Litter Growth Research Articles

269 Bioenergetic Consequences of Pre- and Post-Natal Heat Stress on Swine Productivity

Abstract Heat stress decreases the sustainability and profitability of global swine production and the reductive effects of pre- and post-natal heat stress on pig productivity have been well described. Decreased growth performance and sow milk production during heat stress exposure is generally attributed to reduced energy consumption and a corresponding catabolic state. Moreover, an assumed increase in maintenance costs due to energetic requirements for thermoregulation and greater chemical reaction rates is proposed to reduce energy available for growth and lactogenesis leading to decreased efficiency and productivity. Despite this, recent research has determined that postnatal heat stress can directly impact nutrient partitioning priorities and growth rate independent of energy intake, maintenance costs may be reduced in heat stressed pigs relative to thermoneutral controls, and that heat stress may have a direct negative effect on sow milk production and litter growth performance independent of sow energy intake. In addition to the postnatal consequences of heat stress, prenatal heat stress reduces postnatal growth rate and feed efficiency in pigs independent of the postnatal environment, increases fasting heat production during the growing phase, and alters nutrient partitioning priorities during the finishing phase leading to an increase in adipose tissue accretion at the expense of lean accretion. Furthermore, meat quality and quantity may be negatively impacted by prenatal heat stress exposure. In summary, both pre- and postnatal heat stress exposure elicit bioenergetic changes in pigs that influence postnatal productivity, and mitigating heat stress is and will likely continue to be a priority for the swine industry.

218 Simple Blending of Gestation and Lactation Diets During the Transition Period Minimizes Losses in Back Fat Depth Around Parturition for Primi and Multiparous Sows

Abstract Fifty of each primiparous and multiparous sows were used to evaluate a blending feeding program using gestation and lactation diets during the transition period on sow back fat depth (BF), blood metabolites, and litter growth performance. Sows were randomly assigned to one of two feeding programs in a 2×2 factorial design (n = 25) from 104 ± 1 days of gestation: 1) a unique daily blend of standard gestation [0.58% standardized ileal digestible (SID) lysine and 2419kcal/kg NE] and lactation diets (0.95% SID lysine and 2507kcal/kg NE) until day 5 after farrowing to meet estimated daily SID lysine and net energy requirements (NRC, 2012; TRAN) or 2) approximately 2 kg per day of a standard lactation diet until farrowing (CON). Upon farrowing, sows on the CON feeding program received step-up access to the lactation diet according to a feeding curve. Five days after farrowing, both groups received ad libitum access to the lactation diet until weaning (20.0 ± 0.3 days). Sow body weight (BW) and BFwere measured on day 104 and 110 of gestation (BW only), after farrowing, and at weaning. Fasted blood samples were collected from sows at farrowing and weaning. Litters were standardized to 13 ± 1 piglets and were not provided creep feed. During gestation, TRAN sows consumed more feed than CON sows, which was especially evident for multiparous sows (2.95 vs. 2.13 ± 0.08kg/d for TRAN vs. CON; interaction and main effect; P < 0.05). During lactation, average daily feed intake was not influenced by feeding program but was greater for multi versus primiparous sows (5.98 vs. 4.20 ± 0.30kg; P < 0.001). At all time points, BW was greater for multi versus primiparous sows, regardless of feeding program (P < 0.05). During the gestation period, TRAN sows tended to have greater average daily gain (1.43 vs. 1.00±0.39kg/d; P=0.061) and had less back fat loss (-0.18 vs. -0.92 ± 0.37mm; P < 0.05) versus CON sows, regardless of parity. Only after farrowing, TRAN sows had greater BW and BF than CON sows, regardless of parity (221.5 vs. 215.5 ± 4.1kg and 17.0 vs. 16.3 ± 0.4mm; P < 0.05), but at weaning there were no feeding program-related differences in BW or BF. No feeding program-related differences were observed for litter characteristics, but litter birth weight and piglet BW at weaning were greater for multi versus primiparous sows (P< 0.01). Only after farrowing, serum BHBA (11.9 vs. 19.4 ± 7.8mmol/L) and NEFA (0.34 vs. 0.56 ± 0.10mmol/L) concentrations were less and serum glucose concentrations (4.4 vs. 3.9 ± 0.2mmol/L) were greater for TRAN versus CON sows (P < 0.05), regardless of parity. Therefore, a simple transition feeding program using standard gestation and lactation diets reduced energy mobilization by multi and primiparous sows in late gestation, with no impact on subsequent lactation performance.

Impact of high-fat diet and exposure to constant light on reproductive competence of female ICR mice.

Obesity and exposure to light at night are prevalent in modern society and associated with changes in physiology and behavior that can affect a female's ability to support offspring growth during pregnancy and lactation. A 2X3 factor study of ICR mice was conducted to determine the effect of diet [control (CON; 10% fat) or high fat (HF; 60% fat)] and exposure to regular 12 h light:dark cycles (LD) or continuous low (L5) or high (L100) lux of light on gestation length, birth litter size, milk composition and litter growth to lactation day 12. HF diet reduced birth litter size, but increased postnatal d 12 litter weight (P<0.05), whereas constant light tended to increase litter weight (P=0.07). Continuous light increased gestation length, altered dam feed intake, increased serum prolactin and increased final dam and mammary gland weight (P<0.05), while decreasing mammary ATP content and milk lactose (P<0.05). Correlation analysis indicated a positive relationship between final litter weight and mammary size, metabolic stores (e.g. maternal fat pad weight), kcal of feed intake, and gestation length (P<0.05). Although CON mice spent more time eating than HF dams, the calorically dense HF diet was related to greater rates of litter growth to peak lactation. Constant light circadian disrupting effects appear to be confounded by a potential long day photoperiod response exemplified by higher circulating levels of prolactin and increased body and mammary weight of females exposed to these conditions. Other model systems may be better to study the interacting effects of obesity and circadian disruption on reproductive competence.

Pinecone oil supplemented to multiparous sows from 107 days prenatal to 21 days postpartum improves reproductive performance and milk composition and affects serum parameters.

Pinecone oil (PO) of Pinus koraiensis mainly contains α-pinene, β-pinene, and limonene that may ameliorate animal well-being and growth performance. This study evaluated its effects on feed intake, milk composition and yield, serum parameters, and litter growth of sows. Twenty-seven pregnant sows (parity 2-4) were distributed to three dietary treatments. The trial started on Day 107 of gestation and ended on Day 21 of lactation. Sows were given either a basal diet or the basal diet + 200 or 400 mg/kg PO. Each treatment contained nine sows and each sow was considered an experimental unit. Results showed that the average daily gain and weaned body weight of piglets from the sows fed 400 mg/kg PO supplements were higher (p < 0.05) than the piglets from the control sows. Lactose content in colostrum samples and fat content in milk samples were higher (p < 0.05) in 400 mg/kg PO-treated sows, respectively, than those from the sows fed basal diet. Additionally, cortisol concentration and aspartate aminotransferase concentration in sow serum was lowered (p < 0.05) by 400 mg/kg PO on Day 21 of lactation. In conclusion, supplementation of 400 mg/kg PO during late gestation and lactation contributed to greater offspring growth performance, possibly by enhanced milk quality and alleviated maternal stress.

Capsaicin and 1,25-Dihydroxyvitamin D3 Glycoside: Effects on the Reproductive Performance of Hyper-Prolific Sows.

This study evaluated the effect of a natural source of vitamin D3 [1,25-(OH)2D3] and capsaicin (CAP) in the dietary supplementation of sows in the final phase (85-114 days) of gestation (Gest) and lactation (Lact) on the reproductive performance of the sows and health of piglets through two experiments (Exp I and II). In Exp I, 120 sows were subjected to four treatments: T1-control (without [1,25-(OH)2D3] and supplemental CAP); T2-3.5 µg 1,25-(OH)2D3/Gest/day and 7.0 µg Vit 1,25-(OH)2D3/Lact/day; T3-7.0 µg CAP/Gest/day and 14.0 µg CAP/Lact/day; T4-1.75 µg Vit 1,25-(OH)2D3 + 3.5 µg CAP/Gest/day and 3.5 µg 1,25-(OH)2D3 + 7.0 µg CAP/Lact/day. In Exp II, 200 sows were randomly blocked, factorial 2 × 2 (without or with Vit 1,25-(OH)2D3 and without or with CAP): T1-control (without Vit 1,25-(OH)2D3 and CAP); T2-3.5 µg Vit 1,25-(OH)2D3/Gest/day and 7.0 µg Vit 1,25-(OH)2D3/Lact/day; T3-7.0 µg CAP/Gest/day and 14.0 µg CAP/Lact/day; T4-3.5 µg Vit 1,25-(OH)2D3 + 7 µg CAP/Gest/day; and 7.0 µg Vit 1,25-(OH)2D3 + 14.0 µg CAP/Lact/day. The duration of delivery (3:48 vs. 4:57 h) and the percentage of stillbirths (5.37% vs. 7.61%) were improved (p < 0.05) in the group that received Vit 1,25-(OH)2D3 (Exp II) compared to the control group. Moreover, the dystocia rate decreased (p < 0.05) in Exp II, which received Vit 1,25-(OH)2D3 (4.21 vs. 27.63%), and in Exp I, which received the combination of Vit 1,25-(OH)2D3 + CAP (12 vs. 40%) compared to the respective control groups. Colostrum production was greater (p < 0.05) in sows that received Vit 1,25-(OH)2D3 supplementation compared to the control group, consequently resulting in higher colostrum intake (p < 0.05) of the piglets (330 vs. 258 g/piglet). The additives reduced the incidence of diarrhea (p < 0.05) in piglets (Exp I and II). Thus, the use of additives improved the reproductive performance of sows and contributed to litter growth.

Long-Term Changes in Organic Matter Content and Soil Moisture Determine the Degree of Root and Soil Respiration.

Carbon in soil is one of the most important indicators of soil fertility. Part of the carbon stored in them is returned to the atmosphere during soil respiration. Climate change and inappropriate land use can accelerate these processes. Our work aimed to determine how soil CO2 emissions change over ten years as a result of litter manipulation treatments. Plots at the Síkfőkút DIRT (Detritus Input and Removal Treatments) experimental site include doubling either leaf litter or wood, and removing all aboveground litter, all root inputs, or removing all litter inputs. With the help of this, we were able to examine not only the effects of the different organic matter intake but also the effects of the different microclimates that occur as a result of the treatments. Total soil respiration (root and microbial respiration) is a result of a persistent lack or excess of soil organic matter relative to soil moisture. Based on our studies, the increase in the intensity of root respiration on wetter soils was only half of the increase in respiration associated with decomposition activity. The sustained growth of leaf litter significantly increases soil respiration, which can be partly explained by the more favorable supply of nutrients to the decomposing organisms, and partly by the more favorable microclimatic conditions, however, these effects were only valid in the case of wetter soils. In the dry summer environment, we experienced higher CO2 emissions during litter removal treatments. In the first period between 2002 and 2004, even wetter root removal treatments showed a significantly higher CO2 emission, while in the period 2010-2012, surface litter removal treatments. The permanent removal of surface litter in the drier summer period resulted in the formation of a dense crack network, which increased the CO2 emission of these soils, which increases the soil organic carbon loss of the soil. Our study proves the advantages of mulching in terms of a more favorable microclimate of the soil surface and a balanced carbon balance of the soil-plant system.

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.

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. At approximately d 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 80ppm 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 80ppm from d 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.

Effect of different sow lactation feeder types and drip cooling on sow bodyweight, litter performance, and feeder cleaning criteria.

A total of 600 sows (line 3; PIC, Hendersonville, TN) were used to evaluate the effect of different lactation feeder types and drip cooling on sow farrowing performance and litter growth performance during the summer. For the feeder evaluation, the trial was conducted in two sequential groups with 300 sows per group. Five 60-farrowing-stall rooms with tunnel ventilation were used for each group. On approximately days 110 to 112 of gestation, sows were blocked by body condition score (BCS), parity, and offspring sire (lines 2 or 3 sires; PIC), then randomly allotted to one of three feeder types: 1) PVC tube feeder, 2) Rotecna feeder (Rotecna), or 3) SowMax feeder (Hog Slat). The three feeder types were placed in one of three stalls with the same sequence from the front to the end of all rooms to balance for environmental effects. For drip cooling evaluation, the trial was conducted during the 2nd group of 300 sows. Drippers were blocked in three of every six farrowing stalls to balance feeder type and environmental effects. After farrowing, sows had ad libitum access to feed. For litter performance data, only pigs from sows bred to line 2 sires were recorded. Line 3 sire pigs were not included in litter performance data, but sows of these pigs were included in sow body weight (BW) and feed disappearance data. After weaning, feeder cleaning time was recorded on a subsample of 67 feeders (19, 23, and 25 for PVC tube, Rotecna, and SowMax, respectively). There was no evidence of difference (P > 0.05) in sow entry BW, exit BW, BW change, and litter performance among the different feeder types. However, sows using the SowMax feeders had decreased (P < 0.05) total feed disappearance, average daily feed disappearance, and total feed cost compared to those fed with the PVC tube feeders. There was a marginal difference (P < 0.10) between feeder types in cleaning time, with PVC tube feeders requiring less time than the Rotecna feeders; however, cleaning time varied greatly between the personnel doing the cleaning. Sows with drip cooling had greater (P < 0.05) feed disappearance, litter growth performance, and subsequent total born, and reduced (P < 0.05) BW change. In conclusion, using a SowMax feeder reduced feed disappearance with no effects on sow and litter performance compared to a PVC tube feeder, and drip cooling improved sow and litter performance during summer.

Impact of dietary supplementation of l-Arginine, l-Glutamine, and the combination of both on nursing performance of multiparous sows.

Dietary supplementation with arginine (Arg) or glutamine (Gln) has been considered as an option to improve nursing performance in reproductive sows. This study investigated whether a low-level supplementation of Arg or Gln or a blend of both could modify milk nutrients and improve piglets' growth beyond weaning. Seventy-two multiparous sows were assigned to four groups: one group fed a control diet, three treatment groups fed the control diet supplemented with either 0.35% Arg, 0.35% Gln, or both, from day 108 of gestation until weaning at day 26 of lactation. Immediately after birth, the litters were cross fostered to 13 piglets and monitored until 2 wk after weaning. Sows body condition and litter growth were assessed. Colostrum and milk samples were collected for nutrient analyses. Plasma concentrations of insulin-like growth factor 1 (IGF-1) around weaning were determined in sows and two representative piglets per litter. Supplementing Gln or the combination of Arg and Gln had no effect on the parameters studied. Arg supplementation increased weaning weight, while decreasing the variation of piglet weights 2 wk after weaning. There was no correlation with plasma IGF-1 since the hormone was not altered in sows or piglets. The colostral concentration of fat tended to increase in the Arg-group, whereas protein, lactose, energy, and polyamine concentrations remained unaffected. Milk samples obtained on day 12 and 25 of lactation were not influenced by dietary treatment. The data indicate that there might be a window of opportunity, explicitly at the onset of lactation, for dietary intervention by maternal dietary Arg supplementation.

Evaluation of supplemental fat sources and pre-farrow essential fatty acid intake on lactating sow performance and essential fatty acid composition of colostrum, milk, and adipose tissue.

A total of 91 sows (Line 241, DNA Genetics) were used to evaluate the effects of supplemental fat sources and essential fatty acid intake on sow farrowing performance, litter growth performance, and essential fatty acid composition of colostrum, milk, and adipose tissue. At approximatelyday 107 of gestation, sows were blocked by body weight and parity, then allotted to 1 of 5 experimental treatments as part of a 2 × 2 + 1 factorial arrangement. Experimental diets were corn-soybean meal-based with a control diet that contained no added fat or diets with 3% added fat as either beef tallow or soybean oil, with consumption of the added fat diets starting on day 107 or 112 of gestation and fed until weaning. Thus, sows were provided low essential fatty acids (EFA; as linoleic and α-linolenic acid) without supplemental fat or with beef tallow or high EFA with soybean oil. Sows were provided approximately 2.8 kg/d of their assigned lactation diet pre-farrow and then provided ad libitum access after parturition. Sows consuming diets with beef tallow had greater lactation ADFI (fat source, P = 0.030), but lower daily linoleic acid (LA) and α-linolenic acid (ALA) intake than sows that consumed diets with soybean oil (fat source, P < 0.001). Supplemental fat sources providing either low or high EFA did not influence litter growth performance (fat source, P > 0.05). Sows fed diets with beef tallow did not influence the LA composition of colostrum; however, lactation diets with high EFA provided by soybean oil on day 107 of gestation increased colostrum LA concentration compared to providing diets on day 112 of gestation (fat source × time, P = 0.084; time, P < 0.001). Additionally, regardless of pre-farrow timing, ALA concentration of colostrum increased when sows consumed diets with soybean oil compared to beef tallow (fat source, P < 0.001). Both LA and ALA concentrations of milk at weaning were greater for sows that consumed diets with soybean oil compared to beef tallow (fat source, P < 0.001). Furthermore, concentrations of LA and ALA within adipose tissue were greater at weaning when sows consumed diets with high EFA compared to low EFA (fat source, P < 0.05). These responses suggest that providing dietary fat sources with high concentrations of EFA can increase backfat, colostrum, and milk LA and ALA. However, in this experiment, changes in colostrum and milk composition did not influence litter growth performance.

Precision feeding of lactating sows: implementation and evaluation of a decision support system in farm conditions.

Precision feeding (PF) aims to provide the right amount of nutrients at the right time for each animal. Lactating sows generally receive the same diet, which either results in insufficient supply and body reserve mobilization, or excessive supply and high nutrient excretion. With the help of online measuring devices, computational methods, and smart feeders, we introduced the first PF decision support system (DSS) for lactating sows. Precision (PRE) and conventional (STD) feeding strategies were compared in commercial conditions. Every day each PRE sow received a tailored ration that had been computed by the DSS. This ration was obtained by blending a diet with a high AA and mineral content (13.00 g/kg SID Lys, 4.50 g/kg digestible P) and a diet low in AAs and minerals (6.50 g/kg SID Lys, 2.90 g/kg digestible P). All STD sows received a conventional diet (10.08 g/kg SID Lys, 3.78 g/kg digestible P). Before the trial, the DSS was fitted to farm performance for the prediction of piglet average daily gain (PADG) and sow daily feed intake (DFI), with data from 1,691 and 3,712 lactations, respectively. Sow and litter performance were analyzed for the effect of feeding strategy with ANOVA, with results considered statistically significant when P < 0.05. The experiment involved 239 PRE and 240 STD sows. DFI was similarly high in both treatments (PRE: 6.59, STD: 6.45 kg/d; P = 0.11). Litter growth was high (PRE: 2.96, STD: 3.06 kg/d), although it decreased slightly by about 3% in PRE compared to STD treatments (P < 0.05). Sow body weight loss was low, although it was slightly higher in PRE sows (7.7 vs. 2.1 kg, P < 0.001), which might be due to insufficient AA supply in some sows. Weaning to estrus interval (5.6 d) did not differ. In PRE sows SID Lys intake (PRE: 7.7, STD: 10.0 g/kg; P < 0.001) and digestible P intake (PRE: 3.2, STD: 3.8 g/kg; P < 0.001) declined by 23% and 14%, respectively, and feed cost decreased by 12%. For PRE sows, excretion of N and P decreased by 28% and 42%, respectively. According to these results, PF appears to be a very promising strategy for lactating sows.

Evaluation of essential fatty acids in lactating sow diets on sow reproductive performance, colostrum and milk composition, and piglet survivability.

Mixed parity sows (n = 3,451; PIC, Hendersonville, TN; parities 2 through 9) and their litters were used to evaluate the effects of essential fatty acid (EFA) intake on sow reproductive performance, piglet growth and survivability, and colostrum and milk composition. Our hypothesis, like observed in earlier research, was that increasing linoleic acid (LA) and α-linolenic acid (ALA) would improve sow and litter performance. At approximately day 112 of gestation, sows were randomly assigned within parity groups to 1 of 4 corn-soybean meal-wheat-based lactation diets that contained 0.5 (Control) or 3% choice white grease (CWG), 3% soybean oil (SO), or a combination of 3% soybean oil and 2% choice white grease (Combination). Thus, sows were provided diets with low LA and ALA in diets with CWG or high LA and ALA in diets that included soybean oil. Sows received their assigned EFA treatments until weaning and were then fed a common gestation and lactation diet in the subsequent reproductive cycle. Average daily feed intake during the lactation period increased (P < 0.05) for sows fed the Combination and CWG diets compared with sows fed the Control or SO diet. However, daily LA and ALA intakes of sows fed the Combination and SO diets were still greater (P < 0.05) than those of sows fed 0.5 or 3% CWG. Overall, sows consuming high EFA from the Combination or SO diets produced litters with heavier (P < 0.05) piglet weaning weights and greater (P < 0.05) litter ADG when compared with litters from sows fed diets with CWG that provided low EFA. Despite advantages in growth performance, there was no impact of sow EFA intake on piglet survivability (P > 0.10). Additionally, lactation diet EFA composition did not influence sow colostrum or milk dry matter, crude protein, or crude fat content (P > 0.10). However, LA and ALA content in colostrum and milk increased (P < 0.05) in response to elevated dietary EFA from SO. There was no evidence for differences (P > 0.10) in subsequent sow reproductive or litter performance due to previous lactation EFA intake. In conclusion, increased LA and ALA intake provided by soybean oil during lactation increased overall litter growth and pig weaning weights, reduced sow ADFI, but did not affect piglet survivability or subsequent performance of sows.

119 A Meta-Regression Analysis to Evaluate the Influence of Branched-Chain Amino Acids in Lactation Diets on Sow and Litter Growth Performance

Abstract The branched-chain amino acids (BCAA) Ile, Leu, and Val are 3 dietary essential amino acids for lactating sows; however, effects of dietary BCAA on sow and litter growth performance in the literature are equivocal. Thus, a meta-regression analysis was conducted to evaluate effects of BCAA and their interactions in lactating sow diets to predict litter growth performance, sow bodyweight (BW) change, and sow feed intake. Thirty-four publications representing 43 trials from 1997 to 2020 were used to develop a database that contained 167 observations. Diets for each trial were reformulated using NRC (2012) nutrient loading values in an Excel-based spreadsheet. Amino acids were expressed on a standardized ileal digestible (SID) basis. Regression model equations were developed with the MIXED procedure of SAS (Version 9.4, SAS Institute, Cary, NC), and studies were weighted by the inverse of the squared SEM. Statistically significant (P &amp;lt; 0.05) predictor variables were assessed with a step-wise manual forward selection and required to provide an improvement of at least 2 BIC for model inclusion. Significant predictor variables within 3 equations developed for litter ADG included the count of weaned pigs per litter, dietary concentrations of NE, SID Lys, and CP, sow ADFI, Val:Lys, Ile:Lys, and Leu:Val. For sow BW change, significant predictor variables within 2 developed models included litter size at 24 h, sow ADFI, Leu:Lys, and Ile+Val:Leu. The optimum equation for sow ADFI included Leu:Trp, SID Lys, NE, CP, and Leu:Lys as significant predictor variables. Overall, the prediction equations suggest that BCAA have an important role in litter growth, sow BW change, and feed intake during lactation; however, the influence of BCAA on these criteria is much smaller than that of other dietary components such as NE, SID Lys, sow ADFI, and CP.

246 Awardee Talk: Evaluating the Impact of Essential Fatty Acids in Lactation Diets on Sow and Litter Performance

Abstract Two experiments were conducted to evaluate the effects of supplemental fat sources providing low and high essential fatty acids (EFA) in lactation diets on sow reproductive performance, piglet growth and survivability, and colostrum and milk composition. In Exp. 1, mixed parity sows (n = 91) were allotted to 5 experimental treatments arranged in a 2×2 + 1 factorial. Treatments were corn-soybean meal-based diets that contained no added fat or diets with 3% added fat as either beef tallow or soybean oil starting on d 107 or 112 of gestation. Sows were provided low EFA [linoleic acid (LA) and α-linolenic acid (ALA)] in diets without supplemental fat or with beef tallow or high EFA with soybean oil. Results confirmed that providing fat sources with high EFA can increase colostrum and milk LA and ALA content, regardless of pre-farrow time of diet consumption. However, supplemental fat did not influence litter growth performance (P &amp;gt; 0.05). In Exp. 2, mixed parity sows (n = 3,451) were assigned to 4 corn-soybean meal-wheat-based lactation diets with 0.5 (Control) or 3% choice white grease (CWG), 3% soybean oil (SO), or a combination of 3% soybean oil and 2% choice white grease (Combination) at d 112 of gestation to provide diets with low or high EFA. Lactation ADFI increased (P &amp;lt; 0.05) for sows fed the Combination and CWG diets compared with sows fed the Control or SO diet. Sows fed Combination and SO diets had greater (P &amp;lt; 0.05) LA and ALA intake, LA and ALA in colostrum and milk, litter weaning weights, and litter ADG than sows fed 0.5 or 3% CWG. Sow EFA intake did not affect (P &amp;gt; 0.10) piglet survivability or subsequent sow reproductive performance. In conclusion, increased LA and ALA intake provided by SO during lactation increased overall litter growth and weaning weights but did not affect piglet survivability or subsequent performance.

65 Evaluation of Essential Fatty Acids in Lactating Sow Diets on Sow Reproductive Performance, Colostrum and Milk Composition, and Pre-Weaning Litter Growth and Survivability

Abstract Mixed parity sows (n = 3,451; PIC, Hendersonville, TN) and their litters were used to evaluate the effects of essential fatty acid (EFA) intake on sow reproductive performance, piglet growth and survivability, and colostrum and milk composition. At approximately d 112 of gestation, sows were randomly assigned to 1 of 4 corn-soybean meal-wheat-based lactation diets with 0.5 (Control) or 3% choice white grease (CWG), 3% soybean oil (SO), or a combination of 3% soybean oil and 2% choice white grease (Combination). Thus, sows were provided diets with low EFA [linoleic acid (LA) and α-linolenic acid (ALA)] in diets with CWG or high EFA in diets with SO. Lactation ADFI increased (P &amp;lt; 0.05) for sows fed the Combination and CWG diets compared with sows fed the Control or SO diet. Daily LA and ALA intake of sows fed the Combination and SO diets were greater (P &amp;lt; 0.05) than sows fed 0.5 or 3% CWG. Overall, sows consuming high EFA from the Combination or SO diets produced litters with heavier (P &amp;lt; 0.05) piglet weaning weights and greater (P &amp;lt; 0.05) litter ADG when compared with litters from sows fed diets with low EFA provided through CWG. There was no effect of sow EFA intake on piglet survivability (P &amp;gt; 0.10). Lactation diet EFA concentration did not influence colostrum or milk dry matter, crude protein, or crude fat content (P&amp;gt;0.10). However, LA and ALA content in colostrum and milk at weaning increased (P &amp;lt; 0.05) in response to elevated dietary EFA from SO. There was no evidence for differences (P &amp;gt; 0.10) in subsequent sow reproductive or litter performance due to previous lactation EFA intake. In conclusion, increased LA and ALA intake provided by SO during lactation increased overall litter growth and pig weaning weights but did not affect piglet survivability or subsequent performance.

PSVII-2 Effects of Oxidized Beta-Carotene on Sow Reproduction and Piglet Growth Performance

Abstract As reproductive performance of sows in the commercial U.S. sow herd continues to improve, advancing the impact of gestation and lactation diet supplementation is critical. Beginning on d 60 of gestation through lactation, sows (blocked by parity) were assigned to a standard gestation diet (n = 88), or the standard diet supplemented with 80 ppm OxC-beta (n = 90) provided by Avivagen (Ottawa, ON, Canada) to determine if the supplementation of OxC-beta improves sow reproductive performance, litter growth performance, and alters the abundance of immune cells in sows and piglets. Blood samples were taken from a subset of sows (n = 54 per treatment) at the start of the study, at farrowing, and at weaning; and also, on a subset of piglets at birth and weaning. Also, at birth and weaning, 12 pigs (n = 6 per treatment) were euthanized, and livers were collected and subjected to flow cytometry to analyze phagocytic activity of the Kupfer cells. CD335, CD8, and CD4 populations within whole blood were assessed via flow cytometry. Colostrum at farrowing and milk at weaning were collected for analysis of IgG and IgA. Data were analyzed via SAS 9.4 using PROC GLIMMIX. No differences (P &amp;gt; 0.05) between dietary treatments were observed in sow reproductive performance, sow feed intake, wean to estrus interval, or piglet growth performance. No differences (P &amp;gt; 0.05) were observed for vitamin A in the plasma or liver. No immune differences (P &amp;gt; 0.05) were observed in the piglet’s liver and blood nor sow antibodies in colostrum and milk. Subsequent litter information was obtained from the sows, and no differences (P &amp;gt; 0.05) were observed in reproductive performance. Overall, there were no differences in sow reproductive performance, litter growth performance, and the immune system of sows and piglets of sows supplemented OxC-beta.

A meta-regression analysis to evaluate the influence of branched-chain amino acids in lactation diets on sow and litter growth performance.

The branched-chain amino acids (BCAA) Ile, Leu, and Val are three dietary essential amino acids for lactating sows; however, effects of dietary BCAA on sow and litter growth performance in the literature are equivocal. Thus, a meta-regression analysis was conducted to evaluate the effects of BCAA and their interactions in lactating sow diets to predict litter growth performance, sow bodyweight change, and sow feed intake. Thirty-four publications that represented 43 trials from 1997 to 2020 were used to develop a database that contained 167 observations. Diets for each trial were reformulated using NRC. 2012. Nutrient requirements of swine. 11th ed. Washington, DC: National Academies Press nutrient loading values in an Excel-based spreadsheet. Amino acids were expressed on a standardized ileal digestible (SID) basis. Regression model equations were developed with the MIXED procedure of SAS (Version 9.4, SAS Institute, Cary, NC) and utilized the inverse of reported squared SEM with the WEIGHT statement to account for heterogeneous errors across studies. Predictor variables were assessed with a step-wise manual forward selection for model inclusion. Additionally, statistically significant (P < 0.05) predictor variables were required to provide an improvement of at least 2 Bayesian information criterion units to be included in the final model. Significant predictor variables within three optimum equations developed for litter ADG included the count of weaned pigs per litter, NE, SID Lys, CP, sow ADFI, Val:Lys, Ile:Lys, and Leu:Val. For sow BW change, significant predictor variables within two developed models included litter size at 24 h, sow ADFI, Leu:Lys, and Ile + Val:Leu. The optimum equation for sow ADFI included Leu:Trp, SID Lys, NE, CP, and Leu:Lys as significant predictor variables. Overall, the prediction equations suggest that BCAA play an important role in litter growth, sow BW change, and feed intake during lactation; however, the influence of BCAA on these criteria is much smaller than that of other dietary components such as NE, SID Lys, sow ADFI, and CP.

Protein Digestion Kinetics Influence Maternal Protein Loss, Litter Growth, and Nitrogen Utilization in Lactating Sows

Body protein losses in lactating sows have a negative impact on sow and litter performance. Improving dietary amino acid utilization may limit protein mobilization. The effects of dietary protein kinetics on sow body condition loss, blood plasma metabolites, and plasma insulin-like growth factor-1 (IGF-1), and also on litter gain during lactation, were investigated in this study. In total, 57 multiparous sows were fed one of three lactation diets with the same crude protein level: low level of slow protein diet (LSP) (8% slowly degradable protein of total protein), medium level of slow protein diet (MSP) (12% slowly degradable protein of total protein), or high level of slow protein diet (HSP) (16% slowly degradable protein of total protein) in a complete block design. Our results showed that HSP sows lost the least body weight compared to MSP and LSP sows (11.9 vs. 17.3 and 13.5 kg, respectively; p = 0.01), less body protein than MSP sows (1.0 vs. 2.1 kg; p = 0.01), and tended to lose less loin muscle thickness than LSP sows (1.7 vs. 4.9 mm; p = 0.09) between Day 2 to Day 21 post-farrowing. LSP sows had greatest plasma urea level on Day 6 than MSP and HSP sows (4.9 vs. 3.6 and 3.1 mmol/L, respectively; p < 0.01) and on Day 13 (5.6 vs. 4.1 and 3.7 mmol/L, respectively; p < 0.01). HSP sows had the lowest plasma urea level at Day 20 compared to LSP and MSP sows (4.0 vs. 5.5 and 4.9 mmol/L, respectively; p < 0.01). The average plasma urea level of Days 6, 13, and 20 post-farrowing was negatively correlated with slow protein intake (r = −0.49, p < 0.01). Litter gain, milk composition, and nitrogen output to the environment did not differ significantly among the treatment groups. Therefore, the dietary protein kinetics affected mobilization of maternal reserves in multiparous sows during lactation, with a high fraction of slow protein-sparing protein mobilization.

TRB3 Deletion Has a Limited Effect on Milk Fat Synthesis and Milk Fat Depression in C57BL/6N Mice

ABSTRACTBackgroundRegulation of the endoplasmic reticulum (ER) stress pathway is critical to mammary epithelial cell function throughout pregnancy, lactation, and involution. Treatment with trans-10, cis-12 conjugated linoleic acid (t10c12CLA) suppresses mammary lipogenesis and stimulates the ER stress pathway. The ER stress pathway includes tribbles pseudokinase 3 (TRB3), a protein that regulates cellular energy and insulin signaling.ObjectivesOur objective was to describe the effect of TRB3 deficiency on milk fat synthesis and determine if TRB3 deficiency protects against suppression of mammary lipogenesis.MethodsFirst, mammary Trb3 expression was observed throughout pregnancy and lactation using ancillary microarray data (n = 4/time point). Second, intake, litter growth, and milk clot fatty acid (FA) profile of Trb3 knockout (KO) C57BL/6N mice were compared with wild-type (WT) and heterozygous (HET) mice throughout first (n ≥ 8/group) and second (n ≥ 6/group) lactation. Lastly, the interaction between Trb3 genotype and 2 treatments that suppress mammary lipogenesis, t10c12CLA and high safflower oil (HO) diet, was investigated in a 2 × 2 factorial design (n ≥ 6/group).Results Trb3 expression was higher during late pregnancy and lactation. Trb3 KO and HET mice had lower feed intake, dam weight, and litter growth throughout first, but not second, lactation than WT mice. Treatment with t10c12CLA decreased litter growth (28%; P < 0.0001) and feed intake (8%; P < 0.0001) regardless of Trb3 genotype. When fed the HO diet, Trb3 KO mice had 17% higher mammary de novo synthesized FAs (<16 carbons; Pint = 0.002) than WT mice. Mammary ER stress and lipogenic genes were mostly unaltered by Trb3 deficiency.ConclusionsOverall, TRB3 plays a minor role in regulating mammary lipogenesis, because Trb3 deficiency had only a limited protective effect against diet-induced suppression of lipogenesis.