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The objective of the present study was to evaluate the effects of extensive grazingin a sown pasture with forestland on the health of beef cows by measuring multiple indicators. Ten Japanese Black beef cows were used in this experiment. Five of the ten cows were grazed for two months on a 1.8 ha field. The remaining cows were fed under confinement conditions. Behavioral assessments showed that grazing increased sternum lying with rumination of the cows. The grazing cows did not show any abnormal behaviors. There was a tendency for the numbers of red blood cells and lymphocytes to be lower in grazing cows than in confined cows, whereas the number of neutrophils in grazing cows was significantly higher than that in confined cows. In addition, grazing cows had a higher total antioxidant capacity and glutathione peroxidase activity than confined cows. These results suggest that extensive grazing in a sown pasture with forestland increases natural behaviors, decreases circulating red blood cells and lymphocytes and enhances neutrophil circulation, antioxidant enzyme activity, and antioxidant capacity.

Pseudoachalasia, also known as secondary achalasia, is a clinical condition mimicking idiopathic achalasia but most commonly caused by malignant tumors of gastroesophageal junction (GEJ). Our aim was to systematically review and present all available data on demographics, clinical features, and diagnostic modalities involved in patients with pseudoachalasia. A systematic search of literature published during the period 1978-2019 was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (end-of-search date: June 25th, 2019). Two independent reviewers extracted data with regards of study design, interventions, participants, and outcomes. Thirty-five studies met our inclusion criteria and were selected in the present review. Overall, 140 patients with pseudoachalasia were identified, of whom 83 were males. Mean patient age was 60.13 years and the mean weight loss was 13.91 kg. A total of 33 (23.6%) patients were wrongly 'treated' at first for achalasia. The most common presenting symptoms were dysphagia, food regurgitation, and weight loss. The median time from symptoms' onset to hospital admission was 5 months. Most common etiology was gastric cancer (19%). Diagnostic modalities included manometry, barium esophagram, endoscopy, and computed tomography (CT). Pseudoachalasia is a serious medical condition that is difficult to be distinguished from primary achalasia. Clinical feature assessment along with the correct interpretation of diagnostic tests is nowadays essential steps to differentiate pseudoachalasia from idiopathic achalasia.

Several processing techniques can be used to slow the degradation rate in the rumen and thus provide more bypass crude protein (CP) and starch to the small intestine. The aim of this study was to evaluate the effects of processing methods on cool-season adapted oat grain compared with dry-rolled barley grain, when fed as total mixed ration (TMR) for lactating dairy cows. Eight lactating Holstein cows were used in a replicated 4 × 4 Latin square design with 21-d periods and fed TMR with 1 of 4 treatments: dry-rolled oats, steam-flaked oats, pelleted oats, or dry-rolled barley. Dry matter intake (DMI) ranged from 28.19 to 31.61 kg/d and was lower for rolled oats compared with pelleted oats. Despite the nutrient intake being higher for cows fed pelleted oats, those fed rolled oats had the highest milk production and milk fat percentage (49.23 kg/d and 4%, respectively). Ruminal fermentation characteristics were similar across treatments, with only significant differences in concentrations of acetate (lowest for pelleted oats) and total short-chain fatty acids (highest value for rolled barley) and a lower pH for flaked oats at the 9-h and 12-h points. Dietary treatments did not affect total-tract digestibility of dry matter, organic matter, or CP; digestibility of starch was the lowest for rolled barley (89.04%). Measured blood metabolites, urea, glucose, and β-hydroxybutyrate, were not affected by dietary treatment. Purine derivatives and microbial N supply were also unaffected by dietary treatments. Cows fed flaked oat-based TMR showed the lowest N excretion in milk; however, the lack of difference between diets with regard to urinary N and fecal N excretion resulted in no significant changes in N balance between diets. Therefore, rolled oats allow cows to have higher milk production with lower DMI compared with all other treatments in this study.

The objective of this study was to evaluate the effects of 2 winter (December to April) housing systems on dairy cow hygiene scores, frostbite, teat condition, clinical mastitis, and activity and rumination across 3 winter seasons (2013, 2014, and 2015). Certified-organic cows (n = 268) were randomly assigned to 2 treatments (2 replicates per system): (1) outdoor straw pack (outdoor) or (2) 3-sided compost-bedded pack barn (indoor). Cows calved during 2 seasons (spring or fall) at the University of Minnesota West Central Research and Outreach Center, Morris, Minnesota, organic dairy. Organic wheat straw was used as bedding for the 2 outdoor straw packs, and bedding was maintained by farm management to keep cows dry and absorb manure throughout the winter. The compost-bedded pack barn (2 pens in the barn) was bedded with organic-approved sawdust, and the bedding material was stirred twice per day with a small chisel plow. Hygiene scores were recorded biweekly as cows exited the milking parlor. Incidence of clinical mastitis was recorded in a binary manner as treated (1) or not treated (0) at least once during a lactation. Frostbite incidence was collected monthly. Activity and rumination times (daily and 2-h periods) were monitored electronically using a neck collar sensor (HR-LD Tags, SCR Dairy, Netanya, Israel). Indoor cows had greater udder hygiene scores (1.75 vs. 1.46) and greater abdomen hygiene scores (1.79 vs. 1.43) compared with outdoor cows. Additionally, the indoor cows had greater upper and lower leg hygiene scores compared with outdoor cows. Incidence of clinical mastitis was greater for indoor cows compared with outdoor cows (27.1% vs. 15.1%, respectively). Frostbite incidence was not different between indoor (30.1%) and outdoor (17.5%) cows. Daily rumination was 509 min/d for indoor cows and 530 min/d for the outdoor cows. In summary, lactating cows housed outdoors on straw-bedded packs had cleaner udders and improved udder health compared with cows housed in a compost-bedded pack barn.

Background Hypocalcemia has detrimental effects on health and performance of dairy cows. As hypocalcemic cows show reduced feed intake, we hypothesized that cows with reduced combined rumination and eating time (CRET) may benefit from Ca supplementation. The objective was to evaluate the effect of postpartum oral Ca administration on metabolic status (Calcium [Ca], fatty acids [FA], and β-Hydroxybutyrate [BHB] serum concentrations) and incidence of puerperal metritis (PM) in dairy cows with reduced postpartum CRET. Cows in an organic-certified dairy, diagnosed with reduced CRET (n = 88) during the first day postpartum were assigned into 1 of 2 treatments: i) Calcium administration (CA; n = 45) that received 1 Ca oral capsule (Bovikalc bolus, Boehringer Ingelheim, St. Joseph, MO) containing CaCl2 and CaSO4 (43 g of Ca) once per day, for 3 consecutive days, starting at d 1 postpartum; and ii) Control (CON; n = 43) that did not receive oral Ca. A convenience group consisting of cows with CRET ≥489 min/d was used for comparison and did not receive oral Ca (NOR; n = 96). Results At day 1 postpartum cows with reduced CRET had lower Ca serum concentrations (CA = 2.08 mmol/L; CON = 2.06 mmol/L) compared with NOR cows (2.17 mmol/L). Calcium concentrations at d 3, 5, and 12 postpartum were not different among the three groups. Serum FA concentrations at d 1, 3 and 5 postpartum were higher in both CA and CON cows compared with NOR. At d 12, only CA cows had higher FA concentrations than NOR cows. Serum BHB concentrations at d 3 were highest in CA, with no difference between CON and NOR. At d 5, BHB concentrations were higher in CA, followed by CON, and NOR. No effect was observed for Ca administration on incidence of PM and reproductive performance. CON cows had lower survival at 30 DIM (86.5%) than NOR cows (97.9%). Conclusions The use of remote sensor technology identified cows with reduced rumination and eating time that had lower postpartum serum concentrations of calcium and altered metabolic status. However, oral calcium administration to cows with reduced CRET did not affect incidence of metabolic disorders nor reproductive health and subsequent pregnancy. Although survival at 30 days postpartum was lower for non-Ca supplemented cows, the identification of effective interventions in cows with reduced CRET requires further consideration.

This study aimed to determine if a diet change from a mixed system to a confinement system affects the milk production and composition, behavior and blood biochemistry of dairy cows. Cows were assigned randomly to one of the two treatments: cows fed with TMR (total-mixed-ration) (confined) throughout the period group fed TMR (GTMR, n = 15) and cows that changed their diet from pasture plus TMR to exclusive TMR at 70 ± 14 DIM (GCHD, n = 15). GTMR cows produced more milk and greater lactose and protein yield before the change of diet than GCHD cows (p ≤ .01), but these differences disappeared after the change. GCHD cows decreased the frequency of rumination and lying from before to after the change (p ≤ .03), but in GTMR cows no changes were observed. After diet change, GCHD cows had lower frequency of rumination and lying than GTMR cows (p ≤ .02). Before the change, GCHD cows had greater NEFA (non esterified fatty acids) concentrations than GTMR cows (p = .002). Abrupt change from a mixed system to a confined system was favorable on blood biochemical and milk variables of dairy cows. However, in relation to behavior, the cows expressed difficulties to adapt quickly to the abrupt change of system.

Concern over the carbon footprint of the dairy industry has led to various dietary approaches to mitigate enteric CH4 production. One approach is feeding the electron acceptor NO3-, thus outcompeting methanogens for aqueous H2. We hypothesized that a live yeast culture (LYC; Saccharomyces cerevisiae from Yea-Sacc 1026, Alltech Inc., Nicholasville, KY) would stimulate the complete reduction of NO3- to NH3 by selenomonads, thus decreasing the quantity of CH4 emissions per unit of energy-corrected milk production while decreasing blood methemoglobin concentration resulting from the absorbed intermediate, NO2-. Twelve lactating Jersey cows (8 multiparous and noncannulated; 4 primiparous and ruminally cannulated) were used in a replicated 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments. Cattle were fed diets containing 1.5% NO3- (from calcium ammonium nitrate) or an isonitrogenous control diet (containing additional urea) and given a top-dress of ground corn without or with LYC, with the fourth week used for data collection. Noncannulated cows were spot measured for CH4 emission by mouth using GreenFeed (C-Lock Inc., Rapid City, SD). The main effect of NO3- decreased CH4 by 17% but decreased dry matter intake by 10% (from 19.8 to 17.8 kg/d) such that CH4:dry matter intake numerically decreased by 8% and CH4:milk net energy for lactation production was unaffected by treatment. Milk and milk fat production were not affected, but NO3- decreased milk protein from 758 to 689 g/d. Ruminal pH decreased more sharply after feeding for cows fed diets without NO3-. Acetate:propionate was greater for cows fed NO3-, particularly when combined with LYC (interaction effect). Blood methemoglobin was higher for cattle fed NO3- than for those fed the control diet but was low for both treatments (1.5 vs. 0.5%, respectively; only one measurement exceeded 5%), indicating minimal risk for NO2- accumulation at our feeding level of NO3-. Although neither apparent organic matter nor neutral detergent fiber digestibilities were affected, apparent N digestibility had an interaction for NO3- × LYC such that apparent N digestibility was numerically lowest for diets containing both NO3- and LYC compared with the other 3 diets. Under the conditions of this study, NO3- mitigated ruminal methanogenesis but also depressed dry matter intake and milk protein yield. Based on the fact that few interactions were detected, LYC had a minimal role in attenuating negative cow responses to NO3- supplementation.

In Ireland, milk is primarily produced using a spring-calving grass-based system, with the use of concentrate supplementation mainly when pasture availability and quality are reduced. In the autumn, when cows are in late lactation, reduced pasture productivity results in reduced milk yield and altered milk composition. Nitrogen utilization efficiency also reduces as lactation progresses. Concentrate supplementation has been found to increase milk production and reduce nitrogen (N) excretion, as high-N grass is usually replaced by a lower-N supplement; however, there is a paucity of information with regard to the optimum type of supplementation in late lactation. Therefore, the objective of this research is to investigate the effect of different concentrate supplementation types, based on barley or maize, on milk production, dry matter intake (DMI), rumen fermentation, and N excretion in late-lactation, spring-calving, grazing dairy cows. Thirty-six Holstein Friesian dairy cows were blocked on days in milk (185 DIM) and balanced for parity, pre-experimental milk yield, milk composition, and body condition score. Cows were randomly assigned to 1 of 3 dietary treatments in a randomized complete block design (n = 12). The 3 treatments consisted of a perennial ryegrass-based pasture-only (PO) treatment and pasture plus either of 2 supplementary concentrates, based on barley (PB) or maize (PM). The diets were fed for a 14-d acclimatization period and then for a further 63-d experimental period. Cows offered PO had a lower daily milk yield (15.1 kg) than PB (18.2 kg) or PM (16.8 kg). Similarly, PO had lower daily milk solids yield (1.46 kg) than PB or PM (1.68 and 1.53 kg, respectively). Cows offered PB had a greater milk yield and higher fat and protein yields than those offered PM. Offering PB increased total DMI (19.5 kg) compared with PO (17.7 kg), and milk response to concentrates was also greater for PB compared with PM (1.21 vs. 0.71 kg of milk per kg of concentrate). Cows offered PB had increased N in milk compared with PO. In conclusion, concentrate supplementation based on barley or maize resulted in increased milk and milk solids yield compared with offering PO. Cows offered barley had a greater response to concentrates and increased milk and milk solids yield in comparison to maize and showed increased N partitioning in milk compared with PO. A barley-based concentrate increased total DMI compared with PO.

The purpose of this experiment was to determine the effects of feeding increasing levels of fresh forage (FF) as a proportion of total dry matter intake (DMI) on nutrient intake, rumen digestion, nutrient utilization, and productive performance of total mixed ration (TMR)-fed cows. Twelve dairy cows (90 ± 22 d in milk, 523 ± 88 kg of body weight, 7,908 ± 719 kg of milk production in the previous lactation) were housed in individual tiestalls and assigned to treatments according to a 3 × 3 Latin square design replicated 4 times. Treatments were 100% TMR (T100), 75% TMR plus 25% FF (T75), and 50% TMR plus 50% FF (T50). The experiment lasted 60 d, divided into 3 periods of 20 d each; the first 12 d of each period were used for diet adaptation and the last 8 d for data collection. The TMR (18.1% crude protein, 24.6% acid detergent fiber) and FF (Lolium multiflorum; 15.1% crude protein, 24.1% acid detergent fiber) were prepared and cut daily and offered to each cow individually. The highest DMI was reached in T100 and T75, which was reflected in greater intake of the different nutrients than T50. No differences were detected in the apparent total digestibility of the nutrients, mean ruminal pH, and total volatile fatty acid concentrations among treatments. Cows in T50 resulted in the lowest ruminal N-NH3 concentration and the lowest microbial N flow to the duodenum. Milk yield was 8.5% higher from cows in T100 and T75 compared with T50, but we observed no differences for milk fat or milk protein yield among treatments. Milk fat of cows fed T50 had 8% more unsaturated fatty acids (FA) than that of cows fed T100, mostly because of a higher content of monounsaturated FA. Additionally, cows in T50 had a higher concentration of linoleic acid, vaccenic acid, and rumenic acid than T100. Meanwhile, the concentration of linoleic acid and vaccenic acid in cows fed T75 was higher than T100. The milk fat of the cows fed T50 and T75 had a lower n-6:n-3 ratio than T100. We concluded that including up to 29% of FF in the total DMI in combination with a TMR did not affect the intake or digestion of nutrients or the productive response in dairy cows and resulted in a higher concentration of desirable FA from a consumer's perspective.

The objective of this study was to evaluate the effects of a fermentation byproduct on rumen fermentation and microbial yield in high producing lactating dairy cattle. Eight ruminally cannulated multiparous Holstein cows averaging (mean ± standard deviation) 60 ± 10 d in milk and 637 ± 38 kg of body weight were assigned to 1 of 2 treatment sequences in a switchback design. Treatment diets contained (dry matter basis) 44% corn silage, 13% alfalfa silage, 12% ground corn, and 31% premix containing either a control mix of urea and wheat middlings (CON) or a commercial fermentation byproduct meal (Fermenten, Arm and Hammer Animal Nutrition, Princeton, NJ) at 3% diet inclusion rate (EXP). Diets were formulated to be isonitrogenous and isocaloric, with similar levels of neutral detergent fiber and starch. The trial consisted of three 28-d experimental periods, where each period consisted of 21 d of diet adaptation and 7 d of data and sample collection. Omasal nutrient flows were determined using a triple-marker technique and double-labeled 15N15N-urea. The EXP diet provided 18 g/d more nonammonia N versus the CON diet, representing 3.0% of total N intake. Energy-corrected milk yield (41.7 and 43.1 kg/d for CON and EXP, respectively), milk fat, and protein yield and content did not differ between treatments. Total dry matter intake was similar between treatments (25.5 and 26.4 kg/d for CON and EXP, respectively). Ammonia N concentration and pool size in the rumen was greater in cows fed the EXP diet. No differences were observed in rumen or total-tract dry matter, organic matter, or neutral detergent fiber digestibility. Ruminal degradation of feed N was 15% lower in cows fed EXP diets, resulting in differences in omasal N flows. Results demonstrated the fermentation byproduct meal had a sparing effect on degradable feed protein, but did not increase microbial N flow from the rumen.

The objective of this study was to evaluate the effect of a fermentation by-product on rumen function, microbial yield, and composition and flows of nutrients from the rumen in high-producing lactating dairy cattle. Eight ruminally cannulated multiparous Holstein cows averaging (mean ± standard deviation) 60 ± 10 d in milk and 637 ± 38 kg of body weight were randomly assigned to 1 of 2 treatment sequences in a switchback design. Treatment diets contained (dry matter basis) 44% corn silage, 13% alfalfa silage, 12% ground corn, and 31% protein premix, containing either a control mix of urea and wheat middlings (CON) or a commercial fermentation by-product meal (Fermenten, Arm and Hammer Animal Nutrition, Princeton, NJ) at 3% diet inclusion rate (EXP). The trial consisted of three 28-d experimental periods, where each period consisted of 21 d of diet adaptation and 7 d of data and sample collection. A triple-marker technique and double-labeled 15N15N-urea were used to were used to measure protozoal, bacterial, and nonmicrobial omasal flow of AA. Rumen pool sizes and omasal flows were used to determine digestion parameters, including fractional rates of carbohydrate digestion, microbial growth, and yield of microbial biomass per gram of degraded substrate. Fermentation by-product inclusion in EXP diets increased microbial N and amino acid N content in microbes relative to microbes from CON cows fed the urea control. Microbial AA profile did not differ between diets. Daily omasal flows of AA were increased in EXP cows as a result of decreased degradation of feed protein. The inclusion of the fermentation by-product increased nonmicrobial AA flow in cows fed EXP versus CON. Average protozoal contribution to microbial N flow was 16.8%, yet protozoa accounted for 21% of the microbial AA flow, with a range of 8 to 46% for individual AA. Cows in this study maintained an average rumen pool size of 320 g of microbial N, and bacterial and protozoal pools were estimated at 4 different theoretical levels of selective protozoa retention. Fractional growth rate of all microbes was estimated to be 0.069 h-1, with a yield of 0.44 g of microbial biomass per gram of carbohydrate degraded. Results indicated that fermentation by-product can increase omasal flow of AA while maintaining adequate rumen N available for microbial growth and protein synthesis. Simulations from a developmental version of the Cornell Net Carbohydrate and Protein System indicated strong agreement between predicted and observed values, with some areas key for improvement in AA flow and bacterial versus protozoal N partitioning.

Ten bull calves (n = 5/diet) were cannulated at 3 wk of age and used in a 2 × 2 factorial design with repeated measures over time to compare rumen and whole-tract degradability of 2 calf starter diets and to describe an in situ technique for estimating ruminal degradability of diets in calves at different ages. Calves received milk replacer and 1 of 2 starter diets through wk 7. Mean birth weight was 38.7 ± 1.3 kg. Weaning occurred in wk 8, and calves received only starter (up to 4,500 g/d) through wk 15. Starter diets were a complete pellet (PEL; 42% starch, 13% neutral detergent fiber, NDF) or texturized feed (TEX; 31% starch, 22% NDF). Portions of each diet were dried and ground through a 2-mm screen, and 1.25 g was inserted into concentrate in situ bags (5 cm × 10 cm, 50-µm porosity). Each calf received duplicate bags of each diet for a total of 8 bags/calf (2 diets × 2 time points). All bags were inserted at the time of starter feeding. Half of the bags were removed at 9 h, and the other half were removed at 24 h. After removal from the rumen, bags were rinsed, dried (55°C), and composited by diet and by calf within week for NDF, nitrogen (N), and starch analyses. This process was repeated over 3 d during wk 5, 7, 9, 11, 13, and 15. Daily starter intake and total fecal excretion were recorded during the same 3-d periods. Diets, refusals, and feces were subsampled, dried, ground, composited by calf by week, and analyzed for NDF, N, and starch content. Apparent digestibility coefficients, total intake, and fecal excretion were calculated and analyzed with a mixed models procedure. Intake and fecal excretion of all measured nutrients increased from wk 5 through wk 15 of age and were greater for calves fed TEX, whereas the proportion of dry matter (DM), N, and starch apparently digested through the total tract decreased from wk 5 to 15 and was greater in calves fed PEL. Ruminal disappearance of DM, N, and starch after 9-h incubations increased linearly with age. Likewise, DM, NDF, and N disappearance after 24-h incubations also increased. Ruminal disappearance of DM and NDF was greater for PEL than for TEX. Ruminal disappearance was estimable for DM, NDF, N, and starch. In addition, changes over time and changes due to rumen environment were clearly demonstrated. Based on these data, there is potential to design specific rations and feed processing methods for calves based on their ability to utilize nutrients.

The present study investigated the effects of dietary forage source (quality) and particle size on chewing activity, saliva secretion, and ruminal pH. Twelve multiparous lactating Holstein cows, four of which were ruminally cannulated, were used in a replicated 4 × 4 Latin square experimental design with a 2 × 2 factorial arrangement of treatments. Cows fed wild-rye hay diets had longer daily eating times than cows fed oaten hay diets. Treatments had no effect on ruminating time; therefore, resting time varied inversely to eating time. Neither the rate nor the amount of saliva secretion while eating, ruminating, or resting was affected by diet, resulting in similar total daily saliva secretions across treatments (231 L/day). Total volatile fatty acids (VFAs) in the ruminal fluid from animals fed oaten hay diets were higher than those from animals fed wild-rye hay diets; further, VFAs increased with decreasing forage particle size (FPS). Consistent with elevated VFA concentrations, reducing FPS and including oaten hay in the diet decreased mean ruminal pH and increased the daily time of ruminal pH under 5.8. Results of this study suggest that forage source and particle size affect ruminal pH might be via variations in VFA production rather than increased salivary recycling of buffering substrates.

Carbohydrate-rich diets may increase urinary excretion of chromium (Cr) and increase its requirements. This study was conducted to investigate the effect of grain type (barley v. corn) and Cr supplementation on feed intake, feeding behavior and weight gain in dairy calves. Forty-eight neonatal Holstein female calves were assigned randomly to four experimental diets in a 2×2 factorial arrangement. Experimental diets were either barley-based diet (BBD) or corn-based diet (CBD) supplemented with (+Cr) or without (−Cr) Cr as Cr-methionine (0.05 mg/kg of BW0.75). Chromium was provided in milk (from days 3 to 73 of life) during the pre-weaning period and then in pre-warmed water (from day 74 until day 94 of life) after weaning. Meal length tended to increase in calves fed the BBD v. CBD during the pre-weaning period. During the post-weaning period, meal size, inter-meal interval, and eating rate increased concurrently but meal frequency and eating time decreased in the BBD v. CBD. During the pre-weaning period, feed efficiency, BW at weaning, and heart girth increased and non-nutritive oral behaviors tended to decrease with Cr supplementation. Due to increased meal frequency, the starter feed intake but not eating time increased by Cr supplementation during the post-weaning period. Supplementing Cr increased starter feed intake, final BW, average daily gain and heart girth during the overall period. Rumination time increased in BBD+Cr calves due to increases in the frequency and duration of rumination, or decreased rumination bout interval. Overall, the type of grain had no effect on feed intake and growth performance; however, Cr supplementation decreased non-nutritive oral behaviors and increased starter feed intake via increasing the meal frequency and thereby improved growth performance.

The present study examined the effects of substituting kraft pulp (KP) with corn silage (CS) on dry matter intake (DMI), ruminal mat and rumen fermentation characteristics, and rumination. Four non-lactating, rumen-cannulated Holstein cows were fed a CS diet comprising 36% grass silage (GS) and 64% CS or a KP diet comprising 36% GS, 57% KP, and 7% soybean meal. DMI was significantly lower in cows fed the KP diet than in those fed the CS diet (p < 0.05), whereas rumination time did not significantly differ between the treatments. Dry matter content in the rumen immediately before and 3 h after feeding was significantly higher in cows fed the KP diet than in those fed the CS diet (p < 0.05). The consistency and thickness of the ruminal mat did not significantly differ between the treatments. The ruminal mean retention time of feed particles tended to be longer in cows fed the KP diet than in those fed the CS diet (p < 0.10). The ruminal digestion rate of KP was comparable to that of GS and CS. Because ruminal mat was formed and rumination was stimulated, KP was considered to have the equivalent physical effectiveness as CS.

A clinical case in Belgium demonstrated that feeding a feed concentrate containing considerable levels of deoxynivalenol (DON, 1.13 mg/kg feed) induced severe liver failure in 2- to 3-month-old beef calves. Symptoms disappeared by replacing the highly contaminated corn and by stimulating ruminal development via roughage administration. A multi-mycotoxin contamination was demonstrated in feed samples collected at 15 different veal farms in Belgium. DON was most prevalent, contaminating 80% of the roughage samples (mixed straw and maize silage; average concentration in positives: 637 ± 621 µg/kg, max. 1818 µg/kg), and all feed concentrate samples (411 ± 156 µg/kg, max. 693 µg/kg). In order to evaluate the impact of roughage provision and its associated ruminal development on the gastro-intestinal absorption and biodegradation of DON and its acetylated derivatives (3- and 15-ADON) in calves, a toxicokinetic study was performed with two ruminating and two non-ruminating male calves. Animals received in succession a bolus of DON (120 µg/kg bodyweight (BW)), 15-ADON (50 µg/kg BW), and 3-ADON (25 µg/kg) by intravenous (IV) injection or per os (PO) in a cross-over design. The absolute oral bioavailability of DON was much higher in non-ruminating calves (50.7 ± 33.0%) compared to ruminating calves (4.1 ± 4.5%). Immediately following exposure, 3- and 15-ADON were hydrolysed to DON in ruminating calves. DON and its acetylated metabolites were mainly metabolized to DON-3-glucuronide, however, also small amounts of DON-15-glucuronide were detected in urine. DON degradation to deepoxy-DON (DOM-1) was only observed to a relevant extent in ruminating calves. Consequently, toxicity of DON in calves is closely related to roughage provision and the associated stage of ruminal development.

The aim of this study was to assess differences of ruminal pH and rumination activity between the prepartal and postpartal period of cows and to investigate changes of feeding behaviour and ruminal fermentation depending on postpartal rations with slight differences in roughage energy and fibre concentration. Therefore, 11 rumen-cannulated German Holstein cows were used from 3 weeks antepartum until 16 weeks postpartum. During the dry period, all cows received the same diet. After calving cows were assigned to two groups receiving partial mixed rations with different energy concentrations (6.1 MJ NEL/kg DM [moderate], with 18% straw on dry matter [DM] basis, group MR) or 6.5 MJ NEL/kg DM [high], with 6% straw on DM basis, group HR). In both groups, concentrates were supplied on average at 45% of total DM intake. Circadian measurements of ruminal pH, ruminal temperature and rumination activity were conducted weekly during the transition period and bi-weekly after week 4 postpartum. Throughout the postpartal period, feed intake behaviour was measured, and twice during the experiment, rumen fluid composition and net-acid-base excretion in urine were determined. Mean ruminal pH, feeding behaviour, rumination activity and rumen fluid composition did not differ between the groups, whereas group HR exhibited higher diurnal variations of pH and had a lower rumen temperature than group MR postpartum. However, these differences also occurred during the prepartal period when groups received equal rations. It was observed that ruminal pH values and the risk for subacute ruminal acidosis (SARA) were increased during postpartal period, whereby the circadian pH values showed high cow-individual variations. Overall, differences of energy and fibre concentrations in roughage did not affect the observed variables, whereby it should be noted that the number of cows was quite low in this study. Our results suggest that the ruminal pH characteristics are rather cow individual, indicating that cows presumably differ in their susceptibility to develop SARA.

Difficult calving may adversely affect dairy cow health and performance. Maternal:fetal disproportion is a major cause of dystocia. Therefore, the main objective of this study was to assess the effects of dam:calf body weight ratio (D:C) on calving difficulty, rumination time, lying time, and inflammatory profile in 25 Holstein dairy cows. Using automatic monitoring systems, we monitored behavior and production in 9 primiparous and 16 pluriparous cows between dry-off and 30 d in milk. During the same period, we collected blood samples to monitor metabolism and inflammatory profile of these cows. Calvings were video recorded to assess calving difficulty and observe the duration of the expulsive stage. After parturition, the cows were separated into 3 classes according to their D:C: easy (E; D:C >17), medium (M; 14 < D:C

The objective of this study was to investigate three different calving detection systems in order to assess and compare their efficiency. The study was conducted at a large-scale dairy farm involving 54 Holstein-Friesian dairy cows and heifers. Animals were fitted with multiple devices: a rumination measuring device (Ruminact® (RA)), an intravaginal thermometer (Vel'Phone® (VP)) and a tail movement sensor (Moocall® (MC)) 5 to 7 days before expected calving and were removed after parturition. RA detects rumination time (RT) and calculates it in 2-hr intervals. VP detects a decrease in vaginal temperature that might indicate calving within 48 hr and the drop in temperature resulting from the expulsion of the device at calving (EXP message). MC detected increased tail movements and if they persisted for one hour, 1HA message was sent. If they continued during the subsequent hour, then 2HA message was sent. Messages sent by MC within 4 hr before calving (C4) were selected retrospectively as true positives for the prediction of calving, using the significant changes in RT as a baseline. All other messages were categorized as false positive. The mean value of RT decreased in a non-significant manner between interval -22 and -4 before calving. Significant decrease of RT was detectable between the two intervals of -4 and -2 before calving (24.7 ± 18.6 min/2 hr and 14.0 ± 13.0 min/2 hr, respectively). There was no significant difference between RT of primiparous and multiparous animals. EXP messages were accurate (positive predictive value 100%) indicators of the onset of calving. We received on average 12.7 ± 15.2 messages/animal (11.0 ± 10.1 and 16.6 ± 22.2 for cows and heifers, respectively). Positive predictive value was 12.6%. The number of false-positive messages was significantly higher in heifers. All three automatic systems could be used in a large-scale farm environment.

Although lignin has been negatively correlated with neutral-detergent fibre (NDF) digestibility (NDFD) in ruminants and used to predict potential extent of NDF digestion of forages, selection of an analysis, Klason lignin (KL) or acid-detergent lignin (ADL), to describe that the nutritionally relevant lignin has not been resolved. Dismissed as an artifact is the difference between KL and ADL (ΔL). A question is whether ΔL influences NDFD. We evaluated the relationships of ΔL, KL and ADL with NDFD in order to determine the nutritionally homogeneous or heterogeneous nature of KL. Data sets from two laboratories (DS1 and DS2) were used that included ADL, KL and in vitro NDFD at 48 h (NDFD48). DS1 contained seven C3 grasses, seventeen C4 maize forages and nineteen alfalfas, and DS2 had fifteen C3 grasses, eight C4 forages and six alfalfas. Mean ΔL was greater than ADL in C3 and C4 samples and less in alfalfas. Within forage type and laboratory, ΔL was not correlated with NDFD48 (r −0·34–0·49; all P > 0·17). ADL was more consistently correlated with NDFD48 (r −0·47–−0·95; P < 0·01–0·21) than with KL (r 0·03–−0·91; P < 0·01–0·94). ΔL as a proportion of KL was correlated with NDFD48 in C3 and C4 samples (r 0·44–0·76; P < 0·01–0·08). The differing behaviours of ΔL and ADL relative to NDFD48 indicate that KL is a nutritionally heterogeneous fraction, the behaviour of which may vary by forage type and ratios of ADL and ΔL present.

Increased intestinal permeability can be observed during the physiologic stress response and has been linked to suppression of animal health and performance. Previously published data have shown the efficacy of fluorescein isothiocyanate dextran (FITC-d; 4.17 mg/kg) as a marker of enteric inflammation and mucosal barrier function in multiple species. Fluorescein is a smaller, less expensive alternative molecule possessing similar properties. The following two experiments compared FITC-d and fluorescein as potential indicators of intestinal permeability in pre- and postweaned lambs administered daily intramuscular injections of dexamethasone (Dex; 0.1 mg/kg) for 1 wk. Experiment 1 consisted of five preweaned lambs that were placed in one of two treatment groups: fluorescein with Dex (F+Dex) or fluorescein only (F). On day 7, blood was collected before and 1 h after oral administration of fluorescein (50 mg/kg). Experiment 2 included 12 weaned lambs and four treatment groups: F+Dex, F, FITC-d with Dex (Fd+Dex), and FITC-d only (Fd). On day 7, blood was collected before and 2 h after oral administration of FITC-d (4.17 mg/kg) or fluorescein (50 mg/kg). Plasma fluorescence was reported as the ratio between T1h/T0 or T2h/T0 for experiment 1 or 2, respectively. Experiment 1 showed a significant increase in T1h/T0 ratio of F+Dex relative to F lambs (P = 0.05) indicative of increased leaky gut; however, no differences (P = 0.22) were obtained in experiment 2. Results of these experiments suggest fluorescein may serve as a suitable marker of enteric permeability in preruminant lambs, but not in those with functional rumens.

The objective of the present study was to validate the accuracy of algorithms, implemented in the currently available RumiWatch Converter (RWC) version V0.7.4.5 of the RumiWatch System (RWS), for the classification of behavioural characteristics from jaw and head movements which are monitored by a noseband halter comprising a pressure sensor and a triaxial accelerometer. The accurate classification of behavioural characteristics in different time resolutions is critical for the usage of the RWS for scientific and practical purposes as chewing behaviour provides essential indicators for the assessment of diet adequacy in dairy cows. To validate the RWC V0.7.4.5 classification accuracy for behavioural characteristics of rumination, eating, drinking, other activity and ruminating chews per bolus by direct observation as reference method, 14 dairy cows participated in the trial. Concordance between the consolidated 1-min and 1-h classification results was assessed. The RWC V0.7.4.5 classified only rumination and ruminating chews per bolus precisely, whereas an algorithm optimisation for the classification of eating, drinking and other activity is required. Additionally, classification results from the 1-min and 1-h time summaries were not in agreement with each other except for rumination.

The objective of this study was using a wide range of dietary concentrate levels to investigate the major effects of limit-feeding on heifers. Twenty-four Holstein heifers were blocked into six groups and fed with one of four diets containing different levels of concentrate (20%, 40%, 60% and 80% on a dry matter (DM) basis) but with same intakes of metabolizable energy for 28 days. Increasing levels of dietary concentrate caused decreased (P ≤ 0.02) intakes of dry matter (DMI) and neutral detergent fiber and total rumination time, but increased (P

Supragastric belching is the most important factor in the etiology of excessive belching complaints. Supragastric belching is a belching disorder with a behavioral origin. The standard diagnosis is made by monitoring the esophageal impedance. Supragastric belching has been shown to be associated with globus, as well as reflux symptoms in proton pump inhibitor non-responders in gastroesophageal reflux disease; however, the pathophysiology of supragastric belching in patients with gastroesophageal reflux disease or functional dyspepsia has not been clarified. Patient education with behavioral therapy is the treatment of choice in isolated supragastric belching. On the other hand, the best management of supragastric belching associated with globus, gastroesophageal reflux disease, and dyspepsia remains to be studied.

Giraffes are ruminants feeding on fresh browse and twigs in the wild, but in zoos, their diet is mainly based on alfalfa hay, grains, and pellets occasionally supplemented by twigs and foliage. These diets, which differ in composition and digestibility, affect the behavior of the animals, tooth wear patterns, and chewing efficiency. We quantified several parameters of the rumination process in ten zoo housed giraffes of different sexes and ages fed either with alfalfa hay, fresh browse, or a combination of both. Chewing during rumination was highly ritualized and specimens showed an even distribution of chewing directions during this process, which prevents uneven tooth wear and use of chewing muscles. During rumination of alfalfa hay, chewing cycles of the giraffes took on average 49 s and included 54 jaw movements compared to 37 s and 42 jaw movements during rumination of browse, respectively. Single jaw movements (measured as basic chewing rates) were on average significantly slower during rumination of alfalfa hay (alfalfa: 1.10 chews per second, browse: 1.17 chews per second) and intercycle times between two chewing cycles took significantly longer (alfalfa: 7.77 s, browse: 7.46 s). Our results clearly indicate that several rumination parameters are influenced by the type of diet.

Horses achieve a higher degree of particle size reduction through ingestive mastication than functional ruminants. We characterized mastication using chew-monitoring halters (RumiWatch) in six domestic horses, cattle, and Bactrian camels each. All animals were offered grass hay of the same batch for 15 min. In cattle and camels, measurements were continued after eating until rumination was observed. Except for one horse, 96% of the horses' ingestive mastication data were identified as "rumination" by the proprietary RumiWatch algorithm, whereas ingestion and rumination by cattle and camels were mostly classified correctly. There were no systematic differences between cattle and camels. In cattle and camels, ingestive mastication was less regular than rumination, indicated by significantly higher standard deviations of chewing peak intervals, peak heights, and peak breadths in intraindividual comparisons. The average standard deviations of these measures were lower in horses than in cattle and camel ingestive mastication, indicating a more consistent chewing pattern in horses. Horse values were similar to those of rumination mastication, suggesting equally regular chewing motions. Regular, rhythmic chewing represents a common feature of horses and functional ruminants, but the less uniform ingestive mastication in functional ruminants represents a deviating pattern, the adaptive value of which remains unclear. In particular, it does not appear to promote a higher ingestion rate. A potential cause may be the avoidance of high tooth wear rates by delaying a more regular, systematic mastication until ingesta has been softened and the grit has been washed off in the forestomach.

High environmental temperature is a major constraint in sheep production under semi-arid tropical environment. Behavior is the earliest indicator of animal’s adaptation and responses to the environmental alteration. Therefore, the objective of this study was to assess the effects of high ambient temperature on the behavior of sheep under a semi-arid tropical environment. The experiment was conducted for 6 weeks on 16 Malpura cross (Garole × Malpura × Malpura (GMM)) rams. The rams were divided equally into two groups, designated as C and T. The rams of C were kept in comfortable environmental conditions served as control. The rams of T were exposed to a different temperature at different hours of the day in a climatic chamber, to simulate a high environmental temperature of summer in semi-arid tropic. The behavioral observations were taken by direct instantaneous observation at 15-min intervals for each animal individually. The feeding, ruminating, standing, and lying behaviors were recorded twice a week from morning (0800 hours) to afternoon (1700 hours) for 6 weeks. Exposure of rams to high temperature (T) significantly (P

Rumination involves a complex series of muscle contractions that bring a bolus of ingesta to the mouth for further mastication before it is swallowed again. Healthy cows ruminate 8 to 9 h/d. Hypocalcemia is known to disrupt nerve and muscle function. Our hypothesis was that hypocalcemia in periparturient cows would reduce rumination activity. Twenty-six Holstein cows entering their third lactation or greater were fed a control diet [dietary cation-anion difference (DCAD) = +196 mEq/kg of dry matter (DM)] or a low DCAD diet supplemented with anions (DCAD = -9 mEq/kg of DM) prepartum. Periparturient plasma Ca concentration and rumination rate were determined. Four of 12 control cows developed clinical milk fever, necessitating intravenous Ca therapy. Rumination rate decreased in all cows around the time of calving. Rumination rate on the first and second day of lactation was highly correlated with the cow's plasma Ca concentration on the first day of lactation. In one of our statistical models, a normocalcemic cow was defined as a cow whose plasma Ca concentration remained above 2.00 mM. Cows were retrospectively classified as normocalcemic, subclinically hypocalcemic, or clinically hypocalcemic (milk fever). Only 4 cows were considered normocalcemic, and all had been fed the low DCAD diet. Normocalcemic cows spent more time ruminating on the first day after calving than subclinically hypocalcemic cows or cows with milk fever. Cows with milk fever had a lower rumination rate than normocalcemic cows through d 3 of lactation. Rumination activity in cows with milk fever was almost nondetectable in the hours before and after intravenous Ca treatment for an extended period, despite the return of muscle function that allowed the cows to stand and eructate following treatment. Other statistical models using different definitions of normocalcemia gave qualitatively similar results. Diet had a great effect on plasma Ca concentration and rumination rate. Even when cows with clinical milk fever were removed from the control cow data set, cows on the low DCAD diet had significantly greater plasma Ca concentrations in the first 36 h after calving and a higher rumination rate on d 1 of lactation (248 ± 26 min) than control cows (158 ± 32 min).

The dairy industry in regions with moderate climates, such as Central Europe, will be increasingly challenged in the future by climate change. The problem of heat stress will especially affect dairy husbandry in naturally ventilated barns (NVB). The approach of the study was to determine a heat stress threshold of the average daily temperature-humidity index (THI) that results in changes in the daily rumination time (RT) of lactating, high-yielding cows. The data set was composed of a high sample size of 183 cows and long-duration measurements of 21240 daily observations over two years from June 2015 to May 2017, which were collected in an NVB in Groβ Kreutz, Germany. The THI was calculated in 5-min intervals by data from several sensors in different positions inside the barn. Additionally, every cow from the herd of an average of 53 cows in the experimental procedure was wearing a neck collar with a Lely Qwes HR system that provided the RT 24 h a day (12 2-h recordings were summarized). The study showed that heat stress also negatively influenced RT in moderate climates. The heat stress threshold of 52 THI was determined by broken-stick regression and indicated changes of RT of lactating dairy cows in Germany. During the experimental period, the heat stress threshold for RT was reached from April to September for up to 720 h per month. The changes in RT to the heat stress threshold will be affected by cows' characteristics. Therefore, we considered several cow-related factors, such as milk yield (MY), lactation number (LN), lactation stage (days in milk, or DIM) and pregnancy stage (P) to better understand cows’ individual reactions to heat stress. Multiparous, high-yielding cows in later lactation stages are potentially more strongly affected than other cows.

The objective of this study was to evaluate the effects of supplementing a Saccharomyces cerevisiae fermentation product (SCFP; NutriTek, Diamond V, Cedar Rapids, IA) during the transition period (d -28 ± 3 to 23 ± 3 relative to calving) on rumen fermentation and mRNA abundance of genes in the rumen epithelium of fresh cows (d 1 to 23 ± 3 after calving) fed diets differing in starch content. Eighteen ruminally cannulated multiparous Holstein cows were fed diets with SCFP (n = 9) or without (CON; n = 9) throughout the experiment. All cows were fed a common basal controlled-energy close-up diet (1.43 Mcal/kg, net energy for lactation; 13.8% starch) before calving. Cows within each treatment (CON or SCFP) were fed either a low-starch (LS; 22.1% starch) or high-starch (HS; 28.3% starch) diet during the fresh period. Cows were assigned to treatment after balancing for parity, body condition score, and expected calving date. Rumen pH was measured continuously for 72 h starting on d -10, -3, 1, 7, and 21 relative to calving date. Rumen papillae were collected on d -10 and 21 relative to calving. Supplementation of SCFP had no effect on rumen pH during d -10 to -8, but mean rumen pH tended to be higher (6.64 vs. 6.49) for SCFP cows than for CON cows during d -3 to -1. Feeding SCFP decreased the range of rumen pH variation compared with CON within the HS group during both d 7 to 9 (1.08 vs. 1.38) and d 21 to 23 (1.03 vs. 1.30) after calving. In addition, nadir rumen pH tended to be higher (5.64 vs. 5.44) and duration of pH below 5.8 tended to be shorter (116 vs. 323 min/d) for the SCFP group than for the CON group during d 21 to 23 after calving. Supplementation of SCFP increased the mRNA abundance of insulin-like growth factor-6 (1.10 vs. 0.69) before calving and decreased the mRNA abundance of putative anion transporter isoform 1 (1.12 vs. 2.27) after calving. Nadir rumen pH tended to be higher during d 1 to 3 (5.63 vs. 5.41) for LS cows than for HS cows, but rumen pH was not affected by dietary starch content during other time periods. Dietary starch content had no effect on mRNA abundance of genes in the rumen epithelium after calving. These results suggest that supplementation of SCFP may reduce the range of variation in rumen pH in fresh cows fed HS diets and the duration of subacute ruminal acidosis by the end of the fresh period regardless of dietary starch content and that decreasing dietary starch content during the fresh period may reduce the decrease in rumen pH immediately after parturition.

This research communication addresses the goal of validating an algorithm to monitor natural occurrence of feeding behaviours in dairy Mediterranean buffalo based on the output of a noseband pressure sensor (RumiWatch®, halter). Several characteristics of the feeding behaviour were detected with a very high (ruminating boluses), high (chews per bolus) and moderate degree of correlation (chews per minute) with video analyses (gold standard). All of them were associated with a low mean difference with the gold standard, and the mean relative measurement error ranged between low (ruminating boluses) and moderate (chews per bolus and chews per minute). The proportion of correctly detected events for the variables rumination and eating time was 98 and 99%, respectively. The collection of data and subsequent evaluation of the parameters investigated may provide objective information on Mediterranean Buffalo behaviours allowing for reliable studies of the animal welfare in this ruminant in the future.

The digestive physiology of ruminants is sufficiently different (e.g., with respect to mean retention time of digesta, digestibility of the feed offered, digestion, and fermentation characteristics)that caution is needed before extrapolating results from one type of ruminant to another. The objectives of the present study were (1)to provide an overview of some essential differences in rumen physiology between dairy cattle, beef cattle, and sheep that are related to methane (CH 4 )emission; and (2)to evaluate whether dietary strategies to mitigate CH 4 emission with various modes of action are equally effective in dairy cattle, beef cattle, and sheep. A literature search was performed using Web of Science and Scopus, and 94 studies were selected from the literature. Per study, the effect size of the dietary strategies was expressed as a proportion (%)of the control level of CH 4 emission, as this enabled a comparison across ruminant types. Evaluation of the literature indicated that the effectiveness of forage-related CH 4 mitigation strategies, including feeding more highly digestible grass (herbage or silage)or replacing different forage types with corn silage, differs across ruminant types. These strategies are most effective for dairy cattle, are effective for beef cattle to a certain extent, but seem to have minor or no effects in sheep. In general, the effectiveness of other dietary mitigation strategies, including increased concentrate feeding and feed additives (e.g., nitrate), appeared to be similar for dairy cattle, beef cattle, and sheep. We concluded that if the mode of action of a dietary CH 4 mitigation strategy is related to ruminant-specific factors, such as feed intake or rumen physiology, the effectiveness of the strategy differs across ruminant types, whereas if the mode of action is associated with methanogenesis-related fermentation pathways, the strategy is effective across ruminant types. Hence, caution is needed when translating effectiveness of dietary CH 4 mitigation strategies across different ruminant types or production systems.

Increasing rumen-undegraded protein is one challenge of ruminant nutrition to both meet protein requirements of animals and reduce nitrogen excretion in the environment by increasing nitrogen efficiency. Industrial processes using heat or tanning to reduce rumen protein degradation have certain limitations, such as difficulty in balancing low ruminal degradation and high intestinal digestibility. Reducing the mean retention time (MRT) in the rumen by varying the size and density of particles may be another promising way to increase the rumen-undegraded protein proportion of concentrate feeds and improve the effectiveness of industrial processes. Spherical plastic particles of 3 mean diameter sizes (1, 2, and 3 mm) and 4 densities (0.9, 1.1, 1.3, and 1.5) were used to study the combined effect of size and density on the MRT of particles without interactions with microbial fermentations. Dynamics of fecal excretion of particles were monitored over 106 h (17 sampling times) in a Latin square experiment with 4 lactating cows. Cumulative particle excretion curves were fitted to a double exponential model to calculate total MRT in the digestive tract (TMRT), MRT in 2 compartments (MRT1 and MRT2), and retention time in the intestines' tubular section (TT). Differences in density had a quadratic effect, with densities of 1.1 and 1.3 yielding lower TMRT (29.5 and 31.2 h, respectively) than the densities of 0.9 and 1.5 (TMRT = 64.0 and 51.2 h, respectively). Similar responses were observed for MRT1, which was assumed to be the ruminal MRT for densities 1.1 and 1.3 (8.9 and 10.5 h, respectively) compared with densities 0.9 and 1.5 (39.6 and 22.6 h, respectively). Differences in diameter had a linear effect on TMRT (12.9 h longer for 3 mm than for 1 mm) and on TT. A combined effect of size and density was observed and particle size had no effect on TMRT when density was 1.1 to 1.3; however, outside this range, an increase in particle diameter increased TMRT. Consequently, a density of 1.2 to 1.3 is optimal for the escape of particles. As smaller particles of concentrates lose functional specific gravity more rapidly than larger particles due to their higher fermentation rate, our results, obtained with plastic particles, suggest that a diameter slightly greater than 3 mm seems a compromise to delay the start of fermentation and allow for rapid passage through the reticulo-omasal orifice.

The aim of this research was to determine rumination time (RT) and the subsequent milk yield, along with trait changes during lactation dependent on the reproductive status of dairy cows. 728 cows were selected for evaluation in regards to 1-150 days of milk production (DIM). According to their period of lactation and reproductive status, the cows were selected for the following groups: Inseminated (1-35 days after insemination, n=182), Open (45-90 days after calving, n=126), Fresh (1-44 days after calving, n=45); Not-pregnant (35-60 days after inse- mination and not-pregnant, n=55); Pregnant (35-60 days after insemination and pregnant (n=320). The animals were milked with Lely Astronaut® A3 milking robots. The daily milk yield, rumination time, bodyweight, milk composition (fat, protein, lactose, somatic cell count and gynecological status date) were collected from the Lely T4C management program for analysis. We estimated the lowest productivity in the pregnant cows, where the average milk yield was 28.72 kg and the highest productivity in the fresh cow (p⟨0.001)(Table 1). The longest rumina- tion time was determined for the inseminated cows, statistically significantly higher at 9.92% (p⟨0.001) than in the non-pregnant cows, whose rumination time was the shortest. The statisti- cally reliably RT positively correlated with productivity (r=0.384, p⟨0.001) of the cows (from r=0.302 in the second lactation and r=0.471 in the first lactation to r=0.561 in multiparous cows; p0.001). Rumination time, according to groups of cows by milk yield, had a tendency to increase (2.14 times) from 202.0± 87.38 (in cows with a productivity of less than 10 kg milk) to 431.6±33.91 (in cows with a milk yield higher than 50 kg) by the linear regression equation: y = 38.02x + 232, R² = 0.721 (p⟨0.001). The relation between the gynecological status and milk fat-protein ratio of the cows was statistically significant (χ2=2.974, df= 8, p ⟨0.0001). The longest rumination time was determined for the inseminated cows (1 - 35 days after insemination), and the shortest for the not-pregnant cows (35 - 60 days after insemination and not-pregnant). We can conclude that rumination time, subsequent yield, and milk trait change depends on the period of lactation and reproductive status of a dairy cow.

This study examined the comminution of fresh herbage, subsequent nutrient release, and the characteristics of swallowed boli from three physically and chemically contrasting forages during ingestive mastication by dairy cows. The extent and pattern of nutrient release will determine their availability to rumen microflora, and potentially influence their efficiency of use. The forages evaluated were perennial ryegrass (ryegrass, Lolium perenne L., cv Alto AR37), lucerne (Medicago sativa L., cv Torlesse) and chicory (Cichorium intybus L., cv Choice). Experimental design was a 3×3 cross-over with three forages and three consecutive 1-day measurement periods, conducted twice. Six non-lactating, pregnant, multiparous Holstein-Friesian×Jersey cows (Bos taurus) were used, with the first cross-over applied to three mature (10.1±0.61 years old; BW 631±64 kg) cows, and the second to three young (4.8±0.02 years; BW 505±19 kg) cows. Fresh cut forage was offered to the cows following partial rumen evacuation. Swallowed boli were collected directly at the cardia at the commencement, middle and end of the first feeding bout of the first meal of the day. Forage species did not affect the fresh weight of ingested boli (mean 169 g, P=0.605) but the proportion of saliva in boli varied between forage. Boli of chicory contained the greatest amount of herbage material and least amount of saliva, whereas ryegrass boli were the opposite. Boli fresh weight tended to increase as time in the meal progressed, but the age of the cow was not shown to affect any boli characteristics or nutrient release. Particle size reduction was affected by forage, with 31%, 38% and 35% of chicory, lucerne and ryegrass herbage reduced tolt;2 mm. There was little evidence of relationship between comminution and any physical or chemical characteristic of the forage, except in ryegrass where extent of comminution was moderately correlated with herbage strength. Proportional release of herbage soluble carbohydrate exceeded that of N during mastication. Differences in loss of N were moderately correlated with the amount of N in the herbage (R 2=0.53) but herbage comminution was not strongly correlated with release of either N or carbohydrate. These findings illustrate the complex animal×forage interactions that occur during mastication, and that it is not possible to infer nutrient loss from herbage based on herbage characteristics as the driver for this differ between species.

Diet-induced milk fat depression (MFD) is a multifactorial disorder that can be triggered by a variety of conditions. Feeding high amounts of starch and unsaturated fatty acids has been shown to reduce milk fat yield and composition, as well as alter ruminal biohydrogenation patterns. However, little is known about how starch degradability in the rumen influences recovery from diet-induced MFD and if production of milk fat–inhibiting isomers will persist following an episode of MFD. The objective of this study was to evaluate production performance and ruminal fermentation in cows recovering from MFD when corn with a low or high starch degradability is fed. Six ruminally fistulated Holstein cows were used in a crossover design with 2 periods. During each period, MFD was induced for 10 d by feeding a diet with low fiber, high starch, and high unsaturated fatty acid. The polyunsaturated fatty acid concentration of the diet during the induction phase was modified primarily through inclusion of soybean oil. Following induction, cows were switched to either a high degradable starch recovery diet (HDS) or a low degradable starch recovery diet (LDS) for 18 d. The 7-h starch degradability was 66.5% for LDS and 87.8% for HDS. Milk was collected every 3 d for component and fatty acid analysis. On d 0, 4, 7, 10, 16, 22, and 28 of each period, ruminal pH and rumen fluid were collected every 2 h. Milk fat yield and composition was reduced during MFD induction and progressively increased by day in both HDS and LDS during recovery. Dry matter intake was similar among treatments and increased steadily over time during recovery. Preformed fatty acids were greater for HDS-fed animals, and de novo fatty acid in milk fat was greater for LDS-fed animals. Milk trans-10 C18:1 tended to be greater for HDS, and trans-10,cis-12 conjugated linoleic acid was significantly greater for HDS. cis-9,trans-11 conjugated linoleic acid was not affected by starch degradability during recovery. Total volatile fatty acids, butyrate, and valerate tended to differ or differed with recovery treatment, but ruminal pH and ammonia concentration were unaffected. The HDS diet responded similarly to the LDS diet during recovery with regard to milk fat percentage, but milk and fat yield tended to consistently be lower in HDS. When considering approaches to ameliorate diet-induced MFD, the degradability of the starch within rations should be evaluated. Although animal performance was similar, some trans fatty acid isomers were persistent in the milk through the recovery phase with HDS-fed animals, suggesting that milk fat synthesis might be potentially inhibited and biohydrogenation pathways modified in the rumen following an episode of MFD.

Accurately predicting nitrogen (N) digestion, absorption, and metabolism will allow formulation of diets that more closely match true animal needs from a broad range of feeds, thereby allowing efficiency of N utilization and profit to be maximized. The objectives of this study were to advance representations of N recycling between blood and the gut and urinary N excretion in the Molly cow model. The current work includes enhancements (1) representing ammonia passage to the small intestine; (2) deriving parameters defining urea synthesis and ruminal urea entry rates; (3) adding representations of intestinal urea entry, microbial protein synthesis in the hindgut, and fecal urea-N excretion; and (4) altering existing urinary N excretion equations to scale with body weight and adding purine derivatives as a component of urinary N excretion. After the modifications, prediction errors for ruminal outflows of total N, microbial N, and nonammonia, nonmicrobial N were 29.8, 32.3, and 26.2% of the respective observed mean values. Prediction errors of each were approximately 7 percentage units lower than the corresponding values before model modifications and fitting due primarily to decreased slope bias. The revised model predicted ruminal ammonia and blood urea concentrations with substantially decreased overall error and reductions in slope and mean bias. Prediction errors for gut urea-N entry were decreased from 70.5 to 26.7%, which was also a substantial improvement. Adding purine derivatives to urinary N predictions improved the accuracy of predictions of urinary N output. However, urinary urea-N excretion remains poorly predicted with 69.0% prediction errors, due mostly to overestimated urea-N entry rates. Adding representations of undigested microbial nucleic acids, microbial protein synthesized in the hindgut, and urea-N excretion in feces decreased prediction errors for fecal N excretion from 21.1 to 17.1%. The revised model predicts that urea-N entry into blood accounts for approximately 64% of dietary N intake, of which 64% is recycled to the gut lumen. Between 48 and 67% of the urea recycled to the gut flows into the rumen largely depending on diet, which accounts for 29 to 54% of total ruminal ammonia production, and 65 to 76% of this ammonia-N is captured in microbial protein, which represents 17% of N intake. Based on model simulations, feeding a diet with moderately low crude protein and high rumen-undegradable protein could increase apparent ruminal N efficiency by 20%.

Nitrates have been fed to ruminants, including dairy cows, as an electron sink to mitigate CH4 emissions. In the NO3− reduction process, NO2− can accumulate, which could directly inhibit methanogens and possibly other microbes in the rumen. Saccharomyces cerevisiae yeast was hypothesized to decrease NO2− through direct reduction or indirectly by stimulating the bacterium Selenomonas ruminantium, which is among the ruminal bacteria most well characterized to reduce both NO3− and NO2−. Ruminal fluid was incubated in continuous cultures fed diets without or with NaNO3 (1.5% of diet dry matter; i.e., 1.09% NO3−) and without or with live yeast culture (LYC) fed at a recommended 0.010 g/d (scaled from cattle to fermentor intakes) in a 2 × 2 factorial arrangement of treatments. Treatments with LYC had increased NDF digestibility and acetate:propionate by increasing acetate molar proportion but tended to decrease total VFA production. The main effect of NO3− increased acetate:propionate by increasing acetate molar proportion; NO3− also decreased molar proportions of isobutyrate and butyrate. Both NO3− and LYC shifted bacterial community composition (based on relative sequence abundance of 16S rRNA genes). An interaction occurred such that NO3− decreased valerate molar proportion only when no LYC was added. Nitrate decreased daily CH4 emissions by 29%. However, treatment × time interactions were present for both CH4 and H2 emission from the headspace; CH4 was decreased by the main effect of NO3− until 6 h postfeeding, but NO3− and LYC decreased H2 emission up to 4 h postfeeding. As expected, NO3− decreased methane emissions in continuous cultures; however, contrary to expectations, LYC did not attenuate NO2− accumulation.

The objective of this study was to investigate the effects of concentrations of forages and corn distillers dried grains with solubles (DDGS) on ruminal fermentation, ruminal kinetics, and total-tract digestibility of nutrients in lactating dairy cows. Four lactating Holstein cows with ruminal cannulas were assigned to a 4 × 4 Latin square in a 2 × 2 factorial arrangement of treatments. Diets were formulated to contain low forage [LF; 17% forage neutral detergent fiber (NDF)] or high forage (HF; 24.5% forage NDF) and DDGS at 0 or 18% (0DG or 18DG) of diet dry matter (DM). Intake of DM was not affected by the diets. Daily mean ruminal pH was affected by forage NDF × DDGS interactions, as the lowest ruminal pH was observed among cows fed LF18DG (6.02). Apparent total-tract digestibility for DM, organic matter, crude protein, NDF, acid detergent fiber, and starch was not affected by diets. Cows fed LF diets had a greater total volatile fatty acid concentration compared with cows fed HF (122 vs. 116 mM). Molar proportions of acetate were greater for HF compared with that of LF diets (62.6 vs. 57.5 mmol/100 mmol) and greater for 0DG diet compared with that of 18DG diets (61.3 vs. 58.7 mmol/100 mmol) diets. The molar proportion of propionate was affected by forage × DDGS interaction as the greatest propionate molar proportion was observed with cows fed LF18DG diet (27.7 mmol/100 mmol). Also, molar proportion of butyrate was affected by forage × DDGS interaction, as the greatest butyrate molar proportion was observed in cows fed HF18DG diet (13.5 mmol/100 mmol). Average fractional dilution rate for all diets was 11.9%/h and was not affected by diets. Fractional passage rate of the solid phase was greater for HF than for LF (4.40 vs. 3.76%/h). The ruminal retention time of solid phase was greater for LF compared with HF diets (27.3 vs. 23.3 h). Fractional passage rate of DDGS was affected by forage × DG interaction, as the highest fractional passage rate of DDGS was observed with cows fed HF18DG diet (7.72%/h). Our results demonstrated that concentrations of forage, DDGS, and their interaction influence ruminal degradation and kinetics of diets fed. Diets formulated at 17% forage NDF at 17% (DM basis) can decrease milk fat concentration compared with diets formulated at 25% forage NDF. Additionally, feeding DDGS at 18% DM basis to lactating dairy cows did not affect milk fat concentration or yield.

Glycogen is an α-glucan produced by rumen microbes from various feed carbohydrates. It may be digested ruminally or intestinally to provide nutrients. The physicochemical and enzymatic hydrolysis characteristics of microbial glycogen have not been described in detail, but do influence its conversion to absorbable nutrients in vivo, its nutritional comparability with plant starch sources, and its accurate analysis in vitro. The objectives of this study were to determine presence or absence of a gelatinization response and to describe enzymatic digestion characteristics of glycogen granules isolated from ruminal protozoa obtained from lactating dairy cows. Protozoal glycogen granules were determined to be 98.3% α-glucan. Granules displayed gelatinization, the breaking of hydrogen bonds between molecules or branches, at 65°C compared with purified wheat and corn starches, which initiated gelatinization at 50 and 65°C, respectively. Digestion of ungelatinized samples with amyloglucosidase for 2 h at 39°C showed approximately 3-fold greater hydrolysis to glucose for protozoal glycogen (25.2% of dry matter; DM) than for wheat (9.9% of DM) or corn (8.2% of DM) starches. Based on enzymatic digestion results, protozoal glycogen may be more readily digested than intact corn or wheat starches and should be gelatinized or the hydrogen bonds otherwise disrupted to allow more complete recovery in enzymatic analysis.

The objective of this experiment was to investigate the effects of a Saccharomyces cerevisiae-based direct-fed microbial product (SDM) and an exogenous enzyme product (ENZ) on enteric methane emission, milk yield and composition, total-tract digestibility of nutrients, ruminal fermentation, and nitrogen excretion and secretion in lactating dairy cows. Eighteen Holstein cows were used in a 3 × 3 Latin square design experiment with three 28-d periods. Treatments were (1) control (no additive), (2) 28 g of SDM/d per cow, or (3) 10 g of ENZ/d per cow. Treatments were top-dressed at the time of feeding. The basal diet consisted of (dry matter basis) 60% forage and 40% concentrates and contained 16.5% crude protein and 32.0% neutral detergent fiber. Treatments had no effect on enteric methane production, yield (methane per kg of dry matter intake, DMI), or intensity (methane per kg of energy-corrected milk yield). Carbon dioxide production was similar among treatments. Compared with control, SDM increased milk yield by 2 kg/d without affecting DMI or feed efficiency. Supplementation of the diet with ENZ did not affect DMI, milk yield, or feed efficiency. Concentrations and yields of milk fat, true protein, and lactose, and energy-corrected milk yield were not different among treatments. Neither SDM nor ENZ had an effect on total-tract digestibility of nutrients or nitrogen excretion and secretion. Concentration of total volatile fatty acids (VFA) in ruminal fluid was increased by both SDM and ENZ, and rumen pH was decreased by SDM compared with the control. At levels similar to the control DMI, the increased concentration of VFA in ruminal fluid of cows receiving SDM suggests an increased postruminal supply of energy and may partly explain the increased milk yield with that treatment. However, it is important to note that milk composition and energy-corrected milk yield were not affected by treatment.

International audience; We sought to establish predictive response models of milk fatty acid (FA) yields or concentrations from their respective duodenal flow, rumen digestive parameters, or diet characteristics in dairy cows, with a special focus on cis and trans isomers of C18:1, C18:2, odd- and branched FA, and mammary de novo synthesized FA. This meta-analysis was carried out using data from trials with nature of forage, percentage of concentrate, supplementation of diets with vegetable oils or seeds, and marine products' animal fats as experimental factors. The data set included 34 published papers representing 50 experiments with 142 treatments. Increasing duodenal C18 FA flow induced a quadratic increase in milk total C18 yield and a linear decrease in milk C4:0 to C14:0 concentration. Intra-experirnental predictive response models of individual milk cis C18:1 isomers (Delta 11 to 15 position) from their respective duodenal flows had coefficients of determination (R-2) ranging from 0.74 to 0.99, with root mean square error varying from 0.19 to 0.96 g/d, 0.02 to 0.10% of total FA, and 0.03 to 0.29% of C18 FA. Models predicting milk trans C18:1 isomer yields or concentrations had R-2 greater than 0.90 (except for trans-4 and trans-10 C18:1) with root mean square error varying from less than 0.1 to 5.2 g/d. Linear regressions for C18:2n-6, trans-10,cis-12 CLA, and trans-11,trans-13 CLA were calculated according to their respective duodenal flows. Quadratic models of milk C18:3n-3 yield or concentration from its duodenal flow had R-2 values above 0.97. Models of amounts desaturated from C18:0 into cis-9 C18:1 and trans-11 C18:1 into cis-9,trans-11 CLA indicated that the contribution of C18:0 and trans-11 C18:1 desaturation to respective cis-9 C18:1 and cis-9,trans-11 CLA yields in milk fat was 83.8% (+/- 0.75) and 86.8% (+/- 2.8). Furthermore, when cows were fed marine products, our results could indicate a lower mammary uptake of C18:0 and trans-11 C18:1 in proportion to their respective duodenal flow, with no associated change in mammary Delta(9)-desaturase activity. Yields or concentrations of C15:0, C17:0, iso-C15:0, iso-C17:0, anteiso-C15:0, and anteiso-C17:0 were dependent on their respective duodenal flow or concentration at duodenum, but synthesis of these FA from C3 units for linear-chain odd FA, and from C2 units for branched-chain FA was suggested, respectively. Several milk C18 FA concentrations were closely related to their duodenal concentrations with slopes of the linear models close to the bisector; this could reflect a priority for the use of these duodenal C18 FA by the mammary gland to favor their high concentration in plasma triglycerides arid nonesterified FA, which are preferentially taken up by the mammary gland.

Rumination is the repeated process of regurgitation of a food bolus, followed by chewing, swallowing, and regurgitation, which enhance nutrient assimilation. Time spent in lateral recumbency (i.e., bedded, lying) has often been used as a proxy for time spent ruminating due to difficulties of observing detailed rumination behavior in the field. The actual proportion of time spent ruminating, or other activities, will in turn be affected by the age and sex of an individual but also with changes in food quality. We studied the effects of intrinsic and extrinsic factors on time spent ruminating, bedding, proportion of bedding time spent ruminating, and grazing of individually marked bighorn sheep (Ovis canadensis). Our results show that bighorn sheep spent more time ruminating and less time grazing in summer and autumn. Overall, females spent less time ruminating, and more time grazing than males. Bighorn sheep decreased their time spent ruminating with increasing acid detergent fiber (ADF) content in the forage. Age influenced the time spent grazing, bedded and proportion of bedded time spent ruminating. Older sheep not only increased their bedding time but also their time spent bedded without ruminating compared to younger individuals. The proportion of time spent grazing was also affected by age, with a decrease in the proportion of time spent grazing with increasing age. Our results suggest that these four behaviors are plastic and variable. We thus conclude that bedding time does not reflect time spent ruminating but that the latter is affected by both intrinsic and extrinsic factors.

© 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved, The temporomandibular joint interposal study (TEMPOJIMS) is a rigorous preclinical trial divided in 2 phases. In phase 1 the authors investigated the role of the TMJ disc and in phase 2 the authors evaluated 3 different interposal materials. The present work of TEMPOJIMS - phase 1, investigated the effects of bilateral discectomy and discopexy in sheep mastication and rumination.

Interbeat interval data were collected from 219 Holstein cows in 2 smaller-scale farms and 3 larger-scale farms to investigate the effects of posture (standing vs. lying), rumination (rumination vs. no rumination) and feeding on baseline values of heart rate (HR) and heart rate variability (HRV) parameters reflecting vagal and sympathetic activity. A General Linear Model was used for detecting factors (parity, milking technology, herd size) having possible effects on HRV calculated for undisturbed lying posture. Basal values of cardiac parameters were also compared between larger and smaller-scale farms. Neither parity nor milking technology affected HRV parameters. Sympathetic activity increased in the order of lying, ruminating when lying, standing, ruminating when standing and feeding on both sizes of farms. Vagal activity decreased in that order in both lower- and larger-scale farms. Rumination caused an increase in HR and a decrease in vagal tone in both lower- and larger-scale farms and an increase in sympathetic activity during lying in both farm sizes. Basal vagal activity was lower in larger-scale farms compared to smaller-scale farms, while greater sympathetic activity was found in cows housed on larger-scale farms. Our findings demonstrate that reference values of HRV parameters in lactating dairy cows cannot be generally defined for Holstein cattle as they are affected by physical activity and herd size. Higher HR and sympathetic activity at rest in larger-scale farms compared to farms with lower cow population might be associated with higher levels of social stress and therefore should be considered as a potential welfare concern.