No abstract

Age and diet are among the factors that influence the community composition of the fecal microbiome. Additionally, antimicrobial use can alter the composition of bacterial communities. An 86-d study with finisher pigs aimed to evaluate age-related dynamics (d 98-177 of age), effects of types and levels of dietary fiber, and injectable antimicrobials on the fecal microbiome and antimicrobial resistance (AMR) was conducted. A total of 287 pigs, housed in 36 pens, with 7 to 8 pigs per pen, fed a corn grain and soybean meal-based basal diet, formulated to contain 8.7% neutral detergent fiber (NDF), were randomly assigned to one of three treatments: 1. basal diet with no supplement, 2. basal diet supplemented with 20% distillers dried grains with solubles (DDGS) formulated to contain 13.6% NDF, or 3. basal diet supplemented with 14.5% sugar beet pulp (SBP) formulated to contain 13.6% NDF. Five finisher pigs from each treatment group were selected randomly, and fecal samples were collected on d 98, 110, 144, and 177 of age. In addition, fecal samples were collected from pigs that were injected intramuscularly ceftiofur hydrochloride or penicillin G on d 1 and 3 along with pen-mate untreated controls on d 1. Fecal samples were subjected to 16S rRNA amplicon-based microbiome analysis and culture methods to quantify the abundance of total and AMR coliforms and enterococci populations. The alpha diversity, such as species richness, increased with age, and the overall bacterial composition changed with age (P =0.001) and diet (P = 0.001). Diet-associated shifts in the specific bacterial taxa were observed. The richness, diversity, and evenness of bacterial taxa did not differ between pigs that were injected with ceftiofur versus their untreated pen mates or by dietary treatments, but differed in pigs that received penicillin G injection. Both antimicrobial treatments contributed to changes in the overall fecal bacterial composition at the genus level. Collectively, the data demonstrate that both age and the diet (control vs. DDGS-, control vs. SBP- or DDGS- vs. SBP-based diets) were associated with overall bacterial community composition and the impact of age on variations in fecal microbiome composition was greater than the diet. Antibiotic treatment had minimal effect on bacterial diversity and relative abundance of taxa. Further, diets and antimicrobial treatment had minimal impact on the overall counts of AMR coliforms and enterococci populations in feces.

The objective of this study was to determine the effects of dietary fibre level and source on faecal ceftiofur metabolites concentrations after intramuscular administration of therapeutic ceftiofur hydrochloride in finisher pigs. Pens of finisher pigs (n = 36), with an equal number of barrows and gilts, were randomly assigned to 1 of 3 dietary treatment groups: basal diet composed of corn grain and soy bean meal with no supplement and formulated to contain 8.7% neutral detergent fibre (NDF), supplemented with 20% distillers dried grains with solubles (a byproduct of the ethanol production from corn grain) formulated to contain 13.6% NDF, primarily insoluble fibre or supplemented with 14.5% sugar beet pulp formulated to contain 13.6% NDF. Faecal samples were collected 6–8 hr after ceftiofur injection from treated and untreated pen‐mate pigs on days 1 and 3 of the 3‐day treatment regimen. Faecal concentrations of ceftiofur metabolites, including the major metabolite, desfuroylceftiofur, were analysed by reverse‐phase high pressure liquid chromatography with ultraviolet detection. Overall, the faecal concentrations of ceftiofur metabolites did not differ significantly between the dietary treatments. The mean concentrations of metabolites tended to be lower (p = .1) on day 3 compared to day 1 of the 3‐day treatment regimen. Faecal concentrations of metabolites were not affected by the gender of the finisher pigs. The concentrations of ceftiofur metabolites in the faeces are likely reflective of the microbial activity in the hindgut. Our data suggest that the fibre level and source used in the study did not affect the faecal concentrations of ceftiofur metabolites.

Two experiments were conducted to evaluate the effects of including liquid lactose (LL) and molasses (M) in swine diets on pellet quality and pig performance. In experiment 1, a total of 194 nursery pigs (DNA 241 × 600, initially 6.7 ± 0.4 kg at 27 d of age) were used in a 33-d experiment evaluating the effects of LL (SweetLac 63; Westway Feed Products, Tomball, TX) or cane molasses on nursery pig performance and pellet quality. Pelleted experimental diets were fed from d 0 to 21, and a common pelleted diet fed from d 21 to 33. Dietary treatments consisted of a control diet containing 19.1% total sugars from whey powder and whey permeate and experimental diets with a percentage of whey permeate replaced by either 5% or 10% LL or 9.4% cane molasses (5 LL, 10 LL, and 9.4 M, respectively). Hot pellet temperature and production rate decreased (P < 0.05) from the control to 9.4 M treatments with 5 LL and 10 LL having intermediate effects. Pellet durability index (PDI) increased (P < 0.05) in 5 LL, 10 LL, and 9.4 M, respectively. From d 0 to 7, pigs fed the 10 LL and 9.4 M treatment had the best G:F followed by the control and 5 LL treatments. From d 0 to 21, ADFI had a marginally significant improvement (P < 0.10) in pigs fed up to 10 LL in the diet. Fecal consistency scores at d 7 were also firmer (P < 0.05) in pigs fed 9.4 M compared with pigs fed the control or 5 LL treatments with pigs fed the 10 LL treatment being intermediate. There was no evidence for differences in fecal consistency scores for d 14. In experiment 2, a total of 289 finishing pigs (DNA 241 × 600; initially 53.5 ± 0.5 kg BW) were used in a 53-d experiment evaluating the effects of LL on pellet quality and finishing pig performance. Experimental diets were fed in pelleted form from d 0 to 53 divided into three phases. Dietary treatments were a corn-soybean meal control diet with 0%, 2.5%, 5%, and 7.5% LL added in the place of corn. PDI improved (linear, P < 0.01) with increasing inclusion of LL. There were no differences in ADG, ADFI, final BW, or carcass characteristics. Pigs fed diets with increasing levels of LL tended to have improved (quadratic, P = 0.070) G:F.

The objective of this study was to determine the effects of whole-corn moisture and hammermill screen size on subsequent ground corn moisture, particle size and flowability. Treatments were arranged as a 2 × 2 factorial design with two moisture concentrations (14.5 and 16.7%), each ground using 2 hammermill screen sizes (3 mm and 6 mm). Corn was ground using a lab-scale 1.5 HP Bliss Hammermill at three separate timepoints to create three replications per treatment. Ground corn flowability was calculated using angle of repose (AOR), percent compressibility, and critical orifice diameter (COD) measurements to determine the composite flow index (CFI). There was no evidence for a screen size × corn moisture interaction for ground corn moisture content (MC), particle size, standard deviation, or flowability metrics. Grinding corn using a 3 mm screen resulted in decreased (p < 0.041) moisture content compared to corn ground using the 6 mm screen. There was a decrease (p < 0.031) in particle size from the 6 mm screen to the 3 mm, but no evidence of difference was observed for the standard deviation. There was a decrease (p < 0.030) in percent compressibility as screen size increased from 3 mm to 6 mm. Angle of repose tended to decrease (p < 0.056) when corn was ground using a 6 mm screen compared to a 3 mm screen. For the main effects of MC, 16.7% moisture corn had increased (p < 0.001) ground corn MC compared to 14.5%. The 14.5% moisture corn resulted in decreased (p < 0.050) particle size and an increased standard deviation compared to the 16.7% moisture corn. The increased MC of corn increased (p < 0.038) CFI and tended to decrease (p < 0.050) AOR and COD. In conclusion, decreasing hammermill screen size increased moisture loss by 0.55%, decreased corn particle size by 126 µm and resulted in poorer flowability as measured by percent compressibility and AOR. The higher moisture corn increased subsequent particle size by 89 µm and had improved flowability as measured by CFI.

The objective of this study was to determine the effects of whole corn moisture and hammermill screen size on subsequent ground corn moisture, particle size, and flow-ability. Whole yellow dent #2 corn was used for this experiment. Treatments were arranged as a 2 × 2 factorial design with two moisture concentrations (as-received and high) each ground using 2 hammermill screen sizes (1/8 and 1/4 in). Corn was ground using a laboratory scale 1.5 HP Bliss Hammermill (Model 6K630B) at 3 separate time points to create 3 replications per treatment. Increasing initial whole corn moisture was accomplished by adding 5% water and heating at 55°C for 3 hours in sealed glass jars using a Fisherbrand Isotemp Oven (Model 15-103-051). Ground corn flowability was calculated using angle of repose (AOR), percent compressibility, and critical orifice diameter (COD) measurements to determine the composite flow index (CFI). There was no evidence for a screen size × corn moisture interaction for moisture content, particle size, standard deviation, or flowability metrics. Grinding corn using a 1/8 in screen resulted in decreased (P < 0.041) moisture content compared to corn ground using the 1/4 in screen. There was a decrease in particle size from the 1/4 in screen to the 1/8 in but no evidence of difference was observed for the standard deviation. There was a decrease (P < 0.03) in percent compressibility as screen size increased from 1/8 to 1/4 in. Angle of repose tended to decrease (P < 0 .056) when corn was ground using a 1/4 in screen compared to a 1/8 in screen. For the main effects of moisture content, high moisture corn had increased (P < 0.0001) ground corn moisture content compared to as-received corn. As-received corn resulted in decreased (P < 0.029) particle size and an increased standard deviation compared to the high moisture corn. Increased moisture content of corn increased (P < 0.038) CFI and tended to decrease (P < 0.056) AOR and COD. In conclusion, decreasing hammermill screen size increased moisture loss by 0.55%, corn particle size by 126 μm, and resulted in poorer flowability as measured by percent compressibility and AOR. High moisture corn increased subsequent particle size by 89 μm, therefore improving flowability as measured by CFI.

No abstract

A total of 287 pigs (DNA 600 × 241; initially 111.8 lb) were used in an 86-d experiment to determine the effect of dietary fiber source on finishing pig growth performance and carcass characteristics. There were 12 pens per treatment with 7 or 8 pigs per pen. Pens were randomly assigned to 1 of 3 dietary treatments consisting of a control (8.7% neutral detergent fiber; NDF), 20% dried distillers grains with solubles (DDGS; 13.6% NDF), or 14.5% sugar beet pulp (SBP; 13.6% NDF). Experimental diets were fed from d 0 to 86 in 3 phases; d 0 to 18, d 18 to 39, and d 39 to 86. From d 0 to 86, there was no evidence for treatment difference in ADG or ADFI. Pigs fed DDGS had marginally poorer F/G than the control or 14.5% SBP diets (P < 0.10). Caloric efficiency of net energy (NE) in kcal per lb of live gain was marginally poorer (P < 0.10) in pigs fed DDGS compared to those fed control and SBP. There was a decrease (P < 0.10) in hot carcass weight (HCW) and carcass yield (P < .0.05) in pigs fed DDGS and SBP compared to those fed the control diet. Loin depth marginally decreased (P < 0.10) in pigs fed SBP compared to the control, with those fed DDGS intermediate. Feed cost per pig was greatest (P < 0.05) for pigs fed SBP, followed by DDGS, with those fed the control diet having the least. Feed cost per lb of gain increased (P < 0.05) in pigs fed SBP, followed by DDGS, with those fed the control having the least. Gain value decreased (P < 0.05) in pigs fed SBP compared to the control, with those fed DDGS intermediate. Income over feed cost was poorest (P < 0.05) in pigs fed SBP, followed by DDGS, with those fed the control diet being the greatest. In conclusion, pigs fed DDGS tended to have poorer F/G compared to those fed the control diet or SBP. This can be explained by the overestimation of NE of the diet as demonstrated by an increase in caloric efficiency. Increasing dietary NDF reduced carcass yield and economic return.