Plasma Urea Nitrogen Concentrations Research Articles

97 Effects of crude protein content and supplementing probiotics in late gestation and lactation sow diets on performance of sows and suckling pigs

Abstract The objective of this study was to investigate the effects of crude protein (CP) content and supplementation with Bacillus-based probiotics (PRO) in late gestation and lactation sow diets on performance of sows and suckling pigs. Pregnant sows (n = 120; 60 gilts and 60 2+ parity) were assigned to 4 dietary treatments in a 2 x 2 factorial arrangement (2 CP levels, with or without probiotics) from d 85 of gestation to d 21 of lactation. The experiment was conducted in 4 consecutive periods (half sows and half gilts per period). The diets consisted of 1) a corn-soybean meal (SBM)-based low CP (LCP; 12% CP) diet; 2) LCP + 0.05% probiotic (LCP-PRO); 3) a corn-SBM-based high CP (HCP; 15% CP) diet; and 4) HCP + 0.05% probiotic (HCP-PRO). The diets were formulated for 2 phases: gestation (d 85 – 115) and lactation (d 1 – 21). Sow body weight (BW) and backfat thickness were recorded on d 85 and 111 of gestation and on d 1 and 21 of lactation. Sow blood and milk were sampled on d 1 and 21 of lactation to analyze plasma urea nitrogen (PUN) concentration, and milk fat, protein, and lactose, respectively. Data were analyzed using the PROC MIXED of SAS. The statistical model included diet as fixed effect and period as random effect. There were no significant effects of CP and PRO on sow BW or backfat thickness. There was an interaction (P < 0.05) between CP and PRO on the number of stillbirths, where the number of stillbirths did not differ between LCP and LCP-PRO groups, while the number decreased in sows fed HCP-PRO diet compared with HCP diet. Sows fed LCP diets had reduced (P < 0.05) PUN concentrations on d 1 and d 21 of lactation compared with those fed HCP diets. However, no difference was found in fat, protein, or lactose content in both colostrum (d 1) and milk (d 21). Piglets from the sows fed LCP diets showed heavier (P < 0.05) birth weights (1.58, 1.57, 1.53, and 1.52 kg for diets 1 to 4) than those in HCP groups, however, the average daily gain (ADG) of week 1 (188, 166, 187, and 187 g for diets 1 to 4) was less (P < 0.05) for piglets in LCP groups than HCP groups. No other effects were observed on piglet growth. In conclusion, CP and PRO did not affect sow BW and backfat thickness. There was an interaction effect of CP and PRO on reproductive performance, where stillbirths did not differ between LCP and LCP-PRO groups; however, stillbirths decreased with PRO in HCP diet. Moreover, feeding LCP diets to sows did not influence milk nutrient contents and overall growth performance in suckling piglets.

Total Replacement of Soybean Meal with Sundried Soymilk Residue in the Total Mixed Ration has a Negative Impact on Intake, Digestibility, and Milk Production in Dairy Goats.

This study aimed to evaluate whether total replacement of soybean meal (SBM) with sundried soymilk residue (SSR) in a total mixed ration (TMR) affects intake, digestibility, milk production, and blood metabolites in dairy goats. A total of 12 healthy Saanen dairy goats (40.12 ± 5.80 kg of BW) in midlactation (31.23 ± 10.12 days) were used in a randomized complete design (n = 4 goats/group). Dietary treatments were based on a TMR as follows: control TMR without SSR (CON) or SBM-based TMR with 50% or 100% of SSR replacing SBM (SSR-50 and SSR-100, respectively). All goats had ad libitum access to feed and clean water throughout the experiment. The dry matter (DM) intake decreased (p < 0.05) with the increasing replacement ratio of SBM and was lowest in the SSR-100 group. Similarly, organic matter (OM) digestibility was lowest (p < 0.05) in the SSR-100 group. However, the digestibility of DM, CP, NDF, and ADF did not change (p > 0.05) by dietary treatments. Compared with CON, the milk yield decreased significantly (p < 0.05) with increasing replacement ratio of SBM. In contrast, milk composition such as total solids, solids-not-fat, milk fat, lactose, protein, and pH were not influenced (p > 0.05) by feeding dietary SSR. Compared with other treatments, blood glucose concentration was lower (p < 0.05) in the SSR-100 group. In contrast, packed cell volume, glucose, and plasma urea nitrogen concentrations did not differ (p > 0.05). The results indicated that SSR could replace SBM in a TMR at less than 50%. Thus, the present study provides support for further investigation to enhance the utilization of soybean waste as an alternative protein source in the TMR for dairy goats and potentially other ruminants.

85 Evaluation of a Saccharomyces cerevisiae fermentation product on performance, plasma metabolites, rumen parameters, and fecal pathogen shedding in feedlot steers

Abstract The objective of the experiment was to evaluate a commercial Saccharomyces cerevisiae fermentation product (SCFP; NaturSafe, Dimond V, Cedar Rapids, IA) on performance, plasma metabolites, rumen parameters, and fecal pathogen shedding in feedlot steers. Crossbred steers (n = 61; 271 ± 48.1 kg) were sourced from 3 different research units at Oklahoma State University and assigned to 1 of 3 experimental treatments in a randomized complete block design. Steers were group housed in pens equipped with an automated individual feed intake system. Treatments consisted of a negative control (CON), CON with tylosin phosphate (TYL; 9.9 mg · kg-1 of diet DM), or CON with SCFP (1.63 g · kg-1 of diet DM). Body weight and feed efficiency did not differ among treatments (P ≥ 0.12). However, steers fed SCFP tended to have greater ADG from d 35 to 56 (P = 0.10). In addition, steers fed SCFP exhibited increased DMI from d 56 to 112 (P = 0.03), a tendency for increased DMI from d 112 to final (P = 0.07), and increased DMI overall (P = 0.05). There was no treatment × time interaction for pH, pH change, or lactate concentrations in rumen fluid (P ≥ 0.11), but all were impacted by time (P &amp;lt; 0.01). A treatment × time interaction (P &amp;lt; 0.01) was detected for fecal pH and fecal pH change, with the pH being greater in TYL fed steers on d 56 and in CON fed steers on the final day. Steers that consumed CON had a reduced fecal pH (P &amp;lt; 0.01) and steers consuming SCFP tended to have a reduced fecal pH (P = 0.08) from d 35 to 56 compared with TYL fed steers, while both CON and SCFP fed steers experienced an increase in fecal pH from d 56 to 112 (P &amp;lt; 0.01). A time effect was detected (P ≤ 0.04) for plasma glucose, lactate, urea nitrogen, and non-esterified fatty acid concentrations among treatment groups. A treatment × time interaction was observed (P &amp;lt; 0.02) for stx2 genes of Shiga toxin producing Escherichia coli (STEC) in individual fecal samples where SCFP and TYL fed steers tended to exhibit an increased concentration compared with CON fed steers on d 14, while on d 190 CON and SCFP fed steers exhibited an increased concentration compared with TYL fed steers. Overall, STEC, E. coli O157:H7, and Salmonella concentrations were all impacted by time (P &amp;lt; 0.001). This experiment suggests that SCFP could be utilized as a potential alternative to TYL in feedlot cattle without adversely affecting cattle performance. However, SCFP did not impact pathogen shedding. In addition, CON fed steers performed similarly to both SCFP and TYL fed steers.

Effects of increasing dietary arginine supply during the three first weeks after weaning on pig growth performance, plasma amino acid concentrations, and health status.

A total of 425 weaned pigs (Exp. 1: 225 pigs [5.8 ± 0.9 kg]; Exp. 2: 200 pigs [6.1 ± 1.2 kg]) were used to determine the optimal dietary standardized ileal digestible (SID) arginine (Arg) level in early nursery diets based on growth and health responses. The basal diet in Exp.1 was formulated to meet SID Arg recommendation (0.66%; NRC, 2012) and in Exp. 2, SID Arg was set to simulate current industry practices for feeding nursery pigs (1.15 %). Basal diets were supplemented with 0.3%, 0.6%, 0.9%, and 1.2% of l-arginine to provide five levels of dietary SID Arg. Experimental diets were fed during phases I (days 0 to 7) and II (days 8 to 21) with common diets until market. Feed disappearance and body weight (BW) were measured on days 7, 14, 21, and 43. Final BW was recorded at first removal of pigs for market. Pen fecal score was assigned daily from days 0 to 21. Plasma immunoglobulin A (IgA) was determined on days 0, 7, and 14 and amino acids (AAs) concentration and plasma urea nitrogen (PUN) on days 0 and 14. Orthogonal polynomial contrasts were used to determine the linear and quadratic effects of dietary Arg. Optimal SID Arg was determined by fitting the data with piecewise regression, using growth performance as the primary response variable. In Exp. 1, dietary Arg linearly increased (P < 0.1) BW, average daily gain (ADG), and gain to feed ratio (G:F) ratio on day 21, as well as reduced (χ2 = 0.004) the percentage of pigs that lost weight (PLW) in week 1 by 29%. Dietary Arg resulted in linear improvement (P = 0.082) of ADG for the overall nursery period and quadratic improvement (P < 0.1) of final BW at marketing. In Exp. 2, dietary Arg linearly increased (P < 0.05) ADG and average daily feed intake (ADFI) in week 1, BW and ADFI (P < 0.1) on day 14, as well as reduced (χ2 ≤ 0.001) PLW in week 1. From days 0 to 21, G:F was improved quadratically (P < 0.1). Dietary Arg linearly increased (P < 0.1) ADG and BW on day 43. Dietary Arg supplementation decreased the incidence (χ2 < 0.05) of soft and watery feces during the first weeks after weaning and lower concentration of plasma IgA on days 7 and 14. Dietary Arg linearly and/or quadratically influenced plasma AA concentrations (P < 0.05), including an increase in Arg, Leu, Phe, Val, citrulline, ornithine, and PUN concentrations. Overall, weaned pigs exhibit optimal nursery growth performance and health when provided with dietary SID Arg ranging from 1.5% to 1.9%. This dietary range contributes to a reduction in the occurrence of fall-back pigs and improvements in final BW at marketing.

Dietary crude protein time-dependently modulates the bacterial community and metabolites and changes dietary nutrient efficiency in growing pigs

The reduced nutrient digestibility of low-protein (LP) diets has been shown to be caused by the weakened fermentative capacity of the post-gut flora. The dynamic regulation of dietary protein contents on post-gut microbial population and fermentative metabolism is unclear. Twelve growing barrows (19.9 ± 0.8 kg) fitted with a T-cannula at the blind end of the cecum were randomly administered a high-protein (HP, 21.5% crude protein [CP]) diet or an LP (15.5% CP) diet for 28 d. The cecal content and feces were collected at d 1, 14, and 28 of the experiment for microflora structures and metabolite concentrations analysis. The nutrient digestibility coefficient and plasma biochemical parameters were also determined. Compared with the HP treatment, the LP treatment showed decreased plasma urea nitrogen concentration and apparent total tract digestibility of dry matter, gross energy, and CP (P < 0.01). In addition, urinary nitrogen losses, total nitrogen losses, and daily nitrogen retention in the LP treatment were lower than those in the HP treatment (P < 0.01), and the nitrogen retention-to-nitrogen intake ratio in the LP treatment was increased (P < 0.01). The HP group showed increased cecal total short-chain fatty acids (SCFA) concentration and fecal propionate, butyrate, and total SCFA concentrations (P < 0.05) on d 14 and 28, which may be mainly related to the elevated abundance of SCFA-producing bacteria, such as Ruminococcus, Lactobacillus, and Prevotella (P < 0.05). Probiotics, such as Bifidobacterium, Bacteroidales S24-7, and Rikenella, enriched in the LP treatment possibly contributed to reduced plasma endotoxin content. The differences in the abundances of almost all the above-mentioned flora appeared on d 28 but not d 14. Likewise, differences in the Simpson and Shannon indices and clustering patterns of the microbiota between treatments were also only observed on d 28. To sum up, in a time-dependent manner, the LP diet increased probiotics with gut-improving functions and decreased SCFA-producing bacteria, which may cause enhanced intestine health and reduced nutrient digestibility.

Differential voluntary feed intake and whole transcriptome profiling in the hypothalamus of young sheep offered CP and phosphorus-deficient diets.

A reduction in voluntary feed intake is observed in ruminants consuming nutrient-deficient diets, such as those with a low CP or P content, and has been attributed to active metabolic regulation, rather than a physical constraint. The hypothalamus is the key integrator of feed intake regulation in mammals. The objectives of this experiment were to (1) establish a model of metabolic feed intake regulation in ruminants consuming diets of variable CP and P content, and (2) determine key biochemical pathways and influential points of regulation within the hypothalamus. Merino wethers [n=40; 23.7±1.4kg liveweight (mean±SD)] were fed one of five dietary treatments (n=8/treatment) for 63days in individual pens. The treatments included targeted combinations of high (H) and low (L) CP (110 and 55g/kg DM) and high and low P (2.5 and 0.7g/kg DM) with 9MJ metabolisable energy (ME) per kg DM which were fed ad libitum (UMEI; unrestricted ME intake) resulting in four experimental diets (HCP-HP-UMEI, LCP-HP-UMEI, HCP-LP-UMEI and LCP-LP-UMEI). An additional nutritional treatment (HCP-HP-RMEI) restricted intake of the HCP-HP diet to an equivalent ME intake of wethers consuming the LCP-LP-UMEI treatment. Wethers offered the LCP-HP-UMEI, HCP-LP-UMEI and LCP-LP-UMEI treatments consumed 42, 32 and 49% less total DM (P≤0.05), respectively than the HCP-HP-UMEI treatment, and this was not attributable to any physical limitation of the rumen. Plasma concentrations of urea nitrogen and inorganic phosphate indicated that these nutrient deficiencies were successfully established. To assess potential mechanisms, RNA-seq was conducted on samples from the arcuate nucleus (ARC), ventromedial hypothalamus and lateral hypothalamus of the wethers, yielding a total of 301, 8 and 148 differentially expressed genes across all pairwise comparisons, respectively. The expression of NPY, AGRP and CARTPT, known for their regulatory role in mammalian feed intake regulation, had a similar transcriptional response in the ARC of wethers consuming nutrient-deficient treatments and those consuming a ME-restricted treatment, despite these wethers expressing behaviours indicative of satiated and hungry states, respectively. In addition, genes involved with glycolysis (TPI1), the citric acid cycle (CS, OGDH, GLUD1, GOT1) and oxidative phosphorylation (COX5A, ATP5MC1, ATP5F1B, ATP5MC3) were downregulated in the ARC of wethers fed a nutrient deficient (LCP-LP-UMEI) relative to the non-deficient (HCP-HP-UMEI) treatment. In summary, a model for voluntary feed intake restriction was established to determine genome-wide molecular changes in the hypothalamus of young ruminants.

Inhibiting the phosphatase activity of soluble epoxide hydrolase attenuates chronic kidney disease-induced calcific aortic valve disease in rats

Calcific aortic valve disease (CAVD) is the most frequent valvulopathy ultimaltely leading to aortic stenosis, one of the driving causes of an increased morbidity and mortality in aging and in patients with chronic kidney disease (CKD). Up to date, there is no available pharmacological treatment to prevent the development and progression of CAVD. Previous studies suggested that the bifunctional enzyme, soluble epoxide hydrolase (sEH), is involved in the regulation of cardiovascular calcification development. Our study aimed to investigate whether the phosphatase activity of sEH is involved in CAVD. Sprague Dawley sEH-P knocking rats (sEH-P KI) were generated using CRISPR/Cas9 method. Eighteen-week-old WT and sEH-P KI rats underwent subtotal nephrectomy (5/6Nx) to mimic CKD. These animals were afterword fed with a high-phosphate chow diet (1.8% phosphorus). In parallel, sham-operated animals on a standard diet (0.9% total phosphorus) served as controls. Twelve weeks after surgery, renal and cardiac parameters were determined and histological analysis of aortic valves was performed. Twelve weeks after surgery, the development of renal dysfunction in 5/6Nx + phosphate WT rats was shown by the augmentation in plasma creatinine and urea nitrogen concentrations and the decline in estimated glomerular filtration rate compared to sham-operated WT rats. These animals also displayed anemia, polyuria and polydipsia. The genetic inhibition of sEH-P did not allow to prevent these alterations. However, inhibiting sEH-P limited hydroxyapatite crystals deposition in the aortic valve of 5/6Nx + phosphate rats compared to 5/6Nx + phosphate WT rats (Fig. 1B, C), associated with a prevention of the decrease in intercusp distance and of the increase in aortic valve mean pressure gradient and in peak aortic valve velocity (Fig. 1A). In addition, left-ventricular diastolic (E/e′) and systolic dysfunction (fractional shortening) as well as cardiac fibrosis were prevented by sEH-P inhibition. Additional experiments on recombinant human and rat sEH allowed to demonstrate that sEH-P metabolizes pyrophosphate anions (PPi), a potent inhibitor of cardiovascular calcification, and that PPi degradation is efficiently prevented by sEH-P inhibition. Taking altogether, these results demonstrate that inhibition of sEH-P prevents aortic valve calcification and its hemodynamical consequences in the 5/6Nx + phosphate rat model, and may serve as a potential therapeutic strategy for the treatment of CAVD.

Short-term physiological responses to moderate heat stress in grazing dairy cows in temperate climate.

Even in temperate climate regions, an increase in ambient temperature and exposure to solar radiation can cause heat stress in lactating dairy cows. We hypothesised that grazing dairy cows exhibit short-term physiological changes due to increasing heat load under moderate climate conditions. Over two consecutive summers, 38 lactating Holstein dairy cows were studied in a full-time grazing system. Data were collected in 10 experimental periods of up to three consecutive days with a moderate comprehensive climate index (CCI). The individual animals' vaginal temperature (VT), heart rate, and locomotor activity data were automatically monitored with sensors. Blood samples and proportional whole milk samples were collected at afternoon milking. The concentrations of beta-hydroxybutyrate, glucose, non-esterified fatty acids, urea nitrogen, plasma thyroxine and triiodothyronine were analysed in blood plasma, and fat, protein, lactose, urea nitrogen, cortisol, Na+, K+, and Cl- concentrations were analysed in milk. The daily distribution of VT recordings greater than 39°C showed a circadian rhythm with a proportion of recordings of 2% and lower during the night and a percentage of 10% or higher in the afternoon. The cows' maximal daily vaginal temperature (VTMAX) between 0830 and 1430h was positively related to the mean daily CCI in the same time period (CCIMEAN; mean and SD 23.6±5.4°C). Cows with greater VTMAX had an increased mean heart rate, plasma glucose and milk cortisol concentrations and decreased concentrations of plasma thyroxine and triiodothyronine. The concentration of Na+ in milk was lower, and the concentration of K+ in milk tended to be higher in cows with increased VTMAX. For beta-hydroxybutyrate, non-esterified fatty acids and urea nitrogen concentrations in plasma and fat and lactose concentrations in milk no relationships were found in terms of increasing VT. For milk urea nitrogen and protein concentrations, the proportion of total variance explained by inter-individual or -period variance was high. In conclusion, changes observed in milk and blood likely reflected short-term physiological responses to moderate heat stress. In particular, milk cortisol and Na+ may be useful traits for timely monitoring of heat stress in individual cows because their inter-individual variances were relatively small and samples can be collected non-invasively.

Effects of crude protein and neutral detergent fiber percentages in the diet of Japanese Black steers on rumen fluid properties, blood biochemical properties, and carcass characteristics.

The effects of crude protein (CP) and neutral detergent fiber (NDF) percentages in the diet of Japanese Black steers on rumen fluid properties, blood biochemical properties, and carcass characteristics were examined. Twelve 13-month-old Japanese Black steers were used for this study and slaughtered at 30 months of age. Steers were assigned to a control group (n = 6) and test group (n = 6) and were fed a concentrate containing 12.9%-13.9% CP and 26.5%-29.8% NDF or 9.1%-9.6% CP and 29.9%-31.2% NDF, respectively. Lipopolysaccharide activity levels in rumen fluid were lower in the test group than in the control group. Plasma urea nitrogen concentration and activities of aspartate aminotransferase and γ-glutamyltransferase remained lower in the test group than in the control group. In contrast, plasma vitamin A concentrations remained higher in the test group than in the control group. Carcass characteristics did not significantly differ between the two groups. These results suggest that dietary CP and NDF percentages in feed for Japanese Black steers older than 13 months of age affected rumen fluid properties and blood biochemical properties, indicating a reduced load on the liver with a small effect on carcass characteristics.

Effects of branched-chain amino acids to lysine ratios in corn distillers dried grains with solubles containing diets on growth performance, plasma nitrogen profile, carcass traits, and economic analysis in growing-finishing pigs.

A study was conducted to identify the effects of standardized ileal digestible (SID) branched-chain amino acids (BCAA):lysine (Lys) ratios on the growth performance, plasma nitrogen (N) profile, carcass traits, and economic analysis of growing-finishing pigs fed diets with high corn distillers dried grains with solubles (cDDGS) inclusions. A total of 1,140 pigs (initial body weight [BW] = 28.7 ± 2.0 kg) were housed in 45 pens of 25 or 26 pigs and fed one of five diets in a randomized complete block design. Experimental diets were fed in four phases based on BW. Dietary treatments were a corn-soybean meal (SBM) based diet (PC), a corn-SBM-cDDGS-based diet (NC) with SID BCAA:Lys ratio of PIC (2020) recommendation and NC diets with SID BCAA:Lys ratios targeted for the 73% SID Val:Lys, 60% SID Ile:Lys, and 144% SID Leu:Lys during the growing phases (25 to 80 kg, Grow), targeted for the 78% SID Val:Lys, 70% SID Ile:Lys, and 160% to 170% SID Leu:Lys during the finishing phases (80 to 120 kg, finish), and both during the growing and finishing phases (Grow-Finish). One pig from each pen was bled at the end of 7 and 13 wk. After the 11-wk-feeding trial, pigs were sent to a commercial abattoir to investigate carcass traits. Pigs fed the Finish diet had a greater overall average daily gain (P < 0.05) than pigs fed the other cDDGS diets. Dietary treatments did not affect the hot carcass weight. However, feeding the Finish diet increased (P < 0.05) the iodine value of pork belly samples and decreased (P < 0.05) carcass yield. The plasma urea nitrogen (PUN) concentration at the end of the growing phase and plasma concentrations of Leu and Val were greater (P < 0.05) in pigs fed the Finish diet compared to the other cDDGS diets. Feeding pigs the cDDGS diets with different BCAA:Lys ratios had no difference in income over feed cost and income over feed and facility costs compared to the corn-SBM diet. Therefore, feeding pigs cDDGS diets with SID BCAA:Lys ratios adjusted for the previously determined finishing phase (from 80 to 120 kg of BW) recommendations by SBM inclusion supported growth performance and economic benefits equal to the corn-SBM diet.

Subchronic toxicity of oral deltamethrin in laying chickens.

Pyrethroid pesticides, with low toxicity to birds and mammals and short persistence in the environment, are widely used now. With the development of intensive poultry farming, pesticide application leads to residues in poultry products and pollution in ecological environment. The aim of the present study was to examine deltamethrin subchronic toxicity in laying chickens. One hundred and twelve laying chickens were randomly assigned to 14 groups including 13 groups medicated with deltamethrin (n = 8) and one unmedicated group used as control (n = 8). Tissue samples were collected during and after administration for weighing and histopathological analysis. A single dose of deltamethrin (20 mg·kg-1·BW·d) was administered orally to laying chickens for 14 days. The results showed that deltamethrin has no significant effect on the relative organ weight of laying chickens (p > 0.05). The activities of aspartate aminotransferase and cholinesterase in the plasma gradually decreased over time in the medicated group (p < 0.05). Plasma concentrations of urea nitrogen, uric acid, cholesterol, triglycerides, and creatinine significantly increased during treatment (p < 0.05), and significant liver damage and loss of intestinal villous epithelium were observed. The intestinal wall thickness, villus height, and crypt depth of laying chickens were altered by deltamethrin treatment. During treatment was withdrawn, the intestinal repair was more extensive than the liver repair.

Using whole cottonseed to replace dried distillers grains plus solubles and prairie hay in finishing beef cattle rations balanced for physically effective neutral detergent fiber

The objective of this experiment was to determine the effects of replacing prairie hay and dried distillers grains plus solubles with whole cottonseed (WCS) in diets balanced for physically effective NDF on the growth, intake, feed efficiency, carcass characteristics, and plasma metabolites of finishing beef cattle. Crossbred heifers (n = 103) and steers (n = 104) were blocked by BW within sex and randomly allocated to pens within block (6 pens per treatment) with 17 (n = 10 pens) or 18 (n = 2 pens) animals per pen. Pens were randomly allocated to experimental treatment: either a control diet (CON; prairie hay, dried distillers grains plus solubles, dry-rolled corn, and liquid supplement) or a WCS diet (CTN; WCS, dry-rolled corn, and molasses). A common vitamin and mineral supplement and urea were included in both diets at the same rate. Animals were slaughtered in 3 groups based on BW block. Cattle fed the CTN treatment tended to have a greater final BW (P = 0.10) and had greater overall ADG and G:F (P ≤ 0.05). There was no difference in overall DMI (P = 0.23). Fecal consistency scores were greater for cattle fed the CON treatment on d 42, at the beginning of the β-agonist feeding period, and at the final collection before slaughter (P ≤ 0.03). Cattle fed the CTN treatment had a more neutral fecal pH on d 140 and at the final collection (P < 0.01). No treatment × day interactions (P ≥ 0.70) were detected for plasma glucose, lactate, urea nitrogen, or nonesterified fatty acid concentrations. Cattle fed the CON treatment had greater plasma urea nitrogen concentrations (P < 0.001) and a tendency for a greater plasma lactate concentration (P = 0.06). A day effect was also observed for all plasma metabolites (P < 0.001). This experiment suggests that feeding WCS improves the growth and feed efficiency of cattle when replacing the roughage and byproduct protein and fat sources within a finishing diet.

Effects of dietary branched-chain amino acid supplementation on serum and milk metabolome profiles in dairy cows during early lactation.

The 3 branched-chain AA (BCAA), Val, Leu, and Ile, are essential AA used by tissues as substrates for protein synthesis and energy generation. In addition, BCAA are also involved in modulating cell signaling pathways, such as nutrient sensing and insulin signaling. In our previous study, dietary BCAA supplementation was shown to improve protein synthesis and glucose homeostasis in transition cows. However, a more detailed understanding of the changes in metabolic pathways associated with an increased BCAA availability is desired to fine-tune nutritional supplementation strategies. Multiparous Holstein cows (n = 20) were enrolled 28 d before expected calving and assigned to either the BCAA treatment (n = 10) or the control group (n = 10). Cows assigned to BCAA were fed 550 g/d of rumen-protected BCAA mixed with 200 g/d of dry molasses from calving until 35 DIM, whereas the cows assigned to the control were fed only 200 g/d of dry molasses. Serum samples were collected on d 10 before expected calving, as well as on d 4 and d 21 postpartum. Milk samples were collected on d 14 postpartum. From a larger cohort, we selected 20 BCAA-supplemented cows with the greatest plasma urea nitrogen concentration, as an indicator for greater BCAA availability, for the metabolomics analysis herein. Serum and milk samples were subjected to a liquid chromatography-mass spectrometry-based assay, detecting and measuring the abundance of 241 serum and 211 milk metabolic features, respectively. Multivariable statistical analyses revealed that BCAA supplementation altered the metabolome profiles of both serum and milk samples. Increased abundance of serum phosphocholine and glutathione and of milk Val, Ile, and Leu, and decreased abundance of milk acyl-carnitines were associated with BCAA supplementation. Altered phosphocholine and glutathione abundances point to altered hepatic choline metabolism and antioxidant balance, respectively. Altered milk acyl-carnitine abundances suggest changes in mammary fatty acid metabolism. Dietary BCAA supplementation was associated with a range of alterations in serum and milk metabolome profiles, adding to our understanding of the role of BCAA availability in modulating dairy cow protein, lipid, and energy metabolism on a whole-body level and how it affects milk composition.

347 Using Whole Cottonseed to Replace Dried Distillers Grains Plus Solubles and Prairie hay in Finishing Rations Balanced for Physically Effective Neutral Detergent Fiber

Abstract The objective of this experiment was to determine the effects of replacing hay and dried distillers grains plus solubles (DDGS) with whole cottonseed (WCS) in diets balanced for physically effective neutral detergent fiber (peNDF) on performance, carcass characteristics, and plasma metabolites of finishing cattle. Heifers (n = 103) and steers (n = 104) were blocked by sex and bodyweight (BW) and randomly allocated to pens within block (6 pens per treatment). Pens were randomly allocated to 1 of 2 experimental treatments: a control diet (CON; prairie hay, DDGS, dry-rolled corn, and liquid supplement), and a WCS diet (CTN; WCS, dry-rolled corn, and molasses). A vitamin and mineral supplement and urea were included in both diets at same rate. Data were collected on 14 d intervals through d 56, then every 28 d until harvest. Animals were harvested in 3 different groups based on BW block. Average daily gain (ADG) and gain to feed ratio (G:F) were greater for the CTN treatment overall (P ≤ 0.05), and the CTN treatment tended to have a greater final BW (P = 0.10). Fecal consistency score was greater for CON treatment on d 42, at beginning of the beta-agonist feeding period, and at the final collection (P ˂ 0.03). The CTN treatment had a more neutral fecal pH on d 140 and at the final collection (P ˂ 0.01). No treatment × day interaction (P ≥ 0.70) was detected for plasma glucose, lactate, or urea nitrogen (PUN) concentrations. The CON treatment had greater plasma lactate and PUN concentrations (P ˂ 0.01). A day effect was observed for all analyzed plasma metabolites (P ˂ 0.01). This experiment suggests that WCS improves growth performance and feed efficiency when replacing the roughage and byproduct protein and fat source within a finishing diet.

PSIII-A-7 Conditioning of Goats to Livestock Trailer: Effects on Physiological Stress Responses During Long-Distance Transportation

Abstract Meat goats are often transported long distances under commercial situations in the US. In a split-plot design, 168 twelve-month-old male Spanish goats were used to determine the effects of habituation to trailers on behavior and stress responses when transported for long periods. Animals were separated into two treatment (TRT) groups and maintained on two different paddocks. Concentrate supplement was fed to one group inside two livestock trailers (5.0 × 2.3 m each; habituated group, H), while the other group received the same quantity of concentrate, but not inside the trailers (non-habituated, NH). After 4 weeks of habituation period, goats were subjected to a 10-hour transportation stress in 4 replicates (n = 21 goats/replicate/TRT). Blood samples were collected prior to loading (Preload), 20 min after loading (0 h), and at 2, 4, 6, 8, and 10 h of transportation (Time). Behaviors of goats after loading were not affected by treatment. Plasma cortisol, glucose, and urea nitrogen concentrations and creatine kinase (CK) activities were significantly influenced by Time (P &amp;lt; 0.01). Plasma cortisol was not affected by TRT; however, glucose and CK in the H group tended to be lower than the NH group. Plasma non-esterified fatty acid (NEFA) concentrations were significantly lower (P &amp;lt; 0.01) in the H group than the NH group, likely in response to epinephrine release. There was a TRT × Time effect (P &amp;lt; 0.05) on CK activities, with the values increasing in the NH group and decreasing in the H group during the first two hours of transportation. Lymphocyte to neutrophil ratio also increased (P &amp;lt; 0.01) over transportation time. Habituation to trailer may be beneficial during long distance transportation of goats as indicated by certain physiological stress responses. Habituation may also facilitate the loading process, based on behavioral observations.

265 Effects of non-Starch Polysaccharide Degrading Enzymes + Lysophospholipids in Feeds with Varied ME Contents on Growth Performance and Nutrient Utilization of Pigs from 25 to 75 Kg BW

Abstract This study aimed to investigate efficacy of the combinational use of non-starch polysaccharide degrading enzymes (NSPase) and lysophospholipids (LPL) on growth performance and nutrient utilization in pigs fed feeds with varied metabolizable energy (ME) levels. Grower pigs (n = 270; 28.1 ± 0.6 kg BW) were allotted in a randomized complete block design with a 3 x 3 factorial arrangement of treatments fed for 51 d in 2 phases (30 and 21 d, respectively). Two factors were ME (3,260, 3,335, and 3,410 kcal/kg) and NSPase + LPL (ELPL at 0.00, 0.05, and 0.10%). Growth performance and backfat were measured. Blood was collected to measure plasma urea nitrogen (PUN) concentrations. Data were analyzed using the MIXED procedure on SAS 9.4. Increasing ME tended to increase (P = 0.066) ADG during Grower 2 and increased (P &amp;lt; 0.05) G/F during the overall period. Increasing ELPL supplementation increased (P &amp;lt; 0.05) both ADG and ADFI during Grower 2, whereas it tended to reduce (P = 0.084) G/F during the overall period. Supplemental effects of ELPL on increasing ADG was prominent (P &amp;lt; 0.05) at high ME content (3% above NRC requirement). Supplementation of ELPL tended to reduce (P = 0. 057) G/F during Grower 2 at low ME content (3% below NRC requirements). Backfat thickness and NEFA were not influenced by 2 factors. Increasing ME increased (P &amp;lt; 0.05) PUN during Grower 1 whereas increasing ELPL tended to increase (P = 0.077) PUN during Grower 2. In conclusion, supplementation of ELPL enhanced growth and feed intake of pigs from 50 to 75 kg BW, especially when dietary ME was above NRC requirement (3%) by fat supplementation (4%). These improvements may be due to increased nutrient utilization as indirectly indicated by increased PUN during fed status.

Effect of the timing of sodium acetate infusion on the daily rhythms of milk synthesis and plasma metabolites and hormones in Holstein cows.

Dairy cows have a daily pattern of feed intake which influences ruminal fermentation and nutrient absorption. Milk synthesis also exhibits a daily rhythm and is altered by the timing of feed availability. Nutrients can regulate physiological rhythms, but it is unclear which specific nutrients affect the rhythms of milk synthesis in the cow. The objective of this study was to determine the effect of the timing of acetate infusion on the daily rhythms of feed intake, milk synthesis, milk fatty acids, plasma insulin and metabolites, and core body temperature. Ten lactating ruminally cannulated Holstein cows (127 ± 24.6 d in milk; mean ± standard deviation) were arranged in a 3 × 3 Latin square design. Treatments were ruminal infusions of 600 g/d of acetate either continuously throughout the day (CON) or over 8 h/d during the day (day treatment, DT; 0900 to 1700 h) or the night (night treatment, NT; 2100 to 0500 h). Experimental periods were 14 d with a 7-d washout between periods. Cows were milked every 6 h during the final 7 d of each experimental period to determine the daily pattern of milk synthesis. Blood samples were taken to represent every 4 h across the day and plasma glucose, insulin, β-hydroxybutyrate, urea nitrogen, and acetate concentration were measured. An intravaginal temperature logger was used to measure core body temperature. Data were analyzed with cosinor-based rhythmometry to test the fit of a cosine function with a period of 24 h and to determine the acrophase (time at peak) and amplitude (peak to mean) of each rhythm. Milk yield fit a daily rhythm for all treatments and DT and NT phase-delayed the rhythm and DT increased the robustness of the rhythm. Milk protein concentration fit a daily rhythm for all treatments and DT increased robustness, whereas NT phase-delayed the rhythm. Plasma acetate concentration also fit a daily rhythm in all treatments. Plasma acetate peaked at ∼1600 h in CON and DT and at 0053 h in NT, reflecting the timing of treatment infusions. There was a daily rhythm in plasma β-hydroxybutyrate that reflected the plasma acetate rhythm. Core body temperature fit a rhythm for all treatments, but the amplitude of the rhythm was smaller than previously observed. In conclusion, the timing of acetate infusion influences peripheral rhythms of milk synthesis and plasma metabolites.

Frequency of β-Casein Gene Polymorphisms in Jersey Cows in Western Japan.

Simple SummaryReports presenting survey results for β-casein gene polymorphisms have increased, but none have been about Jersey cows in Asia. This study examined the CSN2 gene variants for 590 Jersey cows in Okayama Prefecture, located in the western region of Japan. Blood samples were collected at eight farms, and nucleotide substitutions were determined by sequencing exon 7 regions of chromosome 6 of the CSN2 gene. Blood biochemical analyses were also performed to clarify if A1A1, A1A2, and A2A2 cows differ in their metabolic profiles. The frequency of the A2 allele found in this study was numerically higher than those reported for Holsteins, crossbreeds, and Mexican and Danish Jerseys. The β-casein genotypes did not affect the metabolism of the major nutrients.This study aimed to investigate β-casein gene polymorphisms in Jersey cows in Japan. Blood samples were collected from 590 cows from eight Jersey farms in Okayama Prefecture, western Japan. Sequence analysis of exon 7 regions in chromosome 6 of the CSN2 gene revealed the genotype and allele frequencies of the β-casein variants. Considering that variant B belongs to the A1 group and variant I to the A2 group, plasma metabolite concentrations were compared among the A1A1, A1A2, and A2A2 group-based genotypes. The most frequent genotype was A2A2 (0.558), followed by A2B (0.190) and A2I (0.103). No variants of A3, F, G, H1, or H2 were found. The frequencies of group-based genotypes were A1A1 (0.032), A1A2 (0.303), and A2A2 (0.665). Although farm-to-farm differences were observed in the plasma concentrations of urea nitrogen, calcium, and phosphorus, no differences were found between the A1A1, A1A2, and A2A2 group-based genotypes; hence, the β-casein genotypes did not affect the metabolism of major nutrients. Owing to the high frequency of the A2 variant, Jersey cows can be considered an attractive breed for marker-assisted selection to create A2A2 herds.

Influences of Dietary Vitamin E, Selenium-Enriched Yeast, and Soy Isoflavone Supplementation on Growth Performance, Antioxidant Capacity, Carcass Traits, Meat Quality and Gut Microbiota in Finishing Pigs.

This study investigated the effects of dietary compound antioxidants on growth performance, antioxidant capacity, carcass traits, meat quality, and gut microbiota in finishing pigs. A total of 36 barrows were randomly assigned to 2 treatments with 6 replicates. The pigs were fed with a basal diet (control) or the basal diet supplemented with 200 mg/kg vitamin E, 0.3 mg/kg selenium-enriched yeast, and 20 mg/kg soy isoflavone. Dietary compound antioxidants decreased the average daily feed intake (ADFI) and feed to gain ratio (F/G) at d 14–28 in finishing pigs (p < 0.05). The plasma total protein, urea nitrogen, triglyceride, and malondialdehyde (MDA) concentrations were decreased while the plasma glutathione (GSH) to glutathione oxidized (GSSG) ratio (GSH/GSSG) was increased by compound antioxidants (p < 0.05). Dietary compound antioxidants increased loin area and b* value at 45 min, decreased backfat thickness at last rib, and drip loss at 48 h (p < 0.05). The relative abundance of colonic Peptococcus at the genus level was increased and ileal Turicibacter_sp_H121 abundance at the species level was decreased by dietary compound antioxidants. Spearman analysis showed a significant negative correlation between the relative abundance of colonic Peptococcus and plasma MDA concentration and meat drip loss at 48 h. Collectively, dietary supplementation with compound antioxidants of vitamin E, selenium-enrich yeast, and soy isoflavone could improve feed efficiency and antioxidant capacity, and modify the backfat thickness and meat quality through modulation of the gut microbiota community.

Comparison of Global Metabolite for Growing Pigs Fed at Metabolizable Energy Requirement for Maintenance.

Though the energy requirement for maintenance is an important part of net energy system, little is known of the metabolic characteristics of maintenance energy expenditure. This study was investigated the effect of feeding level at metabolizable energy requirement for maintenance (FLM) on plasma metabolites in growing pigs. Ten barrows (22.5 ± 0.5 kg BW) were kept in metabolism crates and catheterized in the precaval vein during adaptation period. Pigs were fed a corn-soybean meal diet at 782 kJ ME/kg BW0.6·d−1 during d 1 to 8 and then were refeeding at 2,400 kJ ME/kg BW0.6·d−1 on d 9. Plasma samples of each pig were collected by catheter on the morning of d 1, 3, 5, 7, 9, and 10, respectively, for metabolomics testing. Results showed that the concentration of plasma urea nitrogen decreased under FLM (p < 0.01) and increased significantly after refeeding (p < 0.01). The concentration of total cholesterol, high-density lipoprotein, low-density lipoprotein, and albumin in plasma were decreased significantly after refeeding (p < 0.01). Eleven identified compounds were up-regulated and six ones were down-regulated under FLM. In conclusion, the energy metabolism of growing pigs was relatively stable after 4 days of feeding at FLM.