Feed Intake Pattern Research Articles

Effect of feeding two types of concentrates in morning and evening meals and two types of fat supplement on diurnal patterns of plasma parameters in lactation dairy cows

The diurnal patterns of feed intake and TMR composition influence blood parameters in dairy cows; however, the effect of feeding TMR with different compositions in the morning and evening meals is not well characterized. In a completely random design, forty Holstein cows (110 ± 30 days postpartum) were randomly assigned to four treatment groups, with 10 cows per treatment. The treatments were as follows: a base diet containing 50 % cereal starch from barley grain and 50 % cereal starch from corn grain in the morning and evening meal + either prilled fatty acids supplement (EqP) or calcium salts of fatty acids supplement (EqCS); a base diet containing 25 % cereal starch from barley grain, 75 % cereal starch from corn grain in the morning meal, and 75 % cereal starch from barley grain and 25 % cereal starch from corn grain in the evening meal + either prilled fatty acids supplement (DiP) or calcium salts of fatty acids supplement (DiCS). Dry matter intake was affected by treatments (P ˂ 0.01). The highest intake was observed for EqP, EqCS, DiP,and DiCS. 3.5 % fat-corrected milk and milk fat percentage was significantly higher for EqP than other treatments (P ˂ 0.01), but other milk components were not significantly different among treatments (P ˃ 0.05). A significant difference was observed for glucose, cholesterol, TG, AST, and insulin concentration among treatments (P ˂ 0.01). The concentrations of all plasma parameters (glucose, cholesterol, TG, BUN, AST, insulin, and NEFA) significantly changed over 24-h period (P ˂ 0.01). Plasma concentrations of glucose, cholesterol, TG, BUN, AST, insulin, and NEFA displayed a treatment-by-time interaction (P ˂ 0.01). In general, changes in the cereal starch ratio (corn and barley) in TMR in each meal during a day affect the 24-h concentration of plasma parameters, but there was no strong evidence of leverage for cows’ metabolism.

Distinct patterns of feed intake and their association with growth performance in broilers

Improving feed utilization is a vital strategy to meet the growing global demand for meat and promote sustainable food production. Over the past few decades, significant improvements in the feed intake (FI) and feed utilization efficiency of broilers have been achieved through advanced breeding procedures, although dynamic changes in FI and their effects on the feed conversion ratio (FCR) have remained unclear. In this study, we measured individual weekly FI and body weight of 274 male broilers to characterize the dynamic FI patterns and investigate their relationship with growth performance. The broilers were from 2 purebred lines and their crossbreed and measurements were collected from 4 to 6 wk of age. Overall, a continuous increase in the weekly FI occurred from 4 to 6 wk of age, whereas the body weight gain (BWG) reached an inflection point in wk 5. The dynamic change in weekly FI was observed to follow 3 distinct FI patterns: pattern 1, a continuous weekly increase in FI; pattern 2, an increase followed by a plateau; pattern 3, an increase followed by a decrease. The prevalence of these patterns was similar in the purebred and crossbred populations: pattern 2 was most frequent, followed by a moderate proportion of pattern 1, and the lowest proportion of pattern 3. Broilers following pattern 1 displayed significantly better growth performance and feed utilization efficiency than those following pattern 3, emphasizing the importance of maintaining good appetite in the last stage of broiler production. In summary, this study has characterized the dynamic patterns of FI and their association with growth performance. Our results offer a new foundation for improving feed utilization efficiency and investigating feeding regulation in broilers.

Investigations on Xenopus laevis body composition and feeding behavior in a laboratory setting

The African clawed frog, Xenopus laevis, has been used as a laboratory animal for decades in many research areas. However, there is a lack of knowledge about the nutritional physiology of this amphibian species and the feeding regimen is not standardized. The aim of the present study was to get more insights into the nutrient metabolism and feeding behavior of the frogs. In Trial 1, adult female X. laevis were fed either a Xenopus diet or a fish feed. After 4 weeks, they were euthanized, weighed, measured for morphometrics and dissected for organ weights and whole-body nutrient analysis. There were no significant differences between the diet groups regarding the allometric data and nutrient contents. The ovary was the major determinant of body weight. Body fat content increased with body weight as indicator of energy reserves. In Trial 2, 40 adult female frogs were monitored with a specifically developed digital tracking system to generate heat-maps of their activity before and up to 25 min after a meal. Three diets (floating, sinking, floating & sinking) were used. The main feed intake activity was fanning the feed into the mouth, peaking until 20 min after the meal. The different swimming characteristics of the diets thereby influenced the activity of the animals. Our dataset helps to adjust the feeding needs to the physical composition and also to meet the natural behavioral patterns of feed intake as a prerequisite of animal wellbeing and animal welfare in a laboratory setting.

Size matters: lower body weight pigs have a different response to immune challenge and amino acids supplementation above the estimated requirement compared to heavy pigs.

The immune response varies between pigs, as not all pigs have the same response to a stressor. This variation may exist between individuals due to body weight (BW) or body composition, which may impact the capacity for coping with an immune challenge (IC). Tryptophan (Trp), threonine (Thr), and methionine (Met) requirements might also play a considerable part in supporting immune system activation while reducing variation between pigs; however, the latter has yet to be reported. This exploratory study investigated the effect of initial BW (light vs. heavy-weight) and supplementation of Trp, Thr, and Met above National Research Council (NRC) requirements on feeding behavior and the coping capacity of growing pigs under an IC. Eighty gilts were categorized into 2 groups according to BW: light-weight (LW, 22.5kg) and heavy-weight pigs (HW, 28.5kg). Both BW groups were group-housed for a 28-d trial in a good or poor sanitary condition (SC). Pigs within a poor SC were orally inoculated with 2 × 109 colony units of Salmonella Typhimurium, and fresh manure from a pig farm was spread on the floor. Pigs within good SC were not inoculated, nor was manure spread. Two diets were provided within each SC: control (CN) or supplemented (AA+) with Trp, Thr, and Met at 120% of NRC recommended levels. A principal component analysis was performed in R, and a feeding behavior index was calculated in SAS. Results showed that LW and HW pigs were clustered separately on day 0, where LW pigs had a positive correlation with body lipid percentage (r = 0.83), and HW pigs had a positive correlation with body protein percentage (r = 0.75). After the IC, the cluster configuration changed, with diets influencing LW more than HW pigs within poor SC. On day 14, LW fed AA + diet in poor SC was clustered separately from LW pigs fed CN diet, whereas LW fed AA + and CN diets in good SC were clustered together. For feeding behavior, in both analyzed periods (period 1: days 7 to 14; period 2: days 21 to 28), LW had lower total feed intake and shorter meals than HW pigs (P < 0.10), independent of the SC. Furthermore, LW pigs fed AA + diet had a more regular feed intake pattern than those fed CN diet, while a more irregular pattern was observed for HW pigs fed AA + diet than CN diet at period 2. These findings suggest that supplementing Trp, Thr, and Met above requirements may be a nutritional strategy for LW pigs under IC by improving feed intake regularity and reducing the probability of being susceptible to IC.

296 Short-Term Diurnal Heat Stress Modulation of Growing Gilt and Barrow Growth and Feed Intake

Abstract During summer months, the increase in temperature and humidity can lead to heat stress conditions that have negative impacts on the growth performance of pigs. The objective of this study was to characterize the effects of diurnal heat stress (dHS) on gilt and barrow growth, day-time and night-time feed intake. Twelve gilts and 12 barrows (46.5 ± 2.47 kg BW) were individually housed in metabolism crates over two experimental periods. For Period 1, all pigs were housed in thermoneutral (TN) conditions (20-21°C and 40-60% humidity). Following the TN period, period 2 consisted of four days of dHS (6 h at 32°C, 18 h at 27°C, 40-60% humidity). The conditions in the dHS period were designed to replicate summer, industry-applicable cyclical heat stress conditions. In each period lasting 4 days, pig BW and feed disappearance were recorded and ADG, ADFI and G:F calculated. Additionally, within each day, 0700 to 1700 h (day-time) and 1700 to 0700 h (night-time) feed intake was recorded. Changes in pig body temperatures (BT) and respiration rates (RR) were measured daily at 0800, 1200 and 1800 h. Pig was considered the experimental unit, and all data were analyzed for the fixed effects of period (TN vs. HS), sex, and period-by-sex interaction. There were no period-by-sex interactions observed for any analyzed variable (P &amp;gt; 0.05). As expected, dHS markedly increased pig 3-day average BT and RR compared with their TN values (P &amp;lt; 0.05). Compared with TN, dHS BT measurements at noon, PM, and overall were on average 1.0°C greater (P &amp;lt; 0.0001). The RR was also increased by 200 to 300% for AM, noon, PM, and overall, for the dHS period as compared with TN (P &amp;lt; 0.001). Within the dHS period, BT was highest at the noon and PM recordings, and RR was highest at the noon recording (P &amp;lt; 0.0001). Pigs tended to have reduced ADFI during dHS compared with TN period (1.54 vs 1.70 kg/d, P = 0.051). During the TN period, pigs consumed 61% (1.03 kg) of daily total feed consumption during day-time and 39% (0.67 kg) in the PM period (P &amp;lt; 0.0001). The opposite effect was found during dHS, in which pigs consumed 33.3% (0.52 kg) of their total daily feed during the peak heat conditions (day-time) and 66.7% (1.02 kg) consumed in the cooler night-time period (P &amp;lt; 0.0001). Compared with barrows, gilts tended to have greater overall ADFI (1.61 vs. 1.48 kg/d; P = 0.079). Within both the TN and dHS period, gilts had a lower average noon BT (P &amp;lt; 0.05), and lower morning RR (P &amp;lt; 0.05). Altogether, three days of dHS increased pig RR and BT, and decreased ADFI. However, day- and night-time feed intake patterns changed compared with the TN period. Diurnal heat stress has similar impacts to both gilts vs. barrows.

217 Effect of Sow Feeder Design on Sow Body Weight, Litter Performance, and Feeder Cleaning Criteria

Abstract During lactation, maximizing sow feed intake is critical to sustaining sow body weight (BW) and milk production for litter growth. Farrowing stall design can affect sow feed intake because a good feeder should minimize feed wastage and spoilage and improve sow feed intake by enhancing the accessibility of feed and matching the feed intake pattern of the sow. Therefore, the objective of this experiment was to evaluate the effect of feeder design on sow BW, litter performance, and feeder cleaning criteria during the summer. A total of 600 sows (Line 3, PIC, Hendersonville, TN) were conducted in 2 sequential groups with 300 sows per group. Five 60-stall farrowing rooms (15 stalls per row and 4 rows per room) with tunnel ventilation were used for each group. At approximately d 110 to 112 of gestation, sows were blocked by body condition score (BCS), parity, and offspring sire (Line 2 or Line 3 sires), then randomly allotted to 1 of 3 feeder designs: PVC tube feeder; Rotecna ball feeder (Rotecna, Agramunt, Spain); or SowMax rod feeder (Hog Slat, Newton Grove, NC) with 200 sows per feeder design. The 3 feeder designs were placed in one of 3 sequential stalls with the sequence (Rotecna, SowMax, then PVC tube) continued in each row in all rooms to balance for any environmental effects. After farrowing, sows had ad libitum access to lactation feed. For litter performance data, only piglets from sows bred to Line 2 boars were recorded (441 litters). Line 3 piglets were not included in litter performance data, but sows of these piglets were included in sow BW and feed disappearance data. After weaning, the time for cleaning each feeder design was recorded on a subsample of 67 feeders. There was no evidence of difference (P &amp;gt; 0.05) in sow entry BW, exit BW, BW change, or litter performance among the different feeder designs (Table). However, sows using the SowMax feeders had decreased (P &amp;lt; 0.05) total feed disappearance, average daily feed disappearance, and feed cost per kg of litter weight gain than those fed with the PVC tube feeders, with sows using the Rotecna feeders intermediate. There was a marginal difference (P &amp;lt; 0.10) between feeder designs in cleaning time, with PVC tube feeders requiring less time than the Rotecna feeders; however, cleaning time varied greatly between the personnel doing the cleaning. In conclusion, using a SowMax feeder reduced feed disappearance with no effects on sow and litter performance compared with a PVC tube feeder.

Performance of the long-snouted seahorse, Hippocampus guttulatus, under warming conditions

Temperature is a determinant cue for several behavioral, physiological, and metabolic processes in fish, which occur within a range set to optimize species fitness. Understanding how ocean warming will impact species, at individual and population levels, is, therefore, of utmost relevance for management and conservation purposes. This knowledge assumes particular relevance when it comes to species with unique life history traits that experience multiple threats, such as seahorses. This study aimed to assess the effects of warming on growth, feed intake, and behavioral patterns of the long-snouted seahorse, Hippocampus guttulatus. Fish were collected, before the breeding season, in the Sado estuary, Portugal, and subsequently exposed for an 8-week period to three different temperatures: 17°C, 20°C, and 24°C. Three times a week, behavioral observations were performed. Feed intake was measured every day and individuals were weighed once a week. Results indicate differences in behavioral responses of seahorses exposed to increasingly warming conditions. Under extreme temperature conditions (24°C), fish were more active, and fed more, but this increment of energy through feeding did not translate into increased growth in weight. Altogether, these results indicate that Sado’s population of H. guttulatus may become under thermal stress when exposed, for a long term, to warming conditions that are expected to occur by the end of the century.

Feed intake patterns of modern genetics lactating sows: characterization and effect of the reproductive parameters

BackgroundKnowing the feed intake pattern during lactation of modern genetic sows is crucial because it allows to anticipate possible problems and maximize their performance. On the other side, electronic feeders permit real-time data to be available for a more accurate evaluation of sow eating behavior. This work aimed to characterize the feed intake patterns of lactating highly prolific sows and determine their effect on reproductive performance. A database of 1,058 registers of feed intake collected from a commercial farm was used to identify five consistent sets of clusters (feeding curves) using machine learning. In the second step, the five feeding curves were characterized into five patterns by high, medium and low feed intake during 0–6 d and 7–28 d of lactation: 1-HH, 2-MH, 3-HM, 4-MM and 5-LL.ResultsThe mean daily feed intake of all the sows was 6.2 kg (0.06 SEM) across the 5 patterns. As the pattern numbers increased from 1-HH, 2-MH, 3-HM and 4-MM to 5-LL, their mean daily feed intake decreased from 7.6 to 6.9, 6.4, 5.8 and 4.3 (0.06 SEM) kg, respectively (P < 0.01). Sows with Pattern 1-HH tended to have shorter weaning-to-first service interval (P = 0.06) and had a higher farrowing rate than those with Pattern 5-LL (P < 0.01). Furthermore, contrast analysis showed that sows with Patterns 1-HH and 2-MH tended to have more piglets weaned (P = 0.05) and lower preweaning mortality (P = 0.07) than those with Patterns 3-HM and 4-MM. Also, sows with Patterns 1-HH and 3-HM had fewer stillborn piglets and a lower percentage of stillborn piglets and mummies than those with Patterns 2-MH and 4-MM (P < 0.01).ConclusionsThis study indicates the importance of reaching Pattern 1-HH by rapidly increasing feed intake during early lactation and high feed intake during late lactation, which is associated with high weaning performance and subsequent reproductive performance of the sows. Also, the current study suggests that Pattern 1-HH is linked to good farrowing with a low percentage of stillborn piglets and mummies. Finally, it is critical for producers to timely identify a problem of sows’ eating behavior and to make a prompt decision to intervene.

Importance of circadian rhythms in dairy nutrition

Biological rhythms are repeating patterns that are driven by time-keeping mechanisms within the animal and are adaptive as they coordinate physiology and metabolism with the external environment. The dairy cow has a well recognised natural daily pattern of feed intake and milk synthesis, but regulation of these rhythms has not been well described in the literature or well considered in current dairy management. Recent discoveries have clearly described circadian time-keeping mechanisms in peripheral tissues that are responsive to the timing of food availability. Some management strategies on dairy farms may desynchronise the interactions between central and mammary circadian timekeepers, resulting in reduced milk yield and efficiency. Feeding a total mixed ration is commonly assumed to create constant ruminal conditions, but the large variation in the rate of feed intake across the day causes large fluctuations in rumen fermentation and absorbed nutrients. Milk composition also differs across the day due to both dynamics in nutrient absorption and biological regulation attempting to match milk yield and composition with calf requirements across the day. Recent work has shown that milk synthesis varies over the day and is modified by the timing of feed intake and nutrient absorption. These rhythms have also been shown to be affected by the timing of feed delivery. We expect that maximal milk yield and efficiency are achieved when we have more consistent rumen fermentation and match the timing of nutrient absorption and mammary capacity for milk synthesis. Managing feeding times provides the opportunity to modify feed intake across the day, but behavioural responses are complex. Appreciating the impact of circadian rhythms provides the foundation to develop nutrition and management strategies considering circadian dynamics of intake and milk synthesis and provides opportunities for new gains in cow efficiency, welfare, and health.

Estimation of Number of Pigs Taking in Feed Using Posture Filtration

Pork production is hugely impacted by the health and breeding of pigs. Analyzing the eating pattern of pigs helps in optimizing the supply chain management with a healthy breeding environment. Monitoring the feed intake of pigs in a barn provides information about their eating habits, behavioral patterns, and surrounding environment, which can be used for further analysis to monitor growth in pigs and eventually contribute to the quality and quantity of meat production. In this paper, we present a novel method to estimate the number of pigs taking in feed by considering the pig's posture. In order to solve problems arising from using the pig's posture, we propose an algorithm to match the pig's head and the corresponding pig's body using the major-and-minor axis of the pig detection box. In our experiment, we present the detection performance of the YOLOv5 model according to the anchor box, and then we demonstrate that the proposed method outperforms previous methods. We therefore measure the number of pigs taking in feed over a period of 24 h and the number of times pigs consume feed in a day over a period of 30 days, and observe the pig's feed intake pattern.

An oral gavage of lysine elicited early satiation while gavages of lysine, leucine, or isoleucine prolonged satiety in pigs.

Excess dietary amino acids (AA) may negatively affect feed intake in pigs. Previous results showed that Lys, Leu, Ile, Phe, and Glu significantly increased gut peptide secretion (i.e., cholecystokinin, glucagon-like peptide 1). However, the link between dietary AA and gut peptide secretion with changes in feeding behavior patterns has not been demonstrated to date in pigs. The aim of the present study was to determine the effect of Lys, Leu, Ile, Phe, and Glu, on feed intake and meal patterns in young pigs. Twelve male pigs (Landrace × Large White, body weight = 16.10 ± 2.69 kg) were administered an oral gavage of water (control) or Lys, Leu, Ile, Phe, Glu, or glucose (positive control) at 3 mmol.kg-1 following an overnight fasting. The experiment consisted in measuring individual feed disappearance and changes in meal pattern (including latency to first meal, first meal duration, intermeal interval, second meal duration, and number of meals) based on video footage. Compared to the control group Lys significantly (P ≤ 0.01) reduced feed intake during the first 30 min and up to 2.5 h post-gavage, including a reduction (P ≤ 0.05) in the first meal duration. Similarly, Leu and Ile also significantly decreased feed intake up to 3 h post-gavage on a cumulative count. However, the strongest (P ≤ 0.01) impacts on feed intake by the two branched chained AA were observed after the first- or second-hour post-gavage for Leu or Ile, respectively. In addition, Leu or Ile did not affect the first meal duration (P ≥ 0.05). Leu significantly increased (P ≤ 0.01) the intermeal interval while decreasing (P ≤ 0.05) the number of meals during the initial 2 h following the gavage when compared with the control group. In contrast, the oral gavages of Phe or Glu had no significant impact (P > 0.05) on the feeding behavior parameters measured relative to the control pigs. In turn, glucose had a short-lived effect on appetite by reducing (P < 0.05) feed intake for 30 min after the first-hour post-gavage. In conclusion, the impact of an oral gavage of Lys on feeding behavior is compatible with a stimulation of early satiation and an increased duration of satiety. The main impact of the oral gavages of Leu and Ile was an increase in the duration of satiety. The gastrointestinal mechanisms associated with non-bound dietary AA sensing and the impact on voluntary feed intake warrant further investigations.

Effects of Maternal Protein Supplementation at Mid-Gestation of Cows on Intake, Digestibility, and Feeding Behavior of the Offspring.

Simple SummaryIt is well known that intrauterine growth-restricted offspring present physiologic and metabolic modifications later in life. Therefore, understanding the impact of the maternal nutritional plane on feed intake patterns may lead to new feeding strategies to improve the feed efficiency and performance of beef cattle. In this study, we have evaluated the effect of maternal protein supplementation (PS) during mid-gestation and its interaction with the offspring’s sex on the voluntary feed intake and nutrient use of the progeny. Our results show that PS during mid-gestation increases performance and improves the voluntary feed intake of the offspring. Prenatal PS induced favorable changes in the feeding behavior, in which CON offspring spent more time per day eating supplements and ruminating but spent fewer periods in idleness. Maternal protein restriction demonstrated positive effects on the ability to digest the nutrients of male calves. In summary, our data show that PS alters the gain potential, indirectly demonstrating an increase in their nutritional requirements. In contrast, protein restriction causes a compensatory mechanism on the offspring’s nutrient useability in a sex-dependent manner, increasing the total tract digestibility of nutrients in response to a growth-restriction exposure during intrauterine development.This study aimed to assess the effects of maternal protein supplementation and offspring sex (OS) on the intake parameters of the offspring. Forty-three Tabapuã cows were randomly allocated in the following treatments: protein supplementation (PS) during days 100–200 of gestation (RES, 5.5% total crude protein (CP), n = 2, or CON, 10% total CP, n = 19) and OS (females, n = 20; males, n = 23). The offspring were evaluated during the cow–calf (0–210 days), backgrounding (255–320 days), growing 1 (321–381 days), and growing 2 (382–445 days) phases. The CON offspring tended to present higher dry matter intake (DMI) at weaning (p = 0.06). The CON males presented lower digestibility of major diet components in the growing 2 phase (p ≤ 0.02). The CON offspring spent 52% more time per day eating supplements at 100 days and 17% less time in idleness at 210 days. The CON males spent 15 min more per day ruminating than RES males in the feedlot phase (p = 0.01). We concluded that protein supplementation over gestation alters the offspring feed intake pattern as a whole, while protein restriction promotes compensatory responses on nutrient digestibility in males.

Effect of the timing of sodium acetate infusion on the daily rhythms of milk synthesis and plasma metabolites and hormones in Holstein cows.

Dairy cows have a daily pattern of feed intake which influences ruminal fermentation and nutrient absorption. Milk synthesis also exhibits a daily rhythm and is altered by the timing of feed availability. Nutrients can regulate physiological rhythms, but it is unclear which specific nutrients affect the rhythms of milk synthesis in the cow. The objective of this study was to determine the effect of the timing of acetate infusion on the daily rhythms of feed intake, milk synthesis, milk fatty acids, plasma insulin and metabolites, and core body temperature. Ten lactating ruminally cannulated Holstein cows (127 ± 24.6 d in milk; mean ± standard deviation) were arranged in a 3 × 3 Latin square design. Treatments were ruminal infusions of 600 g/d of acetate either continuously throughout the day (CON) or over 8 h/d during the day (day treatment, DT; 0900 to 1700 h) or the night (night treatment, NT; 2100 to 0500 h). Experimental periods were 14 d with a 7-d washout between periods. Cows were milked every 6 h during the final 7 d of each experimental period to determine the daily pattern of milk synthesis. Blood samples were taken to represent every 4 h across the day and plasma glucose, insulin, β-hydroxybutyrate, urea nitrogen, and acetate concentration were measured. An intravaginal temperature logger was used to measure core body temperature. Data were analyzed with cosinor-based rhythmometry to test the fit of a cosine function with a period of 24 h and to determine the acrophase (time at peak) and amplitude (peak to mean) of each rhythm. Milk yield fit a daily rhythm for all treatments and DT and NT phase-delayed the rhythm and DT increased the robustness of the rhythm. Milk protein concentration fit a daily rhythm for all treatments and DT increased robustness, whereas NT phase-delayed the rhythm. Plasma acetate concentration also fit a daily rhythm in all treatments. Plasma acetate peaked at ∼1600 h in CON and DT and at 0053 h in NT, reflecting the timing of treatment infusions. There was a daily rhythm in plasma β-hydroxybutyrate that reflected the plasma acetate rhythm. Core body temperature fit a rhythm for all treatments, but the amplitude of the rhythm was smaller than previously observed. In conclusion, the timing of acetate infusion influences peripheral rhythms of milk synthesis and plasma metabolites.

O181 Characterization of feed intake patterns of lactating sows

O181 Characterization of feed intake patterns of lactating sows

Social isolation impairs feed intake, growth and behavioural patterns of catfish under culture conditions

Globally, the culture of fishes is important for food production. There is a growing interest in understanding and improving the welfare of cultured fish from both ethical and production perspectives. Social isolation is a common practice in catfish farming. This study assessed how social interactions affect the feeding behaviour, growth performance, and behavioural pattern of Clarias gariepinus under different social conditions. Juveniles of African catfish with a mean weight of 23.6 ± 1.09 g were stocked in 20L-aquaria (1.7 m × 1.2 m × 1.0 m) and fed twice daily in isolated (one fish/tank; N = 6 replicates) and non-isolated (six fish/tank; N = 6 replicates) conditions for a 36-day experimental period. Feed intake and growth response were monitored, while behavioural patterns were observed twice per week using focal sampling techniques for a total of 40 minutes per day. Wilcoxon two-sample tests and GLMs were used to analyse the data. Social context significantly (P < 0.001) affected the feed intake, feeding duration, and other observed behavioural patterns. However, the time of feeding (P > 0.001) did not affect the feed intake or the duration of feeding. Fish cultured in non-isolated conditions consumed more pellets (63 ± 2.36). The duration of feeding was longer in isolated conditions (431 s) while the latency to feed increased significantly (P < 0.001) from the first and fifth day of the experiment for the non-isolated and isolated, respectively. Behaviourally, isolated groups were inactive (Ws = 446.34, z = 5.397; P < 0.01) and displayed fewer aggressive acts (Ws = 0.95, z = 1.19; P < 0.01), while non-isolated groups were more active (Ws = 564.39, z = −5.397; P < 0.01) and displayed more escape attempts (Ws = 11.56, z = −5.47; P < 0.01). Non-isolated groups had higher (Ws = 23.41, z = 1.06; P < 0.01) number of scars and bruises. Furthermore, non-isolated fish had a higher specific growth rate (2.36 ± 0.12), feed conversion ratio (1.27 ± 0.01) and a better condition factor (1.01 ± 0.08). Conclusively, these findings are relevant to African catfish welfare as social isolation changes the behavioural attributes, feeding pattern and growth rate of C. gariepinus. However, social context should be monitored since it resulted in more scars and bruises, which might affect the acceptability and welfare of this aquatic fish species.

102 Reduced Caloric Intake Increases the Incidence Rate of Gastric Ulcers in Growing Pigs

Abstract Our objective was to evaluate effects of a disease feed intake pattern on gastric ulcerations. Eighty mixed sex pigs (27.9 ± 1.45 kg BW) were allotted to individual pens and 2 treatments using a complete randomized design. All pigs were fed a 450 µm ground corn-soybean meal diet. Period 1 (d 0-28), all pigs were fed ad libitum. In period 2 (d 29-42), 40 pigs were fed daily based on their individual body weight (averaging 1.45x maintenance) to mimic a disease feed intake (RF) profile. The remaining pigs stayed on ad libitum feed (Ad). Pigs were weighed at d 0, 28 and 42, and feed disappearance measured to calculate ADG, ADFI and G:F within period. At d 42, all pigs were euthanized, stomach pH recorded, and stomach ulcerations scored (0-3 scale, with 0 being normal). Performance, pH and ulceration frequency data were analyzed with pig as the experimental unit and the fixed effect of feeding level. Performance was not different in period 1 (P &amp;lt; 0.05). Compared with the Ad, RF pigs had lower ADG (1.10 vs 0.24 kg/d, P &amp;lt; 0.0001), ADFI (2.15 vs 0.85 kg/d, P &amp;lt; 0.0001) and G:F (0.51 vs 0.28, P &amp;lt; 0.0001) in period 2. Stomach pH was greater in the RF compared with the Ad pigs (P &amp;lt; 0.001). A greater percentage of Ad pig stomachs scored normal to mild on pars oesophagea ulcerations (85 vs 62%), while a greater percentage of RF pigs had a maximum score compared with the Ad (38 vs 15%, respectively). RF pigs had a higher frequency of severe stomach body ulcerations (score 3) compared with the Ad (20.5 vs 15.0%, respectively). These data suggest that a disease feed intake pattern exacerbates the incidence of gastric ulcerations in grower pigs fed a fine micron ground corn.

Effects of physical activity and feed and water restriction at reimplanting time on feed intake patterns, growth performance, and carcass characteristics of finishing beef steers.

In the feedlot, there can be a decrease in dry matter intake (DMI) associated with reimplanting cattle that negatively affects growth performance. This study was conducted to determine the mechanisms causing a decrease in DMI after reimplanting and identify a strategy to mitigate the decrease. Crossbred steers (n = 200; 10 pens/treatment; initial bodyweight [BW] = 386 ± 4.9 kg) were used in a randomized complete block design experiment. Cattle were implanted with Revalor-IS on day 0. Treatments included a Revalor-200 implant on day 90 before feeding with the following management practices imposed: 1) steers were returned to their home pen immediately after reimplant (PCON); 2) steers were placed in pens and restricted from feed and water for 4 h (RES); 3) steers were walked an additional 805 m after reimplant and then returned home (LOC); 4) steers were restricted from feed and water for 4 h and walked an additional 805 m (RES + LOC); 5) steers were given an oral bolus of Megasphaera elsdenii (Lactipro; MS Biotec, Wamego, KS) and were restricted from feed and water for 4 h, and then walked an additional 805 m (LACT). One hundred steers were given an ear tag to record minutes of activity (ESense Flex Tags, Allflex Livestock Intelligence, Madison, WI). As a percentage of BW, DMI was 5% greater (P = 0.01) from reimplant to end for PCON vs. RES, LOC, and RES + LOC treatments. Likewise, as a percentage of BW, DMI was 6.6% greater (P = 0.03) from reimplant to end and 4.0% greater (P = 0.05) overall for the PCON treatment vs. the LOC treatment. Overall, DMI as a percentage of BW was 3.3% greater (P = 0.02) for PCON vs. RES, LOC, and RES + LOC treatments. There was an increase in G:F from reimplant to end (P = 0.05) for RES + LOC vs. the LACT treatment. From these data, we conclude that restricting cattle from feed and water for 4 h after reimplanting did not alter subsequent DMI. Increasing locomotion had the greatest negative effect on DMI and growth performance. Management strategies to decrease locomotion associated with reimplanting would be beneficial to DMI and overall growth performance of finishing beef steers.

PSIV-B-27 Effect of feed flavour on the feeding behaviour and kinetics of daily feed intake of lactating high-prolific sows during summer

Abstract Increasing voluntary feed intake of the sow is a major challenge for nutritionists in tropical climate conditions. The present study aimed to evaluate the impact of the dietary supplementation of a feed flavour for sows during lactation on their feeding behavior and kinetics of daily feed intake under tropical conditions. A total of 60 high-prolific mixed parity sows divided into 10 batches of 6 sows each were used, distributed in a completely randomized experimental design among 2 dietary treatments (0 or 500 g/ton of Krave®, Adisseo). The average meal size was 107 g/meal lower in sows fed the control diet when compared with flavour fed sows. Daily feed intake was greater in the flavored diet than in the control (6,417 vs. 5,362 g/d; P &amp;lt; 0.05). The flavor improved ingestion time (58.4 vs. 46.6 min/ d, respectively flavour and control; P &amp;lt; 0.05). Sows receiving flavor showed a higher nocturnal (704 vs. 583 g/meal) and diurnal (678 vs. 582 g/meal) feed intake. Sows also showed a higher voluntary intake between 00:00 and 10:00 am, which was equivalent to 83% of the total daily feed intake. From a comparison of hourly feed intakes or variations from hour to hour (during 24 h), the nycthemeral pattern of feed intake peaked twice daily for both dietary treatments. However, the size of the peak was greater (P &amp;lt; 0.05) for flavour fed sows when compared with the control at 0400 and 1900 h (Figure 1a). Diets also influenced on kinetics of daily feed intake during the lactation period.Feed intake was higher for the flavour fed sows from d 3 to 8 and from d 10 to 24 (Figure 1b; P &amp;lt; 0.05).In conclusion, the strategic use of a feed flavour to manipulate the sensorial properties of feed is a viable strategy to increase the sows’ voluntary feed intake.

PSVI-6 Effect of season on the feeding behaviour and kinetics of daily feed intake of high-prolific sows during lactation

Abstract Heat stress can cause changes in the feeding behaviour of lactating sows. The present study aimed to evaluate the impacts of season on the feeding behavior and kinetics of daily feed intake of modern high prolific sows under tropical conditions. A total of 80 high-prolific mixed parity sows divided into 10 batches of 8 sows each were used. Individual feeding behaviour was recorded during the ad libitum period (between d 1 and 23 of lactation), using an Automated Intelligent Feeder (AIF; Gestal Solo, Jyga Technology, Canada). Daily feed intake during lactation was affected by season (P &amp;lt; 0.001), and the feed intake was less during the hot season (5.66 vs. 7.23 g/d; Figure 1a). The daily ingestion time was less in the hot season (36.8 vs. 72.3 min/ d; P&amp;lt; 0.01) and the ingestion time per meal was also lower in the hot compared to the cool season (5.7 vs. 7.5 min/ meal; P &amp;lt; 0.05). The hot season showed a lower (P &amp;lt; 0.01) rate of daily intake when compared to the cool season (36.8 vs. 72.3 g/ min). Sows showed a higher diurnal feed intake (3,546 vs. 2,901 g/ d), whereas meal frequency was not affected (4.2 meals/ d, on average). Irrespective of the season, the nycthemeral pattern of feed intake peaked twice daily: between 0200 and 0900 h and between 1600 and 2000 h (Figure 1b).The present study confirms that lactating sows do not change much their feeding pattern according to season, meaning that they tend to keep the same feeding behaviour during both seasons, with a more pronounced intake between 0200 and 0900 am, approximately 80% of their total daily intake. Sows may not change feeding pattern according to season, but reduce significantly voluntary feed intake under hot climate conditions in order to reduce the thermal effect of feed.

Rearing Environment and Longitudinal Brain Development in the Pig

ObjectivesArtificial rearing of pigs provides a number of advantages over conventional rearing (i.e., true maternal care), including careful control of nutrient intake and environment conditions. Yet there remains a gap in knowledge when comparing brain development between sow-reared and artificially-reared domestic pigs. Thus, our research sought to model brain development and assess recognition memory in a longitudinal manner by directly comparing rearing environments. MethodsForty-four intact (i.e., not castrated) male pigs were artificially-reared or sow-reared from postnatal day 2 until postnatal week 4. After postnatal week 4, all pigs were housed in a group setting within the same environment until postnatal week 24. Magnetic resonance imaging was conducted on pigs at 8 longitudinal time-points to model developmental trajectories of brain macrostrutural and microstructural outcomes. Additionally, pigs behavior were tested using the novel object recognition task at postnatal weeks 4 and 8. ResultsThroughout the 24-week study, no differences between rearing groups were noted in weekly body weights, average growth and feed intake patterns, or feed efficiency. Whole brain, grey matter, white matter, and cerebrospinal fluid growth patterns also did not differ between pigs assigned to different early-life rearing environments. Moreover, minimal differences in regional absolute volumes and fractional anisotropy developmental trajectories were identified, though artificially-reared pigs exhibited higher initial rates of myelination in multiple brain regions compared with sow-reared pigs. Furthermore, behavioral assessment at both PNW 4 and 8 suggested little influence of rearing environment on recognition memory, however, an age-dependent increase in object recognition memory was observed in the sow-reared group. ConclusionsOur findings suggest that early-life rearing environment has little influence on brain growth trajectories and behavior in the domestic pig. Artificial rearing may promote maturation in certain brain areas but does not appear to elicit long-term effects in outcomes including brain structure or behavior. Funding SourcesThe study was funded by Société des Produits Nestlé SA.