Unraveling aerobic cultivable cellulolytic microorganisms within the gastrointestinal tract of sheep (Ovis aries) and their evaluation for cellulose biodegradation

Anaerobic cellulolytic microbes in gastrointestinal tract (GT) of ruminants have been well-documented, however, knowledge of aerobic microbes with cellulolytic activities in ruminant GT is comparably limited. Here, we unraveled aerobic cultivable cellulolytic microbes in GT of Ujimqin sheep (Ovis aries) and evaluated the cellulolytic potential of promising isolates. Twenty-two strains were found to possess cellulose degrading potential by Congo-red staining and phylogenetic analysis of the 16S rDNA/ITS sequence revealed that all strains belonged to nine genera, i.e., Bacillus, Streptomyces, Pseudomonas, Lactobacillus, Brachybacterium, Sanguibacter, Rhizobium, Fusarium, and Aspergillus. Strains with high cellulolytic activities were selected to further evaluate the various enzyme activities on lignocellulosic alfalfa hay (Medicago sativa). Among them, isolate Bacillus subtilis RE2510 showed the highest potential of cellulose degradation considering the high endoglucanase (0.1478 ± 0.0014 IU ml-1), exoglucanase (0.1735 ± 0.0012 IU ml-1) and β-glucosidase (0.3817 ± 0.0031 IU ml-1) after 10-day incubation with alfalfa hay. A significant destruction effect of the cellulose structure and the attachment of B. subtilis RE2510 to the hay were also revealed by using scanning electron microscope. This study expands our knowledge of aerobic cellulolytic isolates from GT of sheep and also highlights their potential application as microbial additive in the aerobic process of cellulose bioconversion.

Growth rate, scrotal circumference, sperm characteristics, and sexual behavior of mixed-breed goat bucks fed three leguminous trees

Aim of study: To investigate the effect of feeding foliage of leguminous trees on growth rate, semen characteristics, and sexual behavior of bucks. Area of study: Northeastern Mexico (23°44' N, 99°8' W). Material and methods: Twenty-two young goat bucks were randomly allocated to one of four treatment groups: 33% alfalfa hay (dry matter basis), 33%; Acacia farnesiana; Leucaena leucocephala; or Prosopis laevigata foliage (n=4 for alfalfa; n=6 for the rest of groups). Main results: Average daily gain (ADG) did not differ between bucks fed alfalfa, A. farnesiana, or L. leucocephala (120 ± 26, 134 ± 37, and 103 ± 29 g/d, respectively), but ADG of bucks offered P. laevigata was the lowest (72 ± 8 g; p<0.05). Bucks fed alfalfa had the highest feed efficiency (6.59 ± 1.25 kg of feed consumed/kg of gain; p<0.05) and bucks offered leguminous trees had the lowest (average 9.85 ± 2.3). Bucks offered alfalfa, and A. farnesiana had increased (p<0.05) scrotal circumference (26.6 ± 0.4 and 25.8 ± 1.5 cm) than bucks fed L. leucocephala, or P. laevigata (24.3 ± 1.2 and 24.1 ± 2.0 cm). Mean ejaculate volume was two-fold higher in alfalfa-fed bucks than all other dietary treatments. Sexual behavior did not differ among bucks fed the different legumes. Research highlights: Foliage of both A. farnesiana and L. leucocephala could totally replace alfalfa hay for rearing growing goat bucks in confinement without affecting daily weight gain, most semen characteristics, and copulation ability. P. laevigata reduced body weight and reproductive function.

Comparison of Ruminal Degradability, Indigestible Neutral Detergent Fiber, and Total-Tract Digestibility of Three Main Crop Straws with Alfalfa Hay and Corn Silage

Three main crop straws including corn straw (Zea mays, CS), rice straw (Oryza sativa, RS), and wheat straw (Triticum aestivum, WS), and two forages including alfalfa hay (Medicago sativa, AH) and corn silage (Zea mays, CSil) were analyzed in order to compare their ruminal degradability, indigestible neutral detergent fiber (iNDF), intestinal digestibility (ID), and their total-tract digestibility (TTD) of crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF) using both an in situ nylon bag technique and a mobile nylon bag technique. The forage samples were incubated in the rumen for 6, 12, 16, 24, 36, 48, 72, and 288 h, respectively, to determine their ruminal degradability. Prior to intestinal incubation, forage samples were incubated in the rumen for 12 h and 24 h to determine the ruminal degradable content of CP, NDF, and ADF, respectively, and for 288 h to determine their iNDF288 content. Residues from the ruminal undegradable fractions (12 h for CP, 24 h for NDF and ADF) were subsequently inserted into the duodenum through a cannula to determine their intestinal digestible content. Here, the TTD of CP, NDF, and ADF were determined as the ruminal degradable content + intestinal digestible content. The results showed that AH had the highest iNDF2.4 (calculated as acid detergent lignin content × 2.4) and iNDF288 values (379.42 and 473.40 g/kg of NDF), while CS and CSil had the lowest iNDF2.4 values (177.44 and 179.43 g/kg of NDF). The ruminal degradability of CP, NDF, and ADF for CS, RS, and WS were lower than those of AH and Csil during the first 48 h of incubation. The potential degradation fraction of CP, NDF, and ADF for CSil was the highest; CS, RS, and WS were intermediate; and AH was the lowest (p < 0.05). CS, RS, and WS had a lower intestinal digestibility with respect to their rumen undegradable content of NDF (p < 0.05), and lower TTD of CP, NDF, and ADF (p < 0.05) compared to AH and CSil. General regression equations with satisfactory accuracy (R2 ≥ 0.828) were derived to predict iNDF288 and TTD based on their chemical compositions and the ruminal degradation kinetics of different forages. Incorporating this information into rations could improve our ability to optimize main crop straws utilization and milk production.

Ginkgo biloba L. Residues Partially Replacing Alfalfa Hay Pellet in Pelleted Total Mixed Ration on Growth Performance, Serum Biochemical Parameters, Rumen Fermentation, Immune Function and Meat Quality in Finishing Haimen White Goats

Sixty castrated male Haimen white growing goats with an initial age of 100 days old and similar body weight (16 ± 1.5 kg) were selected and randomly allocated into five groups with three replicates in each group with four goats in each pen (5 m × 3.2 m). Goats in the control group (CG) were fed a basal pelleted total mixed ration supplemented with 30% alfalfa hay pellet, while experimental treatments (G6, G12, G18, or G24) were supplemented with four levels (6%, 12%, 18%, or 24%) of GBLR replacing alfalfa hay pellet in the diet, separately. Results showed that (1) the final body weight, average daily gain, and average feed intake of G18 was significantly higher (p < 0.05) than CG; in contrast, the feed conversion ratio of G18 was significantly lower than CG and G12 (p < 0.05); the feed cost per head per day of CG was significantly higher (p < 0.05) than that of G18 and G24, and exhibited obvious linearly decrease (p = 0.04) with increasing GBLR supplementation; and apparent total-tract digestibility of DM and NDF in GBLR treatments were significantly higher (p < 0.05) than CG; (2) alanine transaminase (ALT) concentration in the G18 group was significantly lower (p < 0.05) than those in the control group; aspartate transaminase (AST) concentration in the G24 was significantly lower (p < 0.05) than those in the control group, and an increase in dietary level of GBLR tended to result in a linear decrease (p = 0.09) in the concentration of serum AST; (3) the concentration of malondialdehyde (MDA) demonstrated a tendency to decrease (p = 0.06) linearly with increasing GBLR supplementation; however, glutathione peroxidase (GSH-PX) activity in G12 was significantly higher (p < 0.05) than CG, G6, and G24; in addition, superoxide dismutase (SOD) activity in G18 was significantly higher (p < 0.05) than CG and G6; concentration of immunoglobulin M (IgM), immunoglobulin G (IgG), and immunoglobulin A (IgA) were not affected by GBLR, but increasing dietary GBLR showed a tendency (p = 0.08) to linearly increase the IgG concentration; the content of interleukin 4 (IL4) was significantly higher (p < 0.05) in G12, G18, and G24 than that in CG and G6; (4) There were similar NH3-N, pH, TVFA, and butyrate for goats fed different levels of GBLR supplementation; the C2 (p = 0.07) and acetate: propionate (p = 0.06) demonstrated a tendency to increase linearly with increasing level of GBLR supplementation, separately; however, it was observed that concentration of propionate showed a tendency to decrease (p = 0.08) linearly in response to GBLR supplementation; and (5) Increasing dietary GBLR tended to linearly enhance the lightness (L*) (p = 0.07) and yellowness (b*) (p = 0.09) values of longissimus dorsi muscles; the redness (a*) value in G18 was significantly higher than that in CG (p < 0.05).

181 Effect of Application Rate of Sodium Lignosulfonate and Propionic Acid on DM Losses, Nutritional Composition, and Fungal Counts of High Moisture Alfalfa Hay Mini Bales

Our objective was to evaluate the effects of application rate (AR) of sodium lignosulfonate and propionic acid on high moisture alfalfa hay spoilage during storage. Treatments (TRT) were sodium lignosulfonate (NaL) and Propionic Acid (PRP), which were applied at four AR: 0 (CON), 0.25, 0.5 and 1% (w/w fresh basis) to 20% bloom alfalfa hay (second cut) at 68.5% DM and packed into mini bales (10.3x10.8x13cm; 346kg fresh/m3). The treated bales were stored for 33 days in open-top insulation boxes in a room kept at 22°C. Data were analyzed as a randomized complete block design (5 blocks) with a 2 (TRT) x 4 (AR) factorial arrangement, and differences were declared at P ≤ 0.05. At day 0, no differences were observed for DM (68.5 ± 0.61 %), CP (23.2 ± 0.31% DM), and NDF (42.6 ± 0.66% DM), but NaL had more sugars than PRP (0.99 vs. 0.87 ± 0.66% DM) and PRP at 1% reduced mold counts vs. CON (4.71 vs. 4.97 ± 0.05 log cfu/fresh g). At day 33, DM losses were decreased by PRP at 0.5 and 1% (0.9), relative to CON (6.92) and to NaL (6.63 ± 1.13%). Both TRT decreased NDF at 0.25% (46.3) and furthermore at 1% (44.2) relative to CON (49.4), but overall PRP had lower NDF (45.2) than NaL (47.2± 0.81% DM). No differences were observed for sugars and CP. Visual moldiness (0–10) and mold counts were also decreased by PRP at 0.5% (2.4 and 5.30) and 1% (0 and 2.7) relative to CON (6.0 and 7.13) and NaL (5.85 ± 0.67 and 7.21 ± 0.31 log cfu/fresh g, respectively). In conclusion, NaL failed to prevent spoilage of high moisture hay while PRP was effective at doses &gt;0.5%.

PSXI-12 Effect of application rate of sodium lignosulfonate and propionic acid on in vitro digestibility and gas production kinetics of high moisture alfalfa hay mini bales

Our objective was to evaluate the effects of application rate (AR) of sodium lignosulfonate and propionic acid on the in vitro fermentation measures of high moisture alfalfa hay. Treatments (TRT) were sodium lignosulfonate (NaL) and Propionic Acid (PRP), which were applied at four AR: 0 (CON), 0.25, 0.5 and 1% (w/w fresh basis) to 20% bloom alfalfa hay (second cut) at 68.5% DM and packed into mini bales (10.3×10.8×13cm; 346 kg fresh/m3). The treated bales were stored for 33 days in open-top insulation boxes in a room kept at 22°C, after which they were dried, ground to 1 mm and incubated in vitro for 48hr with ruminal fluid from two ruminally cannulated Holstein cows in lactation. Gas kinetics were recorded using the Ankom RF Gas Production System. Data were analyzed as a randomized complete block design (5 blocks) with a 2 (TRT) x 4 (AR) factorial arrangement, and differences were declared at P ≤ 0.05. Both TRT increased apparent in vitro DM digestibility (DMD) at all AR relative to CON (54.3 vs 50.1 ± 1.20%, respectively). PRP increased asymptotic maximal (188.4) and rate of gas production (9.46) compared to NaL (179.7 ± 4.82 ml/g of incubated DM and 8.72 ± 0.45%/h, respectively). Total VFA were higher for PRP (117.5) vs NaL (114.8), and for both TRT at 1% relative to CON (118.9 vs. 113.8 ± 1.68mM). Acetate (A) was increased by both TRT at 1% (~73.5) and propionate (P) was increased by PRP at 1% (26.1) relative to CON (69.9 ± 1.10 and 24.2 ± 0.29mM, respectively), but the A:P ratio was higher for NaL at 1% (3.02) vs. CON (2.89 ± 0.04). In conclusion, NaL and PRP at 1% improved the rumen in vitro fermentation measures of high moisture alfalfa hay but PRP did so to a greater extent.

PSXI-16 Evaluation of supplementation strategies for beef cattle bale-grazing grass hay in Winter

Methods of supplementing beef cows while bale grazing grass hay were investigated in a study conducted for four winters, from 2016 to 2019, at the Central Grasslands Research Extension Center near Streeter, ND. Starting in the fall of each year, cows were assigned to eight groups of similar total body weight (BW) and allowed to bale graze one of four bale grazing treatments as follows: a) grass hay, b) grass hay supplemented with alfalfa hay, c) grass hay supplemented with corn DDGS, and d) grass hay treated with a liquid supplement. Two-day body weights and body condition scores (BCS) were taken at the start and end of the study. Final BW were greater (P ≤ 0.05) when cows were supplemented with DDGS and least when cows were not supplemented. Average daily gains were influenced by method of supplementation and year (P ≤ 0.025). When winters were cold, supplementation with alfalfa hay or a liquid supplement were not adequate to maintain cows resulting with weight loss. Final BCS were greatest (P ≤ 0.05) when cows were supplemented with DDGS and lowest on grass hay. Similarly, change in BCS was greatest in DDGS-supplemented cows and lowest on grass hay only. Calf birth weights, weaning weights and daily gains were not influenced (P &gt; 0.05) by method of supplementation. Results suggest that method of supplementation during bale grazing should be based on prevailing environmental conditions during winter. In severely cold winters, good-quality alfalfa hay or a liquid supplement are not adequate to meet requirements of pregnant beef cows in mid-gestation. Under such conditions, supplements such as corn DDGS will be needed to meet animal requirements. Supplementation with good-quality alfalfa hay or grass hay treated with a liquid supplement may be an option during mild winters.

PSIV-12 Effects of feeding a novel alfalfa leaf pellet product (ProLEAF MAX™) and alfalfa stems (ProFiber Plus™) on production of lactating dairy cows

Alfalfa is a commonly grown forage in the Intermountain west and is often included in lactating dairy cow rations. This study investigated the effects of including novel alfalfa products: ProLEAF MAX™ (PLM), an alfalfa leaf pellet; and ProFiber Plus™ (PFP), alfalfa stems, in the diet of lactating dairy cows on dry matter intake, milk yield, and milk components. Holstein cows were housed in a freestall barn and milked in a free-flow automatic milking system. All cows were fed each treatment for 21-days, then switched to the next treatment utilizing a crossover experimental design. The five treatments were: control (CON, typical diet including alfalfa hay; n = 65); low-quality alfalfa hay (LQ+PLM, a diet that replaced alfalfa hay with low-quality alfalfa hay and PLM; n = 62); PLM+PFP (a diet that replaced alfalfa hay with PLM and PFP; n = 65); PLM (a diet that replaced alfalfa hay with PLM; n = 62); and PFP (a diet that replaced alfalfa hay with PFP; n = 60). Cows were group fed a partial mixed ration balanced for 40.8 kg milk, 3.9% milk fat and 3.3% milk protein. Individual milk yield and milk components were recorded daily by the automatic milking system. Dry matter intake was also recorded daily. When fed the PFP diet, cows had decreased (P &lt; 0.01) dry matter intake compared to the other diets. Milk yield was increased (P &lt; 0.01) when cows received the PLM diet when compared to the other diets. When fed the PFP and PLM+PFP diets, milk fat was increased (P &lt; 0.01) when compared to the other diets. Milk protein was decreased (P &lt; 0.01) when cows were fed the PFP diet when compared to the other diets. These data indicate that inclusion of fractionated alfalfa products in the diet of lactating dairy cows has the potential to increase milk yield and milk components.

Effect of Alfalfa Hay Substitution by Raw Garlic Leaves on In vitro Gas Methane Production and Ruminal Fermentation

Background: The aim of present research was to evaluate under in vitro conditions, the effect of alfalfa hay substitution by raw garlic leaves on ruminal fermentation patterns and methane production in diets ruminants. Methods: Four treatments were evaluated: (T1) alfalfa hay (50%); (T2) alfalfa hay (33%) + raw garlic leaves (17%); (T3) alfalfa hay (17%) + raw garlic leaves (33%) and (T4) raw garlic leaves (50%). Result: The highest values of fractional rate of gas production (kd), ammonia-nitrogen (NH3-N), propionate and microbial biomass synthesis (MBS) was recorded in T4 and the lowest in T1 (P less than 0.05). In contrast, the highest methane production was recorded in T1 and the lowest in T4 (P less than 0.05). It was concluded that the substitution of alfalfa hay by raw garlic leaves in diet with 50% roughages and 50% concentrate result in an improvement in vitro rumen fermentation pattern and decreases the methane production.