Twice-daily Feeding Research Articles

Effect of feeding frequency on reproductive performances and stress responses in gestating sows.

The objective of this study was to investigate the influence of feeding frequency on a sow's reproductive performance and stress response during gestation. A total of twenty multiparous sows (Yorkshire × Landrace) were used in a completely randomized design based on their parity, body weight (BW), and backfat thickness (BFT), and the sows were allotted to two different feeding systems: 1) once daily feeding (OF) and 2) twice daily feeding (TF) in corn-soybean meal based diets. The gestation diet was formulated to contain 3,265 kcal of metabolizable energy (ME) / kg, 12.90% of crude protein (CP), and 0.75 % of total lysine. The lactation diet was formulated to contain 3,265 kcal of ME / kg, 16.80% of CP, and 1.08% of total lysine and provided ad libitum during lactation. In gestation, sow BFT and BF changes were not affected by feeding frequency, but higher BW and BW gain from day 35 to 90 and day 35 to 110 were observed in OF sow (p < 0.10). In lactation, feeding frequency did not influence on BW, BW gain, BFT, BF changes, average daily feed intake, and wean-to-estrus interval. Also, there were no differences in litter size, litter weight and piglet weight in lactating sows. OF sows had higher (p < 0.05; p < 0.10) protein, solid-not-fat, and total solid concentrations in colostrum compared to TF sows, while OF sows had a lower (p < 0.05) lactose concentration in colostrum compared to TF sows. Sows in OF showed significantly lower average daily water consumption (ADWC) from day 35 to 110 of gestation (p < 0.05). While there were no significant differences in stereotypic behaviors and salivary cortisol levels during gestation between treatments, the OF sows showed less time spending on the activity at day 105 (p < 0.05). In conclusion, reduced feeding frequency increased BW gain during gestation, decreased activation time, and changed the colostrum composition. This information may contribute to the understanding of the physiological and behavioral change of gestating sows by manipulating feeding frequency.

The effect of slow-release milk replacer feeding on health and behaviour parameters in dairy breed calves.

The aim of this research paper was to evaluate the effect of a slow-release milk replacer on health and behaviour of neonatal dairy calves. This was done with the potential benefits to welfare during transport in mind. A total of 15 calves were randomly divided into three groups of 5, namely, a control group fed twice in 24 h with 3 l of a conventional milk replacer, a slow-release group fed once in 24 h with 2 l of conventional milk replacer and 1 litre of a specialised micro-encapsulated feed and an enriched-replacer group fed once in 24 h with 3 l of milk replacer enriched with micellar casein. Blood samples were taken before feeding and 6, 12, 18 and 24 h after and analysed for acid-base parameters, electrolytes, glucose, haemoglobin, cortisol, insulin, cholecystokinin and adiponectin. Calf behaviour was recorded between 6 and 14 h after feeding. There was a significant increase in blood pH 6 h after feeding in all groups, but the glucose, HCO3 - and base excess increased significantly in the slow-release group only, whereas sodium increased significantly in the enriched group only. Glucose levels remained significantly higher in the slow-release group, relative to the control, at 6, 12, and 18 h after feeding. Insulin levels changed significantly over time in the enriched and control group but remained constant in the slow-release group. Insulin levels were significantly higher in the control group when compared to the slow-release group after feeding. Adiponectin changed significantly over time after feeding in the control group only, but no significant changes were observed between the feeding groups. Behavioural patterns were similar in control and slow release groups but less favourable (less lying time, more vocalisations) in the enriched group. In conclusion, once-daily feeding of slow-release milk replacer demonstrated favourable patterns of blood variables related to satiety and hunger as well as behavioural patterns that did not differ from conventional twice-daily feeding.

Diet dilution and feeding frequency have only minor effects on the behaviour of broiler breeder pullets

During the rearing period, broiler breeders are feed restricted to prevent the negative impact of fast growth and high body weight on health and reproduction. Feed restriction causes frustration and stress, resulting in stereotypic pecking and hyperactivity. Nutritional strategies have the potential to reduce these welfare issues. Using a 2 × 2 factorial completely randomized block design, pullets were fed with two diet densities and two feeding frequencies during rearing. From 3–23 weeks of age (WOA), pullets received either a standard control diet (CON) or a 16% diluted diet (DIL) containing oat hulls. These diets were provided either once (FO) or twice (FT) a day. After 23 WOA, all pullets received the same standard layer diet once a day. Home pen behaviour was observed by scan sampling at 5, 10, 15, 20, 30 and 39 WOA over eight observation sessions. Furthermore, pullets were subjected to Novel Food Tests (12 and 17 WOA) and Novel Object Tests (5, 10, 15 and 20 WOA). Minor treatment effects were found for foraging and sitting behaviour that varied with age during rearing. Feeding frequency influenced the behavioural patterns of all home pen behaviours (P < 0.001; object pecking P = 0.034), while diet dilution only affected the expression of foraging behaviour during the day (P = 0.007). In all treatment groups, many pullets were observed standing and walking in anticipation of the first meal. After the first meal and before the second meal, more FT pullets were observed standing and walking, while during and after the second meal more FO pullets were observed sitting and performing comfort behaviour. Feeding twice a day resulted in lower daily peaks in drinking behaviour. In the laying period, when all birds received the same layer diet at the same frequency, those who were fed twice daily during rearing foraged more than those who were fed once (P = 0.028) and birds that received a diluted diet during rearing tended to drink more than birds that received the control diet (P = 0.083). Few treatment effects were found in the Novel Food and Novel Object Tests, indicating that diet dilution and/or feeding frequency, as applied here, did not affect fearful behaviour or the motivation to explore. In conclusion, this study showed that neither diet dilution, twice-daily feeding, or the combination of these, improved broiler breeder welfare during rearing and laying. Some changes in the pattern of home pen behaviour were found that indicated a response to the frequency of food provisioning.

Addition different algae (Spirulina) flour to artificial feed on color quality and growth of Koi fish (Cyprinus carpio-Koi)

AbstrakOrnamental fish is one of the fisheries commodities that can be used as a source of foreign exchange income, and has its own beauty to attract the interest of ornamental fish lovers. One of the things that determines beauty in many species of ornamental fish is color. Color is a parameter to determine the value of ornamental fish, which is a brighter color, the higher the value of fish. Spirulina sp. Flour has a high carotenoid and protein content, each of which plays a role in increasing color intensity and growth. The purpose of this study was to determine the effect of concentration Spirulina flour to the color quality and growth of koi fish (Cyprinus carpio). The method used was experimental with Completely Randomized Design (CRD) using 4 treatments 5 replications. The dose of feed used is (Control), (dose 1%), (dose 3%) and (dose 5%), Color quality measurement using Adobe Photoshop CS8 software. The frequency of twice-daily feeding for each treatment resulted in color quality with the best value (3.0200%), absolute length growth (0.9780 cm) and absolute weight growth (3.7240 grams).

Feeding management strategies to optimize the use of suspended feed for Nile tilapia ( Oreochromis niloticus ) cultivated in bioflocs

Feeding strategies of tilapia (initial average weight: 32 g) cultivated with Biofloc technology (BFT) (carbon source: sugarcane, C:N ratio: 6:1) for 56 days were studied. A 4 × 3 factorial experimental design was used with four feeding frequencies (one, two, three and four times a day) and three feeding rates (50%, 75% and 100% consumption in relation to apparent satiety), with four replicates. Lower levels of dissolved oxygen, protein retention rate and body protein content were found in fish fed once a day. The reduction in feeding rate resulted in lower average final weight and reduced growth but promoted a decrease in the concentration of total ammonia nitrogen, solids, hepatosomatic index and body lipids. We found better efficiency of protein utilization at 75% feed. The nutritional value of the floc was not affected by the feeding frequency, and the feeding rate reduction from 100% to 75% did not alter the protein content of the floc. Thus, twice-daily feeding frequency is sufficient for Nile tilapia fingerlings reared in BFT. Although the feeding rate of 100% satiety has led to better performance, it may not be the best option in BFT due to higher feed conversion and reduction of water quality.

Neural correlates of food anticipatory activity in mice subjected to once- or twice-daily feeding periods.

In rodents, restricted food access to a limited period each day at a predictable time results in the appearance of food anticipatory activity (FAA). Two shorter periods of food access each day can result in two FAA bouts. In this study, we examine FAA under 12:12 and 18:6 photoperiods in mice (Mus musculus) with one or two food access periods per day and measure the activation of the suprachiasmatic, dorsomedial and arcuate nuclei by assaying Fos protein expression, while making use of tissue-type plasminogen activator knockout mice to assess the role of neural plasticity in adaptation to restricted feeding cycles. Long days were utilised to allow for temporal separation of two restricted feeding periods during the light phase. Mice fed twice per day generally divided FAA into two distinct bouts, with mice lacking tissue-type plasminogen activator showing reduced FAA. Increases in Fos expression in response to one restricted feeding period per day were seen in the dorsomedial and arcuate nuclei in both 12:12 and 18:6 conditions, with an increase seen in the SCN in only the 12:12 condition. These increases were eliminated or reduced in the two feeding time conditions (done in 18:6 only). Both activity patterns and Fos expression differed for single restricted feeding times between 18:6 and 12:12 photoperiods. Fos activation was lower during RF in 18:6 than 12:12 across all three brain regions, a pattern not reflective of changes in FAA. These data suggest that involvement of these regions in FAA may be influenced by photoperiodic context.

Growth, behavior, and economics of group-fed dairy calves fed once or twice daily in an organic production system

Heifer calves (n = 102) were used to evaluate the effect of once- or twice-daily feeding on growth, behavior, and economics of calves in an organic group management system. Calves were assigned to replicate feeding groups of 10 in superhutches by birth order, during 2 seasons from September to December 2013 and March to May 2014 at the University of Minnesota West Central Research and Outreach Center, Morris. Calves in groups were the experimental unit. Breed groups of calves were Holsteins (n = 26), crossbreds (n = 45) including combinations Holsteins, Montbéliarde, and Viking Red (selected for high production), and crossbreds (n = 31) including combinations of Holsteins, Jersey, Normande, and Viking Red (selected for robustness). Treatment groups were once-daily feeding (1×) or twice-daily feeding (2×). Calves in both groups were fed 6 L per calf/daily of organic milk with 13% total solids and then weaned at 60 d when the group consumption averaged 0.91 kg/d of starter per calf. Body weight and hip height were recorded at birth, once a week, at weaning, and at 90 and 120 d of age. Hobo Pendant G loggers (Onset Computer Corp., Bourne, MA) were applied to the right rear leg of calves to measure total lying and standing time. Data were analyzed using PROC MIXED of SAS (SAS Institute Inc., Cary, NC). Independent variables for analyses were the fixed effects of birth weight (co-variable), season of birth, and treatment group, along with replicate as a random effect. No significant differences were found between feeding groups for body weight, weight gain, average daily gain, hip height, or heart girth. For calves in 1× and 2× groups, respectively, weaning group performance was as follows: gain per day was 0.79 and 0.81 kg, weaning weight was 92.7 and 93.3 kg, and weaning hip height was 95.2 and 95.3 cm. Daily gain to 90 d was 0.85 and 0.85 kg, and daily gain to 120 d was 0.85 and 0.83 kg for 1× and 2× calves, respectively. For lying time, calves in groups 1× (988 min/d) and 2× (995 min/d) did not differ. During the evening hours, 2× calves had lesser lying times (34 min/h for 1×; 28 min/h for 2×) because they were fed at 1800 h every evening. The average cost per kilogram of gain for the 2× ($4.03/kg) calves was greater than that for the 1× ($3.56/kg) calves. In summary, group-fed calves fed once a day in an organic production system had similar average daily gains and body dimensions compared with calves fed twice a day. Our results indicated that there is no need for twice-daily milk feeding under the conditions of the present study.

Lipid digestibility and energy content of distillers' corn oil in swine and poultry.

Two experiments were conducted to determine the DE and ME and apparent total tract digestibility of ether extract of 3 distillers' corn oil (DCO; 4.9, 12.8, or 13.9% free fatty acids [FFA]) samplescompared with a sample of refined corn oil (CO; 0.04% FFA) and an industrially hydrolyzed high-FFA DCO (93.8% FFA) in young pigs and growing broilers. In Exp. 1, 54 barrows (initial age = 28 d) were fed a common diet for 7 d and then fed their allotted dietary treatment (either 100% basal diet or 1 of 5 test diets consisting of 90% basal diet plus 10% test lipid) for the next 7 d in group pens (9 pigs/pen). For the next 10 d, pigs were moved to individual metabolism crates for continued diet and crate adaptation and to a twice-daily feeding regimen. Pigs remained on their respective diets for a 4-d total fecal and urine collection period. For Exp. 2, 567 male broilers were obtained from a commercial hatchery (1 d of age) and reared in grower battery cages that contained 9 chicks per cage. Broilers were fed a common corn-soybean meal starter diet from placement until the beginning of the trial (19 d of age). Birds were then randomly assigned to 1 of 6 dietary treatments (94% basal diet plus 6% dextrose or 94% basal diet plus 6% test lipid substituted for dextrose) on d 19 and were allowed an 8-d dietary acclimation period followed by a 48-h energy balance assay. In Exp. 1, the DCO sample with 12.8% FFA contained the lowest ( < 0.05) DE (8,036 kcal/kg) content compared with the 0.04% refined CO sample and the 4.9 or 93.8% FFA DCO samples (8,814, 8,828, and 8,921 kcal/kg, respectively), with the DCO source containing 13.9% FFA having intermediate DE (8,465 kcal/kg) content. The ME content of these lipid sources also differed among treatments ( < 0.01), following trends similar to their DE values, with no differences noted for ME as a percentage of DE ( > 0.35) content among the lipids evaluated. In Exp. 2, lipids containing 0.04, 4.9, 12.8, and 13.9% FFA had similar nitrogen corrected apparent ME (AME) values (8,072, 7,936, 8,036, and 7,694 respectively), except for the industrially hydrolyzed DCO sample containing 93.8% FFA, which contained 6,276 kcal/kg ( < 0.01). Using published prediction equations, the predicted DE of these lipids for swine was 3.5% greater than the values determined in Exp. 1 for all lipid sources, except for the DCO sample containing 93.8% FFA, which the predicted DE was underestimated. Likewise, the predicted AME of these lipids for broilers was 7.4% greater than the determined AMEn (Exp. 2) for all lipid sources.

The Effect of a Feeding Schedule Change and the Provision of Forage Material on Hair Eating in a Group of Captive Baboons (Papio hamadryas sp.)

Hair eating in nonhuman primates is thought to result from a frustrated appetitive drive produced by an inappropriate diet. To investigate whether hair eating could be reduced through changes in diet, a 2-part study was conducted with a group of baboons (Papio hamadryas sp.). The 1st part involved changing to a twice-daily feeding routine, thus providing prolonged access to an appropriate food source. The 2nd part involved scattering a grain mix to encourage more foraging while maintaining a once-daily feeding routine. Changing the feeding routine unexpectedly resulted in a significant increase in hair manipulation and ingestion. Providing additional grain did not significantly decrease hair manipulation and ingestion, but several individuals did show a reduction in these behaviors. Prolonged access to biscuits and the provision of a grain mix may have failed to satisfy the urge to forage because little effort was needed for their collection prior to consumption. Although the current study failed to significantly decrease hair eating, it provides valuable insight into further avenues of research on the behavior.

The effects of feeding time on milk production, total-tract digestibility, and daily rhythms of feeding behavior and plasma metabolites and hormones in dairy cows

The timing of feed intake entrains circadian rhythms regulated by internal clocks in many mammals. The objective of this study was to determine if the timing of feeding entrains daily rhythms in dairy cows. Nine Holstein cows were used in a replicated 3×3 Latin square design with 14-d periods. An automated system recorded the timing of feed intake over the last 7 d of each period. Treatments were feeding 1×/d at 0830h (AM) or 2030h (PM) and feeding 2×/d in equal amounts at 0830 and 2030h. All treatments were fed at 110% of daily intake. Cows were milked 2×/d at 0500 and 1700h. Milk yield and composition were not changed by treatment. Daily intake did not differ, but twice-daily feeding tended to decrease total-tract digestibility of organic matter and neutral detergent fiber (NDF). A treatment by time of day interaction was observed for feeding behavior. The amount of feed consumed in the first 2h after feeding was 70% greater for PM compared with AM feeding. A low rate of intake overnight (2400 to 0500h; 2.2±0.74% daily intake/h, mean ± SD) and a moderate rate of intake in the afternoon (1200 to 1700h; 4.8±1.1% daily intake/h) was noted for all treatments, although PM slightly reduced the rate during the afternoon period compared with AM. A treatment by time of day interaction was seen for fecal NDF and indigestible NDF (iNDF) concentration, blood urea nitrogen, plasma glucose and insulin concentrations, body temperature, and lying behavior. Specifically, insulin increased and glucose decreased more after evening feeding than after morning feeding. A cosine function within a 24-h period was used to characterize daily rhythms using a random regression. Rate of feed intake during spontaneous feeding, fecal NDF and iNDF concentration, plasma glucose, insulin, NEFA, body temperature, and lying behavior fit a cosine function within a 24-h period that was modified by treatment. In conclusion, feeding time can reset the daily rhythms of feeding and lying behavior, core body temperature, fecal NDF and iNDF concentration, and plasma blood urea nitrogen, glucose, and insulin concentration of dairy cows, but has no effect on daily DMI and milk production.

Short communication: Plasma concentration of glucose-dependent insulinotropic polypeptide may regulate milk energy production in lactating dairy cows

In dairy cows, an increase in plasma concentration of glucose-dependent insulinotropic polypeptide (GIP) is associated with an increase in metabolizable energy intake, but the role of GIP in energy partitioning of dairy cattle is not certain. The objective of this study was to examine the relationship between plasma GIP concentrations and energy partitioning toward milk production. Four mid-lactation, primiparous, rumen-fistulated Holstein-Friesian cows were fed a control diet of 55% forage and 45% concentrate [dry matter (DM) basis] in a 4×4 Latin square design with 4-wk periods. The 4 treatments were (1) control diet fed at 1000 and 1600h, and (2) once-daily (1000h) feeding, (3) twice-daily (1000 and 1600h) feeding, and (4) 4 times/d (1000, 1600, 2200 and 0400h) feeding of the control diet plus 1 dose (1.75kg on a DM basis at 0955h) into the rumen of supplemental vegetable proteins (Amino Green; SCA NuTec Ltd., Thirsk, UK). Measurements of respiratory exchange and energy balance were obtained over 4d during the last week of each period while cows were housed in open-circuit respiration chambers. Blood was collected from the jugular vein every 30min for 12h, using indwelling catheters, starting at 0800h on d 20 of each period. Plasma GIP concentration was measured in samples pooled over each 5 consecutive blood samplings. The relationships between plasma GIP, DM intake, heat production, respiratory quotient (RQ), milk yield, and milk energy output were analyzed using linear correlation procedures, with metabolizable intake as a partial variant. Plasma GIP concentration was not correlated with heat production, or milk yield, but was positively correlated with milk energy yield (correlation coefficient=0.67) and negatively correlated with RQ (correlation coefficient=−0.72). The correlations between GIP with RQ and milk energy output do not imply causality, but support a role for GIP in the regulation of energy metabolism in dairy cows.

Characterizing behavioral sleep using actigraphy in adult dogs of various ages fed once or twice daily

Abstract Adult dogs possess strong diurnal locomotor activity/rest rhythms, and sleep/wake patterns have been characterized. However, behavioral sleep/wake data are lacking related to aging and daily feeding pattern. Three groups (young adults [Y], 1.5–4.5 years; middle-aged adults [M], 7–9 years; and senior, 11–14 years) of beagles (N = 48) wore the Actiwatch activity monitoring system (Respironics Co., Inc., Bend, OR) for 3 days while housed indoors with 12-hour light/dark schedule and fed once or twice daily. Actiware-Rhythm software (version 5.52; Respironics Co., Inc., Bend, OR) was used to estimate behavioral sleep or wake from locomotor activity data. All dogs demonstrated diurnal sleeping patterns. Total wake minutes during the light phase declined with age ( P P P = 0.01) more minutes than young adults. Increased sleep time at night resulted from a longer sleep interval duration ( P = 0.05), delayed morning activity onset time ( P = 0.02), and marginally fewer waking bouts ( P = 0.07). Independent of age, twice-daily feeding significantly influenced daytime sleeping patterns but did not affect total minutes recorded as sleep during the day. Interestingly, napping bouts decreased significantly ( P = 0.01) and napping duration increased ( P = 0.0001) when fed twice-daily. Twice-daily feeding was also associated with earlier sleep onset time at night and onset of morning activity, as well as shortened sleep interval. Clear changes in behavioral sleep patterns were observed with age and daily feeding schedule.

Effect of milk feed source, frequency of feeding and age at turnout on calf performance, live-weight at mating and 1st lactation milk production

Female calves (n = 108) were assigned to 6 cold milk feeding treatments in two experiments for a 70-day period. Live-weight (LW) was measured weekly, with an additional LW taken at day 410 and post-calving for animals in experiment 1. In Experiment 1, the effect of feeding frequency and age of turnout to pasture on calf performance and 1st lactation milk yields were evaluated. The whole milk (WM) feeding treatments applied were (i) once daily feeding (OD), (ii) twice daily feeding (TD), (iii) OD feeding, outdoors at 38 days (ODO). In Experiment 2, the effects of feeding milk replacer (MR) as opposed to WM and age of turnout to pasture on calf performance were evaluated. The treatments applied were (i) OD feeding with WM (OD), (ii) OD feeding with milk replacer (MR) (ODMR), (iii) OD feeding with MR, outdoors at 38 days (ODMRO). Experiment 1: There were no differences (P > 0.05) in LW or average daily gain between TD and OD calves at day 80 or 410. ODO calves had lower LW at day 80 as compared to OD or TD (P < 0.001). Calf LW at day 80 was 86, 89 and 85 kg and at day 410 was 304, 309 and 316 kg for OD, TD and ODO, respectively. Milk feeding frequency or time of calf turnout had no effect on LW post calving, milk composition or 1st lactation milk yields. Experiment 2: Total LW at day 80 was higher (P < 0.05) for ODMR compared to OD or ODMRO calves. Calf LW was 87, 95, and 88 kg for OD, ODMR and ODMRO, respectively. However, LW at day 410 did not differ between treatments.This study showed that while some differences were observed in calf LW at day 80, these differences had no effect on LW at day 410 or 1st lactation milk yield. It can be concluded that calves can be successfully reared when fed OD with WM or MR, indoors and when turned out to pasture at 38 days of age.

Effect of age and feeding schedule on diurnal rest/activity rhythms in dogs

Dogs exhibit biorhythms like diurnal sleep/wake and rest/activity behavior patterns with circadian rhythmicity and, similar to other mammalian species, show age-dependent changes in activity rhythms. This study sought to further characterize night/day locomotor activity patterns in adult dogs of various ages, and to examine the effect of feeding frequency (once vs. twice). Three groups (early adults [EA], 1.5-4.5 years; late adults [LA], 7-9 years; senior, 11-14 years) of beagles (N = 48) wore the Actiwatch activity monitoring system for 3 days while housed indoors with 12-hour light/dark schedule. Activity recording devices were used to collect actigraphy data when dogs were on a once- or twice-daily feeding regimen. All dogs demonstrated a circadian activity pattern with high levels of daytime activity and low levels of nighttime activity. The main effect of age differed for both daytime (P < 0.0001) and nighttime (P = 0.002) activity counts. Daytime activity in senior dogs was 17% and 42% lower compared with LA and EA dogs, respectively. With nighttime activity, both LA and seniors had significantly lower counts compared with the EA. Compared to once-daily feeding, twice-daily feeding significantly increased night activity, night/day activity ratio, and activity counts 60 minutes before the light phase across all 3 age-groups. This study provides a comprehensive characterization of age-related changes in locomotor behavior patterns in dogs and uniquely demonstrates that frequency of feeding can influence nighttime activity levels, which is partially associated with level of prelight onset of activity.

Effect of feeding frequency on feedlot steer performance123

ABSTRACT Crossbred yearling steers (n = 270; mean initial BW = 318 kg) were used to determine the effect of feeding frequency on feedlot performance and carcass characteristics. Steers were stratified by BW and randomly assigned to pens. Pens were then randomly assigned to 1 of 3 treatment groups: once-daily feeding (1X), twice-daily feeding (2X), or 3-times-a-day feeding (3X). Steers were fed a standard high-concentrate steam-flaked-corn based finishing ration for 170 d. Steers were housed in pens measuring 6.1 × 18.3 m. Feed was delivered to steers in fence-line (3.7 m in length) concrete bunks (0.31 m per steer). Pen served as the experimental unit, and cattle were slaughtered at a constant days on feed. Average daily gain was similar for steers fed 1X or 2X per day; however, ADG (P

Effect of Diet on the Cardiovascular System in Healthy Beagles

In management of canine cardiac disorders, cardiac drugs are commonly administered with food, although the cardiovascular effects of feeding and frequency of feeding are unknown. This study investigated the cardiovascular effect of feeding and frequency of feeding using a telemetry monitoring system in unanesthetized and unrestrained dogs. Systolic and diastolic blood pressure, heart rate and double product were steeply elevated during the five minutes immediately before feeding. They showed a sharp fall within 60 min after feeding time, especially the systolic and diastolic blood pressure, which showed lower values than from before feeding time. There were no significant differences in the means of preprandial elevation, postprandial fall or 24-hr averages in the once- and twice-daily feeding periods.

Roles of eating, rumination, and arterial pressure in determination of the circadian rhythm of renal blood flow in sheep1

To assess the roles of feeding behavior (eating and rumination) and systemic arterial pressure (SAP) on determination of the circadian rhythm of renal blood flow (RBF), 20 sheep fitted with ultrasonic flow-metering probes around both renal arteries and a submandibular balloon to monitor jaw movements (6 of them with a telemetry measurement system into the carotid artery for SAP recording), were successively assigned to 6 feeding patterns: once daily in the morning (0900 to 1100 h), afternoon (1700 to 1900 h), or evening (1900 to 2100 h); twice daily at 0900 to 1100 h and 1700 to 1900 h; ad libitum (food renewed each 2 h); and fasting (40 h). All protocols were carried out in autumn-winter, and the fasting pattern was repeated in spring-summer to evaluate the effect of the daylight length on RBF. In the once-daily feeding patterns, a rapid increase in RBF (P < 0.05 vs. 1-h prefeeding mean values) subsequent to the onset of meals was observed, followed by a progressive increase (P < 0.05), reaching a maximum 4 to 6 h after the beginning of eating, and a subsequent gradual decline until the next meal [differences vs. prefeeding values were no longer significant after 11 h (morning pattern), 13 h (afternoon pattern), and 15 h (evening pattern) from the beginning of eating]. In the twice-daily feeding pattern, each meal was also followed by an increase in RBF (P < 0.05 vs. prefeeding values), reaching a maximum 3 to 5 h after the onset of meals, and a posterior decline [differences vs. prefeeding values were no longer significant after 8 h (morning meal) and 5 h (afternoon meal) from the beginning of eating]. In the ad libitum feeding, no apparent rhythm in RBF was found. During fasting, a progressive reduction of RBF was observed from 2 h after the beginning of fasting (P < 0.05 vs. the mean value of the first fasting hour), with a slight rebound (P < 0.05) lasting several hours from approximately 0700 h in autumn-winter and approximately 0500 h in spring-summer. No change in the RBF profile was observed in association with rumination. Except during meals, no correlation was found between RBF and SAP. A detailed description of RBF and SAP recordings is presented. In conclusion, results showed a circadian rhythm of RBF determined by eating behavior, but not by rumination, that was independent of blood pressure and that seemed superimposed on a primary lighting-cycle-dependent RBF rhythm.

Investigation of calf health and welfare on dairy farms in south-west England

A questionnaire was designed to investigate calf health and welfare on dairy farms in the south west of England with regard to the degree of compliance with the Welfare of...

Influence of feed intake fluctuation and frequency of feeding on nutrient digestion, digesta kinetics, and ruminal fermentation profiles in limit-fed steers.

Nine crossbred beef steers (344 +/- 26 kg) fitted with ruminal cannulas were used in a randomized complete block design to evaluate the effects of feeding frequency and feed intake fluctuation on total tract digestion, digesta kinetics, and ruminal fermentation profiles in limit-fed steers. In Period 1, steers were allotted randomly to one of four dietary treatments: 1) feed offered once daily at 0800; 2) feed offered once daily at 0800 with a 10% fluctuation in day-to-day feed intake; 3) feed offered twice daily at 0800 and 1700; and 4) feed offered twice daily at 0800 and 1700 with a 10% fluctuation in a day-to-day feed intake. In Period 2, steers were reallocated across treatments. The 90% concentrate diet was fed at 90% of the ad-libitum consumption by each steer. Chromium-EDTA and Yb-labeled steam-flaked corn were intraruminally infused at 0800 on d 1 and 3 and Co-EDTA and Er-labeled steam-flaked corn were infused on d 2 and 4 of the 4-d collection period. Ruminal samples were collected at 0, 3, 6, 9, 12, 15, 18, and 24 h after the 0800 feeding, and total feces were collected for 4 d. Total tract digestibilities of OM, N, and starch were lowest (fluctuation x frequency, P < .05) when feed was offered twice daily with a 10% fluctuation in intake. Ruminal fluid volume and passage rate were not affected (P > .10) by feeding frequency or intake fluctuation. A frequency x fluctuation x sampling time interaction occurred (P < .01) for ruminal pH. Steers fed a constant amount of feed once daily had higher (P < .05) ruminal pH at 0, 3, 18, and 24 h than steers fed once daily with a 10% fluctuation in feed intake. Total VFA concentration was greater (P < .01) at 9 h after the 0800 feeding when feed was offered once vs twice daily. Feeding twice daily increased (P < .05) the molar proportion of acetate and decreased (P < .05) the molar proportion of propionate. Increasing feeding frequency resulted in a more stable ruminal environment; however, the increased acetate:propionate ratio with twice-daily feeding might result in lower efficiency of energy utilization by limit-fed steers.

Continuous profiles and within-day variations of metabolites and hormones in cows fed diets varying in alimentary supplies before short-term feed deprivation.

We investigated continuous profiles and within-day variations of some metabolites and hormones in four nonpregnant, nonlactating cows fed hay-based diets in two equal meals. Diets supplied either too much or too little N (approximately 1.3 or .8 times the maintenance requirements) and NE1 (approximately 1.2 or .8 times). Continuous collection of ruminal liquor, blood, and urine samples was performed for 42 consecutive hours, the last 16 h covering a period without feed. For twice-daily feeding, nitrogenous and energetic underfeeding decreased average ruminal propionate and the insulin:growth hormone ratio. However, only the energetic underfeeding increased plasma 3-methylhistidine and urinary excretion of 3-methylhistidine, and decreased body weight and ruminal acetate, butyrate, and total VFA. Conversely, only the nitrogenous underfeeding decreased glycemia. Whatever the dietary level, the 42-h patterns of metabolites and hormones were mainly affected by the time from the last meal. An energy deficit progressively took place during feed deprivation and the nocturnal interprandial period but not during the diurnal interprandial period. During the feed deprivation and nocturnal periods, glycemia was maintained despite a shortage in ruminal propionate. We conclude that in twice-daily fed cattle 1) the dietary supply of energy is the main trigger for an energy deficit and the subsequent muscle protein mobilization; 2) the nocturnal interprandial period may be considered as short-term feed deprivation; 3) the diurnal patterns of metabolites and hormones are not affected by the nitrogenous and(or) energetic supplies of the diet.