Effect of Various Strains of Lactobacillus buchneri on the Fermentation Quality and Aerobic Stability of Corn Silage

The aerobic deterioration of silage nutrients is inevitable in tropical countries, causing negative consequences in animal production systems. Aiming to minimize the losses, the effects of Lactobacillus buchneri strains on fermentation profile and aerobic stability of corn silages were evaluated. The experiment was conducted under a completely randomized design with 13 treatments and three replicates. The treatments were noninoculated, commercial L. buchneri (CI), and 11 wild strains of L. buchneri: LB-56.1, LB-56.2, LB-56.4, LB-56.7, LB-56.8, LB-56.9, LB-56.21, LB-56.22, LB-56.25, LB-56.26, and LB-56.27. The treatments could be divided into three different groups according to silage pH and acetic acid concentration. Silages inoculated with LB-56.1, LB-56.4, and LB-56.9 presented higher pH, whereas intermediate values were observed for LB-56.2, LB-56.7, and LB-56.8. The highest acetic acid production was observed for LB-56.1 and LB-56.7. On the other hand, lowest concentrations were found for CI, LB-56.22, LB-56.25, LB-56.26, and LB-56.27. Higher amounts of NH3–N were observed for LB-56.8, LB-56.21, LB-56.22, and LB-56.27 silages than others. Silage inoculation with CI, LB-56.1, LB-56.2, LB-56.4, LB-56.8, LB-56.9, and LB-56.25 strains had higher aerobic stability than others (59.7 vs. 41.2 h). The L. buchneri strains LB-56.1, LB-56.2, LB-56.4, LB-56.8, LB-56.9, and LB-56.25 provided potential features to improve the aerobic stability of corn silage.

In vitro Fermentation Profile and Methane Production of Kikuyu Grass Harvested at Different Sward Heights

Highly digestible forages are associated with an in vitro low-methane (CH4) rumen fermentation profile and thus the possibility of reducing CH4 emissions from forage-based systems. We aimed to assess the in vitro ruminal fermentation profile, including CH4 production, of the top stratum of Kikuyu grass (Cenchrus clandestinus - Hochst. ex Chiov) harvested at different sward heights (10, 15, 20, 25, and 30 cm). Herbage samples (incubating substrate) were analyzed for their chemical composition, in vitro organic matter digestibility (IVOMD), and morphological components. In vitro incubations were performed under a randomized complete block design with four independent runs of each treatment. Gas production (GP), in vitro dry matter digestibility (IVDMD), CH4 production, total volatile fatty acid (VFA) concentration, and their acetate, propionate, and butyrate proportions were measured following 24 and 48 h of incubation. Herbage samples had similar contents of organic matter, neutral detergent fiber, and crude protein for all treatments. However, a higher acid detergent fiber (ADF) content in taller sward heights than in smaller sward heights and a tendency for metabolizable energy (ME) and IVOMD to decrease as sward height increased were found. Similarly, the stem + sheath mass tended to increase with increasing sward height. Amongst the nutrients, ME (r = −0.65) and IVDMD (r = −0.64) were negatively correlated with sward height (p < 0.001) and ADF was positively correlated with sward height (r = 0.73, p < 0.001). Both the GP and IVDMD were negatively related to the sward height at both incubation times. Sward heights of Kikuyu grass below 30 cm display an in vitro profile of VFAs high in propionate and low in acetate, with a trend toward lower methane production of CH4 per unit of IVDMD. These findings are important to aid decision-making on the optimal sward height of Kikuyu grass and manage animal grazing with the opportunity to reduce CH4 production.

Effects of different banana crop residue hays on ensiling BRS capiaçu grass on fermentation profile, aerobic stability and nutritional value of silage

The objective of this study was to evaluate the BRS capiaçu grass silage combined with different hays of banana crop residue on fermentation profile, aerobic stability and nutritional value. The treatments consisted of elephant grass cv. BRS capiaçu (Pennisetum purpureum Schum.) ensiled with 37.44% banana peel hay, 36.06% banana pseudostem hay and 37.00% banana leaf hay, on a dry matter (DM) basis and control silage (no additive). The experimental design used was completely randomized, with five treatments and five replicates. Forage was collected when it reached 3.5 meters in height (90 days). Experimental PVC silos of known weight, 50 cm long, 10 cm diameter, were used for silage making. For all treatments, silage aerobic stability breakdown started after 64 hours exposure to air. The BRS capiaçu grass control silage or silage combined with pseudostem hay (mean of 73.15 kg t GM-1) presented effluent losses 40.46% higher than those observed for BRS capiaçu grass silage + banana leaf hay and 69.17% in relation the BRS capiaçu grass silage + banana peel hay. The inclusion of banana crop residue (hay) when ensiling BRS capiaçu grass decreased 13.93% gas losses compared to the control silage (mean of 3.11% DM). Higher values of total digestible nutrients, metabolizable energy and digestible energy content was found in BRS capiaçu grass silage + with banana peel hay. The greater in vitro dry matter digestibility and in vitro neutral detergent fiber digestibility was observed for BRS capiaçu grass silage combined with pseudostem hay. The inclusion of 37.44% banana peel hay improves the fermentation profile and aerobic stability of BRS capiaçu grass silage.

313 Effects of Bismuth Subsalicylate on Ruminal Fermentation of Cattle Consuming a Feedlot Diet

A replicated 3 × 3 Latin square was used to determine the effects of bismuth subsalicylate on ruminal fermentation parameters of beef cattle consuming a feedlot diet. Six ruminally-cannulated Angus-crossbred steers (n = 3; 573 ± 105 kg BW) and heifers (n = 3; 553 ± 77 kg BW) were assigned 1 of 3 treatments: 1) low sulfur (S = 0.27% diet DM; LSUL); 2) high sulfur (S = 0.38% diet DM; HSUL); and 3) HSUL + 0.33% bismuth subsalicylate in diet DM; (BSS). Cattle were adapted to treatments for 14 d followed by 7 d of collections. Ruminal gas cap samples were collected at 0, 4, 8, and 12 h post-feeding on d 14, and ruminal fluid samples were collected on d 15 every 3 h post-feeding for 24 h. Data were analyzed using the MIXED procedure of SAS. Treatment tended (P = 0.099) to affect H2S concentration where BSS and LSUL were 50 and 61% lesser when compared to HSUL, respectively. A tendency (P = 0.061) was also observed for concentration of NH3-N where HSUL and BSS were lesser than CTRL. There was also a tendency for a treatment effect (P = 0.082) where HSUL had a lower pH than LSUL with BSS being intermediate. Furthermore, treatment tended (P = 0.0712) to affect the concentration of acetate where HSUL was lesser than BSS. No effect of treatment (P ≥ 0.124) was observed on total VFA concentration nor concentrations of butyrate, propionate, or valerate (P ≥ 0.138). Treatment tended (P = 0.084) to affect branched chain VFA concentration where BSS decreased concentrations compared to LSUL. Molar proportions of the major VFA were not impacted by treatment (P ≥ 0.100). In conclusion, BSS appears to decrease H2S production in the rumen without having negative effects on the fermentation profile.

PSVII-12 The effects of parity and diet on the rumen function and apparent digestibility in dairy cattle

The primiparity and multiparity dairy cattle were fed in the same diet and different barn in the scaled farm because heifer has a lower social hierarchy. There is little attention to the rumen function difference of these cattle. Here we selected thirty-two dairy cattle and separated them into four groups: prime-prepartum (PP), prime-lactation (PL), multi-prepartum (MP), and multi-lactation (ML) (n=8). The PP and MP groups were given high-roughage diets, and the other two groups were given high-grain diets. The rumen fluid and feces were sampled from each animal. The rumen fluid enzyme activity, fermentation profile, and apparent digestibility were analyzed using SAS’s PROC MIXED model (SAS version 9.4, SAS Institute Inc., Cary, NC, USA). β-glucosidase and amylase were affected by the parity and diet (P < 0.05). Cellulase was affected by the parity, and dehydrogenase was affected by parity and diet interaction (P < 0.05). Rumen pH, NH3-N, microbial crude protein (MCP), isovalerate, and acetate/propionate (A/P) were affected by parity (P < 0.05). MCP and volatile fatty acid were affected by the diets (P < 0.05). The rumen pH, acetate, propionate, and butyrate were affected by parity and diet interaction (P < 0.05). The apparent digestibility of the neutral detergent fiber, acid detergent fiber, crude protein (CP), and ether extract (EE) were affected by the diet and the interaction of diet and parity (P < 0.05). The CP and EE apparent digestibility were only affected by the parity (P < 0.05). Our results indicated beside the diet, the parity also affected the rumen function and apparent digestibility. Although the dairy cattle in the same physical stage, the parity effects on the rumen function and digestibility should be considered when making the diet formula.