Effects of source of dietary neutral detergent fiber on chewing behavior in beef cattle fed pelleted concentrates with or without supplemental roughage.

Ten 394-kg, ruminally fistulated Hereford steers were used in a replicated 5 x 5 Latin square design to evaluate the effects of source and level of dietary NDF on chewing activities during eating and rumination. Diets contained 62 to 64% TDN and included 1) 80% pelleted concentrate (control; contained ground grains, fibrous byproducts, molasses, and protein, vitamin, and mineral supplements; 36% NDF, 16% CP) and 20% long timothy hay (67% NDF, 8% CP), 2) 80% control concentrate and 20% alfalfa cubes (56% NDF, 15% CP), 3) 90% control concentrate and 10% alfalfa cubes, 4) a completely pelleted diet using corn cobs as the primary NDF source (40% NDF, 17% CP), and 5) 80% textured (coarse instead of ground grains; 42% NDF, 15% CP) concentrate and 20% hay. Diets were formulated to be similar in NDF content, and dietary protein satisfied NRC recommendations. Chewing during eating did not differ (P greater than .10) between diets containing supplemental roughage but decreased (P less than .001) with the corn cob diet. Rumination chewing decreased (P less than .001) with the corn cob and cube diets. The number of chews per day during eating corrected for NDF intake/BW.75 decreased (P less than .05) in the corn cob diet. Rumination periods and duration increased and latency before rumination decreased in hay diets. Steers fed the corn cob diet tended to be more (P less than .10) consistent in time spent eating across 4-h intervals than steers fed the traditional diet. Replacement of long hay with the completely pelleted corn cob diet decreased rumination activity.     

Intake and chewing behavior of steers consuming switchgrass preserved as hay or silage

Effect of preservation method on intake and chewing behavior was examined using a first, late vegetative harvest (mid-June) of Kanlow switchgrass (Panicum virgatum L.). For silage (S), forage was harvested with a commercial field chopper (1.5 to 4 cm average chop length) and ensiled directly in silos 1.2 m in diameter and 3.6 m in height. For hay (H), forage was harvested with a flail-chopper (7 to 15 cm average chop length) and cured as hay in a drier at 77 degrees C. Diets of H and S were fed to six Hereford steers (338+/-5 kg) in a single crossover experiment. Chewing behavior was monitored for 4 d with a computerized system. At feeding, H was higher in DM and contained greater concentrations (DM basis) of NDF, CP, and hemicellulose, but lower concentrations of ADF and cellulose, and had lower in vitro DM disappearance values. Steers fed S had higher intakes of DM (P < .02) and NDF (P < .04) and consumed less water from the water supply (P < .01) than animals fed H. However, total amount of water (from water supply and feed) consumed per kilogram of DMI did not differ between diets. Crude protein intake was similar between diets. Preservation method had no effect on eating time, number of boli ruminated, bolus duration, and number of rumination chews per bolus. Steers fed S made fewer eating chews (P < .10) and ruminated for a longer time (P < .05) while making a greater number of rumination chews (P < .04) than steers fed H. Rumination intercycle time was slightly shorter in steers fed H (P < .05) than in steers fed S. When expressed per kilogram of NDF intake, steers fed S spent less time eating (P < .03) and made fewer eating chews (P < .02) than steers fed H; however, rumination time, number of rumination chews, and number of boli ruminated were not affected by preservation method. Steers fed S ingested feed at a greater rate (P < .03), excreted smaller fecal particles (P < .03), had meals of shorter duration (P < .06), spent less time eating during main meals (meals following feed distribution: P < .05), had more rumination periods (P < .01), and a shorter morning (P < .06) latency time (interval between end of main meal and onset of rumination) than steers fed H. These results indicate that preservation method with its concomitant differences in chop length affected forage chemical composition and voluntary intake, and that differences in chewing behavior occurred mostly during eating.     

The assessment of the frequency of chews during rumination enables an estimation of rumination activity in hay-fed sheep

The objective was to assess rumination behaviour and, more specifically, the intra-individual and inter-individual variation of the frequency of chews during rumination (per min) in five Blackhead sheep fed hay at a level of 100% maintenance (experimental period [EP] I), 50% maintenance (EP II) and ad libitum (EP III). Animals ruminated in EP II less (416 min/day) than in EP I and III (558 and 592 min/day, respectively). Mean inter-individual coefficents of variation (CV) of frequency (defined as number of chews/duration of chewing per cycle) were 12.5%, mean intra-individual CV were 2.5%. The respective CVs for the duration of rumination per day were 8.1 and 9.7%, respectively. The level of intake influenced the frequency of chews significantly. It is concluded that the frequency of chews has to be considered in studies investigating chewing behaviour of ruminants. Under the experimental conditions investigated, number of chews during rumination per day could be estimated by the frequency of chewing with nearly the same precision as by using the duration of rumination per day.     

Dietary forage concentration and particle size affect sorting,feeding behaviour,intake and growth of Chinese holstein male calves

The objective of study was to evaluate the effect of forage concentration (F:C) and forage particle length (FPL) on sorting, feeding behaviour, intake, growth and body measurements of growing calves. Twenty‐eight weaned calves of body weight 156.79 ± 33.44 (mean ± SD) were used in 2 × 2 factorial arrangements with the factors FPL of hay grass (full and short) and hay grass concentrations (low, 50% and high, 65%). The treatments were as follows: full length (FL) with low F:C (50:50), FL with high F:C(65:35), short length (SL) with low F:C (50:50) and SL with high F:C (65:35). Increasing F:C and decreasing FPL enhanced sorting for short and fine particle and sorting against long particle (p < 0.05). Dry matter intake (DMI) was decreased by decreasing the FPL (p < 0.05). Increasing F:C (65:35) increased the DMI (p < 0.05). A positive interaction between FPL and F:C was found for (daily weight gain) DWG, weight gain (WG) and feed conversation ratio (FCR) (p < 0.05). In case of feeding behaviour, interaction for eating time and eating time per kilogram DM was present. Increasing the F:C increased the eating time in both FL and SL (p < 0.05). Chopping of hay had decreased the chewing time (p < 0.05). Increasing F:C increased chewing time per kilogram DMI. High F:C decreased the lying time (p < 0.05) in FL and SL treatments (p < 0.05). Increasing F:C reduced the overall abnormal behaviour (p < 0.05). These results suggested that animals performed better at higher F:C at SL diet. Intensity of sorting for short and fine particle and against long particle increased at higher F:C and SL diets. Eating time and eating time per kilogram DMI increased by increasing F:C level in both FL and SL treatments. Chewing time increased by increasing the FPL, while increasing the F:C enhanced the chewing time per kilogram DMI and reduced animal's abnormal behaviour.     

Behaviour of pigs of Slovenian local indigenous breed and modern hybrid fed with concentrate and hay

Abstract

The aim of the study was to investigate the feeding behaviour differences between Kr?kopolje pig (KP) and a modern hybrid (MH) pig. The behaviour was recorded during concentrate and hay consumption after the body weight of pigs was 100 kg. Animals (N=24) were observed in a straw-bedded system in eight pens of three pigs. During concentrate consumption, feeding, drinking and displacement at the trough (when a pig changed a feeding place) were directly recorded. During hay consumption, hay chewing, resting, exploring, playing and synchronisation while hay chewing were scored. MH ate faster and drank less than KP; however, they changed their feeding places more often and showed a higher probability to chew hay (overall P<0.01). MH pigs tended to chew hay more synchronously than KP (P<0.10). The results show that concentrate and hay consumption habits vary between the Slovene KP and the MH pig.     

Relationships between chewing behavior, digestibility, and digesta passage kinetics in steers fed oat hay at restricted and ad libitum intakes

The objective of this study was to evaluate the relationships between chewing behavior, digestibility, and digesta passage kinetics in steers fed oat hay at restricted and ad libitum intakes. Four Hereford steers, with an initial average BW of 136 kg, were used in an experiment conducted as a balanced 4 × 4 Latin square with 4 treatments (levels of intake) and 4 periods. Animals were fed lopsided oat hay (Avena strigosa Schreb.) at 4 levels of intake (as a percentage of BW): 1.5, 2.0, 2.5, and ad libitum. Digestibility, chewing behavior, and digesta passage kinetic measurements were recorded during the experimental period. Chewing rates during eating and ruminating [(chews?min(-1))/g of DMI?kg(-1) of BW?d(-1)] decreased (P = 0.018 and P = 0.032, respectively) with increased DMI (g?kg(-1) of BW?d(-1)), whereas total chewing and total time spent on each chewing activity increased. Calculated total energy expended by the chewing activity was 4.2, 4.4, 5.2, and 5.3% of ME intake for DMI of 1.5, 2.0, and 2.5% of BW and ad libitum, respectively, indicating that adjustments in animal chewing behavior may be a mechanism of reducing energy expenditure when forages are fed at restricted intake. Hay digestibility decreased (P < 0.001) with increased DMI (r = -0.865). Digesta mean retention time (h) was strongly correlated with DMI (r = -0.868) and OM digestibility (r = 0.844). At reduced intake, hay digestibility was enhanced (P < 0.001) by extending digesta retention time and by increasing chewing efficiency, highlighting the relationship between chewing behavior and the digestive process. Fractional outflow rate of particulate matter from the reticulorumen (k(1)) was positively correlated with total chews, emphasizing that the decrease in particle size caused by chewing facilitates particle flow through the digestive tract. Increased hay intake also increased (P < 0.001) k(1), whereas passage rate of the liquid phase, transit time, and rumen fill were not affected (P > 0.05). The latter was correlated with rumen volume (r = 0.803). In conclusion, the results of this study indicate that animals fed at restricted intake increased chewing rate when eating and ruminating, which, along with a longer digesta retention time, contributed to enhance feed digestibility.     

Discriminant Analysis of Patterns of Jaw Movement During Rumination and Eating in a Cow

Discriminant analysis was used to identify combinations of variables, characterizing patterns of jaw movement (JM) during eating and rumination, that minimize errors when classifying series of successive JM of known behaviour into rumination and eating. JM data from a non-lactating jersey cow were recorded continuously for 72 h. The cow was fed 1800 g of barley straw and 1375 g of dried sugarbeet pulp pellets twice daily. Average times spent eating and ruminating daily were 294 and 462 min. Successive rumination and eating JM were grouped into series when pauses between JM were equal to or longer than a fixed time interval corresponding to the minimum time interval between successive rumination cycles. Time intervals between successive JM, amplitude (the magnitude of the jaw's movement) and number of chews per series of successive JM were calculated for all rumination and eating series and included in the discriminant analyses. The combination of the four variables, basic chewing rate (BCR), mean of amplitude/standard deviation of amplitude, ln(number of chews) and standard deviation of time intervals between successive jaw movements, gave the least minutes of misclassified chewing behaviour per day (3% of total daily chewing time) and yielded a quadratic discriminant function. The order of the variables mentioned rank the variables according to their ability to classify the series. Combinations of the variables BCR and ln(number of chews), and other variables based on mean and standard deviation of time intervals between successive JM and amplitude of JM, can be used with advantage for classifying series of successive JM into rumination and eating behaviour.     

放牧绵羊牧食行为程控遥测记录装置的研制

放牧绵羊牧食行为程控遥测记录装置，采用单片微型计算机系统，对放牧绵羊牧食行为的六项主要指标：采食时间、采食咀嚼次数、采食顿数、反刍时间、反刍食团数和反刍周期数进行程控遥测和记录。具有采集指标多、数据误差小、使用方便等优点     

Comparison of mandibular motion in horses chewing hay and pellets

REASONS FOR PERFORMING STUDY: Previous studies have suggested that temporomandibular joint (TMJ) kinematics depend on the type of food being masticated, but accurate measurements of TMJ motion in horses chewing different feeds have not been published. HYPOTHESIS: The temporomandibular joint has a larger range of motion when horses chew hay compared to pellets. METHODS: An optical motion capture system was used to track skin markers on the skull and mandible of 7 horses as they chewed hay and pellets. A virtual marker was created on the midline between the mandibles at the level of the 4th premolar teeth to represent the overall motion of the mandible relative to the skull during the chewing cycle. RESULTS: Frequency of the chewing cycles was lower for hay than for pellets. Excursions of the virtual mandibular marker were significantly larger in all 3 directions when chewing hay compared to pellets. The mean velocity of the virtual mandibular marker during the chewing cycle was the same when chewing the 2 feeds. CONCLUSIONS: The range of mediolateral displacement of the mandible was sufficient to give full occlusal contact of the upper and lower dental arcades when chewing hay but not when chewing pellets. POTENTIAL RELEVANCE: These findings support the suggestion that horses receiving a diet high in concentrate feeds may require more frequent dental prophylactic examinations and treatments to avoid the development of dental irregularities associated with smaller mandibular excursions during chewing.     

青藏高原天然草场放牧家畜体重和体能量变化动态

用逐月称重法和季节屠宰试验获得青藏高原放牧家畜的体重和体能量沉积的季节动态。结果表明 ,放牧家畜在出生后第 1个冷季的体重下降幅度远低于第 2个冷季 ,高山细毛羊在暖季每千克增重的能量水平保持稳定 ,尽管秋季略有下降 ,但与夏季相比 ,差异不显著 ;牦牛在秋季每千克增重的能量则远高于夏季。牦牛和高山细毛羊在冬季每千克减重的能量水平远高于春季。牦牛和高山细毛羊在第 2个暖季所积累的能量约有一半以上在第 2个冷季被消耗     

Influence of dietary protein level on body composition and energy expenditure in calorically restricted overweight cats

High‐protein (HP) diets help prevent loss of lean mass in calorie‐restricted (CR) cats. However, it is not entirely known whether these diets also induce changes of energy expenditure during periods of CR. To investigate this issue, sixteen overweight cats were fed either a high‐protein [(HP), 54.2% of metabolizable energy (ME)] or a moderate‐protein [(MP), 31.5% of ME] diet at 70% of their maintenance energy intakes for 8 weeks, and energy expenditure, energy intake, body weight and composition, and serum metabolites and hormones were measured. While both groups of cats lost weight at a similar rate, only cats eating the HP diet maintained lean mass during weight loss. Indirect respiration calorimetry measurements revealed that both total and resting energy expenditure (kcal/d) significantly decreased during weight loss for both treatment groups. However, only cats eating the MP diet exhibited significant decreases of total and resting energy expenditures after energy expenditure was normalized for body weight or lean mass. Results from this study suggest that in addition to sparing the loss of lean mass, feeding HP diets to overweight cats in restricted amounts may be beneficial for preventing or minimizing decreases of mass‐adjusted energy expenditure during weight loss.     

Comparative ingestive mastication in domestic horses and cattle: a pilot investigation

It is often assumed that horses chew food more intensively during ingestion than cattle, which ‐ as ruminants ‐ complete part of the mastication during rumination. This has been proposed as a reason for more robust mandibles, larger masseter insertion areas and larger masseter muscles in horses as compared to cattle and other grazing ruminants. In this study, we evaluate results of comparative feeding trials with three horses (338–629 kg) and three cows (404–786 kg), on four different roughages. Ingestion time (s/g dry matter) and chewing intensity (chews/g dry matter) differed among animals within a species, indicating an influence of body mass, and differed significantly between different forages. However, although numerical differences clearly suggest that horses have longer ingestion times and higher chewing intensities on high‐fibre roughage than do cattle, this could not be proven in this dataset, most likely because of the small number of individuals sampled. Further studies are required to corroborate the suspected ingestive behaviour difference between equids and ruminants.     

Potential of alfalfa as a source of calcium for calcium deficient horses

The potential of short-cutting cycle, high temperature-dried alfalfa as a source of calcium for horses was determined by means of a 4 x 4 Latin square digestibility trial using four thoroughbred horses (mean liveweight 531 kg). The four dietary treatments were timothy hay alone, 33 per cent alfalfa and 67 per cent timothy hay, 67 per cent alfalfa and 33 per cent timothy hay, and alfalfa alone. Significantly more calcium and magnesium were absorbed from the alfalfa than from the hay. Phosphorus absorption appeared to be unaffected by treatment. Alfalfa calcium was more available than timothy hay calcium (apparent absorption coefficients of 0.78 and 0.15, respectively) and there was less variation between individual horses in their ability to absorb calcium from alfalfa. Horses fed alfalfa had significantly higher creatinine clearance ratios for calcium (P less than 0.01) and magnesium (P less than 0.001) than horses fed hay, but the creatinine clearance ratio for phosphorus was lower in horses fed hay alone.     

The Effect of Subclinical Hypocalcaemia Induced by Na2EDTA on the Feed Intake and Chewing Activity of Dairy Cows

The effects of induced subclinical hypocalcaemia (SCHC) on feed intake and chewing activity during eating and rumination were studied in dairy cows. Two non-lactating and non-pregnant cows were subjected to three different treatments, with one test per day, such that the plasma free (ionized) calcium (_FCa) concentration was maintained at the eucalcaemic level or at one of two constant SCHC levels. The cows and test days followed a 2×3 crossover design. SCHC was maintained for 7 h by repeatedly infusing 5% Na₂EDTA so that constant _FCa concentrations of 0.8 mmol/L or 0.6 mmol/L in plasma were achieved. Control conditions were achieved by infusing isotonic saline. Feed intake and the number of the rumination periods were recorded during test days. The proportion of feed eaten during each test meal (EatPro) was related to the mean plasma _FCa. An almost linear decrease in EatPro was observed when the plasma _FCa was 0.6–0.9 mmol/L. The cows showed no other clinical signs of hypocalcaemia during Na₂EDTA-infusion. The time spent chewing during eating and rumination, and the number of rumination periods during a test day, decreased with a decline in plasma _FCa concentration.It was concluded that induced SCHC depresses the feed intake and ruminative activity of dairy cows.     

Forage ingestion: effects of sward characteristics and body size

A model of a grazing ruminant in a range environment integrates ingestive behaviors (bite size, chewing rate, movement rate) and processing behaviors (mastication and rumination requirements) with rumen function to predict the combination of behaviors that produces the highest rate of energy digestion per unit of time (DE/T). Ingestive and processing behaviors compensate to maintain DE/T as the environment changes. Compensation for a change in forage density is more complete than for a change in forage quality. Ingestive behaviors alone have limited ability to offset environment changes, and control of passage rate through processing behaviors is an important additional compensatory mechanism. Optimal solutions of the model maintain a high intake by sacrificing diet quality and maintain a high rate of passage by increasing mastication and rumination effort when eating low-quality diets. When the model is scaled to body size, decreases in body size lead to higher selectivity and more pronounced processing behaviors. In no case are optimal solutions characterized by less than maximum rumen fill. The model predicts that the small ruminant derives an increasing proportion of its energy from the cell contents. The model suggests that selection for production has produced plastic ingestive and processing behaviors and has increased body size.     

Effect of hay particle size at different concentrations and feeding levels on digestive processes and feed intake in ruminants. 1. Chewing activity and fermentation in the rumen]

In order to study the main effects of particle size three ruminally fistulated cows were fed a hay rich in fibre in long (28.7 mm), chopped (9.2 mm) and ground (2.9 mm) form in a 3 x 3 Latin square design. In another three factorial experiment with 8 wethers (4 animals were ruminally fistulated) the main effects and interactions of the above mentioned hay particle size at two concentrate levels (10.4 to 13.3 and 29.5 to 40.1% in the ration) and at two feeding levels (restricted and ad libitum) were investigated. There was no effect of chopped hay (9.2 mm) on chewing activity, whereas ground hay (2.9 mm) reduced rumination time (52% in sheep and 36% in dairy cows) and chewing expense (time/unit of DM or NDF intake). These effects were more pronounced at high concentrate intake. Sheep increased feed intake more through reduction of rumination expense than through the extension of rumination time. pH-value, concentration of bicarbonate and C2:C3-ratio indicate favourable fermentation conditions in long (28.7 mm) and chopped hay (9.2 mm), whereas a negative influence of ground hay (2.9 mm) or ruminal fermentation could be observed.     

谷饲、乳饲奶公牛犊直线育肥报告

[目的]为了研究奶公牛犊不同营养水平饲料下增重变化及具体饲料报酬。[方法]本实验将39头奶公牛犊分成四组（A组为精粮型,B组为粗粮型,C组为代乳粉组,D组为全脂奶粉组）进行饲养对比实验。每月进行体重测量和数据统计。[结果]A组体重302．4±38．79kg,日增重1．67±0．27kg,每千克增重饲料成本11．3元,B组体重284．27±26．54kg,日增重1．56±0．24kg。每千克增重饲料成本9．3元,;C组体重261．4±19．96kg,日增重1．556±0．089kg,每千克增重饲料成本27．1元,D组体重278．25±14．53kg,日增重1．585±0．231kg,每千克增重饲料成本27．8元。[结论]各组之间增重差异不显著,但谷饲可以有效降低饲养成本,代乳粉与全脂奶粉对增重影响差异不显著。     

Equine energetics. II. Energy expenditure in horses during submaximal exercise

Energy expenditure was measured in four geldings (433 to 520 kg) during submaximal exercise on a racetrack using a mobile open-circuit indirect respiration calorimeter. A total of 304 5-min measurements of O2 consumed and CO2 produced were taken. Measurements were made with and without riders. The amount of energy expended by the horses was exponentially related to speed and was proportional to the body weight of the riderless horse or the combined weight of the horse plus rider and tack. Total energy expended by the four horses walking, trotting, cantering was best described by the equation: Y = e3.02 + .0065X where Y = energy expended (cal X kg-1 X min-1) and X = speed (m/min). Digestible energy (DE) required above maintenance was calculated as (Formula: see text).     

苜蓿干草切割长度对荷斯坦育成母牛采食与反刍行为和营养物质消化的影响

试验以3头8～10月龄、平均体重(300±22.4)kg的荷斯坦育成母牛为试验动物,采用3×3拉丁方试验设计,对2、4cm和自然全长3种理论切割长度的苜蓿干草对育成母牛采食与反刍行为和日粮营养物质消化的影响进行了研究。结果表明:随着苜蓿干草长度的增加,苜蓿干草采食时间、日粮采食时间、反刍时间、咀嚼时间明显增加(P<0.05);每日采食次数和每次采食的干物质采食量明显降低(P<0.05)。除苜蓿干草以外的日粮其他组分的采食时间、日粮采食时间与反刍时间的比例、日粮常规营养物质的消化率基本不受苜蓿干草长度的影响(P>0.05)。     

Effect of dental correction on voluntary hay intake,apparent digestibility of feed and faecal particle size in horse

Summary In nine adult Warmblood horses with mild to moderate dental findings (no signs of discomfort during chewing), voluntary hay intake before and after dental correction was examined. In a second experiment, digestibility of feed and faecal particle size were determined (3 days of total faecal collection) before and after dental correction. During both digestion trials including a 3‐day adaptation period, the amount of hay and concentrate (mixture of oats, barley and maize) was kept constant in each individual horse before and after dental correction. Voluntary hay intake in individual horses ranged from 11 to 22 g DM/kg BW/day and did not differ before and after dental treatment. Apparent digestibility of DM, energy, crude fibre and Nfe increased significantly after dental correction (energy digestibility before dental correction 46.8 ± 7.4%, after dental correction 51.5 ± 8.5%). Apparent digestibility of feed was higher in horses eating more concentrates than in those eating less concentrates. Improvement of digestibility was more marked in horses eating larger amounts of grain. There was no relationship between severity or type of dental alterations and improvement of apparent feed digestibility. Dental correction had no effect on faecal particle size.