The impact of maturity stages on yield, quality, and nutritive value of ensiled Johnsongrass [Sorghum halepense (L.) Pers].

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.

Impact of concentrations of camphor on the in vitro mixed ruminal microorganism fermentation from goats selected for consumption of low and high levels of Juniperus spp.-2.

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.

Impact of camphor on the in vitro mixed ruminal microorganism fermentation from goats selected for consumption of low and high levels of Juniperus spp. 1.

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 Impact of Pre-Slaughter Fasting on the Ruminal Microbial Population of Commercial Angus Steers.

Diet impacts the composition of the ruminal microbiota; however, prior to slaughter, cattle are fasted, which may change the ruminal microbial ecosystem structure and lead to dysbiosis. The objective of this study was to determine changes occurring in the rumen after pre-slaughter fasting, which can allow harmful pathogens an opportunity to establish in the rumen. Ruminal samples were collected before and after pre-slaughter fasting from seventeen commercial Angus steers. DNA extraction and 16S rRNA gene sequencing were performed to determine the ruminal microbiota, as well as volatile fatty acid (VFA) concentrations. Microbial richness (Chao 1 index), evenness, and Shannon diversity index all increased after fasting (p ≤ 0.040). During fasting, the two predominant families Prevotellaceae and Ruminococcaceae decreased (p ≤ 0.029), whereas the remaining minor families increased (p < 0.001). Fasting increased Blautia and Methanosphaera (p ≤ 0.003), while Campylobacter and Treponema tended to increase (p ≤ 0.086). Butyrate concentration tended to decrease (p = 0.068) after fasting. The present findings support that fasting causes ruminal nutrient depletion resulting in dysbiosis, allowing opportunistic pathogens to exploit the void in the ruminal ecological niche.

Evaluation of the Fecal Bacterial Communities of Angus Steers With Divergent Feed Efficiencies Across the Lifespan From Weaning to Slaughter.

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 (R 2 = 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.

An overview of health challenges in alternative poultry production systems.

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.

Comparison of the ruminal and fecal microbiotas in beef calves supplemented or not with concentrate.

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.