Post-weaning Period Research Articles

PSI-A-5 Effects of Birth Body Weight Classification on Heifer Growth, Dry Matter Intake, Feed Efficiency, and Grazing Performance

Abstract The objective was to evaluate the effect of birth body weight (BBW) classification on post-weaning growth, dry matter intake (DMI), feed efficiency, and grazing performance of fall-born crossbred heifers. Heifers were classified based on BBW as either light (LtBBW, < -0.5 SD from mean), average (AvgBBW, ± 0.5 SD from mean), or heavy (HvyBBW, > +0.5 SD from mean). Angus and Hereford-sired heifers (n = 153) from commercial Angus dams were utilized in the analysis. Heifers were early weaned at 82 ± 7 days of age. Post-weaning management strategy consisted of calves being kept in partially covered drylot pens and fed a high-energy grain diet (35% dried distillers grains with solubles, 30% whole shelled corn, 30% ground fescue hay, and 5% supplement) in GrowSafe bunks. During the post-weaning evaluation (initiated on day 1), heifer (168 ± 23 kg and 156 ± 7 days of age) DMI was collected for 56 days and body weights (BW) were collected every 14 days. Following the intake evaluation, heifers rotated daily for 166 days though 33 paddocks of 2.4 ± 0.5 hectares each and were weighed every 28 days. Data were analyzed using the MIXED procedure of SAS 9.4. As designed, birth body weight differed (P < 0.01) between classifications (27, 32, and 37 kg for LtBBW, AveBBW, and HvyBBW, respectively). Heifers classified as LtBBW were born earlier (P = 0.02) than AvgBBW and HvyBBW. Heifer BBW classification affected (P < 0.01) weaning weights; heifers classified as LtBBW and AvgBBW had lighter weaning weights than HvyBBW heifers. Birth weight category affected (P < 0.01) BW on days 1, 28, and 56. On day 1, heifers classified as LtBBW were the lightest, AvgBBW were intermediate, and HvyBBW were the heaviest; however, on days 28 and 56, heifers classified as LtBBW were lighter than AvgBBW and HvyBBW. Heifers classified as LtBBW and AvgBBW had less (P < 0.01) DMI and average daily gain (ADG) than HvyBBW during the post-weaning evaluation period. Gain to feed during post-weaning evaluation period was not affected (P = 0.94) by heifer BBW classification. Birth weight category affected (P < 0.01) BW during the grazing season on days 28, 56, 84, 113, 141, 168, 196, and 223. On days 84, 96, and 223, heifers classified as LtBBW were lighter than AvgBBW and HvyBBW; however, on days 113, 141, and 168, LtBBW were lightest, AvgBBW were intermediate, and HvyBBW were the heaviest. During the grazing period, ADG did not differ (P = 0.72) between BBW classifications. In conclusion heavy birth weight heifers had greater post-weaning DMI and ADG when fed a high grain diet; however, grazing ADG did not differ. Heavy birth weight heifers were heavier throughout the duration of the experiment.

118 Estimating the Net Energy Requirement of Piglets During the First Three Weeks Post-Weaning

Abstract Previous work has reported that piglets may be unable to increase feed intake to meet energy demands in low-energy diets, contrary to growing pigs. Indeed, poor feed intake in piglets occurs mainly during the first three weeks post-weaning. The approach, in this case, has been to increase the energy density of weaner diets to meet energy requirements even at reduced intakes. Studies estimating the net energy (NE) requirement in piglets in the immediate post-weaning period are lacking. Hence the objective of the present study was to evaluate the dietary NE required to optimize growth and feed efficiency in piglets during the first 21 d post-weaning. A total of 360 mixed-sex piglets (6.4 ± 0.24 kg) were housed with three pigs/pen and 24 pens/treatment (n = 24 pens) and were assigned to 1 of 5 dietary treatments in a dose-response arrangement for 21-d. The experimental diets were formulated to contain graded dietary NE levels (2,200, 2,300, 2,400, 2,500, and 2,600 kcal NE/kg). Diets were isonitrogenous and balanced for amino acids with a constant SID Lys/NE ratio of 1.25 across the treatments. The orthogonal polynomial contrast statement was used in a GLM model (PROC GLM, SAS studio) to determine the linear and quadratic effects of increasing dietary NE level on performance parameters. Results for the overall 21-d period indicated that, as dietary NE increased, average daily gain (ADG) increased linearly (P = 0.03). The average daily feed intake (ADFI) was not significantly (P = 0.157) affected by increasing dietary NE. The gain to feed (G:F) improved linearly as dietary NE increased (P = 0.008). Using the linear-breakpoint model (PROC NLIN), the NE estimated to maximize ADG at 305 g/day was 2,475 kcal NE/kg (P = 0.008). Similarly, for maximum G:F of 0.86 g/g, the linear breakpoint model estimated the NE requirement at 2460 kcal/kg (P = 0.02). No breakpoint was estimated for ADFI, but the model tended (P = 0.08) to show a linear increase in ADFI as NE increased. In summary, the results of this study highlight that, during the first three weeks post-weaning, feed intake of piglets may be more controlled by animal factors (e.g., gut capacity) and, to a lesser extent, energy concentration because feed intake was not affected by the dietary NE level in this study. Further, results show that ADG may be a more accurate measure of the impact of NE concentration than ADFI. In conclusion, dietary NE levels between 2,460 to 2,475 kcal/kg during the first three weeks post-weaning may be ideal to maximize growth performance, provided all other nutrients are not limiting.

32 Effect of Probiotics Supplementation Level on Growth Performance, Blood Parameters and Fecal Metabolites in Nursery Pigs

Abstract This experiment was conducted to evaluate the effects of dietary supplementation level of probiotics on growth performance, blood variables, and fecal metabolites in nursery pigs. Certain strains of Bacillus subtilis have been shown to reduce the incidence and severity of diarrhea and therefore improve growth performance of nursery pigs. A total of 54 newly weaned piglets were allotted to 3 treatments in 3 replicates with 6 pigs per pen based on body weight, gender, and breed for a 28-d feeding trial. Treatments were: 1) Control: no probiotics supplementation, 2) CERTILLUS 1x: probiotics supplementation at the recommended level, and 3) CERTILLUS 10x: probiotics supplementation at 10 times the recommended level. The CERTILLUS products consisted of two strains of Bacillus subtilis at a low and a high dose of 3.75 × 108 CFU/g and 3.75 × 109 CFU/g supplemented at 0.05% resulting in 1.875 × 105 CFU/g diet and 1.875 × 106 CFU/g diet for the 1x and 10x treatments, respectively. Corn-soybean meal-based diets were used for d 0-14 (Phase 1) and d 14-28 (Phase 2) postweaning. Body weight, blood glucose and creatinine, fecal short chain fatty acid (SCFA) and bile acid concentrations were measured at d 14 and 28 postweaning. Body weight at d 14 postweaning (P = 0.06; 11.98, 12.73, and 12.21 kg for the control, 1x, and 10x treatments, respectively) and average daily gain for d 0 to 14 postweaning (P < 0.05; 0.206, 0.259, and 0.222 kg/d, respectively) were greater in the 1x treatment than the control and 10x treatments although there was no significant difference in growth performance at d 28 postweaning. Blood glucose concentrations were greater in both probiotic treatments than the control treatment at d 14 postweaning (P < 0.05; 95.2, 111.7 and 114.3 mg/dL for the control, 1x, and 10x treatments, respectively). In the fecal SCFA concentrations, the butyrate concentrations were greater in the 1x treatment than the control and 10x treatments (P < 0.05; 36.17, 47.57, and 33.23 µmol/g feces for the control, 1x, and 10x treatments, respectively) and the acetate (120.02, 141.87, and 101.17 µmol/g feces, respectively), propionate (62.95, 71.42 and 55.27 µmol/g feces, respectively), and total SCFA (236.72, 282.23, and 205.80 µmol/g feces, respectively) concentrations were greater in the 1x treatment than the 10x treatment with the intermediate value in the control treatment (P < 0.05). There were no significant differences in fecal bile acid concentrations and blood creatinine concentrations at both d 14 and 28 postweaning. In conclusion, dietary probiotics supplementation to nursery diets at the recommended level could improve growth rate in the early postweaning period and increase fecal SCFA concentrations but not at a high level of supplementation.

314 Maxwell Lecture: Role of Amino Acids and Protein in Health-Challenged Nursery Pigs

Abstract The post-weaning period is a critical time in the life of a pig with both short- and long-term consequences for productivity and health. Nutrition has a vital role in this transition period and, as with swine production as a whole, the focus is largely on maximizing growth performance. However, feeding programs also need to account for immature and developing gastrointestinal and immune systems in the newly-weaned pig. In examining the impact of nutrition on gastrointestinal and immune health, it has become evident that protein and amino acids have a vital role. While protein and amino acids are needed to meet requirements for growth, excess protein can predispose pigs to post-weaning diarrhea, thought to be the result of fermentation of undigested protein and proliferation of enteric pathogens. In addition, the source of protein may also have a significant impact on performance and health of nursery pigs. Traditionally, amino acid requirements, and thus dietary inclusion, have been based on maximizing growth performance. It has become evident that the requirements of some amino acids may differ when based on development of the gastrointestinal tract and during times of immune stimulation, such as during disease challenge. The inclusion of some amino acids, such as methionine, threonine, and tryptophan, above the requirements for growth have been shown to improve performance, intestinal health, and immune status in weaned pigs under enteric pathogen challenge. Nursery diet formulations should account for the role of nutrients not only for maximizing growth performance but optimizing gastrointestinal health and immune status including adjustments to protein content and source and amino acid requirements.

Alfalfa intervention alters the colonization of rumen epithelial bacteria to promote rumen development and lamb health during early life

Understanding the rumen epithelial (RE) microbial community structure and population dynamics of young ruminant during development is fundamental in promoting the establishment of a well-developed rumen for animal health and production. In this study, 10-day-old Hu lambs were fed with milk replacer (B-10), milk replacer and starter (STA) or milk replacer and starter supplemented with alfalfa (S-ALF). The RE bacteria of lambs at d10, 17, 24, 38, 45 and 66 were assessed to characterize RE bacterial colonization during early life and its response to fiber intervention. In B-10 lambs, 434 operational taxonomic units (OTUs) belonging to 57 core genera were observed in the RE. A number of the fibrolytic bacteria (Butyrivibrio and unclassified Ruminococcaceae), the pectinolytic bacterium (Treponema), the protein and fat digester (p-75-a5), the short-chain fatty acids producers ([Eubacterium], Succiniclasticum, unclassified Succinivibrionaceae, and Clostridiales), and the non-fermentive bacterium (Mogibacterium) were induced by alfalfa intervention in the S-ALF group during preweaning period, which attributed to a more mature RE bacterial community. OTUs belonging to Butyrivibrio, Succiniclasticum, Bacteroidales, Desulfovibrio, Clostridiales, and Succiniclasticum induced by alfalfa intervention were positively correlated with rumen tissue genes involved in fatty acid metabolism, barrier function, and PI3K-Akt, FoxO, and calcium signaling pathways. During the postweaning period, the RE bacterial composition of STA group changed significantly, while the S-ALF group did not. Our results suggested that alfalfa induced changes in RE bacteria during preweaning period which was associated with rumen health. The findings provide guidance for improving rumen health by manipulating RE bacteria during early life.

Dietary Galactose Increases the Expression of Mitochondrial OXPHOS Genes and Modulates the Carbohydrate Oxidation Pathways in Mouse Intestinal Mucosa

BackgroundProlonged lactation provides substantial health benefits, possibly because of galactose as part of milk sugar lactose. Isocaloric replacement of dietary glucose [16 energy%(en%)] with galactose within a normal diet (64en% carbohydrates) during a 3-wk postweaning period provided substantial benefits on short- and long-term physiologic and metabolic parameters at the whole-body level and liver in female mice, which might be attributable to intestinal function. ObjectivesThis study aimed to investigate if partial dietary replacement of glucose with galactose alters intestinal metabolism underlying hepatic health effects. MethodsProximal intestinal mucosa gene profiles in female mice were analyzed using RNAseq technology, validated, and correlated with hepatic health parameters. ResultsTranscriptome analysis revealed that the presence of galactose primarily affected the pathways involved in energy metabolism. A consistently higher expression was observed in the subset of mitochondrial transcripts (78 of 80, all P.adj < 0.1). Oxidative phosphorylation (OXPHOS) represented the most upregulated process (all top 10 pathways) independent of the total mitochondrial mass (P = 0.75). Moreover, galactose consistently upregulated carbohydrate metabolism pathways, specifically glycolysis till acetyl-CoA production and fructose metabolism. Also, the expression of transcripts involved in these pathways was negatively correlated with circulating serum amyloid A3 protein, a marker of hepatic inflammation [R (−0.61, −0.5), P (0.002, 0.01)]. Accordingly, CD163+ cells were decreased in the liver. Additionally, the expression of key fructolytic enzymes in the small intestinal mucosa was negatively correlated with triglyceride accumulation in the liver [R (−0.45, −0.4), P (0.03, 0.05)]. ConclusionsTo our knowledge, our results show for the first time the role of galactose as an OXPHOS activator in vivo. Moreover, the concept of intestinal cells acting as the body's metabolic gatekeeper is strongly supported, as they alter substrate availability and thereby contribute to the maintenance of metabolic homeostasis, protecting other organs, as evidenced by their potential ability to shield the liver from the potentially detrimental effects of fructose.

Dietary supplementation of zinc oxide modulates intestinal functionality during the post-weaning period in clinically healthy piglets

BackgroundTo improve our understanding of host and intestinal microbiome interaction, this research investigated the effects of a high-level zinc oxide in the diet as model intervention on the intestinal microbiome and small intestinal functionality in clinically healthy post-weaning piglets. In study 1, piglets received either a high concentration of zinc (Zn) as zinc oxide (ZnO, Zn, 2,690 mg/kg) or a low Zn concentration (100 mg/kg) in the diet during the post weaning period (d 14–23). The effects on the piglet’s small intestinal microbiome and functionality of intestinal tissue were investigated. In study 2, the impact of timing of the dietary zinc intervention was investigated, i.e., between d 0–14 and/or d 14–23 post weaning, and the consecutive effects on the piglet’s intestinal functionality, here referring to microbiota composition and diversity and gene expression profiles.ResultsDifferences in the small intestinal functionality were observed during the post weaning period between piglets receiving a diet with a low or high concentration ZnO content. A shift in the microbiota composition in the small intestine was observed that could be characterized as a non-pathological change, where mainly the commensals inter-changed. In the immediate post weaning period, i.e., d 0–14, the highest number of differentially expressed genes (DEGs) in intestinal tissue were observed between animals receiving a diet with a low or high concentration ZnO content, i.e., 23 DEGs in jejunal tissue and 11 DEGs in ileal tissue. These genes are involved in biological processes related to immunity and inflammatory responses. For example, genes CD59 and REG3G were downregulated in the animals receiving a diet with a high concentration ZnO content compared to low ZnO content in both jejunum and ileum tissue. In the second study, a similar result was obtained regarding the expression of genes in intestinal tissue related to immune pathways when comparing piglets receiving a diet with a high concentration ZnO content compared to low ZnO content.ConclusionsSupplementing a diet with a pharmaceutical level of Zn as ZnO for clinically healthy post weaning piglets influences various aspects intestinal functionality, in particular in the first two weeks post-weaning. The model intervention increased both the alpha diversity of the intestinal microbiome and the expression of a limited number of genes linked to the local immune system in intestinal tissue. The effects do not seem related to a direct antimicrobial effect of ZnO.

Essential oil blend supplementation in the milk replacer of dairy calves: Performance and health.

Supplementation of dairy calves with essential oils in the liquid diet can reduce the incidence and severity of infectious diseases and promote better performance. Our objective was to evaluate an essential oil blend containing peppermint, eucalyptus, and menthol crystals and its effect on performance and health during the pre and postweaning period of dairy calves. At birth, 40 dairy calves (34 males and 6 females) were blocked according to sex and birth weight, randomly assigned to one of two treatments-commercial milk replacer diluted at 14% (MR) and the same liquid diet plus essential oil blend (MREO) at a dose of 4 mL per calf per day, divided into two meals during the first 28 days of life. Calves were individually housed and fed 6 L/d of the liquid diet, divided into two meals, and received starter concentrate and water ad libitum. Weaning was gradually reduced by 1L per day at d 51 until complete weaning at 56 days. After weaning, calves were evaluated until 70 days of age, when the experimental period ended. Intake, fecal, and health scores were evaluated daily, weight and body measures were recorded weekly, and blood parameters were evaluated at weeks 1, 2, 3, 4, and 8. Calves fed MREO tended to have higher total dry matter intake during the preweaning period. Furthermore, MREO calves had lower health scores and fewer days with a health score ≥ 4 (suggestive of bronchopneumonia), tended to lower coughing days and fewer veterinary interventions preweaning, and tended to lower health scores postweaning. The supplementation with a blend of essential oils containing peppermint, eucalyptus, and menthol crystals can reduce respiratory problems. Further studies are needed to investigate the dose and the supplementation period.

The Effect of Prebiotic Supplements on the Gastrointestinal Microbiota and Associated Health Parameters in Pigs.

Establishing a balanced and diverse microbiota in the GIT of pigs is crucial for optimizing health and performance throughout the production cycle. The post-weaning period is a critical phase, as it is often associated with dysbiosis, intestinal dysfunction and poor performance. Traditionally, intestinal dysfunctions associated with weaning have been alleviated using antibiotics and/or antimicrobials. However, increasing concerns regarding the prevalence of antimicrobial-resistant bacteria has prompted an industry-wide drive towards identifying natural sustainable dietary alternatives. Modulating the microbiota through dietary intervention can improve animal health by increasing the production of health-promoting metabolites associated with the improved microbiota, while limiting the establishment and proliferation of pathogenic bacteria. Prebiotics are a class of bioactive compounds that resist digestion by gastrointestinal enzymes, but which can still be utilized by beneficial microbes within the GIT. Prebiotics are a substrate for these beneficial microbes and therefore enhance their proliferation and abundance, leading to the increased production of health-promoting metabolites and suppression of pathogenic proliferation in the GIT. There are a vast range of prebiotics, including carbohydrates such as non-digestible oligosaccharides, beta-glucans, resistant starch, and inulin. Furthermore, the definition of a prebiotic has recently expanded to include novel prebiotics such as peptides and amino acids. A novel class of -biotics, referred to as "stimbiotics", was recently suggested. This bioactive group has microbiota-modulating capabilities and promotes increases in short-chain fatty acid (SCFA) production in a disproportionally greater manner than if they were merely substrates for bacterial fermentation. The aim of this review is to characterize the different prebiotics, detail the current understating of stimbiotics, and outline how supplementation to pigs at different stages of development and production can potentially modulate the GIT microbiota and subsequently improve the health and performance of animals.

Viability and adaptability of mestizo female cattle from artificial insemination compared with local

The objective of this study was to determine after 48 months of age, the growth and viability of crossbreds resulting from Artificial Insemination (AI). The methodology used was the follow-up of 39 crossbreds from IA with 40 local sisters whose births coincided. The data collected concerned the weight of calves, mortalities and their causes. The adaptation of mestizos in the environment was evaluated. The results showed that the weights of Mestizos calves from birth 20.65 ± 6.54 kg (Local x MO) and 23.30 ± 5.34 kg (Local x HO) to three months of age 55.12 ± 4 .95 kg (Local x MO) and 56.65 ± 5.08 kg (Local x HO) was higher (p ≤ 0.05) than those of their local counterparts (17.32 ± 3.74 kg and 42. 05±11.89kg). The pre-weaning mortality rate (18.19%) was higher (p ≤ 0.05) than that obtained in the post-weaning period (11.48%) and is mainly due to calf diarrhea (37 ,30%). The Local x MO crossbreds seem better adapted than those resulting from the Locales x HO in the climatic conditions of Togo in terms of consumption skills and sensitivity to heat. In conclusion, the survival of crossbreeds requires permanent health monitoring and good farm management.

Feeding strategies for rearing replacement beef heifers in a grazing system under tropical conditions

Our objective was to evaluate the effects of pre- and post-weaning protein supplement on the productive response and nutritional and metabolic status of replacement beef heifers grazed on tropical pasture. Fifty-six Nellore heifers (7.7 ± 0.1 months age) with an average initial body weight (BW) of 237 ± 3.5 kg were distributed in a completely randomized design in 2 × 2 factorial arrangement. The four strategies were: US-ME, unsupplemented heifers at pre-weaning and supplemented with 5 g/kg BW at post-weaning; US-HI, unsupplemented heifers at pre-weaning and supplemented with 7.5 g/kg BW at post-weaning; ME-ME, heifers supplemented with 5 g/kg BW at pre-weaning and post-weaning; and ME-HI, heifers supplemented with 5 g/kg BW at pre-weaning and 7.5 g/kg BW at post-weaning. On average, crude protein (CP) intake and CP: digested organic matter (DOM) ratio were influenced (P < 0.05) by protein supplement in the post-weaning period, with a higher intake of CP and CP:DOM ratio in HI heifers than in ME heifers (average CP of 0.812 vs 0.665 kg/day and average DOM of 204 vs 174 g CP/kg). Nonetheless, the post-weaning protein supplement did not affect the intake of total dry matter (DM), pasture DM, organic matter (OM), neutral detergent fiber corrected for ash and protein residue (apNDF), non-fibrous carbohydrates, and DOM. The CP digestibility was highest (P = 0.005) for HI heifers than for ME heifers (average of 0.732 vs 0.645 g/g DM). The pre-weaning and post-weaning protein supplement did not affect the concentration of insulin-like growth factor–1 (IGF-1), progesterone, albumin, globulins, glucose, and triglycerides, and liver mRNA expression of carbamoyl phosphate synthetase-1 (CPS-1) and phosphoenolpyruvate carboxykinase (PEPCK). Finally, the pre-weaning and post-weaning protein supplement did not affect growth performance, carcass traits, and body growth in the post-weaning. Supplementation during pre-weaning does not bring any carry-over effect on the productive performance and metabolic status of heifers supplemented during post-weaning. However, supplementation in post-weaning with 5 or 7.5 g/kg BW allows a compensatory growth of heifers that are unsupplemented at pre-weaning. Therefore, the supply of 7.5 g/kg BW of protein supplement for beef heifers only during the post-weaning period is recommended.

The type of lipid supplement has crucial implications for forage particle size in calf starter diets

BackgroundForage inclusion in starters of young dairy calves has become an acceptable strategy in the last decade. To compensate for the lower energy provided by forage, concurrent lipid supplementation can be proposed. However, ruminal microbial activity and forage digestibility may be decreased by lipid supplementation. We hypothesized that the composite effect of forage and lipid supplements may be dependent on forage particle size and the type of lipid supplement. Therefore, we evaluated the effect of long (LP; geometric mean, 4.97 mm) vs. short alfalfa hay particle sizes (SP; geometric mean, 1.26 mm) with either soybean oil (SBO) or palm fatty acids (PLF) as lipid source in a 2 × 2 factorial design with treatments SP-SBO, SP-PLF, LP-SBO, and LP-PLF. Treatments (n = 13 with 6 males and 7 females each) were offered to Holstein calves (3 days old) with equal amounts of lipid (25 g/kg DM) throughout the experimental period. The milk offering scheme (d 1 to 53) was equal for all groups. Data collection continued until 20 d post-weaning.ResultsInteraction between forage particle size and lipid supplement was significant for the following readouts: the highest and lowest starter intakes during the pre-weaning period occurred in LP-PLF and LP-SBO, respectively. This was associated with similarly contrasting changes in average daily gain (ADG) during the post-weaning period, body weight at the end of experiment, withers height, digestibility of organic matter and neutral detergent fiber, and blood serum concentrations of glucose, beta-hydroxybutyrate, and insulin during the pre-weaning period. During both pre- and post-weaning periods, the highest and lowest urinary excretion of allantoin and total purine derivatives, representing microbial protein synthesis, were observed in LP-PLF and LP-SBO, respectively, indicating that those diets were most and least favorable for rumen development. Irrespective of forage particle size, supplemental SBO vs. PLF increased serum malondialdehyde as an oxidative stress indicator across periods, increased blood urea nitrogen and feed efficiency in the pre-weaning period, and reduced hip height during the post-weaning period.ConclusionsIt can be concluded that feeding a rumen-inert, mostly saturated fatty acid source with alfalfa hay as long particle size is recommended with view on performance, whereas a combination soybean oil rich in unsaturated fatty acids should not be provided to milk-fed Holstein calves together with long particle forage. Feeding soybean oil and alfalfa hay as long particles is not advisable mainly due to lower starter consumption and impaired development of ruminal function. If dietary supplementation of soybean oil is applied, incorporation of forage as small particles should be preferred to support rumen development.

Evaluation of the efficacy of two postweaning colibacillosis vaccines in a field herd with PRRS circulation during postweaning stage

Postweaning diarrhea (PWD) and PRRS are two major concerns in swine production, which association has not been consistently explored. In the current scenario of restrictions in the use of antibiotics and ZnO, vaccination is more relevant to control PWD, but PRRS virus circulation may compromise the immune protection conferred by postweaning colibacillosis vaccines. We evaluated the efficacy of two postweaning colibacillosis vaccines (parenteral and oral) in a commercial herd affected by an outbreak of PWD and with PRRS circulation in postweaning. Five groups were studied during the postweaning period: one control (Group 1) and four vaccinated: two with each postweaning colibacillosis vaccine administered alone (Groups 2 and 3) or with sow vaccination against PRRS (Groups 4 and 5). We evaluated the effects on piglet weight, average daily weight gain and in the percentage of piglets with diarrhea, its duration, lethality and mortality. PRRS viremia and anti-PRRS antibodies were evaluated by qPCR and ELISA. Regarding control group, colibacillosis vaccination generally improved most of the measured parameters; but significant improvements were only observed in Groups 4 and 5 (p < 0.05). Moreover, cases of diarrhea occurred at different ages: in Groups 2 and 3 the peak of cases occurred just after ZnO was removed from the feed compared to Group 1, while in Groups 4 and 5 no peak was observed. This suggests that postweaning colibacillosis vaccination may be compromised by the PRRS circulation. In PRRS endemic herds an effective protection against PWD through vaccination may require PRRS vaccination to obtain a better performance.

81 (P7-13). Double-buffered sodium butyrate during the post-weaning period increased weight gain and feed efficiency of piglets

81 (P7-13). Double-buffered sodium butyrate during the post-weaning period increased weight gain and feed efficiency of piglets

The influence of supplementary feeding during suckling and later weaning on growth performance, incidences of post-weaning diarrhoea and immunity of piglets

There is an urgent call for alternative strategies to the use of antibiotics for treatment of diarrhoea during the first 14 days of the post-weaning period. The alternative strategies should be directed at enhancement of the robustness of pigs in terms of body weight at weaning, and contribute to proper functional development and maturation of the intestine before and after weaning. Therefore, both nutrition and physiological age are of high interest. We hypothesised that a liquid nutritional supplement during the suckling period, and/or an increased weaning age, would enhance growth performance of the piglets during the suckling and post-weaning period. A 2 × 2 factorial design with two nutritional strategies; i.e., supplementation with milk replacer/feed (milk replacer provided from day 2 shifted to wet feed at day 12 of age) vs. solely suckling of the sows; and two weaning ages (day 24 vs. day 35) were used. As expected, average weight at weaning and average daily gain after weaning were greater in litters weaned at day 35 (P < 0.001). During the first week after weaning, greater average daily gain (P < 0.001) was observed for litters supplied with milk replacer/wet feed, and greater feed intake (P < 0.001) was observed in piglets supplied with milk replacer/wet feed and weaned at day 35. Piglets weaned at day 35 had greater average body content of protein and fat (P < 0.001) as compared with their littermates weaned at day 24. Provision of the milk replacer/wet feed during suckling increased the faecal dry matter content (P = 0.05) after weaning; while the proportion of piglets with a faecal consistency score >3 was greatest in litters weaned at day 35 and raised solely on sow milk (P = 0.03). The results showed that the nutritional supplementation before weaning had beneficial impact on intestinal functionality (with regard to faecal dry matter content results), while increased weaning age improved growth performance before and after weaning, as well as increased fat depots after weaning. The provision of nutritional supplement and increased weaning age enhanced post-weaning feed intake. In conclusion, the applied management strategies (supplementary feeding during suckling and later weaning) improved piglets’ characteristics before and after weaning, indicating enhanced robustness among weaned piglets.

Assessing the effects of piglet behavior, diet supplementation, and lesion score breeding values of sires on behavior pattern in weaned pigs

The aim of the present study was to study effects of feeding in terms of a herbal diet supplement (HD; basal diet plus a supplement with chicory herbs), of early piglet backtest scores and of relative breeding values for skin lesions (RBV-LS) on behavior pattern of weaned pigs during the post-weaning period. In this regard, we implemented a balanced research design, allowing a semi-randomized allocation of pigs in groups with a very similar number of observations for all sub-cells of diet x backtest score x RBV-LS class combinations. With regard to backtest scores, piglets were classified as high-resisting (HR), low-resisting (LR) or intermediate-resisting (IR). RBV-LS were estimated for the sires based on skin lesions from 993 offspring. The sires were categorized into 2 groups with RBV-LS > 100 (favorable genetic value indicating only a few or no lesions) or RBV-LS ≤ 100 (indicating a large number or severe lesions). Video images were analyzed one day after weaning and 5 weeks later, and considered 300 min per monitoring date for the 8 different possible behavior traits resting time (REST), body contact (BCON), initiating fights (IFIGHT), fighting (FIGHT), refusing of fights (RFIGHT), ear or tail biting (BITE), explorative behavior (EXPLORE) and remaining activities (RACT). Finally, 104 pigs with complete observations over the total video monitoring time at both recording dates, and with complete observations for the explanatory variables sire RBV-LS, backtest score and feeding group, were considered for ongoing association studies. The 104 pigs were crosses from matings of Piétrain boars with German Landrace or German Edelschwein sows. The 104 pigs were offspring of 9 different boars (sire lines). Effects of feeding, backtest score and RBV-LS class on video behaviors were inferred via mixed model analyses, implying 8 different runs for the 8 video behavior traits. Least squares means (lsmeans) significantly (P < 0.05) differed between HD and the control feeding group (CON) for FIGHT and BITE, with longer durations of aggressive behavior for CON pigs. Vice versa, lsmeans for REST indicating calm behavior were larger for the HD group. Pigs classified as HR piglets were more aggressive than the LR and IR contemporaries, with significantly higher lsmeans for FIGHT, BITE and EXPLORE. The pigs allocated to the sire RBV-LS > 100 group had significantly (P < 0.05) longer durations for REST and RFIGHT. Vice versa, pigs allocated to the sire RBV-LS ≤ 100 groups spent more with aggressive behavior in terms of BITE and FIGHT. Consequently, boar RBV-LS were favorably correlated with REST, IFIGHT and RACT. In conclusion, the early piglet backtest scores as well as breeding values from a victim perspective (lesion scores) can be used as indicator traits for selection against aggressiveness. Nevertheless, results from the present study are first indications and breeding value correlations are approximations in this regard, which should be validated in ongoing studies based on larger datasets via real genetic correlation estimates between actor and victim traits, and considering social interactions and interactions between all fixed effects simultaneously.

Performances of Post-weaned Pasundan Calves Fed Extra Diets in an Extensive Grazing System

Changing from the pre-weaning to the post-weaning period is a transition from liquid to solid feed accompanied by a dramatic transformation of the GI tract. Supplemental solid feeding of grazing post-weaning calves is expected to improve their productivity. The study aimed to determine the effect of extra diet on the performances of post-weaned Pasundan calves (15 males and 15 females) that were grazed, using a completely randomized design of 2x3 factorials (two sex factors x three diet factors). The diet treatments were that post-weaned Pasundan calves were grazed: without being given extra diets (grazing/control), extra diets without urea-impregnated zeolite (extra diet-1), and extra diets with urea-impregnated zeolite (extra diet-2). The parameters were diet consumption (only for extra diets, unmeasured grazing consumption), body weights, and body condition. The data were analyzed with GLM Univariate. The results showed: The interaction between diet treatment and sex did not affect all the observed parameters. Consumption of extra diet-1 (529.37±3.06 g DM/head/day) was higher (P0.05) than extra diet-2 consumption (525.17±1.96 g DM/head/day), but after a correction of body weight, the result was no different.  Sex factors did not affect all observed parameters. The ADG of post-weaned calves fed extra diet-1 (155.8±27.5 g), or extra-2 diet (124.2±56.3 g) was higher (P0.05) than the grazing (66.67±35.8 g). The extra diet-1 produced a higher change in body condition (1.8±0.78, P0.05) than extra diet-2 or grazing (1.2±0.42). In conclusion, feeding extra diet-1 to post-weaned Pasundan calves increased ADG by 234% and improved the body condition by 150% better than calves that were only grazed in an extensive grazing system.

Benefits of barley straw as a forage for dairy calves before and after weaning

The aim of this study was to assess the potential consequences on calf intake, performance, behavior, ruminal microbiome, and ruminal epithelium development of combining the inclusion of chopped barley straw and alfalfa hay during the pre- and post-weaning periods keeping concentrate to forage ratio constant among dietary treatments. Forty-five Holstein calves (44 ± 5.7 kg of BW and 3 ± 1.5 d of age) individually penned were blocked by body weight (BW) and randomly assigned to a common pellet concentrate fed ad libitum along with one of following forage feeding strategies: barley straw before and after weaning (SS), barley straw before and alfalfa hay after weaning (SA), or alfalfa hay before and after weaning (AA). All calves received the same milk replacer regimen. Forage was supplied in a separated bucket at the rate of 7.5% (preweaning) and 15% (postweaning) of total solid feed intake of the previous day. Feed intake and BW were recorded daily and weekly, respectively. Rumen samples were obtained via a stomach tube at 53, 66, and 87 d and were composite in 3 samples of 5 animals each for subsequent rumen microbiome analysis. A rumen epithelium sample was taken by endoscopy at 90 d to assess gene expression of occludin, claudin-4, NHE1, NHE3, MCT1, MCT4, IL6, and TGFß1. Data were analyzed with a mixed-effects model accounting for the fixed-effects of block, forage, week of study, and their interaction, and calf as a random effect. The type of forage fed did not affect concentrate feed, forage, or total DM intake before weaning. However, SA and AA calves consumed less concentrate feed and SA calves grew at a lower rate after weaning than SS calves. Expression of the gene coding for MCT1 in the rumen epithelium was greatest in SS among treatments. Rumen microbiome did not differ among treatments, while the relative abundance of Acidaminococcus and Selenomas genera increased, while Alloprevotella, Bifidobaterium, Olsenella and Succiclasticum genera decreased with age. In conclusion, feeding barley straw before and after weaning was more effective than feeding alfalfa hay in promoting concentrate feed intake after weaning and fostering an increase in the expression of MCT1 in the rumen epithelium.

Validation of a methodology for characterization of rumination, lying, standing, and performing non-nutritive oral behaviors and behavioral patterns in Holstein dairy calves

Calf behavior is closely related to its early growth, production performance, and health performance. Continuous behavior recording is the most accurate but also time-consuming method used for monitoring animal behaviors, so the instantaneous sampling method is often adopted to minimize the time required to quantify behavioral observations in animal studies. Moreover, the optimal sampling intervals required to yield accurate information for estimating Holstein dairy calves' behaviors are still unknown. Our primary objective was to determine the most optimal sampling intervals for monitoring behaviors of Holstein dairy calves during preweaning and weaning periods to improve efficiency while maintaining reliability. The secondary objective was to describe their behavioral patterns. Rumination, lying, standing, and non-nutritive oral behavior (NNOB) data of 18 calves (observation time: 360 h/calf, 6,480 h in total) were continuously recorded for 15 d (3 d at 1, 3, 6, 9, and 12 wk of age). The continuous behavioral data were compared with instantaneous sampling at 5 s, 10 s, 15 s, 30 s,1 min, 3 min, 5 min, 10 min, 15 min, 30 min, and 60 min intervals. Sampling intervals were considered accurate if they met 4 criteria: coefficient of determination ≥0.90 (i.e., strongly related to true values), slope = 1, intercept = 0 (i.e., they did not over- or underestimate true values), and relative error <10%. The most optimal sampling interval was considered the highest sampling interval among the 11 sampling intervals that meet the criteria for accurate monitoring. As expected, the strength of the linear relationship between the continuous recording and instantaneous sampling decreased as the sampling intervals increased. The results varied across the different behaviors, with rumination, lying, standing, and NNOB being reliable at instantaneous recordings of 3 min, 10 min, 10 min, and 1 min for the preweaning period (1, 3, and 6 wk of age) and 10 min, 10 min, 15 min, and 3 min for the postweaning period (9 and 12 wk of age). In terms of behavioral patterns, lying time decreased, whereas rumination, standing, and NNOB time increased with age. After weaning, no significant changes in time spent performing these behaviors. Additionally, the rumination behavioral pattern becomes stable after wk 6 with decreasing after the morning feeding and occurring mainly in the morning. In conclusion, instantaneous sampling is a reliable method for monitoring the behaviors of dairy calves, but the optimal sampling intervals should be selected based on different ages and management conditions.

Alterations in skeletal muscle morphology and mechanics in juvenile male Sprague Dawley rats exposed to a high-fat high-sucrose diet

Although once a health concern largely considered in adults, the obesity epidemic is now prevalent in pediatric populations. While detrimental effects on skeletal muscle function have been seen in adulthood, the effects of obesity on skeletal muscle function in childhood is not clearly understood. The purpose of this study was to determine if the consumption of a high-fat high-sucrose (HFS) diet, starting in the post-weaning period, leads to changes in skeletal muscle morphology and mechanics after 14 weeks on the HFS diet. Eighteen 3-week-old male CD-Sprague Dawley rats were randomly assigned to a HFS (C-HFS, n = 10) or standard chow diet (C-CHOW, n = 8). Outcome measures included: weekly energy intake, activity levels, oxygen consumption, body mass, body composition, metabolic profile, serum protein levels, and medial gastrocnemius gene expression, morphology, and mechanics. The main findings from this study were that C-HFS rats: (1) had a greater body mass and percent body fat than control rats; (2) showed early signs of metabolic syndrome; (3) demonstrated potential impairment in muscle remodeling; (4) produced lower relative muscle force; and (5) had a shift in the force–length relationship, indicating that the medial gastrocnemius had shorter muscle fiber lengths compared to those of C-CHOW rats. Based on the results of this study, we conclude that exposure to a HFS diet led to increased body mass, body fat percentage, and early signs of metabolic syndrome, resulting in functional deficits in MG of childhood rats.