Tillering dynamics in spring and summer of marandu palisade grass pastures previously used under deferred grazing

ABSTRACT This work was conducted to evaluate the effect of deferred pasture condition of Brachiaria brizantha cv. Marandu in the late winter on tillering during the growing season. The treatments were three pasture conditions at late winter: short pasture, tall pasture and tall/mown pasture. In September and October, tiller appearance rate (TApR) and tiller mortality rate (TMoR) were greater in the tall/mown pasture. In November and December, tall pasture presented greater TApR. From November to January the TMoR was greater in the tall pasture. The tiller stability index of short and tall/mown pastures were greater in October. The short pasture presented a greater tiller number than the tall and tall/mown pastures during the entire experimental period. Deferred and short pasture of marandu palisade grass at late winter presents in general lower tiller mortality and higher population density of tillers from the early spring onwards, in comparison to tall pasture. The mowing of marandu palisade grass with high forage mass at the late winter, although it only temporarily compromises the population stability of tillers, also stimulates its fast tillering from spring on.

Effects of High-Forage Diets Containing Raw Flaxseeds or Soybean on In Vitro Ruminal Fermentation, Gas Emission, and Microbial Profile

Lipid metabolism plays an important role in the energy economy of ruminants. However, its interactions of fat, rumen fermentation, gas emission, and microorganisms are not yet clear. This study evaluated the effect of adding raw oilseeds to high-forage diets on in vitro ruminal fermentation, gas composition, and microbial profile. Three isoenergetic and isoproteic experimental diets were designed and used as fermentation substrate: control treatment (CON group) was the basal diet lacking oilseeds, the other two treatments were the basal diet supplemented by 100 g/kg dry matter (DM) raw whole soybean (S group) and 50 g/kg DM raw flaxseed (F group), respectively. Data showed that the acetate, butyrate, and total VFA concentration of culture fluids in the S group were lower (p < 0.05) than in the F group. There was a tendency to a higher level (p = 0.094) of propionate concentration in the F group compared with the other two groups. The gas production in the F group was higher (p < 0.05) than in the control group. There was a lower abundance of Sutterella (p < 0.05) and a greater abundance of Butyrivibrio (p < 0.05) in both of the two oilseed treatments. Methanobrevibacter (p = 0.078) in the F group was the lowest. Our results suggested that CH4 emission could be inhibited with flaxseed supplementation by propionate production metabolism, biohydrogenation of unsaturated fatty acid (FA), and toxicity to Methanobrevibacter, while regarding soybean seed supplementation, the emission of CH4 was more likely to be reduced through biohydrogenation of unsaturated FA modulated by Butyrivibrio.

Dependence of the buffer capacity on the chemical composition of dry matter of alfalfa

Annotation It is shown that the buffer capacity of dry matter of alfalfa of the first cut in the flowering phase is 5.66-5.94 mol / liter. With an increase in the content of crude protein and crude ash by 1%, it increases by 0.14-0.40 and 0.49-0.86 mol / liter, respectively, with an increase in the content of soluble carbohydrates by 1%, it decreases by 1.44 mol / liter … The dry matter of the second cut alfalfa has a high forage quality. The content of crude protein from the stemming-beginning of budding phase to the flowering phase is in the range of 23.44-20.20%, crude ash 9.24-8.10%, while the content of crude fiber is reduced to 22.92-29.01%, dry matter - up to 20.84-26.00%. The buffer capacity of dry matter reaches 9.69-7.23 mol / liter. The main influence on the buffer capacity is exerted by the mineral composition of the dry matter. An increase in the content of crude ash by 1% increases the buffer capacity of dry matter by 0.55 ± 0.16 - 1.36 ± 0.14 mol / l, an increase in the content of crude protein by 1% increases the buffer capacity by 0.15 ± 0.06 - 0.39 ± 0.14 mol / liter.

Influence of Phytogenic Feed Additive on Performance of Feedlot Cattle

This study evaluated the influence of a blended phytogenic feed additive on feed intake, feeding behavior, nutrient digestibility, and growth performance during feedlot adaptation, early, and late finishing periods as well as carcass traits. Twenty-six crossbred F1 Angus × Nellore bulls (19 mo ± 4 d) were housed in individually pens and fed a high-forage receiving diet for 7 days. At the end of the receiving period, bulls were weighted [initial shrunk body weight (SBW) 363 ± 20 kg], blocked by SBW and randomly assigned to two treatments; Control: without any additive or PHY: 150 ppm of a phytogenic feed additive fed throughout the adaptation and finishing phases. Bulls were transitioned through four steps over 18 days to a high-grain finishing diet (as % DM, 64% rehydrated corn grain silage, 19% corn gluten feed, 13% sugar cane bagasse and 4% minerals, urea, and vitamins mix). The finishing phase lasted 68 days, with mid-point measurements dividing early and late finishing period. The PHY group DMI was greater during adaptation and late finishing periods (P &lt; 0.05), with a tendency during early finishing period (P = 0.06). Number of daily meals was similar between treatments (P = 0.52), but an increased meal length was noted for PHY group (P &lt; 0.05), which contributed to their greater DMI. Diet digestibility remained similar between groups during the finishing periods (P &gt; 0.1). Ruminitis scores were low and liver abscess similar between treatments. Final SBW tended to be higher (P = 0.09) and hot carcass weight was greater for the PHY group (P &lt; 0.05), with no differences on dressing percentage, ribeye area and marbling score. In conclusion, the PHY treatment had positive effects on intake and carcass weight, without increasing metabolic disorders.

PSXIV-4 Meta-analysis of the effects of monensin on growth and bloat of growing beef calves on pasture

This meta-analysis investigated the impacts of monensin on performance of stocker cattle on high-forage diets. The stocker performance analysis resulted from 38 experiments with 73 mean comparisons; bloat analysis was conducted with 12 experiments with 23 mean comparisons. The metaphor package (version 2.4-0) for R (version 4.0.3; www.r-project.org) was used to determine the overall effect size of monensin compared to a negative control. Each study’s n, means, and SEM or P-value was used to calculate the mean difference and estimate of within study variance for responses of interest. Moderators of monensin response considered in the analysis were delivery method, dose, study duration, initial calf BW, diet ME and CP, and forage category. Initial BW and basal ADG averaged 236 ± 45.9 kg and 0.72 ± 0.28 kg/day, respectively. In the ADG analysis the only significant moderator of those considered was length of the study (P &lt; 0.01), as duration of the study increased the ADG response to monensin decreased by 0.0007 kg/day. For the average 112-day length of study, the average monensin response is estimated to be 0.0784 kg/day increase in average daily gain. Sufficient information was presented in only 18 citations representing 40 mean comparisons for determining the effect of monensin on BW at the end of the experiment, estimated by (P &lt; 0.01) monensin response (increased ending BW, kg) = 22.3 – 0.05 (initial calf BW, kg). Thus, for the average initial BW of 235 kg the average monensin response is estimated to be 10.6 kg increase in average ending BW. The incidence (-20%) and severity (-0.7 bloat scores) of bloat was found to be reduced in bloat prone pastures. There is ample evidence that monensin increases performance of growing calves on high forage diets along with reducing the incidence and severity of bloat.

330 3-nitrooxypropanol Supplementation of a Forage Diet Decreased Enteric Methane Emissions from Beef Cattle Without Affecting Apparent Total-tract Digestibility

Supplementation of ruminant diets with the investigational methane (CH4) inhibitor 3-nitrooxypropanol (3-NOP; DSM Nutritional Products, Switzerland) is as a promising mitigation strategy. However, most studies have examined high grain or mixed forage-concentrate diets. The objective of this study was to evaluate the effects of supplementing a forage diet with 3-NOP on rumen fermentation, CH4 emissions and apparent total-tract nutrient digestibility. Eight ruminally cannulated beef heifers (BW = 514 kg) were randomly allocated to two treatments in a crossover design with 49-d periods. Dietary treatments were: control, high-forage diet (90% forage DM basis) without 3-NOP; and NOP, control diet supplemented with 150 mg 3-NOP/kg DM. After a 14-d diet adaption, dry matter (DM) intake (DMI) was recorded daily. Rumen contents were collected on days 17 and 28 for volatile fatty acid (VFA) analysis, whereas ruminal pH was continuously monitored from day 20 to 27. Diet digestibility was measured on day 38 to 41 by total collection of feces. Enteric CH4 emissions were measured on days 46 to 49 in chambers. Dry matter intake was lower (P = 0.001) for NOP (10.0 kg/d) as compared with control (10.2 kg/d). However, DM, neutral and acid detergent fiber, and crude protein digestibilities were similar between treatments (P ≥ 0.29). Although total VFA concentration was not affected by treatment (P = 0.19), the reduction in acetate and increase in propionate proportion for NOP lowered (P &lt; 0.001) the acetate to propionate ratio by 18% as compared with control. Mean pH was lower (P = 0.03) for control (6.46) than NOP (6.57). Furthermore, CH4 yield (g/kg DMI) was 21.6% less (P &lt; 0.001) for NOP relative to control (25.5 g/kg DMI). Overall, the results indicate that enteric CH4 emissions were effectively decreased with 3-NOP supplementation of a forage diet without affecting apparent total-tract digestibility of nutrients.

PSX-B-8 Effect of supplementing red osier dogwood extract on in vitro gas production, feed digestibility and fermentation characteristics of high-forage diet

Red osier dogwood (ROD) is native shrub plant in Canada and rich in bioactive compounds. The objective of this study was to evaluate the effects of ROD extract supplementation in a high-forage (HF) diet on gas production (GP), dry matter (DM) disappearance (DMD) and fermentation characteristics in batch cultures with varying media pH. The study was a completely randomized design with 4 levels of ROD extract (0, 1, 3 and 5% of substrate) × 2 media pH (5.8 and 6.5) factorial arrangement. The study was conducted in three replicate experiments. Substrate contained 60% barley silage and 40% barley concentrate (DM basis). Inoculum was obtained from 2 ruminally fistulated beef heifers offered the HF diet. Substrate (0.5 g DM) ground (1 mm) was incubated for 48 h in a culture bottle. Data were analyzed using Mixed procedure of SAS with fixed effects of treatments and random effect of experiment. There was no interaction between media pH and level of ROD on GP, DMD and fermentation characteristics. Increased media pH (5.8 vs. 6.5) increased (P &lt; 0.01) GP (averaged 164 vs. 275 ml/g substrate), DMD (50.6 vs. 60.6%), and total VFA production (63 vs. 71 mM). Increasing ROD extract levels did not affect GP but linearly (P = 0.05) decreased DMD from 62.1 to 58.9% at pH 6.5. Although total VFA production was not affected, increasing ROD extract linearly (P &lt; 0.01) increased the proportion of acetate (47.9 to 49.7%) and propionate (20.5 to 22.3%) at pH 5.8; whereas at pH 6.5, acetate to propionate ratio quadratically (P = 0.04) changed to be lower with 3% ROD extract (2.08) than other treatments (2.21). These results indicated that supplementation of HF diet with ROD extract may improve fibre digestion at low media pH, and improve fermentation efficiency at high media pH.

The Effect of Forage-to-Concentrate Ratio on Schizochytrium spp.-Supplemented Goats: Modifying Rumen Microbiota

The inclusion of feed additives and the implementation of various nutritional strategies are studied to modify the rumen microbiome and consequently its function. Nevertheless, rumen enzymatic activity and its intermediate products are not always matched with the microbiome structure. To further elucidate such differences a two-phase trial using twenty-two dairy goats was carried out. During the first phase, both groups (20HF n = 11; high forage and 20HG n = 11; high grain) were supplemented with 20 g Schizochytrium spp./goat/day. The 20HF group consumed a diet with a forage:concentrate (F:C) ratio of 60:40 and the 20HG-diet consisted of a F:C = 40:60. In the second phase, the supplementation level of Schizochytrium spp. was increased to 40 g/day/goat while the F:C ratio between the two groups were remained identical (40HF n = 11; high forage and 40HG n = 11; high grain). By utilizing a next-generation sequencing technology, we monitored that the high microalgae inclusion level and foremost in combination with a high grains diet increased the unmapped bacteria within the rumen. Bacteroidetes and Prevotella brevis were increased in the 40HG -fed goats as observed by using a qPCR platform. Additionally, methanogens and Methanomassiliicoccales were increased in high microalgae-fed goats, while Methanobrevibacter and Methanobacteriales were decreased. Fibrolytic bacteria were decreased in high microalgae-fed goats, while cellulolytic activity was increased. Ammonia was decreased in high grains-fed goats, while docosapentaenoic and docosahexaenoic acids showed a lower degradation rate in the rumen of high forage-fed goats. The alteration of the F:C ratio in goats supplemented with Schizochytrium spp. levels modified both ruminal microbiota and enzymatic activity. However, there was no significant consistency in the relations between them.

Chemical Identification of Specialized Metabolites from Sulla (Hedysarum coronarium L.) Collected in Southern Italy

Sulla (Hedysarum coronarium L.) is a biennal forage legume originated from the Mediterranean basin and used for animal feeding due to its high forage quality and palatability. Several species of Hedysarum have been considered for their nutritional, pharmaceutical, and biological properties, and different applications have been reported, both for human consumption and animal nutrition. Although a systematic investigation of the chemical constituents of Hedysarum spp. has been performed in order to provide chemotaxonomic evidences for the genus and to support the pharmacological application of several species within the genus, few data are available on the chemical constituents of H. coronarium, and only the content of condensed tannins and flavonoids in leaves has been previously reported. In the present paper, results from a detailed chemical analysis of the extracts from the leaves and flowers of H. coronarium grown wild in southern Italy are presented. Identification of the main specialized metabolites within the chemical classes of flavonoids, proanthocyanidins and saponins, is described, including considerations on their content in the two plant organs. Information acquired from this study expands the knowledge on H. coronarium as a source of valuable phytochemicals for different applications in human and animal health and nutrition.