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Johnsongrass [Sorghum halepense (L.) Pers.] is a non-native, invasive species that causes substantial losses in row crops and hay fields, which could be minimized by using Johnsongrass as a conserved forage. Two experiments were conducted to evaluate the yield and quality of Johnsongrass ensiled at four maturities: harvested every 3 weeks (3WK), boot stage (BOOT), flower stage (FLOWER), and dough (DOUGH) stages. In experiment 1, yield, botanical composition, nutritive value, and fermentation characteristics of Johnsongrass were measured. In experiment 2, Johnsongrass silage was incubated for 48 h for assessment of gas production, pH, in vitro dry matter digestibility (IVDMD), and volatile fatty acids. The experimental area consisted of 16 plots (2.74 m × 4.57 m) divided into four blocks, and treatment was randomly assigned to plot within block. Each year, silage was prepared for each plot from the two cutting closest to July 1. After 10 weeks, the silos were opened, and silage samples were frozen for further analysis. Data from both experiments were tested for the effects of maturity stage and harvest timing (first and second harvest). The results from experiment 1 showed an increase (P < 0.0001) in dry matter yield from 3WK stage to DOUGH. Johnsongrass, as a proportion of the total botanical composition, declined at the end of the growing season for 3WK but increased in FLOWER (P = 0.0010). In the first harvest, 3WK and BOOT stage silages had the greatest concentrations of crude protein and total digestible nutrients and lowest of fiber (neutral detergent fiber and acid detergent fiber; P < 0.0001). In the second harvest, differences in nutrient content were significant only for 3WK silages, which showed the best nutritive value (P < 0.0001). In experiment 2, IVDMD of silage followed the same trends described for nutritive value from experiment 1. Overall, these results demonstrate that Johnsongrass can be successfully ensiled, but to optimize forage nutritive value and quantity, Johnsongrass should be ensiled before it reaches the flower stage.

Encroaching plant species in West Texas continues to significantly reduce livestock production capacity and cause an imbalance between plant and livestock ecology. Juniperus ashei and Juniperus pinchotii are encroaching species rarely used by browsing animals, mainly due to phytochemical defenses. Juniperus spp. contain large concentrations of monoterpenes in their essential oil profiles to deter herbivory. Since 2003, two divergent bloodlines of meat goats have been selected to consume low or high (LJC or HJC) amounts of juniper foliage, through screening fecal samples with near-infrared reflectance spectroscopy. However, it remains unclear whether HJC goats expressed a physiological ability to consume a greater amount of juniper or if they were colonized by a ruminal microbial population that could detoxify juniper phytochemicals. Therefore, this study aimed to investigate the impact of 0.00 and 1.97 mM of camphor on the mixed ruminal microorganism fermentation after 0, 1, 2, 4, 12, and 24 h of incubation. Five LJC and five HJC goats were fed a juniper-free diet (n = 10) and five LJC and five HJC goats (n = 10), were fed a diet containing 30% fresh J. ashei leaves for 21 days prior to ruminal fluid collection. In vitro fermentations used LJC and HJC, ruminal fluid inoculum was added (33% v/v) to anoxic media in sealed Balch tubes. Total short-chain fatty acid (SCFA) production and acetate to propionate ratio were increased (P < 0.05), but there was no effect on pH (6.56 ± 0.09). Goats that received the juniper-free diet had higher (P < 0.05) SCFA production than juniper-containing diets. There was no consistent difference in LJC and HJC microbial fermentation end products caused by the addition of 1.97 mM of camphor, and goats receiving a juniper-free diet consistently generated more SCFAs in the presence of 1.97 mM of camphor. Furthermore, bloodline differences in juniper consumption were likely related to physiological adaption capacities within the animal and not a ruminal microbial detoxification advantage.

The microbial population in the gastrointestinal tract of ruminant animals aids in the utilization of forages with high levels of secondary plant compounds. Two divergent bloodlines of meat goats have been selected by screening fecal samples with near-infrared reflectance spectroscopy to assess the goat’s consumption of high or low levels of Juniperus sp. leaves containing several monoterpenes, including camphor. The mechanism by which these goats can consume greater concentrations of Juniperus spp. leaves than their counterparts is unclear, and therefore, this study was designed to determine if differences existed between the ruminal microbial populations of the low and high juniper-consuming bloodlines (LJC vs. HJC) by analyzing their ruminal microbiota and fermentation end products. In the present study, concentrations (0.00, 0.5, 0.99, 1.97, or 5.91 mM) of camphor were added to mixed ruminal microorganism fermentation. Five LJC and five HJC goats were fed a juniper-free diet (n = 10), and five LJC and five HJC goats (n = 10) were fed a diet that contained 30% fresh Juniperus ashei leaves for 21 d prior to ruminal fluid collection. In vitro fermentations used LJC and HJC, ruminal fluid inoculum added (33% v/v) to anoxic media in sealed Balch tubes. Camphor increased (P < 0.05) total short-chain fatty acid (SCFA) concentrations for all but one experimental group. Between the main dietary and bloodline goat effects, the diet was significant for all SCFA results except butyrate. In contrast, bloodline was only significant for acetate and butyrate molar proportions. Rumen fluid from juniper-free-fed goats exhibited greater concentrations of Ruminococcaceae, whereas juniper-fed goats contained more Coriobacteriaceae. Results demonstrated that mixed ruminal microorganisms fermentations from HJC goats did not produce greater concentrations of SCFAs or have the ability to degrade camphor at a higher rate than did that from LJC goats. Results suggest that camphor tolerance from J. ashei, was related to hepatic catabolic mechanisms instead of ruminal microbial degradation; however, further in vivo work is warranted.

Due to consumer demand and changing welfare standards on health, ecology, equity, and safety concepts, poultry production has changed markedly over the past 20 y. One of the greatest changes to poultry production standards is now offering poultry limited access to the outdoors in alternative and organic poultry production operations. Although operations allowing access to the outdoors are still only a small portion of commercial poultry production, it may impact the gastrointestinal (GIT) health of the bird in different ways than birds raised under conventional management systems. The present review describes current research results in alternative systems by identifying how different poultry production operations (diet, environmental disruptive factors, diseases) impact the ecology and health of the GIT. Various research efforts will be discussed that illustrate the nutritional value of free-range forages and how forages could be beneficial to animal health and production of both meat and eggs. The review also highlights the need for potential interventions to limit diseases without using antibiotics. These alternatives could enhance both economics and sustainability in organic and free-range poultry production.

Numerous studies have examined the link between the presence of specific gastrointestinal bacteria and the feed efficiency of cattle. However, cattle undergo dietary changes during their productive life which can cause fluctuations in their microbial consortium. The objective of the present study was to assess changes in the fecal microbiome of beef steers genetically selected to be divergent in feedlot feed efficiency, to determine whether differences in their fecal microbiomes could be detected as early as weaning, and continued throughout the rearing process regardless of dietary changes. Fecal samples were collected at weaning, yearling age, and slaughter for a group of 63 steers. Based on their feedlot-finishing performance, the steers were selected and divided into two groups according to their residual feed intake (RFI): efficient steers (low-RFI; n = 7) and inefficient steers (high-RFI; n = 8). To ascertain the fecal microbial consortium and volatile fatty acid (VFA) content, 16S rRNA gene sequencing and VFA analysis were performed. Overall, bacterial evenness and diversity were greater at weaning compared to yearling and slaughter for both efficiency groups (P < 0.001). Feedlot RFI linearly decreased as both Shannon diversity and Ruminococcaceae abundance increased (R2 = 65.6 and 60.7%, respectively). Abundances of Ruminococcaceae, Rikenellaceae, and Christensenellaceae were higher at weaning vs. yearling age and slaughter (P < 0.001); moreover, these families were consistently more abundant in the feces of the low-RFI steers (for most of the timepoints evaluated; P ≤ 0.05), compared to the high-RFI steers. Conversely, abundances of Bifidobacteriaceae were numerically higher in the feces of the high-RFI steers throughout their lifespan. Total VFA concentrations increased at slaughter compared to weaning and yearling for both efficiency groups (P < 0.001). The acetate:propionate ratio decreased linearly (P < 0.001) throughout the life of the steers regardless of their efficiency, reflective of dietary changes. Our results indicate that despite fluctuations due to animal age and dietary changes, specific bacterial families may be correlated with feed efficiency of steers. Furthermore, such differences may be identifiable at earlier stages of the production cycle, potentially as early as weaning.

Volatile oils have potent antimicrobial activities that have allowed them to be used as food preservatives for millennia. The impact of concentrations of the monoterpene volatile oils camphor and eucalyptol on the growth of the cattle and foodborne pathogen Salmonella Newport was evaluated by examining changes in optical density (600 nm). Cultures of S. Newport were grown in Tryptic Soy Broth (TSB) overnight and inoculated into fresh TSB tubes at an initial concentration of ~106 CFU/mL in the presence of monoterpene concentrations (0 – 9.85 mM) and were incubated at 39℃. Final optical density and maximum specific growth rates (h-1) were determined. Data were analyzed using a PROC GLM procedure in SAS 9.4 for a 2*5 repeated measure factorial. Overall, there was a concentration (P < 0.01) and a time by concentration (P < 0.01) effect, but no differences between monoterpene types (P = 0.28) were observed. Camphor and eucalyptol concentrations of 3.28 and 9.85 mM reduced (P < 0.05) S. Newport growth. The highest dose (9.85 mM) of camphor and eucalyptol immediately inhibited S. Newport growth. Maximum specific growth rate was reduced (P < 0.01) by both monoterpenes compared to controls, most particularly at 9.85 mM concentrations, but were not different between the two monoterpenes. Collectively, our results suggest that monoterpenes at high concentrations can reduce the growth of Salmonella Newport; however, to fully understand practical implementation of monoterpene effects on foodborne or animal pathogens, studies using both mixed culture and in vivo models are needed. Tuesday, July 21, 2020

Abstract: Encroaching plant species in West Texas continue to significantly reduce livestock production capacity and cause an imbalance between plant and livestock ecology. Juniperus ashei and J. pinchotii are encroaching species, mainly due to evolutionary measures, such as phytochemicals that deter herbivory. These plants contain large percentages of monoterpenes in their essential oil profiles. Since 2005, two divergent bloodlines of meat goats have been selected to consume low or high (LJC or HJC) amounts of juniper foliage, through the use of screening fecal samples with near-infrared reflectance spectroscopy. Through the breeding process, it became unclear whether the HJC goats expressed a physiological ability to consume a greater amount of juniper or if there was a ruminal microorganism advantage in which the microbes where less susceptible to the juniper phytochemicals. Therefore, this study aimed to investigate the ruminal fermentation byproduct impact of 0.00 and 1.97 mM of camphor at 0, 1, 2, 4, 12, and 24 hr of incubation at 39°C. Five LJC and five HJC goats were fed a juniper-free diet and five LJC and five HJC goats were fed a diet containing 30% fresh J. ashei leaves for 21 days prior to ruminal fluid collection. In vitro fermentations used LJC and HJC ruminal fluid inoculate (33% v/v) in anoxic media in sealed Balch tubes. Across all treatment groups, 1.97 mM of camphor increased propionate and decreased A:P (P < .05) at each incubation time point without negatively impacting pH (6.56 ± 0.09). Results suggested that there is no consistent difference in LJC and HJC microbial fermentation byproducts from the addition of 1.97 mM of camphor; however, the results suggest that camphor could increase propionate production and create more gluconeogenic potential.

An in vitro experiment was performed to evaluate the effect of quality and supplementation (CON-control, no supplement, DDG-dried distillers grains, 29.32% CP, LFD-liquid feed, 56.45% CP) on IVDMD, NDF disappearance (NDFD) and ruminal fermentation parameters of Tifton 85 Bermudagrass (Cynodon dactylon). Forage was harvested at 2, 4, 6, 8, and 10 wk over three growing seasons to simulate various forage management practices. Samples were analyzed by Near-infrared spectroscopy and stratified by relative forage quality (RFQ). Samples were selected to represent high (120), medium (100) and low (80) RFQ. The LFD was added at 5.4% of DMI, equivalent to 0.91 kg (as fed) per head per day. The DDG was included at equivalent of 16.99%, 14.36%, and 12.23% of total DM for the high, medium, and low low RFQ forages, respectively, to make the treatments isonitrogenous to the LFD treatments. Fermentations were carried out for 48 h on 3 d. The experiment was analyzed as a 3 x 3 factorial; arrangement with RFQ and type of supplement as factors. The IVDMD (46.9, 54.6, and 62.8%) and NDFD (41.7, 53.8, and 56.1%) increased (P < 0.001) as RFQ increased. Supplementation increased (P < 0.009) NDFD (39.7, 49.5, and 59.5%) but only the LFD increased IVDMD (52.7, 55.4 and 56.2%). An RFQ x supplement interaction was observed for IVDMD (P < 0.001) and NDFD (P < 0.007). No effects of supplementation were observed for high RFQ. For medium RFQ forage quality only LDF increased IVDMD and DDG was not different from CON or LDF; and no effect of supplementation was observed for NDFD. Supplementation increased IVDMD and NDFD for low RFQ forage. There was no effect of supplementation on total gas production or total VFA concentrations. Supplementation with LFD and DDG improves IVDMD and NDFD in low RFQ Bermudagrass, and LFD supplementation can enhance IVDMD in medium RFQ forage quality

The objective of this study was to determine the effect of altering dietary levels of manganese and selenium on growth performance and MnSOD specific activity. Weaned piglets were blocked by weight (n = 216; 5.21 ± 1.17 kg; 21 ± 3 d) and sex (2 barrows and 2 gilts/pen). Pens within a block were randomly assigned to dietary treatments in a factorial design with main effects of Se (0.1 and 0.3 ppm) and Mn (0, 12, and 24 ppm). Diets (n = 9 pens/treatment) were fed in three phases (P1 = d 1–7, P2 = d 7–21, P3 = d 21–35). Pigs and orts were weighed weekly and pigs were bled on d 0, 7, 21, and 35 for analysis of specific activity of red blood cell MnSOD. Data were analyzed as 2x3 factorial design via SAS PROC GLM. There were no Se effects or Mn x Se interactions observed. There was a linear increase (P < 0.05) in overall ADG (397, 424, and 438 g day-1pig-1 for 0, 12, 24 ppm Mn, respectively). There was a linear trend (P < 0.1) in overall ADFI (557, 560, 592 g day-1pig-1 for 0, 12, 24 ppm Mn, respectively). Feed efficiency (d 0–35) across increasing Mn levels were 0.71, 0.76, 0.74 (P > 0.1). MnSOD activity in RBC increased from d 0–7, peaked on d 7 and decreased to d 35. On d 7, diets with 12 and 0 ppm Mn had significantly increased (P < 0.05) MnSOD activity (0.91 and 0.87 IU mg-1 protein, respectively) compared to diets with 24 ppm Mn (0.67 IU mg-1 protein). The dietary treatment that best maintained MnSOD activity was 0.3 ppm Se and 12 ppm Mn supplemented, while ADG was maximized in the diet with 0.3 ppm Se and 24 ppm Mn supplementation.

Most of the research efforts involving the bovine gastrointestinal microbiota have focused on cattle's forestomach, particularly the rumen, so information concerning the bovine fecal microbiota is more scarce, especially in young beef cattle. The present study was performed to evaluate the ruminal and fecal microbiotas of beef calves as they reached the end of their nursing phase. A total of 18 Angus cow/calf pairs were selected and assigned to one of two treatment groups for the last 92 days of the calves' nursing period, as follows: 1) calves were supplemented with concentrate in a creep feeding system; or 2) control group with no supplementation of calves. After 92 days, ruminal and fecal samples were individually obtained from calves in both groups, and their microbiotas were evaluated using 16S rRNA gene sequencing. Ruminal samples were predominated by Prevotella (18 to 23% of the total bacterial abundance), regardless if calves received supplementation or not; however, in the feces, Prevotella was only the seventh most abundant genus (0.6 to 2.1% of total bacterial abundance). Both the rumen (P = 0.01) and the feces (P = 0.05) of calves that received supplementation had greater abundance of Firmicutes. In addition, calves that were supplemented had lower abundance of Fibrobacteres (P = 0.03) in their rumens. Regardless if the calves were supplemented or not, Faith's Phylogenetic Diversity index (P ≤ 0.007) and total concentration of short chain fatty acids (P < 0.001) were both greater in the rumen than in the feces of calves. In summary, the ruminal and fecal microbiotas of weanling beef calves were considerably distinct. Additionally, supplementation with creep feed caused some significant changes in the composition of the gastrointestinal microbiota of the calves, especially in the rumen, where supplementation caused an increase in Firmicutes and a decrease in abundance of Fibrobacteres.