Lactation Diet Research Articles

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.

Dietary Supplementation of Enzymatically Treated Artemisia annua L. Improves Lactation Performance, Alleviates Inflammatory Response of Sows Reared Under Heat Stress, and Promotes Gut Development in Preweaning Offspring.

Artemisia annua L., which is known for its antimalarial compound artemisinin, has commonly been used for its anti-inflammatory and antibacterial functions. Enzymatically treating Artemisia annua L. can improve its bioavailability. The purpose of this study was to investigate the effects of dietary enzymatically treated Artemisia annua L. (EA) supplementation in late gestation and lactation diets on sow performance, serum hormone, inflammatory cytokines, and immunoglobulin level of heat-stressed sows. A total of 135 multiparous sows (Large White × Landrace) on day 85 of gestation were selected and randomly distributed into 3 groups with 45 replicates per group. The control group was reared under standard conditions (temperature: 27.12 ± 0.18°C, THI (temperature-humidity index): 70.90 ± 0.80) and fed with basal diet. The heat stress (HS) and HS + EA groups were raised in heat-stressed conditions (temperature: 30.11 ± 0.16°C, THI: 72.70 ± 0.60) and fed with basal diets supplemented with 0 or 1.0 g/kg EA, respectively. This trial lasted for 50 consecutive days until day 21 of lactation. Compared with the control group, HS increased the concentrations of serum endotoxin and heat shock protein 70 (HSP-70), and inflammatory cytokines in serum, colostrum, and 14 day milk of sows. Meanwhile, the EA supplementation decreased levels of serum endotoxin, HSP-70, and inflammatory cytokines in both sows and offspring and increased serum triiodothyronine (T3) level and average daily feed intake (ADFI) of sows. In addition, EA significantly improved average daily gain (ADG) and altered intestinal morphology with an increased villus height in the duodenum and ileum of piglets. Collectively, EA supplementation at 1.0 g/kg in late gestation and lactation diets alleviated the adverse effects of HS, which were reflected by enhancing ADFI and decreasing endotoxin as well as inflammatory cytokine levels in the serum and colostrum of heat-stressed sows, while promoting ADG and gut development of their offspring.

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.

Linseed supplementation during uterine and early post-natal life markedly affects fatty acid profiles of brain, liver and muscle of lambs

This study investigated the effects of maternal linseed supplementation during gestation and lactation on muscle, brain and liver tissues composition and fatty acid (FA) profile in lambs. In a 2 × 2 factorial design, a total of 36 Sarda dairy ewes were fed a control diet (CON, n = 18) or a diet containing linseed (LIN, n = 18) during the last 8 weeks of gestation. After lambing, 9 ewes per group changed to the other diet, moving from CON to LIN and vice-versa. The single-born lambs (n = 36) were reared exclusively on milk and were slaughtered at 4 weeks of age and samples of muscle, brain, and liver tissues were collected. Data were analysed with a general linear model to test the effects of mothers’ gestation and lactation diets, their interaction and the effect of lamb sex. Experimental results evidenced that lambs from mothers fed LIN diet during lactation had a greater content of almost all C18:1 and conjugated linoleic acid (CLA) isomers, both in muscle (P < .01) and in the liver (P < .05), than those from mothers fed CON. Linseed supplementation during gestation generally increased the content of C22:5n3 (P < .01) and C22:6n3 in the brain. In conclusion, experimental results evidenced that the supplementation of ewes’ diet with linseed during lactation strongly affected the muscle and liver FA profile of lambs. The effect of linseed was effective also during gestation, especially on brain tissue, but to a minor extent. Highlights Results of the present work confirm the large impact of maternal diet on the fatty acid composition of lamb tissues Linseed supplementation during gestation generally increased the content of PUFA n3 in the brain of lambs Linseed supplementation of mothers during lactation affects the muscle and liver FA profile of sucking lambs

Influence of Feeding Compound Feed Rich in Fibre during Parturition and Lactation on Health and Performance of Sows.

Simple SummaryAlthough it is known that restriction of feed negatively influences the behaviour and welfare of sows, it is widely adopted during the gestation period to counteract nutrient oversupply. Nonetheless, a healthy gut needs its fuel and is a prerequisite for preventing birth-associated health disorders. Including high amounts of fibre in diets around parturition could be the solution for behavioural disorders and health problems in sows and therefore in piglets as well. The purpose of this study was to investigate the influence of ad libitum access to compound feeds rich in fibre (ante partum and peri partum) and a lactation diet (post partum) on the performance and health of sows. This study indicated that a higher feed intake of a fibre-rich diet ante partum did not interfere with any birth-associated disorders. In addition, ad libitum-fed sows showed higher dry matter (DM) intake throughout lactation, which led to beneficial effects on the body condition scores of sows. Due to the high fibre intake, the excretion of C. perfringens via sows’ faeces could be significantly reduced, which could be a helpful tool in reducing the risk of neonatal diarrhoea caused by C. perfringens.The aim of this study was to investigate the influence of ad libitum access to compound feeds rich in fibre (ante partum (a.p.) and peri partum) on the DM intake, body mass development and performance of sows as well as excretion of Clostridium (C.) perfringens via sows’ faeces. From day 109 (d-7) of gestation, 25 of 48 sows (23 considered as control) received access to one of two different high-fibre pellets from d-7 until the second day post partum (p.p.) (d2) (fibre groups (FG) 1 and 2) in additional to a lactation diet. The additional DM intake of the high-fibre pellets a.p. was 2.13 ± 1.15 kg in FG 1 and 3.14 ± 0.68 kg in FG 2. This led to higher DM intake in the first lactation week and significantly lower losses of weight and back fat thickness during lactation. The bacterial counts of C. perfringens in sows’ faeces directly p.p. were 10 times lower in FG 1 and 100 times lower in FG 2 compared to the controls. High amounts of fibre led to higher DM intake throughout lactation, which had beneficial effects on sows’ body conditions. It seems that high fibre intake influenced the excretion of C. perfringens at parturition, which could improve the health of newborns.

Effects of dietary and milking frequency changes and administration of cabergoline on clinical udder characteristics in dairy cows during dry-off

We investigated the effects of 2 diet energy densities [normal lactation diet (NORM) vs. energy-reduced diet (REDU), both fed for ad libitum intake] and 2 daily milking frequencies [twice (2×) vs. once (1×)] during 1 week before the dry-off day, as well as effects of an injection of either a dopamine agonist [cabergoline (CAB); Velactis, Ceva Santé Animale, Libourne, France; labelled for use only with abrupt dry-off, e.g. no reduction in diet energy density or milking frequency before the last milking] or saline (SAL) following the last milking, on clinical udder characteristics of Holstein cows. During a week before and after the last milking, the following measures were recorded: palpation-based udder firmness and soreness; image-based hock-hock distance; responsiveness to mechanical udder stimulation and degree of udder fill measured with a dynamometer. Before the last milking, REDU cows displayed lower odds of having a firm udder and lower degree of udder fill, as well as lower responsiveness to mechanical udder stimulation, than NORM cows. After the last milking, REDU cows displayed shorter hock-hock distance compared with NORM cows. The effects of milking frequency on the clinical udder characteristics were unclear. Within 24 h following injection, CAB cows showed lower odds of having a firm udder, shorter hock-hock distance, and lower degree of udder fill than SAL cows, irrespective of treatment group before dry-off. In this study, reducing diet energy density prior to dry-off, and to some extent administering the dopamine agonist cabergoline after the last milking, resulted in fewest clinical udder changes.

Evaluation of Essential Fatty Acids in Lactating Sow Diets on Sow Reproductive Performance, Colostrum and Milk Composition, and Piglet Survivability

A total of 3,451 mixed parity sows and their litters were used to evaluate the effects of essential fatty acid intake on sow reproductive performance, piglet growth and survivability, and colostrum and milk composition. At approximately d 112 of gestation, sows were blocked by parity within farrowing room and randomly assigned to 1 of 4 experimental treatments. Lactation diets were corn-soybean meal-wheat-based and included 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 essential fatty acid (EFA; as linoleic [LA] and α-linolenic acid [ALA]) in diets with choice white grease or high EFA in diets with soybean oil. Prior to farrowing, sows were provided 4 lb/d of their assigned lactation diet and then allowed ad libitum access after parturition. Overall lactation ADFI increased (P < 0.001) when sows were fed the Combination and CWG treatments compared to sows fed the Control or diet with 3% SO. Regardless of differences among ADFI, daily LA and ALA intake of sows assigned to the Combination and SO treatments were greater (P < 0.001) than sows fed diets with lower EFA provided as CWG. There was no effect of sow EFA intake on piglet survivability from birth to 24 h or from 24 h to weaning (P > 0.10). Overall, sows consuming high EFA provided in the Combination and SO diets produced litters with greater (P < 0.05) litter gain and litter ADG during the lactation period and heavier (P < 0.001) piglet weaning weights when compared to litters from sows fed diets with low EFA provided through CWG. Lactation diet EFA composition did not influence colostrum or milk dry matter, crude protein, or crude fat content (P > 0.10). However, LA and ALA content in both colostrum and milk at weaning increased (P < 0.05) in response to increased EFA levels in diets that contained SO. There was no evidence for differences (P > 0.10) in wean-to-estrus interval, percentage of sows bred by d 7, percentage of sows bred by d 12, farrowing rate, or subsequent farrowing performance due to sow lactation EFA intake. In conclusion, increased LA and ALA intake during the lactation period from soybean oil addition increased overall litter growth and average weaning weights of pigs but did not affect piglet survivability or subsequent reproductive performance of sows.

The Effect of Lactation Diets Supplemented with Krave AP on Sow and Litter Performance

A total of 105 sows (Line 241, DNA) were used across four batch farrowing groups to evaluate the effects of feeding a feed flavor in lactation diets on sow and litter performance. Sow groups 1 and 2 farrowed in an old farrowing house during the summer months and groups 3 and 4 farrowed in a new farrowing house during the winter months. The farrowing house used for groups 1 and 2 was environmentally regulated by fans and drip coolers to adjust ambient temperature. The farrowing house used for groups 3 and 4 was environmentally controlled to maintain a target temperature by cool cells and fans. Sows were blocked by BW within parity on d 110 of gestation and allotted to 1 of 2 dietary treatments. Dietary treatments were a standard corn-soybean-based lactation diet (control) or the control diet with the addition of 0.05% feed flavor (Krave AP, Adisseo, Alpharetta, GA). Sows were fed their treatment diet from entry to the farrowing house (d 110 of gestation) until weaning at around 19 days of age. Farrowing house environment had a large impact and resulted in many interactions with the lactation feed flavor treatment. Sows fed the flavor treatment had a tendency (P = 0.093) for a higher ADFI overall compared with control fed sows. Adding the feed flavor to the diet increased feed intake and piglet ADG in an environment that was warmer where feed intake was suppressed, but had no effect in the new farrowing house where feed intake of all sows was much greater.

A review of branched-chain amino acids in lactation diets on sow and litter growth performance.

Branched-chain amino acids (BCAA) are three essential amino acids (AA) for lactating sows; however, the effects of dietary Leu, Val, and Ile on sow and litter performance within the literature are equivocal. The BCAA are structurally similar and share the first steps of their catabolism pathway where Leu, Val, and Ile are transaminated through BCAA aminotransferase and irreversibly decarboxylated by the branched-chain α-ketoacid dehydrogenase complex. Although these steps are shared among BCAA, Leu is recognized as the primary stimulator due to Leu’s greater affinity towards the enzymes compared to Val and Ile. Since the late 1990s, sows are producing larger and heavier litters and generally consume diets with greater concentrations of Leu and crystalline AA, which may create imbalances among dietary BCAA. Research conducted with growing-finishing pigs confirms that high concentrations of Leu can impair BCAA utilization and growth performance. However, the effects of BCAA on lactating sow and litter performance are not as clearly understood. Within mammary tissue, BCAA uptake is greater than milk output of BCAA since Val, Ile, and Leu are catabolized to form non-essential AA, lactose, fatty acids, and other metabolites. Within the mammary gland, BCAA aminotransferase activity is much higher than within skeletal muscle, liver, or small intestine. Thus, competition among the BCAA, namely, between Leu and Val, can significantly inhibit Val uptake within mammary tissue. Therefore, dietary modifications that mitigate BCAA competition may positively influence Val utilization for colostrum and milk synthesis. Little data exist on Ile and Leu requirements for modern lactating sows. Although Val requirements have been extensively researched in the last 25 yr, an ideal Val:Lys has not been consistently established across experiments. Some studies concluded that total Val concentrations above 120% of Lys optimized performance, whereas others determined that increasing SID Val:Lys from 55% to 136% did not improve piglet growth performance. Although increasing dietary Val positively influences fat and protein composition of colostrum and milk, litter growth during lactation is not always positively affected. Given the competition among BCAA for utilization within mammary tissue, research evaluating the Leu and Ile requirement of modern lactating sows is warranted to fully understand the influence and interactions of BCAA on reproductive and litter growth performance.

Effect of Saccharomyces cerevisiae boulardii on sows' farrowing duration and reproductive performance, and weanling piglets' performance and IgG concentration.

We studied the effects of Saccharomyces cerevisiae boulardii CNCM I-1079 (LSB) supplemented to lactating sows on reproductive traits and farrowing duration and to piglets from day 7 of life on post-weaning performance and IgG concentration. Ninety-six Landrace × Yorkshire sows started the trial 5 days before the expected farrowing date. Sows were distributed into 2 groups according to parity number and backfat thickness: control (CON: regular lactation diet) and LSB (CON + LSB at 2 × 109 colony forming units [CFU]/kg of feed). Seven days after birth, litters were randomly selected from each group and supplemented creep feed with or without LSB at 2 × 109 CFU/kg. At weaning, piglets from CON sows were shifted to a commercial farm and allocated to 14 pens in groups of 25 piglets/pen according to the creep feed supplemented during lactation. Piglets followed a 3-phase feeding program: creep, pre-starter and starter, with or without LSB at 2 × 109 CFU/kg LSB in creep and pre-starter, and 1 × 109 CFU/kg LSB in starter. The piglets were vaccinated against classical swine fever on days 41 and 72 of life. One day before each vaccination and at the end of the trial, blood samples were collected from 15 randomly selected piglets per treatment and assessed for total IgG. Supplemented sows with non-supplemented litters displayed the lowest backfat thickness loss during lactation (p < 0.05). The LSB supplementation shortened farrowing duration (p < 0.05) and increased feed intake (p < 0.05) during the first week of lactation. The LSB-fed piglets were heavier at the end of creep (p < 0.05), pre-starter (p < 0.05), and the trial (p < 0.05); grew faster during creep (p < 0.05), starter (p < 0.05), and overall (p < 0.05); and displayed an improved feed conversion ratio during creep (p < 0.05). Total IgG content was higher at days 40 (p < 0.05) and 71 (p < 0.05) in LSB-fed piglets. We conclude that supplementing sows with Saccharomyces cerevisiae boulardii CNCM I-1079 from late gestation until weaning shortens farrowing duration, increases feed intake, and minimizes backfat losses during lactation. When supplemented to piglet diet, post-weaning performance is improved. This improvement observed could be linked to a better immune status, as suggested by the higher IgG.

Effect of Sow Feeder Type and Drip Cooling on Sow Body Weight, Litter Performance, and Feeder Cleaning Criteria

A total of 600 mixed parity sows (PIC, Line 3) were used to evaluate the effect of different lactation feeders and drip cooling on lactating sow farrowing performance and litter growth performance during summer conditions. For the lactation feeder evaluation, the trial was conducted in 2 sequential groups with 300 sows per group in the same facility in central Arkansas. Five rooms with 60 farrowing stalls per room were used for each group. At approximately d 110 to 112 of gestation, sows were blocked by body condition score (BCS), parity, and offspring genetics (Line 2 or Line 3 sires). Sows were then randomly allotted to 1 of 3 feeder designs: 1) PVC tube feeder; 2) Rotecna ball feeder (Rotecna, Agramunt, Spain); or 3) SowMax rod feeder (Hog Slat, Newton Grove, NC). The three feeder designs were placed in one of 3 farrowing stalls with the same sequence (Rotecna, SowMax, and then PVC tube feeder) from the front to the end of all farrowing rooms to balance the environmental effect in each room. For the drip cooling evaluation, the trial was conducted during the second group of 300 sows. Water drippers were blocked in 3 of every 6 farrowing stalls to balance the feeder types and the environmental effect in each room. Sows were weighed before entering the farrowing house and at weaning. Sows were provided approximately 4 lb per day of the lactation diet pre-farrowing. After farrowing, sows were provided ad libitum access to lactation feed. The weaning age was between 19 to 22 d. Viable piglets from sows bred to line 2 boars (7,562 piglets from 441 sows) were individually tagged with an RFID tag within 24 h after birth. Line 3 piglets were not tagged and not included in the litter performance data, but the sows of these piglets were included in the sow BW and feed disappearance data. After weaning, the cleaning times for each feeder type were recorded on a subsample of feeders (n = 67). For the effect of lactation feeders, there was no evidence of difference (P > 0.05) in sow entry BW, exit BW, BW change, and litter performance between sow lactation feeders. However, sows on SowMax feeders had lower (P < 0.05) total feed disappearance, average daily feed disappearance, and total feed cost than sows on the tube feeders. Therefore, the feed cost per pig weaned from sows on the SowMax feeder

Modern view on the etiology, pathogenesis and diagnosis of mastitis in cows

Mastitis in cows is currently a pathology that causes great economic damage to livestock farms around the world. The quantitative and qualitative indicators of milk are decreasing. Prevention and treatment of breast inflammation in cows is one of the main tasks of veterinarians. For successful treatment, it is necessary to understand the etiology, especially in infectious mastitis. The degree of inflammatory reaction depends on the invading pathogen and the state of the animal's body, including such indicators as the stage of lactation, age, immune status, genetics and feeding diet. Almost 200 microorganisms that cause bovine mastitis have been identified, including bacteria, yeast, fungi and viruses. More than 150 species of bacteria that cause mastitis in cows have been identified, with bacterial mastitis being the most common. Mastitis can be caused by gram-positive bacteria, the most common of which are staphylococci and streptococci, and gram-negative bacteria, more often Escherichia coli and Klebsiella pneumoniae. Laboratory diagnostics is necessary to isolate and identify the relevant pathogen, which is necessary for the successful prevention and treatment of mastitis. The most commonly used method of diagnosing mastitis in cows is to measure the number of somatic cells. Express diagnostics are often used, which do not give a numerical result, but indicate only low or high indicators, while the causative agent of mastitis is not identified. The cultivation method is still the main criterion for detecting microorganisms, but it is a very time-consuming and expensive method. With the development of molecular methods, rapid and accurate diagnosis of diseases in animals has become possible. Recently developed diagnostic tests have shown high specificity and sensitivity.

Lactational High Fat Diet in Mice Causes Insulin Resistance and NAFLD in Male Offspring Which Is Partially Rescued by Maternal Metformin Treatment.

Maternal metabolic disease and diet during pregnancy and lactation have important implications for the programming of offspring metabolic disease. In addition, high-fat diets during pregnancy and lactation can predispose the offspring to non-alcoholic fatty liver disease (NAFLD), a rising health threat in the U.S. We developed a model of maternal high-fat feeding exclusively during the lactation period. We previously showed that offspring from dams, given lactational high-fat diet (HFD), are predisposed to obesity, glucose intolerance, and inflammation. In separate experiments, we also showed that lactational metformin treatment can decrease offspring metabolic risk. The purpose of these studies was to understand the programming implications of lactational HFD on offspring metabolic liver disease risk. Dams were fed a 60% lard-based HFD from the day of delivery through the 21-day lactation period. A subset of dams was also given metformin as a co-treatment. Starting at weaning, the offspring were fed normal fat diet until 3 months of age; at which point, a subset was challenged with an additional HFD stressor. Lactational HFD led male offspring to develop hepatic insulin resistance. The post-weaning HFD challenge led male offspring to progress to NAFLD with more severe outcomes in the lactational HFD-challenged offspring. Co-administration of metformin to lactating dams on HFD partially rescued the offspring liver metabolic defects in males. Lactational HFD or post-weaning HFD had no impact on female offspring who maintained a normal insulin sensitivity and liver phenotype. These findings indicate that HFD, during the lactation period, programs the adult offspring to NAFLD risk in a sexually dimorphic manner. In addition, early life intervention with metformin via maternal exposure may prevent some of the liver programming caused by maternal HFD.

Maternal Dietary Nitrate Supplementation Lowers Incidence of Stillbirth in Hyper Prolific Sows under Commercial Circumstances.

Simple SummaryOver recent decades, the number of piglets and, therefore, the number of stillborn piglets per litter have been increasing. Blood and oxygen supply are crucial for piglets to survive the birth process. Blood flow might be increased through vasodilation by dietary nitrate supplementation, which is known in sports nutrition to increase endurance. The current study evaluated the effects of nitrate supplementation to sows on the incidence of stillbirth at a commercial farm. In total, 120 sows received either a control diet or a diet containing 0.1% of calcium nitrate from approximately 5 days until 4 days after farrowing. The number of piglets born alive, stillborn, or that died from birth to weaning were recorded. Piglets were weighed at birth, after cross-fostering, 24 h after cross-fostering, at 3 days of age, and at weaning. Placentas were collected after expulsion and were visually scored on redness. No effect of nitrate supplementation to the sow was found on placental redness, piglet weights, and growth or incidence of death after being born. Dietary nitrate supplementation decreased the stillbirth percentage from 9.9 to 7.4%, making it a potential approach to decrease stillbirth.The objective of the current experiment was to investigate whether or not maternal dietary nitrate supplementation, a nitric oxide (NO) precursor, could reduce piglet losses under commercial circumstances. In the current experiment, 120 hyper prolific gilts and sows (Landrace x Yorkshire: Danbred) on a commercial farm in Denmark received either a control lactation diet or a lactation diet containing 0.1% of calcium nitrate (containing 63.1% of nitrate) from approximately 5 days pre-farrowing until day 4 of lactation. The number of piglets born total, alive, and stillborn, as well as birth weights, weights after cross-fostering (approximately 1 day of age), 24 h after cross-fostering, day 3 of age, and at weaning was recorded. Placentas of sows were collected after expulsion and scored on redness. No effect of nitrate supplementation was found on piglet weight, piglet growth, placental redness score, and pre-weaning mortality during lactation. Maternal dietary nitrate supplementation decreased stillbirth percentage with 2.5% (9.9 vs. 7.4%; p = 0.05). It can be concluded that maternal dietary nitrate supplementation shows the potential to decrease the incidence of stillbirth in hyper prolific sows.

3. Conjugated linoleic acid fed at a low inclusion rate in the late gestation and lactation diet can improve farrowing outcomes for primiparous sows and their progeny

3. Conjugated linoleic acid fed at a low inclusion rate in the late gestation and lactation diet can improve farrowing outcomes for primiparous sows and their progeny

2. The effect of inclusion of a specific mix of encapsulated fatty acids in gestation and lactation diets on sow and piglet performance during lactation

2. The effect of inclusion of a specific mix of encapsulated fatty acids in gestation and lactation diets on sow and piglet performance during lactation

Milk metabolites and fatty acids as noninvasive biomarkers of metabolic status and energy balance in early-lactation cows

The objective was to study the effects of week of lactation (WOL) and experimental nutrient restriction on concentrations of selected milk metabolites and fatty acids (FA), and assess their potential as biomarkers of energy status in early-lactation cows. To study WOL effects, 17 multiparous Holstein cows were phenotyped from calving until 7 WOL while allowed ad libitum intake of a lactation diet. Further, to study the effects of nutrient restriction, 8 of these cows received a diet containing 48% straw (high-straw) for 4 d starting at 24 ± 3 days in milk (mean ± SD), and 8 cows maintained on the lactation diet were sampled to serve as controls. Blood and milk samples were collected weekly for the WOL data set, and daily from d -1 to 3 of nutrient restriction (or control) for the nutritional challenge data set. Milk β-hydroxybutyrate (BHB), isocitrate, glucose, glucose-6-phosphate (glucose-6P), galactose, glutamate, creatinine, uric acid, and N-acetyl-β-d-glucosaminidase activity (NAGase) were analyzed in p.m. and a.m. samples, and milk FA were analyzed in pooled p.m. and a.m. samples. Average energy balance (EB) per day ranged from -27 MJ/d to neutral when cows received the lactation total mixed ration, and from -109 to -87 ± 7 MJ/d for high-straw (least squares means ± standard error of the mean). Plasma nonesterified FA concentration was 1.67 ± 0.13 mM and BHB was 2.96 ± 0.39 mM on the d 3 of high-straw (least squares means ± standard error of the mean). Milk concentrations of BHB, glucose, glucose-6P, glutamate, and uric acid differed significantly between p.m. and a.m. milkings. Milk isocitrate, glucose-6P, creatinine, and NAGase decreased, whereas milk glucose and galactose increased with WOL. Changes in milk BHB, isocitrate, glucose, glucose-6P, and creatinine were concordant during early lactation and in response to nutrient restriction. Milk galactose and NAGase were modulated by WOL only, whereas glutamate and uric acid concentrations responded to nutrient restriction only. The high-straw increased milk concentrations of FA potentially mobilized from adipose tissue (e.g., C18:0 and cis-9 C18:1 and sum of odd- and branched-chain FA (OBCFA) with carbon chain greater than 16; ∑ OBCFA >C16), and decreased concentrations of FA synthesized de novo by the mammary gland (e.g., sum of FA with 6 to 15 carbons; ∑ C6:0 to C15:0). Similar observations were made during early lactation. Plasma nonesterified FA concentrations had the best single linear regression with EB (R2 = 0.62). Milk isocitrate, Σ C6:0 to C15:0. and cis-9 C18:1 had the best single linear regressions with EB (R2 ≥ 0.44). Milk BHB, isocitrate, galactose, glutamate, and creatinine explained up to 64% of the EB variation observed in the current study using multiple linear regression. Milk concentrations of ∑ C6:0 to C15:0, C18:0, cis-9 C18:1, and ∑ OBCFA >C16 presented some of the best correlations and regressions with other indicators of metabolic status, lipomobilization, and EB, and their responses were concordant during early lactation and during experimental nutrient restriction. Metabolites and FA secreted in milk may serve as noninvasive indicators of metabolic status and EB of early-lactation cows.

PSVII-16 Effects of different forms of Cu on in vitro ruminal fermentation and digestibility of a lactation diet

Abstract Vistore® mineral products are hydroxychloride minerals that feature high metal content and improved bioavailability. This study was conducted to compare different sources of copper (Cu) on in vitro rumen fermentation parameters. Three ruminally-cannulated Jersey heifers were adapted to a lactation diet for two weeks before being used as donors. Three sources of Cu at 4 ppm: No supplemental Cu (CON), CuSO4, Vistore Cu, and another Cy hydroxychloride product (Vistore-competitor). The concentration of Cu in this study was selected from a titration study (0 to 8 ppm CuSO4) to identify the minimum concentration of CuSO4 affecting rumen fermentation. The lactation diet (TMR) was dried and ground to 1mm and used as the substrate. Rumen fluid was collected two hours after feeding. Substrate (0.5 g) was inoculated with 100 mL of a 3:1 McDougall’s buffer: ruminal fluid mixture at 39ºC for 24 h. Each treatment was run in triplicate and in three runs. Data were analyzed with R 4.0. The model included fixed effect of treatment and random effect of run. CuSO4 tended to increase lag time (0.78 vs -0.57 h, P = 0.06), reduced (P &amp;lt; 0.05) DMD (52.4 vs. 56.1%), cellulose digestibility (4.9% vs. 41.9%), isobutyrate molar % (0.58 vs. 0.78%) and NH3-N concentration (5.46 vs. 6.91 mg/dL). Vistore and Vistore-competitor maintained the fermentation and digestibility compared to CON. In general, Vistore Cu and Vistore-competitor maintained ruminal fermentation and digestibility parameters while negative effects of CuSO4 were observed. These results indicate different Cu mineral sources may affect the rumen differently.

PSXIII-8 Effects of different sources of Zn on in vitro ruminal fermentation and digestibility of a lactation diet

Abstract Vistore® minerals are hydroxychloride minerals that feature high metal content and improved bioavailability. This study was conducted to compare different sources of zinc (Zn) on in vitro rumen fermentation parameters. Three ruminally-cannulated Jersey heifers were adapted to a lactation diet for two weeks before used as donors. Three sources of Zn were tested at 20 ppm: No supplemental Zn (CON), ZnSO4, Vistore Zn, and another Zn hydroxychloride (Vistore-competitor). The concentration of Zn in this study was selected from a titration study (0 to 40 ppm ZnSO4) to identify the minimum concentration of ZnSo4 affecting rumen fermentation. The lactation diet (TMR) was dried and ground to 1mm and used as substrate. Rumen fluid was collected two hours after feeding. Substrate (0.5 g) was inoculated with 100 mL of 3:1 McDougall’s buffer: ruminal flued mixture at 39ºC for 24 h. Each treatment was run in triplicate and in three runs. Data were analyzed with R 3.0. The model included fixed effect of treatment and random effect of run. ZnSO4 reduced (P &amp;lt; 0.05) maximum gas production, DMD (54 vs. 55.9%) and cellulose (27.5 and 40.7%) digestibility. acetate to propionate ration (2.20 vs. 2.24) and NH3-N concentration (6.0 vs. 7.0 mg/dL), increased (P &amp;lt; 0.05) propionate % (27.2 vs 26.7%) compared to control. Vistore had higher pH than control (6.44 vs. 6.40, P = 0.02) but did not affect other parameters compared to CON. Vistore-competitor reduced total VFA production compared to control, ZnSO4, and Vistore (94 vs. 102, 106 and 107 mM, respectively, P = 0.01) but did not affect other parameters. In general, Vistore Zn maintained in vitro ruminal fermentation and digestibility, while ZnSO4 had negative effects on both fermentation and digestibility and Vistore-competitor reduced total VFAs. Results indicate hydroxychloride minerals may stabilize rumen parameters versus sulfate sources but different hydroxychloride sources appear to influence rumen parameters differently.

227 Awardee Talk: Advances in Lipid Nutrition of Modern Sows

Abstract The modern lactating sow is a highly productive female capable of producing large quantities of milk to support large, rapidly growing litters. The associated high energy and nutritional demands are challenging to meet, especially during heat stress, when tissue loss is extensive. Supplemental lipids are efficient energy sources with a high energy density and low heat increment associated with digestion and metabolism. Besides serving as concentrated energy sources, unsaturated lipids are important sources of essential fatty acids (EFA; linoleic acid, C18:2n-6; and α-linolenic acid, C18:3n-3). These EFA are precursors of various prostanoids that are important regulators of reproductive processes. Lactating sows fed diets devoid of supplemental lipids exhibited poor reproduction but was significantly improved by inclusion of only 2% unsaturated lipids. It was shown that lactation diets were deficient in both linoleic and α-linolenic acid and tissue reserves were inadequate in mature sows. A multi-trial meta-analysis showed that more sows were successfully bred and maintained pregnancy when they consumed supplemental linoleic acid. Further, increased linoleic acid intake during lactation progressively reduced the number of sows removed from the herd due to reproductive failure (sows not returning to estrus, returning to estrus after breeding, pregnancy loss). Based on dose-response curves, the near maximum response was achieved when sows consumed a minimum of 125 g/d of linoleic acid and 10 g/d of α-linolenic acid during lactation. Recent studies also demonstrated improved subsequent reproduction with supplemental linoleic and α-linolenic acid during lactation, but not during the post-weaning period. Responses appeared to be related to heavier fetoplacental units, elevated allantoic fluid volume, and higher embryo survival measured on day 30 of gestation in sows supplemented with linoleic acid during lactation and early gestation. Research demonstrated the importance of both EFA in lactating sows and their critical role in improving reproduction, thus resolving seasonal anestrus.