for insulin, insulin-like growth factor 1 (IGF-1), prolactin, glucose, and urea concentrations. Fecal samples were collected on days 103 to 104 of gestation to determine nutrient digestibility, and feeding motivation was investigated on day 104. Litter characteristics and sow feed intake were recorded for 7 d postfarrowing. Three piglets per litter were selected at weaning, fed standard diets, and followed to market. Treatment had no effect on feeding motivation, piglet characteristics at birth, estimated milk production, and offspring BW at market or carcass quality. Processed straw improved DM digestibility and energy content and the effect was greater with oat straw (straw × processing effect, P < 0.05). Pre- and postprandial glucose concentrations tended to decrease (P < 0.10) with processing of wheat, but not oat straw, and this effect was more apparent in the preprandial samples. Preprandial prolactin concentration increased with oat but decreased with wheat straw, whereas postprandial IGF-1 and prolactin concentration increased with processing of wheat, but not oat straw (straw × processing, P < 0.05). Sow lactation feed intake improved (P < 0.05) with oat straw supplementation relative to wheat straw. Piglet weaning weight increased (P < 0.05) with oat straw supplementation and processing improved (P < 0.05) nursery exit BW. However, straw supplementation, regardless of processing, had no effect on offspring BW at market or carcass quality. Overall, oat straw supplementation had a greater impact on sow physiology and provided benefits for sows in late gestation, and there was some indication that further benefits could be obtained through mild processing.