Feed Sorting Research Articles

Effects of heat stress abatement on behavioral response in lactating dairy cows prior to and following an intramammary lipopolysaccharide infusion

The assessment of animal behavior serves as a valuable approach to identify illness and animal responses to environmental stimuli. Both heat stress and mastitis are reported to impact the behavioral responses of dairy cattle. However, little is known about the effects of heat stress on the lactating cow's behavioral responses to mastitis. The aims of the current study were to evaluate the effects of deprivation of evaporative cooling on behavioral responses of lactating dairy cows before and following mammary inflammation induced by intramammary lipopolysaccharide (IM-LPS) infusion and to characterize the impact of deprivation of evaporative cooling on feed sorting in lactating dairy cows during summer. Multiparous mid-lactating Holstein dairy cows (n = 18, parity = 2.4 ± 0.6, DIM = 136 ± 61 d) were randomly assigned to: evaporatively cooled (CL, n = 9) or not cooled (NC, n = 9) for 36 d (average temperature-humidity index = 78.4). The evaporative cooling system included misters and fans. Misters were installed on the front face of each fan, which was placed over both feed bunk and free stalls. On d 30, the left rear quarters of a subset of cows (n = 14, 7/treatment) were infused with a bolus of LPS (10 µg of Escherichia coli O111:B4 LPS). Feeding and resting behaviors were recorded throughout the experiment using automated sensor devices (NEDAP). Sorting activity based on particle size separation using a Penn State Particle Separator was assessed at d 3, 16, and 26 of the experiment. Before IM-LPS, NC cows had lower ruminating and eating time, and consequently greater inactive time compared with CL cows. Relative to CL cows, NC cows had reduced lying time, and greater standing and walking time. The NC cows also had greater standing bouts, only at the beginning of the experiment, relative to CL cows. Additionally, NC cows sorted more for long particles (NC: 99.4% vs. CL: 94.4%) and sorted against medium and short particles on d 3 of the experiment compared with CL cows. However, following IM-LPS, no significant differences in behavioral responses were observed between NC and CL cows. In conclusion, deprivation of evaporative cooling negatively affected the behavioral responses of lactating dairy cows during summer. Further, heat-stressed cows without evaporative cooling sorted more for long particles of the diet potentially as a response to cope with the reduced rumen pH. However, deprivation of evaporative cooling does not have a significant impact on the lactating cow's behavioral responses to LPS induced mammary inflammation.

Isoacid supplementation influences feed sorting, chewing behaviors, and enteric methane emissions differentially in mid-lactation dairy cows depending on dietary forage level

Past studies have shown that isoacids (ISO) improve dairy cow performance, with effects varying based on dietary forage levels, leading us to speculate that ISO supplementation may also differentially affect enteric methane (CH4) emissions depending on dietary forage levels. Therefore, our primary objective was to examine the effects of ISO supplementation on enteric CH4 emissions in lactating dairy cows fed 2 forage NDF levels (FL), along with monitoring feed particle sorting and chewing behaviors to assess any potential interactions. Sixty-four (64) mid-lactation Holstein cows were utilized in a 10-wk long randomized complete block design trial. Parity, DIM, and prior milk yield (MY) for multiparous cows or genetic merit for primiparous cows were used as blocking factors. Cows were randomly assigned to 1 of 4 diets (n = 16 per diet) with a 2 × 2 factorial arrangement of treatment combinations, including 2 FL, 17 (LF) and 21% forage NDF (HF), without or with ISO supplementation (7.85 mmol/kg DM for isobutyrate and 3.44 mmol/kg DM for 2-methylbutyrate, respectively). Enteric CH4 and chewing activity (rumination and eating time) were measured using the GreenFeed system and sensor-based ear tag system, respectively. The particle size of each diet and ort from individual cows was measured using the Penn State Particle Separator, and a sorting index was calculated. A sorting index of 100 indicates no sorting, while values above or below 100 indicate sorting for or against, respectively. Data were analyzed using a mixed model including FL, ISO, and FL × ISO as fixed effects and block as a random effect (lme4 in R). Our result shows that ISO increased sorting index for long particle in LF (96.1 vs. 109; P < 0.01) but decreased it in HF (100.8 vs. 92.5; P = 0.04). In contrast, ISO did not affect the physically effective particle sorting index (P = 0.51) or intake (P = 0.27) regardless of FL. In alignment with the long particle sorting index, ISO decreased eating and chewing time in the HF but increased them in the LF diet (P < 0.01). In contrast, rumination time was comparable between FL (P = 0.70) and ISO levels (P = 0.19). In the LF diet, ISO supplementation reduced daily CH4 production (g/d) by 9% and intensity (g/kg of MY) by 18% (P < 0.01). In the HF diet, ISO supplementation led to a 10% increase in daily CH4 (P < 0.01) but did not change CH4 intensity (P = 0.17; g/kg of MY) due to improved milk production. Overall, ISO altered feed sorting, feeding behaviors and enteric CH4 emissions depending on FL.

Intake pattern and feed sorting of beef cattle fed different sources of corn in a feedlot

The objective of this experiment was to determine the feed intake pattern and feed sorting of 30 Nelore males finished in a feedlot fed diets based on three different sources of corn: whole crop silage (WCS), high moisture corn (HMC) or corn grain (CG). Feed intake pattern and feed sorting were determined on days 13, 27, 41, 55, 69, and 83 days after the beginning of the experiment in three times relative to feed delivery (4, 10, and 24 hours). Diets were size-separated using the three-screen (19, 8, and 4 mm) and a bottom pan to yield long (&gt;19 mm), medium (&lt;19, &gt;8 mm), short (&lt;8, &gt;4 mm) and fine (&lt;4 mm) particles. Feed sorting was calculated by the actual dry matter (DM) intake of each particle size expressed as a % of the theoretical DM intake of the corresponding particle size. There was no response (p&gt;0.05) of corn source on feed intake pattern. Regardless of the source of corn, animals expressed a preferential consumption or sorting for the long (104.01% for WCS, 126.99% for HMC, and 132.58% for CG) and medium (116.66% for WCS, 109.95% for HMC, and 135.14% for CG) particles of the diets, which may be a beneficial aspect in terms of rumen motility as well as maintaining rumen pH in an adequate range.

An easy decision-making graphic tool to improve herd level milk yield in a local scale dairy farming system

Several features prevent dairy farms from reaching their full potential milk yield levels. A plurality of methods are available to analyse a farm’s yield gap, but in practice, farmers rarely use them to understand their main constraints to production. We propose a simple and graphical approach to tune the limiting (feed-related) or reducing (management-related) factors to evaluate the likelihood of being a high-yielding farm. We gathered data from 32 farms within a local-scale dairy system in Northern Italy. Data regarded milk yield (MY), dry matter intake (DMI), feeding ration’s homogeneity index (Hi), feed sorting (Si) index, ration’s geometric mean particle length (GMPL), ration digestibility, income over feed cost (IOFC) and MY summer-winter ratio (SWR). Farms were classified according to their MY levels into high (H) and low or medium (L + M), with a 36.7 kg × cow−1 day−1 threshold. At an ANOVA model for MY class, H farms resulted in higher IOFC (p < 0.001), GMPL (p = 0.046), DMI (p = 0.006), digestible DM (DDM, p = 0.013), digestible crude protein (DCP, p = 0.011), digestible starch (Dstarch, p = 0.001), and feed efficiency (FE, p = 0.003). At a logistic AIC stepwise regression, the GMPL (odds = 6.528, 95% CI = 1.11-64.2) and DMI (odds = 3.889, 95% CI = 1.43-16.5) favoured farms being classified in the H production class. The nomogram was used to calculate a confusion matrix, achieving an overall accuracy of 0.70, demonstrating its ability to transform predictive models into a graphical, realisable tool.

Dietary supplementation with live or autolyzed yeast: Effects on performance, nutrient digestibility, and ruminal fermentation in dairy cows

This study was conducted to evaluate the effects of live or autolyzed yeast supplementation on dairy cow performance and ruminal fermentation. Two experiments were conducted to evaluate performance, feed sorting, total-tract apparent digestibility of nutrients, purine derivatives excretion, N utilization, ruminal fermentation, and abundance of specific bacterial groups in the rumen. In Exp. 1, 39 Holstein cows (171 ± 40 d in milk and 32.6 ± 5.4 kg/d milk yield) were blocked according to parity, days in milk, and milk yield and randomly assigned to the following treatments: Control (CON); autolyzed yeast (AY) fed at 0.625 g/kg DM (Levabon, dsm-firmenich); or live yeast (LY) fed at 0.125 g/kg DM (Vistacell, AB Vista). Cows were submitted to a 2-wk adaptation period followed by a 9-wk trial. In Exp. 2, 8 ruminal cannulated Holstein cows (28.4 ± 4.0 kg/d milk yield and 216 ± 30 d in milk), of which 4 multiparous and 4 primiparous, were blocked according to parity and enrolled into a 4 × 4 Latin square experiment with 21 d-periods (the last 7 d for sampling). Cows within block were randomly assigned to treatments sequences: control (CON2); live yeast (LY) using the same product and dietary concentration as described in Exp. 1; or autolyzed yeast fed at 0.625 g/kg DM (AY) or 0.834 g/kg DM (AY2). In Exp. 1 and 2, nutrient intake and total-tract apparent digestibility were not affected by treatments. Sorting for long feed particles (>19 mm) tended to be greater in cows fed yeast supplements than CON in Exp.1. Efficiency of N conversion into milk N was increased when feeding yeast supplements in Exp. 1. 3.5% Fat-corrected milk yield tended to be greater in cows fed yeast supplements than CON. Feed efficiency was increased when yeast supplements were fed to cows in relation to CON in Exp. 1. In Exp. 2, yield of fat-corrected milk and fat were greater in cows fed yeast supplements compared with CON2. Uric acid concentration and output in urine were increased when feeding yeast supplements when compared with CON2. Neither ruminal pH nor total volatile fatty acids were influenced by treatments. The current study did not reveal treatment differences in ruminal abundance of Anaerovibrio lipolytica, genus Butyrivibrio, Fibrobacter succinogenes, Butyrivibrio proteoclasticus, or Streptococcus bovis. Yeast supplementation can increase feed efficiency without affecting nutrient intake and digestibility, ruminal volatile fatty acid concentration, or ruminal abundance of specific bacterial groups. Supplementing live or autolyzed yeast, regardless of the dose, resulted in similar performance.

Particle Size Distribution and Feed Sorting of Hay-Based and Silage-Based Total Mixed Ration of Calabrian Dairy Herds

Dietary particle size is one of the most relevant factors influencing rumen function and the selection of the most palatable components of the total mixed ration (TMR) by cows. The aim of this study was to evaluate the particle size distribution (PSD), homogeneity, sorting level, physically effective NDF (peNDF) content of TMRs, and production performances in Calabrian commercial dairy herds in southern Italy. The research was conducted in 13 farms, including 8 with hay-based TMR and 5 with silage-based TMR. All herds delivered fresh feed once a day. At each farm, the TMRs were examined with the Penn State Particle Separator (PSPS) to determine PSD, homogeneity, and feed sorting at two time points (i.e., at fresh feed delivery = T0 and 24 h after feed delivery = Tf). None of the diets that were evaluated met the recommended PSD, showing an excess of long fraction, very short fraction, or both. The homogeneity was good except for three diets, but particle selection raised some concerns in 85% of the farms due to the preferential consumption of the very short fraction by the cows, with rejection of the long fractions. All the diets analyzed met the Penn State University recommended neutral detergent fiber (NDF) values (&gt;28%) except for one farm’s diet. In three of the TMRs observed, however, the content of peNDF &gt; 8 mm was less than 15%. NDF and peNDF &gt; 8 mm values of TMRs showed statistically significant correlations with milk fat content. Therefore, it is important to evaluate the chemical and physical properties of TMR to provide a consistent diet and prevent feed sorting.

Dairy sheep and goats sort for particle size and protein in mixed rations

Sorting for specific parts or nutrients in feed is a natural behavior of ruminants, but for intensive dairy systems it is disadvantageous if it leads to nutritional imbalances for the individual or the herd. To prevent feed sorting in cattle, mixed rations (MR) are fed and forage components are cut as short as possible. In small ruminants, feed sorting is well documented but not well studied in relation to MR. The aim of this study was to investigate the ability of dairy sheep and goats to feed sort in MR. Experiments were conducted with each of 12 pairs of female adult dairy sheep and goats. In the first experiment, three MR composed of different forages (hay, grass silage, maize silage) were tested consecutively, each in a long and short cutting length variant. In the second experiment, two short cut variants of a grass silage-hay MR were investigated that differed in nutritional value. For all experiments, animals received each variant of MR for five consecutive days. The composition of feed rests at 11:00, 15:00 and the next day were compared to the ration fed at 09:00. Both species sorted all of the offered MR for large particles, and sheep but not goats sorted for protein. In the short cut MR variants, particle size sorting was reduced in the first two hours after feed delivery (09:00–11:00), but cutting length had no relevant effect thereafter, or on protein sorting. The nutritional value of the MR had no detectable influence on feed sorting. Both species sorted for larger particles in both variants, and goats sorted against protein in the first two hours after feed delivery, whereas sheep sorted for protein thereafter. These results show that sheep and goats are able to change the composition of MR within two hours after feed delivery. A short cutting length delayed feed sorting to a limited extent. Maintaining the feed quality of a mixed ration throughout the day is important for the health and welfare of dairy sheep and goats but seems to be a major challenge for feeding management.

223 Impacts of Active Dry Yeast (Saccharomyces cerevisiae) on Gut Permeability in Finishing Beef Cattle

Abstract The objectives of this study were to examine the impacts of active live yeast (Saccharomyces cerevisiae) as a dietary feed additive on dry matter intake, feed sorting, gut permeability, ruminal pH and volatile fatty acids (VFA) concentration, as well as fecal pH and VFA concentration in cattle fed a high-grain finishing diet and subjected to a ruminal acidotic challenge. Fifteen Hereford X Charolais heifers were blocked by BW into three blocks. Heifers were randomly assigned within block to one of two dietary treatments; CON (no additive), or YST (3 g· animal-1· day-1 of active live S. cerevisiae) added to a steam-flaked corn diet (83% steam-flaked corn, 8% wheat straw, 5% soybean meal protein mix, 4% vitamin and minerals on a DM basis). The experimental timeline was as follows: 30 d adaptation (ADPT), 5 d baseline (BASE), 5 d ruminal acidosis challenge (CHAL), and three subsequent 5 d recovery phases (REC1, REC2, and REC3). On day 2 of each phase and days 2 and 4 of CHAL, 179 mM Cr-EDTA and 360 mM Co-EDTA were infused into the omasum and rumen, respectively, as gut permeability markers. Within each phase, in-dwelling pH probes were used to capture reticulo-ruminal pH every 5min for 96 consecutive hours, rumen fluid and fecal grab samples were collected once for every 3 h in a 24 h period, and blood was collected at 2, 4, 12, and 24 h after each Co and Cr infusion. Dry matter intake and feed sorting were measured daily for each animal. Statistical analysis was conducted using PROC GLIMMIX in SAS as a randomized complete block design with block, treatment, and phase as fixed effects and animal as a random effect. Ruminal acidosis was successfully induced using this method, as suggested by the statistically significant reduction in minimum pH and increase in pH range in the CHAL phase compared with other phases of the experiment (P ≤ 0.02). Recovery from the ruminal acidosis challenge was detected within the REC1 phase when comparing minimum pH (CHAL 5.25 vs. REC1 5.54; P = 0.001). Additionally, the sorting behavior of some particle sizes was significantly impacted by phase (P ≤ 0.01). Overall, the addition of yeast to the diet did not impact feed intake, sorting behavior, spot ruminal and fecal pH, volatile fatty acid concentrations in ruminal fluid or feces, or the uptake of Cr-EDTA and Co-EDTA. These results suggest that adding live S. cerevisiae yeast at this dose in a high-grain finishing diet does not impact feed intake, gut permeability, or the production of VFA when ruminal acidosis is induced.

Dynamics of chewing and eating behavior, lying behavior, and salivary characteristics associated with duration of high grain feeding in cows with or with no phytogenic supplement

This study evaluated the adaptive changes in chewing and eating behavior, lying behavior, and salivary properties due to the switch from forage to high grain and the duration of high grain feeding in cows, with or without a phytogenic feed additive. Nine non-lactating cannulated Holstein cows were used in a cross-over design with two experimental periods. Each period included one week of forage feeding, one week of diet transition, and four weeks of high grain feeding (35:65 forage to concentrate ratio; DM basis). Cows were either not supplemented (CON) or supplemented with a phytogenic additive (PHY) characterised by menthol, thymol and eugenol. Switching to high grain decreased (P < 0.01) rumination time compared to forage feeding; however, compared to week 2, rumination time increased (P < 0.01) by 73.8 and 53.21 min/d in weeks 3 and 4 on high grain, respectively. In week 4 on high grain, the PHY-supplemented cows tended (P = 0.08) to ruminate (263 vs. 204 min/d) and chew (406 vs. 347 min/d) longer compared to CON counterparts. The change to high grain increased (P < 0.05) sorting for long and medium size feed particles compared to forage diet, and there was a further increase (P < 0.05) in sorting for long and medium size feed particles in week 3 and 4 on high grain compared to the initial stage of the high grain challenge. Interestingly, PHY supplementation contributed to a more uniform intake of the diet by reducing (P < 0.05) the sorting of both medium and fine particles. Compared to week 1, lying time increased (P < 0.05) by 50 min/d in week 3 on high grain. High grain diet decreased (P < 0.05) salivary pH in week 1, while PHY supplementation helped maintaining this variable at physiological level during this initial grain challenge. Salivary bicarbonate was lower (P < 0.05) in weeks 3 and 4 compared to week 2 on high grain. Overall, the switch to high grain and the duration of feeding influenced chewing and eating behavior, lying behavior and salivary characteristics. Effects were still found 3 or 4 weeks after the diet switch; whereas PHY supplementation contributed to a more uniform nutrient intake by decreasing sorting behavior, which was reflected in stabilized salivary pH at the beginning of the grain challenge, and a tendency for increased chewing activity. However, more research is warranted to evaluate the positive role of PHY supplementation in decreasing feed sorting on metabolic health status and welfare of high-producing dairy cows, which are commonly affected due to high grain feeding.

Feeding encapsulated pepper to dairy cows during the hot season improves performance without affecting core and skin temperature.

Peppers (Capsicum spp.) contain capsaicin, an organic compound with a group of alkaloids that has shown thermoregulation properties in humans and mice, and may influence glucose and lipid metabolism in ruminants. An experiment was conducted to evaluate different doses of a feed additive containing encapsulated pepper on milk yield and composition, dry matter intake, feed sorting index, total-tract apparent digestibility of nutrients, purine derivatives excretion, and serum concentrations of urea-N and glucose, N excretion, respiration rate, rectal temperature, and skin temperature in different regions (forehead, face, and rumen). Thirty-six Holstein cows (150 ± 102.1 d in milk and 29.3 ± 5.81 kg/d milk yield) were used in a 9-wk randomized complete block (n = 12) design experiment. Following a 2-wk covariate period, cows were blocked according to parity, days in milk, and milk yield and were randomly assigned to the following treatments: 0 (CAP0), 0.75 (CAP75), or 1.5 (CAP150) g/d of a feed additive containing encapsulated pepper (1 g/kg, Capcin; NutriQuest) added to the concentrate along with minerals. Treatment differences were evaluated through orthogonal contrasts (CAP0 vs. CAP75 + CAP150 or CAP75 vs. CAP150). The average temperature-humidity index during the experiment was 72.0 ± 2.07. Dry matter intake was greater in cows fed a feed additive containing encapsulated pepper (CAP) treatments (CAP75 and CAP150) compared with CAP0. Cows fed CAP150 tended to have greater dry matter intake than those in CAP75 group. Feeding CAP decreased sorting for feed particles with size between 8 and 4 mm. An interaction effect between treatment and week was observed for crude protein digestibility whereas cows fed CAP150 had the greatest digestibility on the third week of experiment. Orthogonal contrasts did not detect differences in serum concentrations of glucose and urea-N, or purine derivatives excretion. Nitrogen excretion (as % of N intake) in milk, urine, and feces was not altered by treatments. Feeding CAP increased yields of 3.5% fat-corrected milk, fat, protein, and lactose. A tendency toward greater milk protein content was observed for cows fed CAP150 than CAP75. No differences were detected on respiration rate, rectal temperature, and skin temperature of cows. A feed additive containing encapsulated pepper fed at 0.75 or 1.5 g/d can improve yield of fat-corrected milk and milk solids by increasing feed intake without affecting nutrient digestibility and body temperature of lactating cows during the hot season.

Effects of concentrate starch level and free-choice provision of straw on performance, feeding behaviour and feed sorting of fattening lambs

The importance of forage in small ruminants’ behaviour is well known, but very few experimental studies have investigated the feeding behaviour of lambs offered ad libitum and as a free choice provision of concentrate and wheat straw. This experiment was conducted to investigate the effect of concentrate starch level on growth performance and behaviour, preference toward straw and rumen fermentation in lambs offered ad libitum forage and concentrate. Twenty-four Iranian Arabic male lambs (mean ± standard deviation; 18.8 ± 2 kg of BW) were used in a completely randomized design with 3 treatments (8 lambs per treatment) for a period of 84 days. Experimental treatments were included 3 levels of starch (27.1%, 35.4% and 43.6% of dietary dry matter (DM)) and wheat straw was offered as a free-choice provision. Total DMI was not different among treatments; however, intakes of straw (P < 0.01), peNDF (P = 0.003), water (P = 0.05), and ME (P = 0.005) linearly increased with increasing level of starch in the concentrates. The increased dietary starch concentration linearly increased total gain (P = 0.02), and average daily gain (P = 0.01), but linearly decreased feed conversion ratio (P = 0.02). Increasing starch in the concentrates linearly increased sorting for straw particles retained on the 19-mm sieve and tended to increase sorting for particles retained on the 8-mm sieve. In contrast, sorting against the fine particles was observed with increasing starch content of the concentrates. Eating time decreased linearly as the amount of starch in the diets increased. Time spent ruminating per kg DM and NDF intake linearly increased with increasing starch in the diet. Standing time increased linearly (P = 0.04) as starch content of the diets increased. Lambs fed low starch diet had higher pH values than medium starch (at 2, 4, and 6 h post-feeding) and high starch (at 0, 2, 4 and 6 h post-feeding) diets. These findings suggest that under free-choice provision of straw and concentrate lambs are able to adjust their sorting behaviour in favor of physically effective NDF and more forage intake with increasing concentrate starch level, which could be an adaptive response to attenuate low rumen pH.

Evaluation of wood chips and rice hulls as alternative fiber sources in rations self-fed to early-weaned calves

Two experiments were conducted to evaluate the merit of wood chips (WCH, Exp. 1) or rice hulls (RH, Exp. 2) as the sole fiber source in a high-concentrate diet fed to early-weaned calves as well as their method of delivery (hand-feeding versus self-feeder). Rations were formulated to contain similar concentrations of N, energy and NDF and were offered ad libitum. In Exp. 1, 36 Hereford calves (84.4 kg SE 4.5) were randomly allocated to nine pens and one of three dietary treatments: (1) 160 g/kg of sorghum silage (SS) and 800 g/kg of concentrate hand-fed, 2) 80 g/kg of WCH and 920 g/kg concentrate hand-fed, and (3) same ration as in (2) but self-fed. In Exp. 2, 36 early-weaned Hereford calves (97.4 kg SE 1.7) blocked by BW were randomly allocated to nine pens and one of three dietary treatments: (1) 200 g/kg of alfalfa hay (AH) plus 800 g/kg of concentrate hand-fed, (2) 80 g/kg of RH plus 920 g/kg of concentrate hand-fed, and (3) same ration as in 2) but self-fed. In both experiments animals were weighed (BW) every 14 days, dry matter intake (DMI) was measured weekly, and daytime animal behavior was observed. Gain-to-feed ratio (GF), NEg and a sorting index to characterize the selective consumption of specific fractions, were calculated. Data were analyzed according to a randomized complete plot (Exp. 1) or block (Exp. 2) design, with repeated measures. Fiber source and delivery method effects were tested through orthogonal contrasts. In Exp. 1, replacing SS with WCH did not affect body BW gain, DMI, GF, or NEg. No differences were observed either in feed sorting or eating activity (EA). Using a self-feeder to deliver the WCH ration reduced EA (P < 0.05), without affect GF. In Exp. 2, replacing AH with RH did not affect BW gain or DMI but it improved GF (P < 0.05). Higher sorting against large particles (>8 mm) and ADF were observed for AH compared to RH (P < 0.05). Using a self-feeder to deliver the RH ration reduced DMI and EA (P < 0.05) without affecting BW gain and improving GF (P = 0.01) compared to hand-feeding. Also, it increased selective refusal of ADF (P < 0.05) but not of NDF, without affecting rumination. Treatments did not affect peNDF supply. Results from both experiments show the viability of the use of WCH and RH as a source of fiber in high-concentrate rations for early-weaned calves, as well as their suitability for delivery in self-feeders.

Dry malt extract from barley partially replacing ground corn in diets of dairy cows: Nutrient digestibility, ruminal fermentation, and milk composition

Dry malt extract (DME) has been used in animal nutrition as an alternative source of rapidly fermentable carbohydrate. An experiment was conducted to evaluate the partial replacement of ground corn with DME in diets of dairy cows on apparent digestibility, ruminal fermentation, predicted rumen microbial protein supply, N excretion, serum urea-N concentration, and milk yield and composition. Twenty-eight Holstein cows (35.3 ± 5.88 kg/d milk yield and 148 ± 78 d in milk), 4 of which were rumen cannulated, were blocked according to the presence of rumen cannulas, parity, milk yield, and days in milk and enrolled into a crossover design experiment. Experimental periods lasted 21 d, of which the first 14 d were allowed for treatment adaptation and 7 d were used for data collection and sampling. Treatment sequences were composed of control (CON) or DME from barley (Liotécnica Tecnologia em Alimentos) replacing ground corn at 7.62% diet dry matter (~2 kg/d). Data were analyzed using the MIXED procedure of SAS (SAS Institute Inc.) modeling the fixed effects of treatment, period, and their interaction, in addition to the random effect of animal. Ruminal fermentation data were analyzed as repeated measures including time and its interaction with treatment in the previous model as fixed effects. Treatments did not affect nutrient intake or feed sorting. Dry malt extract increased apparent digestibility of CP. Feeding DME decreased ruminal pH and molar percentage of butyrate and increased molar percentage of acetate. No treatment effects were detected for predicted rumen microbial protein supply or N excretion. Cows fed DME had lower serum urea-N concentration than CON cows. Dry malt extract increased yields of actual milk, 3.5% fat-corrected milk, fat, and protein, and improved feed efficiency (fat-corrected milk ÷ dry matter intake). Cows fed DME had lower milk urea nitrogen content in comparison with CON cows. Dry malt extract can partially replace ground corn in the diet while improving milk yield and feed efficiency.

Assessment of the Effectiveness of a Portable NIRS Instrument in Controlling the Mixer Wagon Tuning and Ration Management.

Simple SummaryThe total mixed ration is widely adopted in herds feeding, and its success has paved the way for the use of the feed mixer wagon. The increase in milk production demands a higher feed efficiency that considers the chemical and physical quality of the ration, even in terms of fiber physical effectiveness, ration homogeneity, and cow feed sorting. These requirements presuppose a correct ration formulation and accurate preparation, even through an optimal mixer wagon setting. Here, we proposed an efficient, rapid, and easy method for ration preparation and quality control. A portable Near-InfraRed instrument was tested for primary chemical and physical evaluation of the ration, including the particle size and the physical effective fiber content. Moreover, the instrument allowed the calculation of two indexes to evaluate the ration homogeneity and cow sorting activity. Finally, these traits were compared with the feed mixer wagon setting and feed characteristics. As a result, we found that for the overload of the feed mixer wagon, the higher humidity and fiber contents of the ration caused a lower homogeneity, and the higher fiber content facilitated the cow sorting activity.The adoption of the mixer wagon and total mixed ration aimed to decrease dysmetabolic diseases and improve feed efficiency in dairy cows. Differences between theoretical and eaten diets are imputable to errors in diet preparation or cow feed sorting. We proposed a method to measure the chemical composition and particle size distribution of the ration and determined its peNDF content through a portable Near Infra-Red spectrophotometer that allowed the calculation of two indexes: the homogeneity and the sorting indexes. In a cohort of 19 Italian Holstein breeding farms, we studied the correlation of these indexes with the mixer wagon settings. Determination coefficients in the validation (Rv2) for dry matter, crude protein, aNDF, and starch were 0.91, 0.54, 0.86, and 0.67, respectively. The ration fractions (%, w/w of wet weight) retained by the 3.8 and 1.8 mm sieves, and the bottom showed Rv2 of 0.46, 0.49, and 0.53, respectively. The homogeneity index regressed negatively with the mixer wagon load fullness (R2 = 0.374). The homogeneity-binary classification showed an odds ratio of 1.72 for dry matter and 0.39 for aNDF (p < 0.05). The sorting-binary classification showed an odds ratio of 2.54 for aNDF (p < 0.05). The studied farms showed low peNDF values (median = 17.9%).

PSX-B-20 Effect of shifting from forage to high grain diet on chewing, feed sorting and lying behavior of cows supplemented with or without a phytogenic additive

Abstract The aim was to evaluate the effect of changing from forage to a high grain diet on chewing, feed sorting and lying behavior of cows supplemented with or without a phytogenic feed additive. Nine cows were blocked in two groups and used in a change-over design. Each experimental run consisted of one week of forage feeding, one week of diet transition, and four weeks of high grain feeding (65% concentrate). During the washout period of 10 weeks between the two runs, cows grazed on pasture. Cows were fed either a control diet (CON) or a diet with a phytogenic additive (PHY) based on menthol, thymol and eugenol. Data on chewing, feed sorting and lying behavior were analyzed using SAS with week of feeding and supplementation as fixed effects, and cow as random effect. Data across weeks from the same cow were processed using a first order variance-covariance structure matrix taking into account that the covariance decays with time. We found a reduction (P &amp;lt; 0.01) in rumination time by 53% with diet change. Within the high grain feeding, rumination reached lowest value in the second week (160 min/d). The high grain diet increased (P &amp;lt; 0.01) selection for long size particles by 20%. Although lying time was not affected immediately after diet change, it increased (P &amp;lt; 0.01) by 8% from the second week of high grain consumption. In the fourth week of grain feeding, there was a tendency for PHY to increase rumination (P = 0.07) and total chewing time (P = 0.10), but with no effect on sorting for fiber or lying time. The high grain diet decreased chewing and standing time, and increased sorting for fibrous ingredients especially after one week of feeding. The phytogenic feed additive may contribute to stimulate chewing in long term supplementation.

Effects of sodium bicarbonate and chromium propionate supplementation on growth performance, blood indices of Beetal bucks under heat stress.

The objective of the current experiment was to determine the effects of sodium bicarbonate (SBC) and chromium propionate (Cr) supplementation on dry matter intake (DMI), growth performance, blood indices, feed sorting behavior, and digestibility of nutrients during the hot and humid condition in Beetal bucks. Twenty-eight Beetal bucks were randomly assigned to four concentrates treatments (n = 7 bucks/treatment) under 2 × 2 factorial arrangements. The factors were (1) chromium supplementation, basal diet without any supplementation (C) and basal diet with Cr @ 1.5mg Cr/head/day (Cr), and (2) sodium bircbonate supplementation, basal diet supplemented with SBC @15g/kg of DM (SBC) and diet containing SBC @ 15g/kg of DM) and Cr @ 1.5mg/day/animal (SBC + Cr). Chromium was drenched to each animal during the morning feeding. The average daily noon temperature-humidity index (THI) was 86.37 ± 4.01. The daily DMI and ADG was higher (P < .0001) in the SBC, and trend for daily DMI was observed (P < 0.01) for the Cr. The feed to gain ratio was tended to improve (P = 0.056) by the supplementation of Cr. Plasma glucose, cholesterol, and catalase concentration were lower (P < 0.05) in the Cr supplemented, whereas plasma BUN and TPP were not influenced (P > 0.05) by the Cr or the SBC supplementation. The feed selection index indicated that supplementation of Cr and SBC had no effects on selection or rejection of feed particles. In Cr-supplemented bucks, there was a trend for higher ADF digestibility. Digestibility of dry matter, organic matter, NDF, and ADF were not affected by Cr or SBC supplementation. In conclusion, co supplementation of Cr @ 1.5mg/d and SBC @ 15g/kg resulted in highest DMI, ADG and improved the feed efficiency in heat-stressed fattening bucks by alleviating negative impacts of HS.

Effects of replacing steam-flaked corn with shredded sugar beet pulp on feed sorting, behavior, blood metabolites, and growth performance of dairy calves.

This experiment was conducted to investigate the effects of partial replacement of steam-flaked corn (SFC) with shredded sugar beet pulp (SBP) in the starter diet on selective intake (sorting), feeding and chewing behavior, blood biochemical parameters, and growth in newborn female Holstein dairy calves. A total of 48 calves (3 d old; 40.1 ± 0.84 kg body weight; mean ± SE) were randomly assigned to 1 of 2 feeding treatments containing 0 or 25% SBP (percentage of dry matter [DM]) in the starter diet. Calves were weaned on d 61 and remained in the study until d 81. Intake of starter feed and total intake of DM (milk DM + starter feed DM), crude protein, and neutral detergent fiber were increased (P < 0.05) by feeding SBP; however, intake of starch (P < 0.01) and total intake of ether extract (P = 0.03) were decreased with no apparent effect on total intake of ME. Average daily gain, feed efficiency, final weight, and skeletal growth also showed no significant changes. Circulating concentrations of glucose, total protein, and albumin were not affected by partial replacement of SBP with SFC; however, higher concentrations of blood urea-N (P = 0.01) and a lower albumin-to-globulin ratio (P = 0.03) were observed in SBP- vs. SFC-fed calves. Calves fed SBP sorted more for particles retained on the 4.75-mm sieve (P = 0.02) and against particles retained on the 0.6-mm sieve and bottom pan (P < 0.01). Intake of neutral detergent fibers and starch from particles retained on all sieve fractions was increased and decreased (P < 0.01), respectively, by replacing SFC with SBP. Replacement of SBP with SFC was associated with increased meal length and meal size and increased rumination frequency and length, but decreased intervals between rumination (P ≤ 0.01). Calves fed SBP spent more time eating, rumination, and standing and less time lying and non-nutritive oral behaviors (P < 0.01). In general, 25% replacement of SFC with SBP did not affect calf performance but increased time spent rumination and eating and decreased non-nutritive oral behaviors.

Evaluation of production parameters, feed sorting behaviour and social interactions in dairy cows: Comparison of two total mixed rations with different particle size and water content

Dairy cow performance is affected by both the nutritional composition and the physical structure of the diet. The structure of total mixed rations (TMR) largely depends on the ingredient composition and structure of forage, dry matter (DM) content, mixing time and type of mixer used. This study investigated feed intake, eating time, milk production, DM digestibility, ruminal pH, time budget, and sorting and antagonistic behaviours in lactating dairy cows fed grass/clover silage and concentrate, either in a TMR or in a compact total mixed ration (CTMR) with decreased particle size and DM content due to addition of water. Two cross-over experiments (3-week periods), each involving 40 lactating dairy cows of the Swedish Red and Holstein breeds, were run simultaneously. Experiment 1 was designed to measure production parameters, feed digestibility and ruminal pH, while Experiment 2 was designed to measure time budget, feed sorting behaviours and antagonistic behaviours at the feed bunk. Diets were fed ad libitum, with the same ingredient composition and a forage:concentrate ratio of 60:40 (DM basis). Decreased particle size in the CTMR diet was achieved by mixing the grass-clover silage in a feed mixer with a vertical auger with knives, before mixing with concentrate in a feed mixer without knives. Decreased DM content in CTMR was achieved by adding water to the mix. Mean DM content of the diet was 51% DM for TMR and 37% DM for CTMR. The results showed lower daily DM intake (26.7 kg DM) and shorter eating time (242 min) in cows fed CTMR than in cows fed TMR (28.5 kg DM and 278 min). Feed digestibility, ruminal pH, daily milk yield (35.1 kg and 35.8 kg for CTMR and TMR, respectively) and milk composition did not differ between the diets. Cows fed CTMR showed less sorting and fewer antagonistic behaviours at feeding than cows fed TMR. The daily time budget of the cows also differed, with cows fed CTMR spending more time resting (+45 min) than cows fed TMR.

Short- and long-term effects of early life exposure to concentrate or hay on feed sorting and rumen fermentation

Feed sorting is a common issue on dairy farms. Cows prefer smaller grain particles over long forage particles, leading to increased volatile fatty acids (VFA) and consequently subacute ruminal acidosis (SARA). The purpose of this study was to investigate the short and long-term effects of early life exposure to different feed sources on feed sorting and rumen fermentation of calves. Forty newborn female Holstein calves were randomly assigned at birth (38.5 ± 2.4 kg of BW) to 1 of 2 treatments: (1) the provision of concentrate (CON) only or (2) provision of hay (HAY) only as the source of solid feed during the milk-feeding stage (d 1–56). Afterward, all calves were offered a total mixed ration until the end of the experiment (d 57–196). Calves were raised in individual hutches from d 1–70. The calves were then transferred into a heifer barn with pens and housed in pairs (2 calves/pen) as per the previous treatments. Rectal temperature, feed intake, body weight and body structural measurements were recorded throughout the study. Fresh feed and orts were sampled daily in the first two weeks (d 57–70) of feeding TMR and in the last week of the experiment (d 190–196) to analyze feed sorting behaviour. Rumen fluid samples were collected from d 14–190 for detecting VFA concentrations. Our findings showed that early feed exposure did not influence calf health and growth performance but affected feed sorting over a short period. Upon transition to the same mixed diet, differences were found in the sorting of different particle fractions between treatments. In the first two weeks (wk 9 and 10) after transition to TMR, calves exposed to concentrates early began to sort for fine particle and against the long particle fractions. In contrast, calves fed hay early sorted for the long particle and against the fine particle fractions, resulting in a higher preference for fine particle fractions (P < 0.01) and a lower preference for long particle fractions (P < 0.01) in calves fed concentrate early than those fed hay early. However, no carryover effects were observed, such that differences between treatments in sorting for long (P = 0.43) and fine (P = 0.45) particle fractions faded away by the last week (wk 28) of the experiment. All calves sorted for short and fine particle fractions and against long and medium particle fractions. Although the pattern of feed sorting initially differed between treatments, rumen fermentation parameters, such as total VFA (P = 0.54), acetate (P = 0.83), propionate (P = 0.21), butyrate (P = 0.20), were not altered once all calves transitioned to a total mixed ration. These results suggested that the feed familiarity established early in life would not affect diet selection and rumen fermentation in heifer later in life. Moreover, the effect of feeding a total mixed ration after transition could eventually override the effect of feeding concentrate or hay early in life.

Feeding fennel (Foeniculum vulgare) seed as potential appetite stimulant to newborn Holstein dairy calves: Effects on meal pattern, ingestive behavior, oro-sensorial preference, and feed sorting

This trial was performed to investigate the effects of feeding graded levels of fennel seed powder (FSP) on nutrient intake, meal and rumination patterns, chewing and sorting behaviors in newborn Holstein dairy calves. Forty-eight calves (27 males and 21 females; n = 16 per treatment group; 3 d of age; 36.3 ± 1.06 kg of BW; mean ± SE) were assigned randomly to receive incremental levels of FSP at 0.0 (FSP0), 1.5 (FSP1.5) or 3.0 g/d (FSP3) in milk (morning feeding; during the first month of study period) and then in the starter feed (as top-dressed; from d 31 until weaning). Calves were weaned on d 71 and remained in the study until d 81. Starter feed dry matter (DM) intake increased linearly with increasing amount of FSP and increased and tended to increase in FSP3 and FSP1.5 as compared with FSP0, respectively. Growth rate increased linearly with increasing amount of FSP and was greater in FSP supplemented calves than in control calves. Overall body weight but not feed conversion ratio was greater in FSP supplemented calves compared with FSP0. Oro-sensorial preferences were greater in FSP supplemented calves and it was also greater in FSP3 compared with FSP1.5. Sorting index decreased linearly with increasing amount of FSP and decreased in FSP3 compared with FSP0 for particles retained on the 2.36, 1.18, and 0.6 mm sieves and tended to decrease in FSP1.5 compared to FSP0 for particles retained on the 2.36 and 1.18 mm sieves with significant difference for particles retained on the 0.6 mm sieve. Sorting index increased linearly with increasing amount of FSP and increased and tended to increase in FSP3 and FSP1.5 compared with FSP0 for feed materials retained on the bottom pan, respectively. Irrespective of the amount of FSP fed, all calves sorted for particles retained on all studied sieves and against feed materials on the bottom pan. Starter feed DM intake from particles retained on all studied sieves (except for 4.75 mm sieve) and feed materials retained on the bottom pan increased linearly with increasing amount of FSP and increased in FSP supplemented calves compared with control calves. Calves fed FSP initiated to eat their first solid feed in a shorter timeframe after starter feed provision with no changes in first meal duration among treatment groups. Despite of linear increase in eating rate and meal size in FSP supplemented calves, meal and rumination patterns and time devoted to eating, ruminating, resting, drinking, standing, and lying were not affected by treatment; however, non-nutritive oral behaviors were linearly decreased with increasing amount of FSP and decreased and tended to decrease in FSP3 and FSP1.5 compared with FSP0, respectively. In general, feeding FSP shortened time-delay to initiate first solid feed consumption by increasing oro-sensorial preference of the feed, increased feed intake through increases in the rate of eating and thereby the meal size, decreased non-nutritive oral behaviors without affecting chewing behavior, and improved growth performance.