Red Clover Hay Research Articles

PSIII-24 Effect of Curing Extent on Red Clover Hay and Silage in Situ Degradability Kinetics in Dairy Cattle

Abstract This objective was to evaluate the effects of insufficient (WET) or ample (CUR) curing on red clover silage (29.4 and 45.3% DM, respectively) and hay (65.1 and 89.1% DM, respectively) ruminal degradation. The red clover field was divided into 5 blocks and each block was divided into 2 plots and then assigned randomly to silage and hay. Hay was packed into mini-bales (~500 fresh g; ~232 kg DM/m3) and silage into mini-silos (19.5 L; ~214 kg DM/m3). Measurements were taken once storage processes had stabilized for hay and silage (50 and 78 d, respectively). Samples were ground to pass 4-mm screen and weighed (5 g DM) into 10 x 20 cm ANKOM R1020 in situ bags. Bags were hooked to a rope, placed in the ventral sac of the rumen of 2 dairy cows for 0, 3, 6, 12, 24, 48, 72, and 96 h. All bags were removed simultaneously, washed, dried, and weighed. This procedure was conducted separately for each block. Data were analyzed as a randomized complete block design (5 blocks) with a 2 (curing extents) x 2 (storage methods) factorial. Differences were declared at P ≤ 0.05. Discrete lag times were higher for WET than CUR (0.23 vs. 0 ± 0.08 h, respectively). The potentially degradable fraction was greater in hay than in silage (50.2 vs. 45.1 ± 1.32% of DM, respectively). Moreover, WET had a greater potentially degradable fraction than CUR (49.6 vs. 45.7 ± 1.32% of DM, respectively). The degradation rate was less in hay than silage (5 vs. 8 ± 0.4%/h, respectively). The WET treatment had a decreased degradation rate than CUR (5 vs. 7, respectively). The undegradable fraction was not different between WET and CUR hay (x̅ = 23.3 ± 1.13% of DM). In contrast, WET silage had a decreased undegradable fraction than CUR silage (17.1 vs. 20, respectively). In conclusion, haymaking increased the potentially degradable fraction relative to ensiling but reduced the rate of digestion. For both storage methods, curing reduced the potentially degradable fraction but increased the rate of digestion.

326 Effect of Curing Extent on Ruminal in Vitro Gas Production Kinetics of Red Clover Hay and Silage Across Storage Phases

Abstract This study evaluated the effects of insufficient (WET) or ample (CUR) curing on red clover silage (29.4 and 45.3% DM, respectively) and hay (65.1 and 89.1% DM, respectively) in vitro fermentation measures. Measurements were taken at the start of storage (STRT), after 14 d (MicA), and once storage processes had stabilized for hay and silage (50 and 78 d, respectively; LATE). The red clover field was divided into 5 blocks and each block was divided into 2 plots and then assigned randomly to silage and hay (storage methods). Hay was packed into mini-bales (~500 fresh g; ~232 kg DM/m3) and silage into mini-silos (19.5 L; ~214 kg DM/m3). Samples at each storage stage were analyzed for in vitro gas production (48 h). 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 (curing extents) x 2 (storage methods) x 3 (storage phases) factorial. Differences were declared at P ≤ 0.05. The data was analyzed using the GLIMMIX procedure of SAS 9.4. At STRT, the Asymptotic maximal gas production (M) and fermentation rate (k) were not different between CUR and WET hay (x̅ = 240.5 ± 7.33 mL/g incubated DM and x̅ = 13.2 ± 0.56% of gas production/h, respectively). However, at MicA, CUR hay had a greater M and k than WET hay (232.7 vs. 192.6 and 13.9 vs. 9.33, respectively). The same was observed at LATE (237.6 vs. 197.6 and 13 vs. 8.36, respectively). At STRT, the CUR and WET silage was not different for M and k (x̅ = 233.4 ± 7.33 mL/g incubated DM and x̅ = 14.06 ± 0.56% of gas production/h, respectively). A similar trend was observed at MicA (x̅ = 220 and 13.6, respectively) and LATE (x̅ = 219.7 and 14.7). In conclusion, ample curing of red clover hay preserves the fermentation kinetics relative to insufficient curing, especially after 14 d of storage. In the case of red clover silage, the fermentation kinetics was not affected by the curing extent across the storage period.

Red clover supplementation modifies rumen fermentation and promotes feed efficiency in ram lambs.

Red clover produces isoflavones, including biochanin A, which have been shown to have microbiological effects on the rumen while also promoting growth in beef cattle. The objective was to determine if supplementation of biochanin A via red clover hay would produce similar effects on the rumen microbiota and improve growth performance of lambs. Twenty-four individually-housed Polypay ram lambs (initial age: 114 ± 1 d; initial weight: 38.1 ± 0.59 kg) were randomly assigned to one of three experimental diets (85:15 concentrate:roughage ratio; N = 8 rams/treatment): CON-control diet in which the roughage component (15.0%, w/w, of the total diet) consisted of orchardgrass hay; 7.5-RC-red clover hay substituted for half (7.5%, w/w, of the total diet) of the roughage component; and 15-RC-the entire roughage component (15.0%, w/w, of the total diet) consisted of red clover hay. Feed intake and weight gain were measured at 14-d intervals for the duration of the 56-d trial, and rumen microbiological measures were assessed on days 0, 28, and 56. Red clover supplementation impacted growth performance of ram lambs. Average daily gains (ADG) were greater in ram lambs supplemented with red clover hay (7.5-RC and 15-RC) than for those fed the CON diet (P < 0.05). Conversely, dry matter intake (DMI) was lower in 7.5-RC and 15-RC than for CON lambs (P = 0.03). Differences in ADG and DMI resulted in greater feed efficiency in ram lambs supplemented with red clover hay (both 7.5-RC and 15-RC) compared to CON (P < 0.01). Rumen microbiota were also altered by red clover supplementation. The total viable number of hyper-ammonia-producing bacteria in 7.5-RC and 15-RC decreased over the course of the experiment and were lower than CON by day 28 (P ≤ 0.04). Amylolytic bacteria were also lower in 15-RC than in CON (P = 0.03), with a trend for lower amylolytic bacteria in 7.5-RC (P = 0.08). In contrast, there was tendency for greater cellulolytic bacteria in red clover supplemented lambs than in CON (P = 0.06). Red clover supplementation also increased fiber utilization, with greater ex vivo dry matter digestibility of hay for both 7.5-RC and 15-RC compared to CON by day 28 (P < 0.03). Results of this study indicate that low levels of red clover hay can elicit production benefits in high-concentrate lamb finishing systems through alteration of the rumen microbiota.

House crickets (Othroptera: Gryllidae: Acheta domesticus) reared in small-scale laboratory conditions harbour limited viral flora

Insects, such as crickets, are being used as a viable food source in many regions of the world, given their nutritional value for human and animal consumption. This study investigated the viral communities present in European house crickets and whether feed influences the composition of the crickets’ virome. The crickets were reared under environmentally controlled conditions and fed fresh red clover (fresh), red clover haylage (haylage), red clover hay (hay) or control feed. The viral metagenomic analysis of six replicates from each feed treatment showed that only a few reads were classified as viruses, mainly assigned to phages and insect-related viruses. A significant difference (P&lt;0.001) was observed between the different treatments in regard to the number of viral reads. The highest number of viral reads was identified in the fresh treatment (2,568 reads), whereas the control treatment had the fewest viral reads (90). Phages were identified in all the treatments; however, they were clearly dominant in the fresh and hay feed treatments. A limited number of insect and plant viral reads from Xinmoviridae, Polydnaviridae, Metaviridae, unclassified and ‘other’ viruses were also found in all the feed treatments. The results from this study may indicate that the feed for the crickets determines the richness of the viral flora of crickets, but overall, very few viral reads were identified, making it hard to draw any conclusion regarding the impact of the feed on viral richness.

83 Acceptability of red clover hay and associated eating behaviors of horses when compared to timothy hay

Forage preference and eating behaviors are influenced by prior exposure to a forage species and forage maturity. Therefore, introducing new forages to horses can be challenging. This study aimed to compare horse behavior and acceptance of hay, when given a choice between timothy hay (TH) and red clover hay (RCH); a subobjective of a study also evaluating in vitro fermentation. Twelve Thoroughbred horses were blocked by weight and sex and randomly assigned to TH (n = 8) or TH + 20% RCH (n = 4) diet, the unbalanced design due to a dietary treatment not reported here. The study included 2 periods of 4 weeks (n = 6/period) to accommodate the 12 horses. Horses were housed and fed in partially covered individual runs (3 × 12m) and turned out daily in paddocks with muzzles (9:00–15:00) that allowed water consumption. Horses participated in 3 preference tests (PF): one in wk 2 and 2 in wk 4. Horses were on pasture before the study, and transitioned to hay only diets during wk 1. Each successive PF served to test acceptability with continued exposure. On PF days horses were brought inside from turnout, but instead of receiving a full allotment of hay, were provided with a pre-weighed amount of hay in bins and observed for 1 h. Orts was weighed back. Horses (n = 8) allocated to TH diet received TH in both bins, serving as controls. Horses (n = 4) allocated to TH + RCH treatment received TH in one bin, and RCH in the other. Each PF occurred over 2 consecutive days, where hays were switched between bins and results averaged between days. Behavior assessment included the first bin approached, sniffed and consumed from, drinking water, switching bins, or no eating. Data were analyzed as repeated measures ANOVA (SAS 9.4). Bin placement had no effect ( P > 0.05). The PF total hay intake did not differ between TRT or time ( P > 0.05). Consumption of RCH decreased from PF 1 to 2 ( P < 0.01) and then remained the same ( P = 0.71). Horses consumed 47%, 26%, and 20% of total intake as RCH during each PF respectively, therefore replacing RCH with TH over time. Horses first approached and sniffed RCH 86% and 79% of the time, but only consumed RCH first 50% of the time. Horses on average drank twice, the first drink within 27 min of PF. Horses stopped eating (>1 min) on average 3 times. Behavior observations indicated a willingness to eat both hays, but TH was preferred over the long-term, whether due to differences in maturity or other sensory factors. Average voluntary RCH intake was 30.7%. In practice RCH will likely be fed at 15–20% of total intake. Thus, willingness to consume RCH at these reported levels is a valuable outcome for practical application.

Microbial communities and food safety aspects of crickets (Acheta domesticus) reared under controlled conditions

In an approach combining microbiological culture methods with high-throughput sequencing, this study investigated the microbial communities (bacteria, moulds and yeasts) in Swedish-produced edible crickets (Acheta domesticus) reared in a controlled environment. The effects of different feeds on microbial loads and populations in crickets were also studied. The crickets used were third-generation offspring from wild-caught individuals from Sweden, which are adapted to grow in a laboratory environment. The efficiency of rinsing to decrease microbial load was evaluated not obtaining a significant decrease of plating counts for total aerobic counts (TAC) and Enterobacteriaceae. Crickets were divided into three batches and fed different diets (control feed, early-cut red clover hay (ECH), late-cut fresh red clover (LCF)) for 62 days. Bacterial numbers (TAC and Enterobacteriaceae) on whole raw crickets ranged between 7 and 8 log cfu/g. Pre-rinsing in water did not reduce these levels (P=0.19). All batches tested negative for the food-borne bacteria Salmonella, Listeria monocytogenes, Bacillus cereus and Clostridium perfringens. The mean mould count for crickets fed control feed was 2.8 log cfu/g, while the values for crickets fed ECH and LCF were 4.2 and 4.5 log cfu/g, respectively. The dominant bacterial communities were Proteobacteria, Bacteroidetes and Firmicutes, with Firmicutes and Proteobacteria dominating in crickets fed control feed, Firmicutes dominating in crickets fed LCF and Proteobacteria dominating in crickets fed ECH. Aspergillus flavus, a fungus that is capable of producing mycotoxins, was detected in control feed and ECH reared crickets. More work is needed to identify specific food-borne pathogens in edible crickets and establish possible bacterial quality reference values, as an important step in developing microbial quality and safety parameters to ensure consumer safety.

Effect of red clover-only diets on house crickets (Acheta domesticus) growth and survival

This study evaluated the potential of red clover as a sole diet for house crickets (Acheta domesticus, AD) and the effect of ensiling or drying red clover biomass on growth, survival and water consumption of AD. Wild AD were caught near Uppsala, Sweden, and reared in a climate-controlled room under a 12-h light regime. One day-old third-generation cricket nymphs (n=2,880) were used in a 56-day feeding trial. The experimental diets (n=8) were early-cut (pre-bloom) and late-cut (late-bloom) red clover, preserved as frozen-fresh, dry-silage, haylage and hay, and a control diet. All clover diets were fed as sole diets with salt block available ad libitum in every treatment. Feed dry matter intake, feed conversion ratio (FCR, kg feed dry matter per kg weight gain), number and weight of crickets and water consumption were recorded every five days. FCR was higher for late-cut than early cut-red clover, but overall cricket weight and survival rate did not differ between cutting times (P=0.939). FCR, weight and survival were not affected by forage conservation method. Total feed consumption was highest for red clover hay. Crickets fed red clover diets had lower (P&lt;0.01) weight and higher FCR than crickets fed the control diet, but their survival rate was not different from that of control crickets during the first 25 days of life. Water consumption of AD fed the control diet was about half that reported for pigs and poultry. Crickets fed on fresh red cover had lower (P=0.04) water consumption compared with crickets fed dried or ensiled red clover, but ensiling did not reduce water consumption compared with hay. Red clover cannot be recommended as a sole feedstuff for AD, but early and late-cut red clover had similar effects. The possibility to partly include late cut red clover in cricket diets is interesting from an ecosystem service perspective since the flowering crop will provide feed for declining populations of bees and other pollinators.

Isoflavone supplementation, via red clover hay, alters the rumen microbial community and promotes weight gain of steers grazing mixed grass pastures.

Biochanin A, an isoflavone present in the pasture legume red clover (Trifloium pratense L.), alters fermentation in the rumen of cattle and other ruminants. Biochanin A inhibits hyper-ammonia-producing bacteria and promotes cellulolytic bacteria and fiber catalysis in vitro and ex vivo. Consequently, biochanin A supplementation improves weight gain in grazing steers. Red clover contains biologically active isoflavones that may act synergistically. Therefore, the objective was to evaluate the effect of two levels of red clover hay on growth performance and the microbial community in growing steers grazing mixed grass pastures. A grazing experiment was conducted over 2 early growing seasons (2016 and 2017) with 36 cross-bred steers and twelve rumen-fistulated, growing Holstein steers for evaluation of average daily gain and rumen microbiota, respectively. Steers were blocked by body weight and assigned to pastures with one of four treatments: 1) pasture only, 2) pasture + dry distillers’ grains (DDG), 3) pasture + DDG + low level of red clover hay (~15% red clover diet), or 4) pasture + DDG + high level of red clover hay (~30% red clover diet). DDG were added to treatments to meet protein requirements and to balance total protein supplementation between treatments. All supplementation strategies (DDG ± red clover hay) increased average daily gains in comparison to pasture-only controls (P < 0.05), with a low level of red clover supplementation being the most effective (+0.17 kg d-1 > DDG only controls; P < 0.05). Similarly, hyper-ammonia-producing bacteria inhibition (10–100-fold; P < 0.05), fiber catalysis (+10–25%; P < 0.05) and short chain fatty acid concentrations were greatest with the low red clover supplement (+~25%; P < 0.05). These results provide evidence that lower levels or red clover supplementation may be optimal for maximizing overall microbial community function and animal performance in grazing steers.

PSIX-6 Effects of a live yeast product on ruminal bacterial diversity and metabolome of beef cattle

Abstract This study utilized 16S ribosomal ribonucleic acid (rRNA) sequencing and liquid chromatography-mass spectrometry (LC-MS)-based metabolomic profiling to evaluate the effects of a live yeast product on ruminal bacterial diversity and metabolome of beef steer. Eight rumen-cannulated Holstein steers were assigned randomly to 1 of 2 treatment sequences in a study with two 25-d experimental periods and a crossover design. The steers were fed 50% concentrate-mix and 50% red clover hay ad libitum. Dietary treatments were (1) control (CON; basal diet) and (2) yeast (YEA; basal diet plus 15 g/d of live yeast product; PMI, Arden Hills, MN, USA). Bacterial diversity was examined by sequencing of the V3-V4 region of the 16S rRNA gene. Metabolome analysis was performed using an ultra-performance LC-MS system. Relative abundance of bacteria was analyzed using the GLIMMIX procedure of SAS and a model that included the effects of treatment, period, and their interaction. Significant differences were declared at P ≤ 0.05. Differential metabolites were filtered using significance estimate of P ≤ 0.10 using Metaboanalyst 4.0. Pearson correlation was used to examine associations between the relative abundance of ruminal bacteria and rumen metabolites. Yeast supplementation increased (P ≤ 0.05) the relative abundance of Ruminococcaceae NK4A214, Christensenellaceae R-7, Ruminococcaceae UCG-010, Ruminococcus 2, and Ruminococcaceae UCG-005, Candidatus saccharimonas, Anaerovorax, and Lachnospiraceae. Yeast supplementation increased (P ≤ 0.10) the concentrations of 4-cyclohexanedione and β-d-glucopyranoside, and decreased concentrations of threonic acid, xanthosine, deoxycholic acid, lauroylcarnitine, methoxybenzoic acid, and pentadecylbenzoic acid. Bacteroidales BS11, Christensenellaceae R-7, and Candidatus saccharimonas showed positive correlations with metabolites involved in amino acid biosynthesis and metabolism of energy substrates; the functions of these bacteria are not fully understood in relation to the mode of action of yeast. This study confirms the usefulness of LC–MS-based metabolomics in deciphering the mode of action of live yeast in the rumen.

PSIX-5 Effects of live yeast on functional attributes of rumen microbiota in beef cattle

Abstract This study applied whole-metagenomics shotgun sequencing to evaluate the effects of live yeast supplementation on functional potential of rumen microbiota in beef cattle. Eight rumen-cannulated Holstein steers were assigned randomly to 1 of 2 treatments in cross-over design with two 25-d experimental periods and a 10-d wash-out between the two periods. The steers were housed in individual pens and were fed 50% concentrate and 50% red clover hay ad libitum. Dietary treatments were (1) control (CON; basal diet) and (2) yeast (YEA; basal diet plus 15 g/d of yeast product; PMI, Arden Hills, MN, USA). Rumen fluid samples were collected at 3, 6 and 9 h after feeding on the last day of each period. Sequencing was done on an Illumina HiSeq 2500. Differences in the relative abundance of taxa at the species level were analyzed using the GLIMMIX procedure of SAS using a model that included the effects of treatment, period, and their interaction. Dietary yeast supplementation increased (P &amp;lt; 0.05) the relative abundance of carbohydrate-fermenting bacteria, such as Ruminococcus albus, R. champanellensis, R. bromii, and R. obeum, and lactate-utilizing bacteria, such as Megasphera elsdenii, Desulfovibrio desulfuricans, and D. vulgaris. A total of 154 differentially abundant microbial genes (DAGs) were obtained (false discovery rate &amp;lt; 0.01). Kyoto Encyclopedia of Genes and Genomes annotation analysis of the DAGs revealed that pathways involving amino sugar and nucleotide sugar metabolism, oxidative phosphorylation, pantothenate and CoA biosynthesis, beta-alanine metabolism, and polyketide sugar unit biosynthesis were enriched in steers fed YEA. Annotation of the DAGs in carbohydrate-active enzymes database revealed that genes coding for enzymes belonging to glycoside hydrolases, glycosyltransferases, and carbohydrate binding modules were enriched in steers fed YEA. These findings confirm the efficacy of live S. cerevisiae product at reducing redox potential and increasing cellulolytic and lactate-utilizing activities in the rumen.

Effect of Diet and Type of Pregnancy on Transcriptional Expression of Selected Genes in Sheep Mammary Gland.

Simple SummaryAn experiment was designed to determine the effect of diet and type of pregnancy on the mammary gland development, measured by the transcriptional expression of genes involved in angiogenesis and cell turnover/lactogenesis. To that end, twin and single-bearing ewes were fed naturalized pasture or red clover from day −45 pre-partum until day +60 post-partum, taking samples of mammary tissue at day −10, +30 and +60 post-partum. The results showed that the group of twin-bearing ewes fed red clover was the best combination to increase the expression of genes associated to angiogenesis and cell turnover/lactogenesis in the mammary gland.These trials were carried out to determine firstly the effect of diet and type of pregnancy on the transcriptional expression of genes involved in angiogenesis and cell turnover/lactogenesis inside the sheep mammary gland from late gestation to late lactation. Eighteen Ile de France sheep, 8 twin- and 10 single-bearing ewes were alloted into two groups according to their diet, either based on ad libitum naturalized pasture or red clover hay plus lupine from day −45 pre-partum until day +60 post-partum. Samples from diets and mammary glands were collected at day −10 pre partum (time 1), day +30 (time 2) and day +60 post-partum (time 3) and analyzed by qRT-PCR. Additionally, samples from longissimus dorsi muscle were taken from lambs twice, at weaning and 45 days later, to determine the effect of the maternal treatment with regard to diet and type of pregnancy, on the mRNA expression of genes involved in lipid metabolism. The data was processed using the lme4 package for R, and SPSS Statistics 23.0 for Windows®. The results showed that the group of twin-bearing ewes fed red clover showed a higher expression of genes involved in angiogenesis before lambing and in cell turnover/lactogenesis during late lactation, explained by a lamb survival mechanism to delay apoptosis as a way to keep a secretory cells population and boosted by the diet quality, assuring a longer milk production potential during late lactation. Regarding lambs, apparently the maternal diet would influence the transcriptional expression of lipogenic enzymes in the longissimus dorsi muscle after weaning, but further studies are necessary to validate these results. In summary, Twin-bearing ewes fed red clover performed best at increasing the expression of genes associated with angiogenesis and cell turnover/lactogenesis in the mammary gland.

Effect of diet and type of pregnancy on plasma metabolic response in sheep and its further effect on lamb performance.

This trial evaluated the individual and interactional effects of diet and type of pregnancy (twin or single) on plasma metabolic response in ewes and their lambs from late pre-partum to late post-partum. Thus, a flock of 18 Ile de France breed sheep, consisting of 8 twin-bearing and 10 single-bearing ewes, were allocated to one of two groups according to their diet, either based on ad libitum naturalized pasture hay (NPH) or red clover hay (RCH), from d 45 pre-partum to d 60 post-partum. Plasma samples were collected at different times to determine albumin, cholesterol, total protein and urea, plus glucose and β-hydroxybutyrate (BHB) concentration in ewes. The data was processed using the lme4 package for R, and SPSS Statistics 23.0 for Windows. The results showed that both diet and type of pregnancy influenced the metabolic profile in ewes, showing an inverse relationship between single- and twin-bearing ewes regarding glucose and especially BHB proportions from pre-partum to birth. During post-partum, higher urea concentrations were observed in twin- and single-bearing ewes fed RCH in contrast to those fed NPH, as a result of the higher-quality forage offered to ewes. Regarding lambs, the diet and type of pregnancy influenced the total protein and urea levels, where an inverse relationship at birth and early post-partum between albumin and cholesterol vs. total protein and urea was detected, reflecting a trend (P value between 0.06 and 0.07) to a better performance by groups of single lambs, especially those from single-bearing ewes fed RCH. Finally, under the conditions of this study, the maternal diet and type of pregnancy influenced the plasma metabolic response in ewes and their lambs, affecting the lamb performance especially at birth.

Contamination of cattle feed with molds and mycotoxins

The total number of potentially toxigenic molds (fungi), total aflatoxins, zearalenone (ZON), and deoxynivalenol (DON), as well as the joint appearance of ZON and DON have been investigated in 67 samples of cattle feed (concentrate (n=21), silage of whole maize plant (n=18), beet pulp (n=4), brewer's malt (n=2), alfalfa and grass (n=1), alfalfa hay (n=12), meadow hay (n=7), pea and oat hay (n=1), and red clover hay (n=1) originating from private farms from 10 districts of the Republic of Serbia. The total number of fungi per 1 g feed ranged from 0 (silage of brewer?s malt) to 12 x 104 (concentrate). Eight fungi genus species have been identified: Acremonium, Alternaria, Aspergillus, Fusarium, Mucor, Penicillum, Rhizopus and Trichoderma. The presence of ZON (100%) was established in all the examined cattle feed samples, while 98.5% samples were contaminated with total aflatoxins and 92.5% samples were DON positive. The joint appearance of ZON and DON was established in 92.5% samples. ZON was present in the highest average concentration in the sample of alfalfa and grass silage (2477.5 ?g kg-1) and in the lowest in beet pulp silage samples (64.9 ?g kg-1). Total aflatoxins were established in the highest average concentration in the pea and oat hay silage sample (7.9 ?g kg-1) and in the lowest average concentration in beet pulp silage samples (1.6 ?g kg-1). DON was detected in the highest average concentration in concentrate samples (694.2 ?g kg-1) and in the lowest average concentration in the red clover hay sample (11.0 ?g kg-1), while DON was not detected in brewer's malt silage samples (0.0 ?g kg-1). In all the examined cattle feed samples, between moisture content (up to 20%) and the concentration of examined mycotoxins, a negative correlation was established (r=-0.26) with total aflatoxins and a positive correlation with ZON (r=0,36) and DON (r=0,60). Furthermore, a positive correlation (r=0.22) was established between ZON and DON concentrations.

Canopy Cover and Root-zone Heating Effects on Fall- and Spring-grown Leaf Lettuce Yield in Ohio

Low and high tunnels and root-zone heating systems are proven tools in horticultural production. However, impacts of their separate and combined application on crop yield, composition, and microclimates are underreported. We addressed these gaps in the literature by exposing lettuce (Lactuca sativa) to four microclimates established with low and high tunnels and root-zone heating during the spring and fall of 2 years in Wooster, OH. Red-leaved romaine lettuce cultivars Outredgeous and Flagship were direct-seeded into raised beds in both outdoor and high-tunnel settings in early October and late March and harvested multiple times over 4 weeks. Half of all plots in each setting were underlain by electric heating cables, and half were covered with 0.8-mil, clear, vented, low tunnels. A growing medium consisting of peat moss, compost, soil, and red clover (Trifolium pratense) hay was used, and all plots were overhead-irrigated. Soil and air temperatures were monitored throughout the experiments, which were repeated four times (2 seasons/year × 2 years). Here, we report primarily on treatment effects on crop yield and related variables. Root- and shoot-zone conditions and cultivar significantly affected leaf biomass in both settings (outdoor, high tunnel), while population was more often affected in the outdoor experiments. Microclimate main effects were more prevalent than cultivar effects or interactions. Leaf yield was greater in low-tunnel-covered and bottom-heated plots than in uncovered and unheated plots. We take these data as further evidence of the potential to alter lettuce yield through root- and shoot-zone microclimate modification, particularly in regions prone to dynamic seasonal and within-season temperature and light conditions. The data also suggest that the relative performance of low and high tunnels in the production of short-statured, quick-cycling crops during fall and spring be more thoroughly evaluated.

Effect of diet on fecal and urinary estrogenic activity

The United States Environmental Protection Agency has identified estrogens from animal feeding operations as a major environmental concern, but few data are available to quantify the excretion of estrogenic compounds by dairy cattle. The objectives of this study were to quantify variation in estrogenic activity in feces and urine due to increased dietary inclusion of phytoestrogens. Ten Holstein heifers were assigned to 2 groups balanced for age and days pregnant; groups were randomly assigned to treatment sequence in a 2-period crossover design. Dietary treatments consisted of grass hay or red clover hay, and necessary supplements. Total collection allowed for sampling of feed refusals, feces, and urine during the last 4 d of each period. Feces and urine samples were pooled by heifer and period, and base extracts were analyzed for estrogenic activity (estrogen equivalents) using the yeast estrogen screen bioassay. Feces and urine samples collected from 5 heifers were extracted and analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to quantify excretion of 7 phytoestrogenic compounds. Excretion of 17-β estradiol equivalents in urine was higher and tended to be higher in feces for heifers fed red clover hay (84.4 and 120.2 mg/d for feces and urine, respectively) compared with those fed grass hay (57.4 and 35.6 mg/d). Analysis by LC-MS/MS indicated greater fecal excretion of equol, genistein, daidzein, coumestrol, and formononetin by heifers fed red clover hay (1634, 29.9, 96.3, 27.8, and 163 mg/d, respectively) than heifers fed grass hay (340, 3.0, 46.2, 8.8, and 18.3 mg/d, respectively). Diet had no effect on fecal biochanin A or 2-carbethoxy-5, 7-dihydroxy-4’-methoxyisoflavone. Four phytoestrogens were detected in urine (2-carbethoxy-5, 7-dihydroxy-4’-methoxyisoflavone, daidzein, equol, and formononetin) and their excretion was not affected by diet. Identifying sources of variation in estrogenic activity of manure will aid in the development of practices to reduce environmental estrogen accumulation.

Evaluating Soil Management Using Particulate and Chemically Labile Soil Organic Matter Fractions

Particulate organic matter (POM), an established soil quality indicator, is too costly for routine testing by analytical labs. Chemical oxidation of labile soil organic matter is less costly and may prove to be an equally effective indicator. The objectives of this study were to test the relationship between POM and chemically labile organic matter (CLOM) and to evaluate the effects of soil management on POM and CLOM. The study was conducted within a long‐term crop rotation × fertility treatment study in central Pennsylvania. Crop rotation sequences were continuous corn (Zea mays L.), corn–soybean [Glycine max (L.) Merr.], 4 yr of corn followed by 4 yr of alfalfa hay (Medicago sativa L.), and corn–oat (Avena sativa L.)–winter wheat (Triticum aestivum L.)–2 yr of red clover hay (Trifolium pratense L.). Fertilizer treatments were mineral fertilizer, N‐based liquid dairy manure, and P‐based liquid dairy manure. A significant linear relationship between POM‐C and CLOM‐C treatment means was observed (r2 = 0.74). Both POM‐C and CLOM‐C concentrations were greatest for manure‐based fertility treatments and for crop rotations receiving the most frequent applications of manure. Only CLOM‐C, however, distinguished between the N‐based and P‐based manure treatments. Further development of CLOM‐C as a soil quality indicator may yield a reliable, cost‐effective soil quality management tool.

Effect of feeding pasture-finished cattle different conserved forages on Escherichia coli in the rumen and faeces

The effects of eight different pre-slaughter diets on gut microflora, pH and dry matter were evaluated in 112 slaughter-weight, pasture-finished heifers. Hide dirtiness at slaughter, plasma cortisol, meat pH and stickiness, and liveweight loss, were also examined. The pre-slaughter diets were: 48 h of 100% meadow hay, lucerne hay, red clover hay, perennial ryegrass hay, haylage, haylage supplemented with maize silage, pasture, or 24 h fasting before transport. Fasted animals had the highest counts of rumen Escherichia coli and Enterobacteria compared to other treatments ( P<0.001), while red clover hay and haylage had the lowest ( P<0.05). Faecal E. coli counts were also highest for fasted animals ( P<0.05). Rumen E. coli and Enterobacteria counts were positively correlated with rumen pH ( P<0.001), and negatively correlated with fibre intake ( P<0.001). Diet significantly affected the pH of both the rumen and faeces ( P<0.001), with fasted animals having the highest rumen pH and haylage and red-clover hay-fed animals the lowest. Dry matter (%) of the rumen contents was also significantly affected by diet ( P<0.001). The mean carcass weight of fed heifers was 5 kg heavier than that of the fasted heifers ( P<0.05). A pH/volatile fatty acid (VFA) dependent mechanism is suggested as the major mode for E. coli suppression by feeds used in the study. Coumarins may have contributed to lower ruminal and faecal E. coli counts with E. coli counts negatively correlated with expected coumarin ingestion ( P<0.01). Feeding pasture-fed cattle conserved herbaceous forages, in preference to fasting, before transport for slaughter may prove beneficial in reducing the risk of carcass contamination with E. coli and other bacteria of digesta and/or faecal origin, and in protecting carcass weight.

Application of the Gompertz model to describe the fermentation characteristics of chemical components in forages

AbstractIn the experiment, four grass (tall fescue hay and Italian rye grass hay, harvested in March and May) and four legume (lucerne hay, harvested in March and May; and red clover hay, harvested in March and April) forages were used. Duplicate samples were incubated in sacco in the rumens of three fistulated mature cows for 2, 4, 8,16, 2i, 48 and 72 h and the degradabilities of dry matter (DM), nitrogen, neutral-detergent fibre (NDF), cellulose and hemicellulose were measured. The maximum degradation rate (MDR) and time of maximum degradation rate (TMDR) were calculated from the first and second derivatives of a Gompertz equation.The MDR differed between chemical components and was generally higher for cellulose (from 2·31 to 6·95% per h) and nitrogen (from 2·06 to 6·75% per h) in all forages studied. Lignin content of forages was found to be well correlated with the MDR of the fibre components (r = -0·74 for NDF, -0·72 for cellulose and -0·84 for hemicellulose).The TMDR values were much shorter for DM and nitrogen (&lt; 4·2 h) than for the fibre fractions (from 6·8 to 14·0 h). Furthermore, in grasses, hemicellulose TMDR occurred before those of cellulose, while in legumes the order of TMDR was less clear. Elevated positive correlation coefficients between the fibre components and their TMDR possibly indicate that the structural arrangement and types of linkages within and between these components regulate their fermentation process.The possibility of using the Gompertz first and second derivatives to study the synchrony of the release of nitrogen and organic matter into the rumen was examined.

Red clover: milk production and growth rate responses

Grasslands Pawera, a late flowering tetraploid red clover cultivar, has transformed what was previously low fertility pastures dominated by browntop and annual grasses with low summer productivity, into legume-dominant pastures over the summer to mid-autumn period on a Bay of Plenty dairy farm. Neither N nor supplements were used on this farm. The red clover was introduced into the pastures by (1) feeding out red clover hay; and (2) grazing red clover pastures after seed set. Milk production (kg milk solids /ha) for the 1995/96 season, compared to the zone average, was: * 24% higher for the full season * 30% higher in the November to April period when pastures were red clover-dominant * 35% higher in the December to February (summer) period. Trials were carried out in the Manawatu in which milk production of Romney ewes, and growth rates of suckling and weaned lambs, were monitored weekly over periods ranging from 10 to 12 weeks. Treatments comprised either red clover or ryegrass- white clover pastures. Compared with ryegrass-white clover * ewes grazing red clover produced 24% more milk * suckling lambs on red clover had 20% higher rates of growth * weaned lambs on red clover had 24% higher rates of growth It is concluded that red clover has the potential to increase milk production and growth rates over what is achievable on ryegrass-white clover pastures. Keywords: dairy cattle, ewes, milk yield, Trifolium pratense

Energy and protein value of combinations of maize silage and red clover hay for ruminants, using adult sheep as a model

Four combinations of maize silage and artificially dried red clover were fed consecutively to adult wether sheep ad libitum and at a level designed to maintain liveweight. On a dry matter (DM) basis, the diets contained silage and clover at ratios 1 :0, 2: 1, 1:2, and 0:1. A fifth diet contained maize silage plus urea (as 1% of the silage DM). Energy, nitrogen (N), and carbon balances were measured at both feeding levels and while fasting. The maize silage contained 11 g N and 41 1 g cell wall organic matter/kg DM; corresponding values for red clover hay were 37 and 290 g. Energy and protein metabolisms were monitored on the 5 diets and were related to dietary N content. Feed intake and digestibility increased with the proportion of clover in the diet and, hence, with increasing dietary N content. Energy losses from methane and heat production did not differ among diets, whereas urine energy losses were smallest, and therefore, efficiencies of utilisation of metabolisable energy (ME) greatest, on the silage-only and silage + urea diets. Greater urinary N losses on the diets of 1 : 2 silage: clover and clover-only led to lower N balances at the same apparently digested N intake on these 2 diets. There were positive associative effects between the silage and clover for voluntary feed consumption; digestibilities of energy, N, and cell wall organic matter; and energy and N balances. A ratio of ME to digestible energy of 0.81 underestimated the content of ME in silage by 0.5 MJ/kg DM, yet overestimated it in clover by 0.4 MJ/kg DM. The ME value of the silage + urea diet (11.6 MJ/kg DM) was one of the highest reported in sheep for maize silage using indirect calorimetry.