Supplementation of l-arginine in pregnant gilts affects the protein abundance of DNMT1 in 35-day fetuses.

Maternal nutrition is one of the main environmental factors regulating gene expression during fetal development through epigenetic modifications. Some nutrients, such as the amino acid l-arginine, are added to maternal diets to modulate gene expression, improve the reproductive performance of females, and enhance conceptus development. This study investigated the hypothesis that supplementation of pregnant gilts with l-arginine regulates gene expression in conceptuses through epigenetic mechanisms. For this, fetal programming phenotypic markers, the expression of key epigenetic genes, and the abundance of DNA methylation proteins (DNMT3A and DNMT1) were evaluated in 25- and 35-day conceptuses from gilts supplemented (ARG) or not (CON) with 1.0 % l-arginine during early gestation. At 25 days, there were no significant differences in phenotypic markers between CON and ARG embryos (P > 0.05). Similarly, no differences were found between CON and ARG fetuses at 35 days (P > 0.05). Maternal supplementation with l-arginine did not influence the expression of the evaluated key epigenetic genes in pig embryos or fetuses, nor DNMT3A protein abundance (P > 0.05); on the other hand, DNMT1 protein abundance was lower in ARG fetuses (P = 0.002). It is concluded that supplementation of l-arginine in pregnant gilts affects epigenetic mechanisms, such as DNA methylation, in 35-day fetuses through regulation of DNMT1 levels. Further studies using transcriptomic and proteomic analysis could reveal additional epigenetic modifications in embryos and fetuses following maternal supplementation with l-arginine.

Carbohydrases and Phytase in Poultry and Pig Nutrition: A Review beyond the Nutrients and Energy Matrix.

This review aimed to clarify the mechanisms through which exogenous enzymes (carbohydrases and phytase) influence intestinal health, as well as their effects on the nutrients and energy matrix in diets fed to poultry and pigs reared under sanitary challenging conditions. Enzyme supplementation can positively affect intestinal microbiota, immune system, and enhance antioxidant status. Although enzymes have been shown to save energy and nutrients, their responses under sanitary challenging conditions are poorly documented. Immune system activation alters nutrient partitioning, which can affect the matrix values for exogenous enzymes on commercial farms. Notably, the carbohydrases and phytase supplementation under sanitary challenging conditions align with energy and nutritional valorization matrices. Studies conducted under commercial conditions have shown that matrices containing carbohydrases and phytase can maintain growth performance and health in poultry and pigs. However, these studies have predominantly focused on assessing a single level of reduction in energy and/or available phosphorus and total calcium, limiting our ability to quantify potential energy and nutrient savings in the diet. Future research should delve deeper into determining the extent of energy and nutrient savings and understanding the effects of alone or blended enzymes supplementation to achieve more specific insights.

Do carcass traits influence consumer perception of pork eating quality?

The objective of this study was to assess carcass traits' influence on pork eating quality as evaluated by consumers. A total of 1360 pork chops were used, with 824 from the sirloin end and 536 from the butt end of the loin (Longissimuss thoracis et lumborum), to produce 340 packages, each containing four pork chops. Untrained participants received one package of either sirloin or butt chops, being two pork chops from barrows and two from gilts. Participants answered a survey rating the tenderness, juiciness, flavour, and overall acceptability of each chop on an 8-point scale. Correlation analysis was conducted between carcass traits and pork eating quality attributes. For the descriptive analysis, classes (low, medium, and high) for carcass traits, Warner-Bratzler shear force (WBSF) and cooking loss were created based on our consumer responses dataset for palatability attributes. No significant correlations (P > 0.05) were observed between carcass traits and pork eating quality traits. Tenderness and overall acceptability were negatively correlated (P < 0.05) with cooking loss and WBSF. Loin intramuscular fat (IMF) content showed a weak negative correlation (P < 0.05) with WBSF and cooking loss. Consumers rated chops from the high and medium/high backfat thickness and loin IMF classes slightly higher for tenderness and juiciness, respectively. Additionally, chops from the low and/or medium WBSF and cooking loss classes received slightly higher scores for tenderness and juiciness than pork chops in the high classes. In conclusion, the study indicated that carcass traits had minimal impact on overall acceptability of pork by consumers.

Effects of crude protein and non-essential amino acids on growth performance, blood profile, and intestinal health of weaned piglets.

This study investigated the effect of crude protein (CP) and non-essential amino acid (NEAA) supplementation on the growth performance, blood profile, intestinal morphology, mRNA relative abundance of inflammatory and antioxidant markers, and tight junction proteins in piglets over the first 2 weeks after weaning. Ninety 21-day-old piglets (7.55 ± 0.72 kg) were assigned in a randomized block design to one of three dietary treatments: (1) high CP, a diet with 24% CP; (2) low CP, a diet with 18% CP; and (3) low CP + NEAA, a diet with 18% CP supplemented with 5 g/kg Arg (L-arginine; purity >99%) and 10 g/kg Glu + Gln (minimum 10% L-glutamine and minimum 10% L-glutamate). Piglets were fed with corn-soybean meal basal diets in a 14-day trial. There was an improvement (p < 0.05) in the feed conversion ratio of piglets fed the high-CP diet compared to treatments with low CP or low CP + NEAA. Serum urea nitrogen was higher (p < 0.05) in piglets fed high CP compared to other dietary treatments. In the duodenum, the villus height of animals fed the low-CP + NEAA diets was greater (p < 0.05) than those fed with the high- and low-CP diets. The goblet cell proportion of piglets fed low CP + NEAA or high CP was higher (p < 0.05) compared to low CP. In the jejunum, the crypt depth of the piglets with the high-CP dietary treatment was greater (p < 0.05) in comparison with low CP + NEAA. In the jejunum, IFN-γ mRNA expression was higher (p < 0.05) in animals fed the high-CP diets compared to other dietary treatments. However, superoxide dismutase and occludin mRNA expression were higher (p < 0.05) in animals fed low CP + NEAA than in piglets on the high-CP diets. In the ileum, the number of Peyer's patches in piglets fed high CP was higher (p < 0.05) compared to other dietary treatments. In conclusion, the high-CP diet (24% CP) improves the feed conversion of piglets in the first 2 weeks after weaning compared to the low-CP diet (18% CP) supplemented or not with NEAA. However, the low-CP diet supplemented with NEAA (Arg, Gln, and Glu) improves intestinal health in piglets by promoting greater villus height and proportion of goblet cells in the duodenum, reducing jejunal crypt depth, and reducing Peyer's number patches in the ileum. In addition, piglets that received the low-CP + NEAA diet showed an increase in superoxide dismutase and occludin and a lower expression of IFN-γ mRNA.

Effect of antibiotics and low-crude protein diets on growth performance, health, immune response, and fecal microbiota of growing pigs.

This study aimed to investigate the effects of diets with and without antibiotics supplementation and diets with 18.5% and 13.0% crude protein (CP) on growth performance, carcass characteristics, disease incidence, fecal microbiota, immune response, and antioxidant capacity of growing pigs. One hundred and eighty pigs (59-day-old; 18.5 ±â€…2.5 kg) were distributed in a randomized complete block design in a 2 × 2 factorial arrangement, nine replicates, and five pigs per pen. The factors were CP (18.5% or 13.0%) and antibiotics (none or 100 mg/kg tiamulin + 506 mg/kg oxytetracycline). Medicated diets were fed from days 59 to 73. After that, all pigs were fed their respective CP diets from 73 to 87 days. Data were analyzed using the Mixed procedure in SAS version 9.4. From days 59 to 73, pigs fed antibiotics diets had higher (P < 0.05) average daily feed intake (ADFI), average daily weight gain (ADG), gain to feed ratio (G:F), compared to the diets without antibiotics. From days 73 to 87 (postmedicated period), any previous supplementation of antibiotics did not affect pig growth performance. Overall (days 59 to 87), pigs-fed antibiotics diets had higher (P < 0.05) G:F compared to pigs-fed diets without antibiotics. In all periods evaluated, pigs fed 18.5% CP diets had higher (P < 0.05) ADG and G:F compared to pigs fed 13.0% CP. Pigs fed the 13.0% CP diets had lower (P < 0.05) fecal score and diarrhea incidence than those fed 18.5% CP. Pigs fed 18.5% CP diets had improved (P < 0.05) loin area compared to pigs-fed diets with 13.0% CP. At 66 days of age, pigs-fed antibiotics diets had lower (P < 0.05) alpha diversity estimated with Shannon and Simpson compared to the pig-fed diets without antibiotics. At family level, pigs fed 18.5% CP diets had higher (P < 0.05) relative abundance of Streptococcaceae, and lower (P < 0.05) relative abundance of Clostridiaceae at days 66 and 87 compared with pigs fed 13.0% CP. Pigs-fed antibiotics diets had lower (P < 0.05) immunoglobulin G and protein carbonyl concentrations at day 66 compared to the pigs-fed diets without antibiotics. The reduction of dietary CP from 18.5% to 13.0% reduced the growth performance and loin muscle area of growing pigs, although it was effective to reduce diarrhea incidence. Antibiotics improved growth performance, lowered diarrhea incidence, improved components of the humoral immune response, and reduced microbiota diversity. However, in the postmedicated period, we found no residual effect on the general health of the animals, and considering the overall period, only G:F was improved by the use of antibiotics.

Dietary antibiotics have been used in pig farming practices to avoid health problems and improve animal growth performance. However, their use in production animals is considered a global health challenge, due to its association with selection of resistance in zoonotic bacteria. Another negative impact of pig farming that has gained attention is related to environmental pollution due to the excretion of nitrogenous compounds. Reducing dietary crude protein content has become a goal in the pig feed industry due to the limited availability and high cost of dietary protein sources, as well as the aim of enhancing gut health in pigs. Thus, the aim of this study was to investigate the effects of diets with and without antibiotics supplementation and diets with 18.5% and 13.0% crude protein for pigs. The reduction of dietary crude protein in this study reduced growth performance, although it was effective to reduce diarrhea incidence. Antibiotics improved growth performance, positively affected the overall health of animals, and reduced microbiota diversity. However, during the postmedicated period, we found no residual effect on the general health of the animals, and considering the overall period, only gain to feed ratio was improved by the use of antibiotics.

Performance, Carcass Traits, Pork Quality and Expression of Genes Related to Intramuscular Fat Metabolism of Two Diverse Genetic Lines of Pigs.

We aimed to evaluate the performance, carcass and pork quality traits, as well as the mRNA expression of genes related to intramuscular fat deposition in female pigs from different genetic lines. A total of eighteen female pigs (Large White × Landrace × Duroc × Pietrain) × (Large White × Landrace) (Hybrid) averaging 88.96 ± 3.44 kg in body weight and twelve female pigs (Duroc) × (Large White × Landrace) (Duroc) averaging 85.63 ± 1.55 kg in body weight were assigned to a completely randomized design experimental trial that lasted 45 days. Pigs from both genetic lines received the same diet, which was initially adjusted for their nutritional requirements from 0 to 17 days of age and subsequently adjusted for nutritional requirements from 17 to 45 days of age. The performance of pigs did not differ among groups (p > 0.05). Duroc pigs showed a lower backfat thickness (p < 0.03) and greater intramuscular fat content (p < 0.1). A greater mRNA expression of the peroxisome proliferator-activated receptor gamma gene (PPARγ, p = 0.008) and fatty acid protein translocase/cluster differentiation (FAT/CD36, p = 0.002) was observed in the Longissimus dorsi muscle of Duroc pigs. Similarly, a greater expression of PPARγ (p = 0.009) and FAT/CD36 (p = 0.02) was observed in the Soleus muscle of Duroc pigs. Overall, we observed that despite the lack of differences in performance between the genetic groups, Duroc pigs had greater intramuscular fat content than hybrid pigs. The increased intramuscular fat content was associated with an increase in the mRNA expression of key transcriptional factors and genes encoding enzymes involved in adipogenesis and lipogenesis in glycolytic and oxidative skeletal muscle tissues.

Effects of feeding ractopamine hydrochloride with or without supplemental betaine on live performance, carcass and meat quality traits, and gene expression of finishing pigs.

The objective of this study was to evaluate the effects of ractopamine and betaine, supplemented alone or in combination, on live performance, carcass and meat quality traits, and gene expression (in both skeletal muscle and subcutaneous adipose tissue) of finishing pigs. Seventy-two pigs averaging 89.0 ± 3.44 kg were assigned to a control diet (CTRL-without ractopamine and betaine); CTRL+20 mg/kg ractopamine (RAC); CTRL+2.5 g/kg betaine (BET); or RAC + 2.5 g/kg betaine (RAC + BET). Pigs fed RAC and RAC + BET had greater average daily gain and carcass yield compared to CTRL. Pigs fed RAC, BET, and RAC + BET had greater loin muscle area, while backfat thickness was lower in pigs fed RAC + BET compared to CTRL. Pork from BET had lower shear-force and greater intramuscular fat content compared to CTRL. Regarding adipose tissue, RAC and BET increased expression of genes related to lipolysis and ß-oxidation. These data indicate that performance and carcass traits of pigs can be improved with ractopamine, whereas betaine (when fed independently from ractopamine) increased the loin muscle area and pork quality.

Effect of amino acid blend as alternative to antibiotics for growing pigs.

This study aimed to evaluate the effect of supplementing arginine (Arg) + glutamine (Gln) replacing antibiotics on performance, immune response, and antioxidant capacity of pigs in the growing phase. One hundred fifty 63-d-old pigs with initial body weight (BW) of 25.0 ± 1.46 kg were distributed in a randomized block design, with three treatments and ten replicates. The three diets were control; antibiotic, control + 100 mg/kg tiamulin and 506 mg/kg oxytetracycline; amino acid, control + 10 g/kg Arg and 2 g/kg Gln. Dietary treatments were fed from 63 to 77 d. Following the treatment period, all pigs were fed the control diet from 77 to 90 d. Data were analyzed using GLIMMIX and UNIVARIATE in SAS 9.4. From 63 to 70 d, pigs fed diets with antibiotics had improved (P < 0.05) average daily feed intake, average daily weight gain (ADG), gain to feed ratio (G:F), and 70-d BW compared to those fed control or amino acid diets. From 70 to 77 d, including antibiotics in the diet increased (P < 0.05) ADG and 77-d BW. From 77 to 90 d, pigs fed control or amino acid diets had greater (P < 0.05) ADG than those fed an antibiotic diet. From 63 to 90 d, although pig performance was not affected (P > 0.05), growth curve of pigs fed the antibiotic diets was different (P < 0.05) from those fed the control and amino acids diets. At 70 d, serum tumor necrosis factor-α and diamine oxidase (DAO) were lower (P < 0.05) in pigs fed the antibiotic diet than the control diet, and pigs fed the amino acid diet had intermediate results. Ferric reducing antioxidant power (FRAP) was lower (P < 0.05) in pigs fed the amino acid diet than the antibiotic diet, and pigs fed the control diet had intermediate results. Serum immunoglobulin A was lower (P < 0.05) in pigs fed the antibiotic diet. At 77 d, DAO and serum immunoglobulin G were lower (P < 0.05) in pigs fed the antibiotic diet. FRAP was lower (P < 0.05) in pigs fed the amino acid and control diets. Serum malondialdehyde was higher (P < 0.05) in pigs fed the amino acid diet than those fed the control diet, and pigs fed the antibiotic diet had intermediate results. At 90 d, antibiotics or amino acids did not affect (P > 0.05) serum parameters. Amino acid blend supplementation at the selected doses in this study did not positively affect growing pigs. Although from 63 to 77 d, antibiotics improved performance, when considering the overall study period, growing pigs did not benefit from a diet containing antibiotics.

Dietary antibiotics have been used in pig farming practices to avoid health problems, improving animal growth performance. However, antimicrobial resistance due to the use of antibiotics in farms is considered to be a global health challenge. Arginine and glutamine are amino acids with potential to improve gut health, immune function, and growth performance. Thus, the study aimed to evaluate the supplementation of those amino acids as an alternative to the use of dietary antibiotic for pigs. Moreover, after a 14-d treatment phase, we still monitor the pigs to evaluate the carryover effects of the antibiotics and amino acids. Amino acid supplementation at the selected doses in this study did not positively affect pigs. Although during the treatment phase, antibiotics improved performance, when considering the overall study period, pigs did not benefit from a diet containing antibiotics. Thus, antibiotics caused transient alterations in pig performance and should be further investigated, potentially guiding future research on its use and alternative technologies.

L-Arginine Supplementation for Nulliparous Sows during the Last Third of Gestation.

We evaluated the effects of L-arginine supplementation during the last third of gestation on molecular mechanisms related to skeletal muscle development of piglets and litter traits at birth. Twenty-three nulliparous sows averaging 205.37 ± 11.50 kg of body weight were randomly assigned to the following experimental treatments: control (CON), where pregnant sows were fed diets to meet their nutritional requirements; arginine (ARG), where sows where fed CON + 1.0% L-arginine. Skeletal muscle from piglets born from sows from ARG group had greater mRNA expression of MYOD (p = 0.043) and MYOG (p ≤ 0.01), and tended to present greater mRNA expression (p = 0.06) of IGF-2 gene compared to those born from CON sows. However, there were no differences (p > 0.05) in the histomorphometric variables of fetuses' skeletal muscle. The total weight of born piglets, total weight of born alive piglets, piglet weight at birth, coefficient of variation of birth weight, and the incidence of intrauterine growth restriction (IUGR) piglets did not differ between groups. No stillborn piglets (p < 0.01) were verified in the ARG sows compared to CON group. The blood levels of estradiol (p = 0.035) and urea (p = 0.03) were higher in ARG sows compared to those from the CON group. In summary, our data show that arginine supplementation of nulliparous sows at late gestation enhance mRNA expression of key myogenic regulatory factors, which likely contribute to improve animal growth rates in later stages of development.

Dietary supplementation of chromium for finishing pigs / Suplementação de cromo na dieta de suínos em terminação

ABSTRACT: Increasing fat deposition and feed conversion ratio over the days in finishing phase directly influence pork quality and productive profitability. Nonetheless, the slaughter of heavier pigs can result in benefits for the slaughterhouse due to dilution of production and processing costs, as well as economic benefits for the pig producer resulting from the dilution of production costs. Therefore, dietary supplementation of chromium for finishing pigs of high lean-genotypes is a strategy to increase lean tissue accretion and minimize fat deposition, reflecting positively on growth performance. This review discussed recent studies results and mechanisms of action of this modifier of performance and carcass a traits in finishing pigs. Chromium increases the insulin action, facilitating insulin binding to the receptors on cell membrane. As a result, insulin-sensitive cells uptake more glucose, which will be later converted into energy. This additional energy is use to increase protein synthesis, thereby increasing the amount of lean tissue and reducing fat content in the carcass, without altering protein intake by pigs. Chromium also reduces lipid oxidation rate maintaining meat quality for longer period. In conclusion, dietary Cr supplementation for finishing pigs have shown that 0.2 mg/kg of organic Cr sources for pigs from ~60 kg until the slaughter can improve growth performance, lean gain and reduce fat content in carcass. However, the development of nanotechnology has allowed the use of inorganic Cr source at 0.2 mg/kg of inclusion, leading to improve the growth performance and carcass traits of finishing pigs.

RESUMO: O aumento na deposição de gordura e da conversão alimentar durante a fase de terminação são fatores que implicam diretamente na qualidade da carne e também na rentabilidade da cadeia produtiva. Apesar disso, o abate tardio dos suínos pode resultar em benefícios para o frigorífico, pela redução dos custos operacionais por suíno abatido e melhor utilização dos equipamentos, bem como vantagens econômicas para o produtor resultantes da diluição dos custos de produção. Portanto, a suplementação de cromo na ração de suínos de linhagens com maior potencial para deposição de músculo, é uma estratégia para aumentar a deposição de tecido magro e minimizar a deposição de gordura, refletindo positivamente no desempenho. Em vista disso, objetivou-se com este trabalho, apresentar e discutir os mecanismos de ação, finalidades e resultados recentes de estudos na literatura sobre a suplementação desse modificador de carcaça na ração de suínos em terminação. O principal papel do cromo é potencializar a ação da insulina, facilitando a ligação entre a insulina e os seus receptores na membrana celular. Com isso, as células sensíveis à insulina captam maior quantidade de glicose, que posteriormente serão convertidas em energia. Essa energia adicional pode ser utilizada para aumentar a síntese proteica, aumentando assim, a quantidade de carne magra e reduzindo o teor de gordura na carcaça, sem alterar o consumo de proteína pelos animais. O cromo também diminui a taxa de oxidação lipídica, mantendo a qualidade da carne por mais tempo. Em conclusão, a suplementação dietética de Cr para suínos em terminação mostra que 0,2 mg/kg de fontes orgânicas de Cr para suínos de ~ 60 kg até o abate podem melhorar o desempenho, ganho de massa magra e reduzir o teor de gordura na carcaça. No entanto, o desenvolvimento da nanotecnologia tem permitido o uso de fonte inorgânica de Cr na dose de 0,2 mg/kg de inclusão, melhorando o desempenho e as características de carcaça de suínos em terminação.

Effects of crude protein and lactose levels in diets on growth performance, intestinal morphology, and expression of genes related to intestinal integrity and immune system in weaned piglets.

To evaluate the effects of crude protein (CP) and lactose (LAC) for weaned piglets on performance, intestinal morphology, and expression of genes related to intestinal integrity and immune system, 144 piglets with initial weight 7.17 ± 0.97 kg were allotted in a randomized design, in a 2 × 3 factorial arrangement (20.0% and 24.0% CP and 8.0%, 12.0%, and 16.0% LAC) with eight replicates. Piglets fed 20.0% CP had greater weight gain and feed intake. Including 12.0% LAC in the 20.0% CP diet provided higher villous height in the duodenum than 8.0% LAC, and 12.0% or 16.0% LAC in the 24.0% CP diet resulted in higher villous height in the jejunum and ileum, and higher villi/crypt ratio in the ileum than 8.0% LAC. No effects of CP and LAC on interleukin-1ß and tumor necrosis factor-α mRNA were observed. The 16.0% LAC diet provided higher gene expression of transforming-ß1 growth factor. Feeding 20.0% CP resulted in better performance than 24.0% CP. The 12.0% LAC diet promoted greater genetic expression of occludin and zonula occludens. Including 12.0% LAC in the diet may improve intestinal epithelial morphology and integrity, and these improvements are more evident when piglets are fed diets with 24.0% CP.

l-Arginine supplementation of gilts during early gestation modulates energy sensitive pathways in pig conceptuses.

Dietary l-arginine (ARG) supplementation has been studied as a nutritional strategy to improve reproductive performance of pregnant sows, since arginine is a conditionally essential amino acid. However, reports addressing the molecular mechanisms that mediate supplementation effects on embryos and fetuses development are still scarce. Therefore, we aimed to evaluate the effects of 1.0% ARG supplementation of commercial pregnant gilts on genes and proteins from energy metabolism and antioxidant defense pathways in embryos and fetuses. We also analyzed the global transcriptome profile of 25- and 35-day-old conceptuses. At Day 25, we observed a lower abundance of phospho-AMP-activated protein kinase (phospho-AMPK) protein and downregulation of oxidative phosphorylation system genes in ARG embryos. On the other hand, ARG fetuses showed greater expression of MLST8 and lower expression of MTOR genes, in addition to lower abundance of phospho-AMPK and phospho-mammalian target of rapamycin (phospho-mTOR) proteins. Transcriptome analysis at Day 35 did not present differentially expressed genes. For the antioxidant defense pathway, no differences were found between CON and ARG conceptuses, only trends. In general, supplementation of gilts with 1.0% ARG during early gestation affects energy sensitive pathways in 25- and 35-day conceptuses; however, no effects of supplementation were found on the antioxidative defense pathway in 25-day embryos.

Variability of piglet birth weights: A systematic review and meta-analysis.

The objective of the study was to evaluate the effects of litter size and supplementation of functional amino acids on the piglet birth weight variability through of a systematic review and meta-analysis. PubMed, ISI Web of Science, Science Direct, Scopus and SciELO are the main used databases and were searched in January 2019 by using the following keywords and their combinations: within-litter birth, weight variability, piglets, litter size, sow, amino acids, gestation, uniformity, CV and/or SD. Of the 64 pre-selected articles, only articles presenting the coefficients of variation and/or standard deviations according to the litter size and different levels of amino acid supplementation in the sow diets during gestation were selected. The average birth weights of total and live piglets were 43% lower in litters from sows with high prolificacy than those from sows with low prolificacy. The weight variability was affected by high prolificacy sows, with increases of 4.04% and 4.54% in the coefficients of variation of total and born alive piglets respectively (p = .074; p = .009). The standard deviation increased by 180 g in born alive piglets to high prolificacy sows. The coefficients of variation of total and live piglets born from high prolificacy sows showed an increase of 4.04% and 4.54% respectively (p = .07; p < .05). There was a tendency for reduced weight variability with amino acids supplementation when considering the standard deviation of total born (p = .072). However, reproductive performance was not significantly influenced (p > .05). In conclusion, the average litter weight and the number of piglets born influence weight variability. Amino acids supplementation may reduce the birth weight variability between piglets. However, this effect depends on the amino acid used, the levels of supplementation and on other factors not completely addressed in this study. Thus, more research is necessary to fully elucidate this topic.

Guanidinoacetic acid supplementation on growth performance and molecular mechanisms of lean mass gain in nursery pigs / Suplementação de ácido guanidinoacético no desempenho e mecanismo moleculares de ganho de massa magra em leitões

ABSTRACT: The objective with the present study was to evaluate the effect of guanidinoacetic acid (GAA) on the growth performance of nursery piglets as well as a possible molecular mechanism of action on lean mass gain. Seventy-two pigs, weaned at 21 d, weighing 6.80 ± 1.2 kg were distributed in a completely randomized design into one of three dietary treatments (control, control + 1.2 g/kg GAA or control + 2.4 g/kg GAA) and 8 replicates per treatment. The control diet was an animal protein-free diet based on corn and soybean meal. Body weight, average daily weight gain, average daily feed intake and feed efficiency were evaluated at 35, 49, and 56 days. At the end of the experiment, one animal per pen was slaughtered and samples of the vastus lateralis muscle were collected for RT-qPCR and protein abundance analysis. Overall (from 21 to 56 d), GAA supplementation improved feed efficiency (P < 0.03). Skeletal muscle of pigs fed with GAA diet had greater mRNA expression of Akt (P < 0.04) and RPS6KB2 (P<0.01). In conclusion, supplementation with 2.4 g/kg GAA to nursery piglets improves feed efficiency and activates molecular mechanisms important to lean mass gain.

RESUMO: O objetivo do presente estudo foi avaliar o efeito do ácido guanidinoacético (GAA) no desempenho de leitões, bem como um possível mecanismo de ação molecular no ganho de massa magra. Setenta e dois leitões, desmamados aos 21 dias, pesando 6,80 ± 1,2 kg, foram distribuídos em um delineamento inteiramente casualizado com três tratamentos dietéticos (controle, controle + 1,2 g / kg ou controle + 2,4 g / kg GAA) e 8 repetições por tratamento. A dieta controle não continha proteína animal e foi formulada a base de milho e farelo de soja. O desempenho dos animais foi avaliado aos 35, 49 e 56 dias. Ao final do experimento, um animal por unidade experimental foi abatido e amostras do músculo Vastus lateralis foram coletadas para análise de RT-qPCR e abundância de proteínas. A suplementação com GAA melhorou a eficiência alimentar (P<0,03) aos 56 dias. O músculo dos leitões suplementados apresentou maior expressão de mRNA de Akt (P<0,04) e RPS6KB2 (P <0,01). Em conclusão, a suplementação de 2,4 g / kg de GAA em leitões (21 a 56 d) melhora a eficiência alimentar e ativa mecanismos moleculares importantes para o ganho de massa magra.

Dietary L-arginine supplementation during early gestation of gilts affects conceptuses development.

l-arginine supplementation of sows has led to improvement of reproductive performance, but the mechanisms responsible for the positive effects of arginine during gestation on conceptuses survival and development are still poorly understood. Thus, we aimed to evaluate effects of 1.0% l-arginine supplementation (ARG) on phenotypic traits of commercial gilts, embryos and fetuses, concentration of gilts' blood metabolites, expression of developmental and cellular apoptosis genes in conceptuses of 25 and 35 days. At 25 days, IGF1 gene was more expressed in embryos from ARG than in embryos from control gilts (CON) (P = 0.05). At this same gestational age, ARG embryos tended to be heavier compared to CON (P = 0.07) and ARG gilts showed a trend to have a greater arginine concentration in blood plasma (P = 0.06). However, at 35 days of gestation, arginine concentration in blood plasma of ARG gilts tended to be lower compared to CON (P = 0.06) and ARG fetuses showed smaller cephalic-caudal length (P = 0.05). These results indicate that duration of supplementation is determinant for arginine effects, not only on the females performance but also on the conceptuses, since supplementation upregulated IGF1 expression at 25 days, in addition to the reduction of cephalic-caudal length of 35-day fetuses.

Effectiveness of citrulline and N-carbamoyl glutamate as arginine precursors on reproductive performance in mammals: A systematic review.

The use of functional nutrients has been proposed to reduce the occurrence of intrauterine growth retardation in animals at birth in several mammalian species. The objective of this study was to verify the effectiveness of citrulline and N-carbamylglutamate (NCG) dietary supplementation as arginine precursors for mammalian species, and the effects on fetal development through a systematic review. The search for studies was performed during August 2018 in the PubMed, ISI Web of Science, Science Direct, and Scopus databases. The literature search was conducted using "arginine precursor", "citrulline", or "N-carbamylglutamate" as keywords, combined with "gestation", "pregnancy", "fetus", "newborn", or "reproduction". Studies in which arginine precursors were evaluated in gestating mammals and their effects on parameters related to the intrauterine development of the conceptus were selected. Of 1,379 articles, 18 were selected, primarily based on the title and the abstract. Supplementation with NCG (0.5 g to 2 g/kg of feed) increased maternal plasma arginine concentrations in all studies that evaluated this variable. Fetal number increased in 55.56% of the studies that evaluated it, and fetal weight increased in the majority (62.5%) of the studies evaluating this variable. By supplementing citrulline, only fetal weight was improved, with an increase in maternal plasma arginine in 40% of the studies. In conclusion, N-carbamoyl glutamate seems to be an arginine precursor more effective than L-citrulline during gestation; however, both precursors, beside L-Arginine, should be evaluated in similar conditions to confirm the existence of specific particularities such as periods and levels of supplementation, which need to be considered for different species of animals. The supplementation of NCG increases arginine concentrations in maternal plasma, thus improving mammalian reproductive efficiency and fetal development, mainly by promoting higher birth weight.

Alternatives to antibiotics in diets of weaned piglets / Alternativas de antibióticos para leitões desmamados

ABSTRACT: This experiment was conducted to evaluate the effect of growth promoter additives an alternative to antibiotics on performance, intestinal morphology and on microbiota of 21-to-35-day-old piglets. A total of 160 commercial crossbred piglets (males and females) with initial weight of 6.10±0.709kg were allotted in a completely randomized design with five treatments: Basal diet - Negative Control (NC); Basal diet + antibiotic (PC); Basal diet + mannanoligosaccharides (MOS); Basal diet + organic acids (OA), Basal diet + mannanoligosacharides + organic acids (MOS+OA), eight replicates and four piglets per experimental unit. The inclusion of additives in the diets had no effect (P>0.05) on the final average weight of piglets. Similarly, no effects (P<0.05) were observed on average daily feed intake and on average daily weight gain. The feed conversion improved (P<0.01) with the inclusion of additives in the diets compared to piglets fed with the NC. There was no effect (P>0.05) of the dietary additives on intestinal morphology and microbiota composition (enterobacteria and lactobacilli). Use of antibiotics, prebiotics, organic acids or prebiotics associated with organic acids in the diet improves feed conversion of piglets from 21 to 35 days of age. The additives have no major effects on piglets' intestinal morphology and microbiota.

RESUMO: O experimento foi conduzido com o objetivo de avaliar o efeito de aditivos promotores de crescimento como alternativa ao uso de antibióticos no desempenho, na morfologia intestinal e na microbiota de leitões dos 21 aos 35 dias de idade. Um total de 160 leitões híbridos comerciais, machos castrados e fêmeas, com peso inicial de 6,10±0,709kg, foram distribuídos em delineamento inteiramente casualizado, com cinco tratamentos: Ração basal - Controle Negativo (CN); Ração basal + antibiótico (CP); Ração basal +mananoligossacarídeo (MOS); Ração basal + ácido orgânico (AO); Ração basal + mananoligossacarídeo + ácido orgânico (MOS+AO), oito repetições e quarto animais por unidade experimental. A inclusão dos aditivos não teve efeito (P>0,05) no peso médio final dos leitões. Da mesma forma, não foram observados efeitos (P>0,05) dos aditivos no consumo de ração médio diário. A conversão alimentar melhorou (P<0,01) com a inclusão dos aditivos na ração comparados com os animais alimentados com a ração CN. Não houve efeito (P>0,05) dos aditivos na morfologia do epitélio intestinal e na composição da microbiota (enterobactérias e lactobacilos). A utilização de antibiótico, probióticos, ácidos orgânicos ou de probióticos associado com ácidos orgânicos na ração melhora a conversão alimentar de leitões, dos 21 aos 34 dias de idade. Os aditivos não tiveram efeitos na morfologia intestinal e na microbiota dos leitões.

Prebiotic and antimicrobials on performance, carcass characteristics, and antibody production in broilers / Prebiótico e antimicrobianos sobre o desempenho, características de carcaça e produção de anticorpos em frangos de corte

ABSTRACT: To evaluate the effect of supplementation with mannan oligosaccharides, avilamycin and halquinol, alone or in combination, on the performance, carcass characteristics and antibody production in broilers (1-49 days old), male broiler chicks (n=1440; Cobb 500; one day old) were housed and distributed into a completely randomized design into six treatments (eight replicates; 30 animals per pen). To produce the experimental diets, three types of performance enhancer additives were used. Halquinol (HAL), avilamycin (AVI) and mannan oligosaccharides (MOS) were included (alone or in combination) in the basal diet (instead of corn starch). Effects of diet were observed on results of animal performance in the period 1-21 and 1-42 days old. Broilers fed with a diet without growth promoter showed lower weight gain in relation to those fed with diets with antimicrobials, MOS or a combination of them. In the period 1-49 days old, feed conversion increased in broilers fed with rations without promoter. At the end of the experimental period no influence of diets was observed on the carcass yield and cuts, and titles of specific antibodies to avian infectious bronchitis. The use of MOS and/or antimicrobials (AVI or HAL), alone or in combination, improves feed conversion of broilers reared until 49 days of age.

RESUMO: Para avaliar o efeito da suplementação com mananoligossacarídeo, avilamicina e halquinol, isoladamente ou combinados, sobre o desempenho, características de carcaça e produção de anticorpos em frangos de corte (1-49 dias de idade), pintos machos de corte (n=1440; linhagem Cobb 500; idade: um dia) foram alojados e distribuídos em delineamento experimental inteiramente casualizado com seis tratamentos (oito repetições; 30 animais por unidade experimental). Para compor as rações experimentais, três tipos de aditivos melhoradores de desempenho foram usados. Halquinol (HAL), avilamicina (AVI) e mananoligossacarídeo (MOS) foram incluídos (isoladamente ou em associação) na ração basal (em substituição ao amido de milho). Foi observado efeito das rações sobre os resultados de desempenho dos animais no período 1-21 e 1-42 dias de idade. As aves alimentadas com ração sem melhorador de desempenho apresentaram menor ganho de peso em relação àquelas que consumiram rações com antimicrobianos, MOS ou uma combinação deles. No período 1-49 dias de idade, a conversão alimentar aumentou nas aves alimentadas sem melhorador de desempenho. No final do período experimental, não foi observado efeito das rações sobre o rendimento de carcaça e cortes e títulos de anticorpos específicos contra bronquite infecciosa aviária. A utilização de mananoligossacarídeo e/ou antimicrobianos (avilamicina e halquinol), isoladamente ou combinados, melhora a conversão alimentar de frangos de corte criados até 49 dias de idade.

Phosphorus on performance, hematological, biochemical, and bone parameters of growing pigs / Influência de fósforo disponível sobre parâmetros de desempenho, hematológicos, bioquímicos e ósseos de suínos em crescimento

ABSTRACT: The purpose of this study was to assess the levels of available phosphorus (AP) in the diet of growing pigs selected for lean deposition on the hematological, biochemical, and bone performance parameters. A total of 64 commercial hybrid pigs (32 castrated males and 32 females; mean initial weight: 23.31±2.4kg; age: 55-90 days) were used. Animals were distributed into a randomized block design with four treatments, eight replicates, and two animals (one male and one female) per experimental unit. The treatments consisted of a basal diet and another three diets, which were obtained by supplementing the basal diet with dicalcium phosphate replacing the inert phosphate, resulting in four diets with 0.100, 0.180, 0.260, and 0.340% of available phosphorus. The levels of available phosphorus quadratically influenced the daily weight gain, feed consumption, and feed conversion, which increased up to the estimated levels 0.331; 0.330, and 0.302% of available phosphorus. Levels of phosphorus showed no influence on the hematological parameters, which remained within the reference values. Levels of available phosphorus increased linearly the ash and phosphorus contents in the metacarpal bone and decreased linearly the alkaline phosphatase activity. Levels of available phosphorus (0.331 and 0.302%, corresponding to a daily intake of 5.73 and 5.18g d-1) provided respectively the best results for weight gain and feed conversion in pigs with high genetic potential, without change in hematological parameters.

RESUMO: O objetivo deste estudo foi avaliar níveis de fósforo disponível em rações para suínos em crescimento, selecionados para deposição de carne, sobre os parâmetros de desempenho, hematológico, bioquímico e ósseo. Foram usados 64 suínos híbridos comerciais (32 machos castrados e 32 fêmeas; peso médio inicial: 23,31±2,4 kg; idade: 55-90 dias). Os animais foram distribuídos em blocos casualizados com quatro tratamentos, oito repetições e dois animais (um macho e uma fêmea) por unidade experimental. Os tratamentos consistiram em uma ração basal e em outras três rações, obtidas pela suplementação da ração basal com fosfato bicálcico em substituição ao inerte, resultando em quatro rações com 0,100, 0,180, 0,260, 0,340% de fósforo disponível. Os níveis de fósforo disponível influenciaram de forma quadrática o ganho de peso diário, o consumo de ração e a conversão alimentar, que aumentaram até o nível estimado de 0,331, 0,330 e 0,302% de fósforo disponível, respectivamente. Não houve influência dos níveis de fósforo sobre os parâmetros hematológicos que permaneceram dentro dos valores de referência. Os níveis de fósforo disponível influenciaram de forma linear crescente os teores de cinzas e fósforo no metacarpo dos animais e, de forma decrescente, a atividade da fosfatase alcalina. Os níveis de fósforo disponível, de 0,331 e 0,302%, correspondentes ao consumo diário de 5,73 e 5,18g d-1, proporcionaram, respectivamente, os melhores resultados de ganho de peso e conversão alimentar em suínos de alto potencial genético, sem alterações nos parâmetros hematológicos.

Níveis de fitase sobre o desempenho, parâmetros ósseos e bioquímicos de suínos alimentados com ração de origem vegetal sem inclusão de fosfato bicálcico / Phytase levels on performance, bone and biochemical parameters of pigs fed with diet of vegetable origin without inclusion of dicalcium phosphate

Este estudo foi conduzido com o objetivo de avaliar os níveis de fitase em rações para suínos em crescimento selecionados para deposição de carne. Foram utilizados 64 suínos mestiços (32 machos castrados e 32 fêmeas), híbridos comerciais, com peso médio inicial de 23,311±2,254 kg, distribuídos em delineamento de blocos casualizados, com quatro tratamentos, oito repetições e dois animais (um macho e uma fêmea) por unidade experimental. Os tratamentos foram constituídos por uma ração controle de origem vegetal, sem inclusão de fosfato bicálcico e fitase, contendo 0,100% de fósforo disponível; e de outras três rações obtidas pela inclusão de 300, 600 e 1200 unidades de fitase (UFT kg-1) à ração controle. Os níveis de fitase influenciaram de forma linear o ganho de peso diário e consumo de ração, aumentando até o nível de 293 e 307 UFT kg-1 de ração, respectivamente, a partir do qual permaneceram em um platô. A conversão alimentar diminuiu até 255 UFT kg-1 de ração, a qual permaneceu em um platô. Os níveis de fitase não influenciaram os teores de cinzas e fósforo no metacarpo dos animais. Houve efeito linear decrescente dos tratamentos sobre o resultado bioquímico de fosfatase alcalina. Os melhores resultados de ganho de peso, consumo de ração e conversão alimentar foram obtidos, respectivamente, com os níveis de 293, 307 e 255 UFT kg-1 de ração, em suínos de alto potencial genético para deposição de carne na fase dos 55 aos 90 dias de idade.

This study was carried out to determine the phytase levels in diets for growing swine selected for meat deposition. Sixty-four crossbred swine (32 barrows and 32 females), with an average initial weight of 23.311±2.254 kg were distributed in a block design with four treatments and eight replications of two animals (one male and one female) each. The treatments consisted of a control diet with vegetables ingredients, without dicalcium phosphate and phytase inclusion, containing 0.100% available phosphorus and three other diets obtained by the inclusion of 300, 600 and 1200 phytase units (FTU kg-1) to the control diet. Levels of phytase influenced linearly the daily weight gain and feed intake, increasing to the level of 293 and 307 FTU kg-1 diet, respectively, from which remained on a plateau. Feed conversion ratio decreased to 255 FTU kg-1 diet, and remained on a plateau. Levels of phytase did not affect the levels of ash and phosphorus in animal bone. There was decreasing linear effect of treatments on the biochemical results of alkaline phosphatase. The best results in weight gain, feed intake and feed conversion were obtained, respectively, with levels of 293, 307 and 255 FTU kg-1 of feed for pigs of high genetic potential for lean deposition during the 55 to 90 days of age.