PSXII-4 Serum citrulline concentration of unweaned calves transported by road as a potential biomarker of gut functionality

Abstract In human’s serum citrulline concentration (SCC) have been proposed as a biomarker of small intestinal absorption. We hypothesize that the stress and feed restriction that unweaned calves suffer during transport impairs gut functionality reducing SCC. The aim of this study was to evaluate if road transport hours and adaptation period after arrival would affect SCC in unweaned calves. A total of 1,601 calves (3–4 wk of age; 65 ± 9 kg of BW) were transported with 8 trucks (n = 4 each journey): short transport (ST; < 9 h), and long transport with a rest stop proving feed and water to the calves (LT; > 9 h). A subset of 20 calves for each truck were sampled for SCC at arrival (t0), and 14 d after arrival (t14); in case of LT, also at arrival at the resting facility (t-1). SCC was analyzed using a commercial kit (intra- and inter-assay CV were 12.62% and 6.32%). Data was analyzed using a mixed model with journey hours and day as main effects, and calf and truck as random effects. SCC tended (P = 0.08) at t0 to be greater in LT (47.7 ± 3.39 mM) compared to ST (42.6 ± 2.46 mM). At t14 SCC increased in ST and LT calves; however, no differences were observed in SCC (55.9 ± 3.42 mM vs. 58.8 ± 2.52 mM for LT and ST, respectively). In LT calves rest stop did not affect SCC (43.2 ± 1.74 mM vs. 39.8 ± 1.76 mM for t-1 and t0, respectively), while at t14 (50.6 ± 1.86 mM) SCC was greater (P < 0.001) than t0 and t-1. The effect of transport type and evolution after transport on serum plasma citrulline concentrations may suggest that it’s a potential indicator of gut functionality in unweaned calves.

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Effects of kinship correction on inflation of genetic interaction statistics in commonly used mouse populations

G3 Genes|Genome|Genetics ◽

10.1093/g3journal/jkab131 ◽

2021 ◽

Author(s):

Anna L Tyler ◽

Baha El Kassaby ◽

Georgi Kolishovski ◽

Jake Emerson ◽

Ann E Wells ◽

...

Keyword(s):

Mixed Model ◽

Linear Mixed Model ◽

Genetic Interaction ◽

Recombinant Inbred Lines ◽

Test Statistics ◽

Test Statistic ◽

Kinship Matrix ◽

Main Effect ◽

Main Effects ◽

Interaction Test

Abstract It is well understood that variation in relatedness among individuals, or kinship, can lead to false genetic associations. Multiple methods have been developed to adjust for kinship while maintaining power to detect true associations. However, relatively unstudied, are the effects of kinship on genetic interaction test statistics. Here we performed a survey of kinship effects on studies of six commonly used mouse populations. We measured inflation of main effect test statistics, genetic interaction test statistics, and interaction test statistics reparametrized by the Combined Analysis of Pleiotropy and Epistasis (CAPE). We also performed linear mixed model (LMM) kinship corrections using two types of kinship matrix: an overall kinship matrix calculated from the full set of genotyped markers, and a reduced kinship matrix, which left out markers on the chromosome(s) being tested. We found that test statistic inflation varied across populations and was driven largely by linkage disequilibrium. In contrast, there was no observable inflation in the genetic interaction test statistics. CAPE statistics were inflated at a level in between that of the main effects and the interaction effects. The overall kinship matrix overcorrected the inflation of main effect statistics relative to the reduced kinship matrix. The two types of kinship matrices had similar effects on the interaction statistics and CAPE statistics, although the overall kinship matrix trended toward a more severe correction. In conclusion, we recommend using a LMM kinship correction for both main effects and genetic interactions and further recommend that the kinship matrix be calculated from a reduced set of markers in which the chromosomes being tested are omitted from the calculation. This is particularly important in populations with substantial population structure, such as recombinant inbred lines in which genomic replicates are used.

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The influence of xylanase on the fermentability, digestibility, and physiochemical properties of insoluble corn-based fiber along the gastrointestinal tract of growing pigs

Journal of Animal Science ◽

10.1093/jas/skab159 ◽

2021 ◽

Author(s):

Amy L Petry ◽

Nichole F Huntley ◽

Michael R Bedford ◽

John F Patience

Keyword(s):

Mixed Model ◽

Linear Mixed Model ◽

Nutrient Digestibility ◽

Growing Pigs ◽

Neutral Detergent Fiber ◽

Adaptation Period ◽

High Fiber ◽

Gross Energy ◽

Digesta Viscosity ◽

The Impact

Abstract In theory, supplementing xylanase in corn-based swine diets should improve nutrient and energy digestibility and fiber fermentability, but its efficacy is inconsistent. The experimental objective was to investigate the impact of xylanase on energy and nutrient digestibility, digesta viscosity, and fermentation when pigs are fed a diet high in insoluble fiber (>20% neutral detergent fiber; NDF) and given a 46-d dietary adaptation period. Three replicates of 20 growing gilts were blocked by initial body weight, individually housed, and assigned to 1 of 4 dietary treatments: a low-fiber control (LF) with 7.5% NDF, a 30% corn bran high-fiber control (HF; 21.9% NDF), HF+100 mg xylanase/kg [HF+XY, (Econase XT 25P; AB Vista, Marlborough, UK)] providing 16,000 birch xylan units/kg; and HF+50 mg arabinoxylan-oligosaccharide (AXOS) product/kg [HF+AX, (XOS 35A; Shandong Longlive Biotechnology, Shandong, China)] providing AXOS with 3-7 degrees of polymerization. Gilts were allowed ad libitum access to fed for 36-d. On d 36, pigs were housed in metabolism crates for a 10-d period, limit fed, and feces were collected. On d 46, pigs were euthanized and ileal, cecal, and colonic digesta were collected. Data were analyzed as a linear mixed model with block and replication as random effects, and treatment as a fixed effect. Compared with LF, HF reduced the apparent ileal digestibility (AID), apparent cecal digestibility (ACED), apparent colonic digestibility (ACOD), and apparent total tract digestibility (ATTD) of dry matter (DM), gross energy (GE), crude protein (CP), acid detergent fiber (ADF), NDF, and hemicellulose (P<0.01). Relative to HF, HF+XY improved the AID of GE, CP, and NDF (P<0.05), and improved the ACED, ACOD, and ATTD of DM, GE, CP, NDF, ADF, and hemicellulose (P<0.05). Among treatments, pigs fed HF had increased hindgut DM disappearance (P=0.031). Relative to HF, HF+XY improved cecal disappearance of DM (162 vs. 98g; P=0.008) and NDF (44 vs. 13g; P<0.01). Pigs fed xylanase had a greater proportion of acetate in cecal digesta and butyrate in colonic digesta among treatments (P<0.05). Compared with LF, HF increased ileal, cecal, and colonic viscosity, but HF+XY decreased ileal viscosity compared with HF (P<0.001). In conclusion, increased insoluble corn-based fiber decreases digestibility, reduces cecal fermentation, and increases digesta viscosity, but supplementing xylanase partially mitigated that effect.

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PSIV-1 Apparent and Standardized Ileal Digestibility of Amino Acids in Dry Extruded-Expelled Soybean Meal Fed to Growing Pigs Without or With Organic Acids and Multi-Carbohydrase

Journal of Animal Science ◽

10.1093/jas/skaa278.497 ◽

2020 ◽

Vol 98 (Supplement_4) ◽

pp. 275-276

Author(s):

Jichen Song ◽

Charles Martin Nyachoti

Keyword(s):

Soybean Meal ◽

Mixed Model ◽

Interactive Effect ◽

Latin Square ◽

Growing Pigs ◽

Final Model ◽

Ileal Digestibility ◽

Positive Effects ◽

Dietary Treatments ◽

Main Effects

Abstract Dry extruded-expelled soybean meal (DESBM) is an attractive feed ingredient for swine not only as a protein source but also as a good source of energy because of its high fat content. Apparent (AID) and standardized (SID) ileal amino acid (AA) digestibility in DESBM fed without or with organic acid (OA) and a multicarbohydrase (MC) supplementation to growing pigs were determined. Ten ileal-cannulated barrows (17.3 ± 0.4 kg BW) were randomly assigned to 1 of 5 dietary treatments in a replicated 5 × 4 incomplete Latin square design with 4 periods, each consisting of 5 d of adaptation and 2 d of ileal digesta collection. Four cornstarch-based diets with 44.4% DESBM as the only source of AA, without or with OA and MC supplementation, and a 5% casein-cornstarch diet were used. All diets contained 0.3% titanium dioxide. Data were analyzed using the MIXED model procedures of SAS, with the final model including OA, MC, and the interaction between OA and MC as the main effects. The SID of indispensable AA in DESBM fed to growing pigs were: Arg, 93.2%; His, 85.1%; Ile, 87.1%; Leu, 87.6%; Lys, 88.7%; Met, 87.8%; Phe, 88.4%; Thr, 81.4%; Trp, 73.6%; Val, 84.5%. OA supplementation decreased the AID and SID (P < 0.05) of Arg, Ile, Asp, and Glu, and tended (P < 0.10) to decrease the AID and SID of Phe, Trp, Cys, Gly, and Tyr. MC supplementation did not affect the AID and SID of AA, and no interactive effect on AA digestibility was observed between OA and MC supplementation. In conclusion, dietary supplementation of OA and MC showed no positive effects on improving AA digestibility in DESBM fed to growing pigs.

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