Feed Intake Pattern Research Articles

Influence of Rearing Environment on Longitudinal Brain Development, Object Recognition Memory, and Exploratory Behaviors in the Domestic Pig (Sus scrofa).

IntroductionOver the last 40 years, the domestic pig has emerged as a prominent preclinical model as this species shares similarities with humans with regard to immunity, gastrointestinal physiology, and neurodevelopment. Artificial 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 macrostructural 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, gray 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.ConclusionOur findings suggest that early-life rearing environment influences the rate of development in some brain regions but has little influence on overall brain growth and object recognition memory and exploratory behaviors 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 object recognition memory.

PSI-9 Factors associated with birthing interval and total farrowing duration in sows and gilts within a production setting

Abstract Common sow barn protocol is to provide farrowing assistance (i.e. sleeving) when 20 min has elapsed since the previous piglet to reduce the incidence of stillbirths with limited consideration for parity, litter size or sow energy status. The objective of this study was to evaluate the impact of litter size, birth order, parity, and feed intake before farrowing on total farrowing duration and birthing interval. Farrowing duration and piglet birth interval were measured in 80 farrowings (PIC 1050 gilts and multiparous). Farrowing was supervised by trained technicians 24 h/d starting at d114 of gestation. The time of each piglet birth was documented, and the total farrowing duration was determined as the time elapsed between the birth of the first and last piglet. Sleeving protocol used when 60 min had elapsed since the previous piglet, oxytocin provided when farrowing was deemed complete to aid in milk let down. Information from the electronic lactation feeding system was used to characterize the feed intake pattern of sows before farrowing. Data was analyzed by PROC MIXED procedure (SAS Inst., Inc., Cary, NC). The overall rate of stillbirths was 8.3%. Sows with litters >14 piglets had shorter birthing interval than sows with litters < 14 piglets (P < .0001) resulting in 9 min shorter total farrowing with larger litter sizes (Table 1). Order of birth affected birth interval (P = 0.014), where piglets of order 1 to 4 had the longest birth interval and orders 9 to 12 shortest. Sow feed intake prior to farrowing and parity did not affect total farrowing duration or birthing interval; however, farrowing duration of mid parity sows was 30 to 50 min shorter than young and older females. Sow barn farrowing care protocols may need to be revised considering sow parity and number of piglets born.

Genetic analysis of disease resilience in wean-to-finish pigs from a natural disease challenge model.

The objective was to estimate the genetic parameters of performance and resilience of growing pigs under disease. Data were from 3,139 Yorkshire × Landrace wean-to-finish pigs that were exposed to a natural polymicrobial disease challenge that was established by entering naturally infected animals into a nursery barn, targeting various viral and bacterial diseases. The challenge was maintained by entering batches of 60 or 75 healthy nursery pigs every 3 wk in a continuous flow system. Traits analyzed included average daily gain (ADG), feed intake (ADFI) and duration (ADFD); feed conversion ratio (FCR); residual feed intake (RFI); mortality (MOR); number of health treatments (TRT); health scores (HScore); carcass weight (CWT), back fat (CBF) and loin depth (CLD); dressing percentage (DRS); lean yield (LYLD); day-to-day variation in feed intake and duration (VARFI and VARDUR); and the proportion of off-feed days (OFFFI and OFFDUR). Analyses were performed by mixed linear models with genomic relationships. The resilience traits, such as TRT, MOR, and HScore, were lowly heritable (up to 0.15) but had high genetic correlations with each other. Performance traits, such as ADG, ADFI, ADFD, FCR, RFI, and carcass traits, were moderate to highly heritable (0.17 to 0.49). Heritabilities of resilience indicator traits such as OFF and VAR had low to moderate heritabilities (0.08 to 0.23) but were higher when based on duration vs. amount. ADFI had a low genetic correlation with ADFD (0.13). ADG in the challenge nursery had stronger negative genetic correlations with both TRT and MOR than ADG in the finisher (-0.37 to -0.74 vs. -0.15 to -0.56). ADFI and FCR had moderate negative (-0.21 to -0.39) and positive (0.34 to 0.49) genetic correlations, respectively, with TRT and MOR. ADFD and RFI had very low genetic correlations with TRT and MOR. CWT and DRS were moderately negatively correlated with TRT and MOR (-0.33 to -0.59). Resilience indicator traits based on feed intake or duration had moderate to high positive genetic correlations with TRT (0.18 to 0.81) and MOR (0.33 to 0.87). In conclusion, performance and resilience traits under a polymicrobial disease challenge are heritable and can be changed by selection. Phenotypes extracted from feed intake patterns can be used as genetic indicator traits for disease resilience. Most promising is day-to-day variation in intake duration, which had a sizeable heritability (0.23) and favorable genetic correlations with MOR (0.79) and treatment rate (0.20).

Time-based feed restriction and group composition in growing rabbits: Effects on feed intake pattern, growth performance, carcass traits and meat quality

This study aimed to evaluate the effects of the feeding system (AL: ad libitum, R: feed restriction) and group composition (X: only females, Y: only males, XY: mixed sex) on the feed intake pattern, growth, and slaughter results in growing rabbits. A total of 288 crossbred rabbits were housed in 18 pens (16 animals per pen) from weaning to slaughter (33 to 75 d of age). At the beginning of the trial, R rabbits had access to the feeders for 10 h/d, afterwards, feeding time increased by 1 h every 3-4 d in the first three weeks until 16 h/d was reached, and by 1 h per day until 24-h access to feeders was reached in the 4th week; thereafter, all animals were fed ad libitum. On average, the feed intake pattern of AL rabbits was characterized by small and frequent meals throughout the day, with minimum intakes (about 2-3 g/h) occurring in the morning and maximum intakes (7-10 g/h) in the evening. During the restriction period, R rabbits showed a lower daily feed intake (-6 g/d; P < 0.01), better feed conversion (2.29 vs. 2.42; P < 0.001), and a higher hourly feed intake compared to the AL rabbits, reaching peaks of 18, 15, and 14 g/h when the feeding time was 11, 13, and 16 h/d, respectively (P < 0.001). In the second period, once the rabbits were fed freely, R rabbits achieved the same intake as AL rabbits but with a higher feed conversion (4.10 vs. 3.89; P < 0.001). In this study, the feeding system did not affect growth performance, health (mortality 1.4% on average), carcass traits, and meat quality. In terms of group composition, the daily growth and feed conversion were worse in the Y groups than in the X and XY groups in the second period (P ≤ 0.01), with no other differences observed throughout the whole trial. Dressing out percentage was significantly different among the three groups (61.8%, 61.0% and 60.2% in group Y, group XY and group X, respectively; P < 0.001). In conclusion, time-based feed restriction during the first three weeks (based on an access to the feeders increasing from 10 h/d at the beginning until 16 h/d) reduced the feed intake to 95% of ad libitum, without compromising growth performance and slaughter results, but modified the rabbit feed intake pattern during the restriction phase. In terms of gender composition, the separate housing of male and female rabbits was not justified by our results.

The effects of feeding a high-fiber or high-starch pellet at two daily allocations on feed intake patterns, rumen fermentation, and milk production of mid-lactation dairy cows

The objective of this experiment was to determine the effect of pellet type and feeding amount on feeding behavior, dry matter intake, rumen fermentation, and milk production of lactating dairy cows. An experimental diet was formulated to provide an adequate amount of nutrients to a 650-kg cow producing 40 kg of milk per day, with a portion of the diet removed as a high-fiber (33.2% neutral detergent fiber; F) or high-starch (56.8% starch; S) pellet. Pellets were fed at a low (1 kg; L) or high (3 kg; H) amount twice per day alongside a partial mixed ration (PMR). Four complementary PMR were formulated for each pellet treatment such that the overall diet (pellet + PMR) offered to the cows was the same among all treatments. Eight ruminally cannulated cows were used in a 4 × 4 Latin square design with 14-d periods. Cows were fed PMR once daily at 1200 h, and pellet twice daily at 0600 and 1800 h. Data and samples were collected on d 11 to 14 of each period. By design there was a difference in pellet intake between the H and L treatments (5.31 vs. 1.81 kg/d), and PMR intake was reduced when H pellet was fed (22.9 vs. 25.3 kg/d); however, feeding H tended to increase total dry matter intake. Feed disappearance, which was measured as the amount of PMR consumed every 3 h following PMR delivery, was affected by the nutrient composition of the PMR as cows fed S (with high-fiber PMR) consumed 28.6% of their PMR intake within 3 h of delivery, whereas cows fed F (with high-starch PMR) consumed 33.5%. Duration that pH was below 5.8 tended to be lower when cows were fed the S pellet (270 vs. 125 min/d) compared with F. In addition, feeding the S pellet (with high-fiber PMR) decreased plasma concentrations of glucose (66.0 vs. 70.0 mg/dL) and insulin (1.90 vs. 2.25 ng/mL) compared with F. These results suggest that the composition of the PMR dictates rumen fermentation to a greater extent than composition of pellets. The S pellet was fed alongside a high-fiber PMR, which was more filling in the rumen, less fermentable, and contained more neutral detergent fiber. Although no difference was observed in milk production among treatments, the fact that feed intake pattern and rumen fermentation are better explained by nutrient composition of the PMR should be considered when formulating diets for lactating cows fed pellet and PMR, such as those milked with automated milking systems.

Repeatability of traits for characterizing feed intake patterns in dairy goats: a basis for phenotyping in the precision farming context

In ruminants, feeding behaviour variables are parameters involved in feed efficiency that show variation among individuals. This study aimed to evaluate during the first two production cycles in ruminants the repeatability of feed intake pattern, which is an important aspect of feeding behaviour. Thirty-five dairy goats from Alpine or Saanen breeds were housed in individual pens at four periods (end of first gestation, middle of first and second lactations and middle of second gestation which is also the end of first lactation) and fed a total mixed ration (TMR) ad libitum. Individual cumulative dry matter intake (DMI) was automatically measured every 2 min during the last 4 days of each period. Feed intake pattern was characterized by several measures related to the quantity of feed eaten or to the rate of intake during the 15 h following the afternoon feed delivery. Two main methods were used: modelling cumulative DMI evolution by an exponential model or by a segmentation-clustering method. The goat ability to sort against dietary fibre was also evaluated. There was a very good repeatability of the aggregate measures between days within a period for a given goat estimated by the day effect within breed and goat, tested on the residual variance (P > 0.95). The correlations between periods were the highest between the second and either the third or fourth periods. With increasing age, goats sorted more against the fibrous part of the TMR and increased their initial rate of intake. Alpine goats ate more slowly than Saanen goats but ate during a longer duration. Principal component analysis (PCA) was performed on all the aggregate measures of feed intake patterns. The factor score plots generated by the PCA highlighted the opposition between the different measures of feed intake patterns and the sorting behaviour. The projection of the animals on the scoring plots showed a breed effect and that there was a continuum for the feed intake pattern of goats. In conclusion, this study showed that the feed intake pattern was highly repeatable for an animal in a given period and between periods. This means that phenotyping goats in a younger age might be of interest, either to select them on feeding behaviour and choose preferentially the slow eaters or to adapt the quantity offered and restrict feed delivery to the fast eaters in order to increase feed efficiency and welfare by limiting the occurrence of acidosis, for example.

Effects of an artificial hay aroma and compound feed formulation on feed intake pattern, rumen function and milk production in lactating dairy cows

The Kempen system is a dairy feeding system in which diet is provided in the form of a compound feed (CF) and hay offered ad libitum. Ad libitum access to CF and hay allows cows in this system to achieve a high DM intake (DMI). Out of physiological concerns, the voluntary hay intake could be increased and the consumption pattern of CF could be manipulated to maintain proper rumen functioning and health. This study investigated the effects of an artificial hay aroma and CF formulation on feed intake pattern, rumen function and milk production in mid- to late-lactating dairy cows. Twenty Holstein–Friesian cows were assigned to four treatments in a 4 × 4 Latin square design. Diet consisted of CF and grass hay (GH), fed separately, and both offered ad libitum, although CF supply was restricted in maximum meal size and speed of supply by an electronic system. Treatments were the combination of two CF formulations – high in starch (CHS) and fibre (CHF); and two GH – untreated (UGH) and the same hay treated with an artificial aroma (TGH). Meal criteria were determined using three-population Gaussian–Gaussian–Weibull density functions. No GH × CF interaction effects on feed intake pattern characteristics were found. Total DMI and CF intake, but not GH intake, were greater (P < 0.01) in TGH treatment, and feed intake was not affected by type of CF. Total visits to feeders per day, visits to the GH feeder, visits to the CF feeder and CF eating time (all P < 0.01) were significantly greater in cows fed with TGH. Meal frequency, meal size and meal duration were unaffected by treatments. Cows fed CHF had a greater milk fat (P = 0.02), milk urea content (P < 0.01) and a greater milk fat yield (P < 0.01). Cows fed TGH had a greater milk lactose content and lactose yield (P < 0.05), and milk urea content (P < 0.01). Cows fed TGH had smaller molar proportions of acetic acid and greater molar proportions of propionic acid compared with UGH. In conclusion, treatment of GH with an artificial aroma increased CF intake and total DMI, but did not affect hay intake. Additionally, GH treatment increased the frequency of visits to both feeders, and affected rumen volatile fatty acid profile. Type of CF did not affect meal patterns, ruminal pH, nor fermentation profiles.

Feed intake patterns nor growth rates of pigs are affected by dietary resistant starch, despite marked differences in digestion

Current feed evaluation systems often assume that fermented starch (i.e. resistant starch (RS)) yields less energy than digested starch. However, growth rates of pigs fed low and high RS diets are often the same when feed is available ad libitum. This may be explained by its effect on digestive processes changing feeding behavior, and consequently energy utilization. This study aims to investigate the effect of RS on nutrient digestion and digesta passage rate in pigs, in combination with its effect on feeding behavior and growth performance under ad libitum conditions. In experiment 1, 20 male pigs (40 ± 2.82 kg) were fed diets containing either 50% waxy maize starch (low in RS (LRS)) or high-amylose maize starch (high in RS (HRS)), and soluble and insoluble indigestible markers. After 14 days of adaptation to the diets, pigs were fed hourly to reach steady state (6 h), dissected, and digesta were collected from eight segments. From the collected samples, nutrient digestion and passage rate of the solid and liquid digesta fraction were determined. In experiment 2, 288 pigs (80 ± 0.48 kg; sex ratio per pen 1 : 1; boar : gilt) were housed in groups of 6. Pigs were ad libitum-fed one of the experimental diets, and slaughtered at approximately 115 kg. Feed intake, growth and carcass parameters were measured. Ileal starch digestibility was greater for LRS-fed than for HRS-fed pigs (98.0% v. 74.0%; P < 0.001), where the additional undigested starch in HRS-fed pigs was fermented in the large intestine. No effects of RS on digesta passage rate of the solid or liquid digesta fraction and on feeding behavior were observed. Growth rate and feed intake did not differ between diets, whereas feed efficiency of HRS-fed pigs was 1%-unit higher than that of LRS-fed pigs (P = 0.041). The efficiency of feed used for carcass gain did not differ between diets indicating that the difference in feed efficiency was determined by the non-carcass fraction. Despite a 30% greater RS intake (of total starch) with HRS than with LRS, carcass gain and feed efficiency used for carcass gain were unaffected. RS did not affect digesta passage rate nor feeding behavior suggesting that the difference in energy intake between fermented and digested starch is compensated for post-absorptively. Our results indicate that the net energy value of fermented starch currently used in pig feed evaluation systems is underestimated and should be reconsidered.

Effect of Energy Levels in the Diet of Large White Yorkshire Pigs on Growth and Feed Intake Pattern

Effect of Energy Levels in the Diet of Large White Yorkshire Pigs on Growth and Feed Intake Pattern

Growth Performance Indices of New Zealand White Rabbits Administered Panax ginseng Extracts

Treatment with Panax ginseng has been reported to elicit various biological effects in both animal and human models. Among the reported effects on animal are protein synthesis and growth promoting ability. For a better understanding, the current experiment was conducted to evaluate the effect of oral administration of P. ginseng extracts (PGEs) on growth performance parameters of growing New Zealand White (NZW) rabbits. A total of 48 NZW male and female rabbits, with the average age of two months were used for the experiment, conducted in a Randomized Complete Block Design (RCBD). The rabbits were organized into 3 groups of 16 rabbits each (8 males and 8 females), on weight equalization basis and randomly assigned to 3 treatments: T1, T2 and T3, containing PGEs at 0.0, 200.0 and 400.0 mg/ml, respectively. Final body weight and total body weight gain of the male rabbits on T2 and T3 were significantly (p &lt; 0.05) higher than those of male rabbits on T1, while feed conversion ratio for the male rabbits recorded a higher (p &lt; 0.05) value in T1 than in T2 and T3, which were similar (p &lt; 0.05). Trunk length and breast girth of the male rabbits were significantly (p &lt; 0.05) higher in T3 than in T1 and T2. Feed intake pattern was similar among the male rabbits, but different between males and females. Significant (p &lt; 0.05) differences were not observed in all parameters measured among female rabbits, but all experimental rabbits followed the same pattern of body weight gain. Oral administration of Panax ginseng extracts at 200 and 400 mg/ml levels enhanced feed conversion ratio in male NZW rabbits, thereby increasing body weight gain, trunk length and breast girth, while feed intake patterns slightly differed between the male and female growing rabbits.

172 Effects of net energy levels on feed intake pattern and growth performance of growing-finishing gilts monitored using a computerized feed intake recording system

Abstract This study evaluated the effects of dietary net energy concentrations on feeding behavior and growth performance of growing-finishing pigs monitored using a feed intake recording equipment (FIRE). Two hundred and sixteen (48.8 ± 5.6 kg) gilts were blocked by bodyweight and assigned randomly to 1 of 3 dietary treatments, which included low (2,350 kcal/kg), medium (2,450 kcal/kg), and high (2,550 kcal/kg) dietary NE levels. Pigs were housed in 18 pens for 68 d in four phases with 12 pigs and one FIRE station per pen. Bodyweight, feed consumption, and the amount of time and visit at the station of individual pigs were monitored every day by using FIRE. Pigs fed low NE diet spent more time (min) at the station during the first two weeks and visited the station more times with fewer amounts of time (min) per visit after two weeks compared with pigs fed medium and high levels of NE diets (P &amp;lt; 0.05). The speed (g/min) and amount (g/visit) of feed intake were lower (P &amp;lt; 0.05) during phase 3 and the overall period in low NE diet compared with pigs fed medium NE diet. Pigs fed medium NE diet tended to have a greater (P = 0.066) average daily feed intake at phase 4 than pigs fed low NE diet. Increasing NE levels linearly improved (P &amp;lt; 0.05) average daily gain, feed conversion ratio, and final BW during phase 3 and the overall period. However, the overall energy efficiency (Mcal NE/ kg gain) was linearly decreased with increasing NE levels. In conclusion, decreasing dietary NE to 2350 Mcal/kg resulted in more visits to feeders with slow ingestion speed compared with pigs fed diets with 2450 or 2550 Mcal/kg NE. Increasing dietary NE levels linearly improved daily gain and feed conversion ratio, but linearly decreased energy efficiency.

The intake pattern and feed preference of layer hens selected for high or low feed conversion ratio.

Feed accounts for the greatest proportion of egg production costs and there is substantial variation in feed to egg conversion ratio (FCR) efficiency between individual hens. Despite this understanding, there is a paucity of information regarding layer hen feeding behaviour, diet selection and its impact on feed efficiency. It was hypothesised that variation in feed to egg conversion efficiency between hens may be influenced by feeding behaviour. For this experiment, two 35-bird groups of ISA Brown layers were selected from 450 individually caged hens at 25–30 weeks of age for either low FCR < 1.8 ± 0.02 (high feed efficiency (HFE) or high FCR > 2.1 ± 0.02 (low feed efficiency (LFE)). For each of these 70 hens, intake of an ad-libitum mash diet at 2-minute time intervals, 24 h a day, for 7 days was determined alongside behavioural assessment and estimation of the selection of components of the mash. The group selected for HFE had a lower feed intake, similar egg mass and associated lower FCR when compared with the LFE group. Whilst feed intake patterns were similar between HFE and LFE hens, there was a distinct intake pattern for all layer hens with intake rate increasing from 0300 to 1700 h with a sharp decline to 2200 h. High feed efficiency hens selected a diet with 25% more ash and 4% less gross energy than LFE hens. The LFE hens also spent more time eating with more walking events, but less time spent resting, drinking, preening and cage pecking events as compared with HFE hens. In summary, there was no contrasting diurnal pattern of feed consumption behaviour between the groups ranked on feed efficiency, however high feed efficiency hens consumed less feed and selected a diet with greater ash content and lower gross energy as compared with LFE hens. Our work is now focused on individual hen diet selection from mash diets with an aim of formulating precision, targeted diets for greater feed efficiency.

Chewing patterns in horses during the intake of variable quantities of two pelleted compound feeds differing in their physical characteristics only

Pelleted feeds (PF) are popular in horse nutrition because of high palatability and improved feeding hygiene, but ingestion is faster for PF than for cereals or muesli feed. The aim of the study was to evaluate whether variable amounts of two PFs produced with different physical properties from the same batch of feed can affect feed intake patterns in horses. Chewing patterns were measured in six warmblood mares (519 ± 36.3 kg) on two PFs (small-sized PF1: ø 5 mm, length 21.9 ± 4.97 mm, large-sized PF2: edge length 15.6 ± 0.14 × 15.6 ± 0.08 mm, length 54.4 ± 9.59 mm) in three different amounts (1.0, 1.5, 2.0 kg) once per day additional to hay. PF 2 was ingested faster than PF1 for the meal size 1.0 kg, but PF 1 was ingested more rapidly with a reduced chewing intensity if the offered meal size increased. The ingestion of PF 2 tendentially elevated the chewing intensity at higher meal sizes. An additional, but inverted meal size effect compared to 1.0 kg, was observed for 1.5 kg, where PF 1 was ingested at a higher speed combined with a lower chewing intensity compared to PF 2. Independent from the offered amount, PF 2 induced a markedly increased saliva production combined with a higher daily water intake. Larger-sized pellets seem to intensify the chewing process and decelerate the ingestion time if the meal size becomes larger.

SUBSTITUTING SORGHUM GRAIN WITH CRUDE GLYCEROL IN DIETS FOR BEEF CATTLE

The expansion of the biodiesel industry has created opportunities for crude glycerol use in beef cattle diets. The objective of this study was to determine the effects of substituting sorghum grain with crude glycerol on dry matter intake (DMI), growth performance and feed intake pattern of 28 non-castrated Nelore males with initial body weight (BW) of 441 kg and 21.5 months of age housed in individual or collective pens. Crude glycerol was included at 15% of the ration dry matter as a replacement for sorghum grain. Orts were collected and weighed daily, and DMI was calculated by difference between feed offered and feed refused. Feed intake pattern was determined every two weeks after the beginning of the study in three intervals relative to feed delivery (0-4, 4-10, and 10-24 hours post-feeding). Animals’ BW was obtained on days 1, 14, 28, 42, 56, 70, and 84 days of the trial after a 12-hour solid fasting. Crude glycerol did not alter (P>0.05) DMI, growth performance, hot carcass weight and dressing percentage compared with the control diet. A treatment × days of experiment response (P<0.05) occurred due to a decreased DMI in animals fed crude glycerol during the first 14 days of the trial. Crude glycerol-fed animals decreased (P<0.05) the NDF intake pattern in individual and collective pens. Crude glycerol can be used as a substitute for sorghum grain in beef cattle diets.

Substituição do sorgo grão por glicerol não refinado em dietas para bovinos de corte

A expansão na indústria de biodiesel tem criado oportunidades para o uso do glicerol não refinado em rações de bovinos de corte. Objetivou-se neste estudo determinar os efeitos da substituição do sorgo grão pelo glicerol não refinado sobre o consumo de matéria seca (CMS), ganho de peso e padrão de alimentação de 28 machos Nelore não castrados com peso corporal (PC) inicial de 441 ± 40,2 kg e 21,5 ± 0,5 meses de idade alojados em baias individuais ou coletivas. O experimento teve duração de 98 dias (29 de junho a 5 de outubro de 2015) com período de adaptação de 14 dias e 84 dias para coleta dos dados. Incluiu-se o glicerol não refinado em 15% da matéria seca (MS) da ração como substituto do sorgo grão. As sobras foram coletadas e pesadas diariamente e o CMS foi calculado pela diferença entre o oferecido e sobras. Determinou-se o padrão de alimentação a cada 2 semanas após o início do estudo em 3 intervalos relativos ao início da alimentação (0-4, 4-10 e 10-24 horas pós-alimentação). Obteve-se o PC dos animais nos dias 1, 13, 27, 41, 55, 69 e 83 dias da pesquisa após jejum de sólidos de 12 horas. O glicerol não refinado não alterou (P&gt;0,05) o CMS, ganho de peso, peso da carcaça quente e rendimento de carcaça comparado à dieta controle. Houve resposta (P

Grain source and chromium supplementation: effects on feed intake, meal and rumination patterns, and growth performance in Holstein dairy calves

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

Feed intake pattern of broiler chickens under intermittent lighting: Do birds eat in the dark?

This paper reflects the results of a short experiment conducted in parallel with a larger trial which aimed to test the assumption that ‘consumption of feed by broiler chickens during periods of darkness is largely negligible’. To that effect, on d 31, feeders of birds raised under intermittent lighting (IL), i.e. 1 h of light [1L]:3 h of dark (3D):1L:3D:1L:3D:1L:3D:2L:6D, were weighed at the onset and at the end of each period of darkness (or scotoperiod). Moreover, in order to compare the feeding behavior of IL birds with that of broilers raised under continuous lighting (CL, i.e. 18L:6D), their feeders were weighed in parallel and at the same time points. On d 31, feed intake of IL birds during scotoperiods represented 45% of their 24 h feed intake. Both CL and IL birds presented anticipatory feed intake prior to the long nocturnal period of darkness (6D), as well as higher feed intake right at the onset of lighting at 06:00. Feed intake of CL birds during the 6D nocturnal scotoperiod was negligible at around 2% of their total feed intake. Intermittent lighting birds exhibited excitement at the start of each hour-length scotoperiod and, within that time, ingested around 2.5 times the amount of feed ingested by CL birds. Although short, this study revealed several interesting observations which might be worth further exploring in a larger, lengthier, behavior-focused experiment. Amongst other factors, it might be interesting to understand whether the high feed intake observed during scotoperiods for IL birds in reflective of the whole flock or rather a coping mechanism developed mainly by hierarchically lower-ranking birds to achieve their daily feed intakes requirements.

The effects of source and concentration of dietary fiber, starch, and fatty acids on the daily patterns of feed intake, rumination, and rumen pH in dairy cows

The daily patterns of feed intake and rumination influence rumen fermentation, rumen pH, and timing of absorbed nutrients in the dairy cow, but the effects of diet composition on these patterns are not well characterized. Data from 3 previously published experiments were examined to determine the influence of dietary starch, fiber, and fatty acids (FA) on daily patterns of intake, rumination, and rumen pH. Dietary neutral detergent fiber (NDF) and starch were investigated in 2 experiments, each with duplicated 4 × 4 Latin square designs with a 2 × 2 factorial arrangement of treatments in cows fed cows 1×/d at 1200 and 1400 h, respectively. To investigate fiber content and digestibility in the first experiment, brown midrib or isogenic conventional corn silage were fed in low- and high-NDF diets (29 and 38%, respectively). To investigate starch source and concentration in the second experiment, ground high-moisture corn or dry ground corn were fed in low- and high-starch diets (21 and 32%, respectively). Effect of fat concentration and saturation was investigated in the third experiment using a replicated 4 × 4 Latin square design that fed cows 1×/d at 0900 h; treatments included a control diet with no added fat and 2.5% added saturated FA, unsaturated FA, or a mixture of the saturated and unsaturated FA. In the first 2 experiments, intake followed a similar daily pattern regardless of starch and NDF concentration or digestibility. Rumination displayed a treatment by time interaction for both NDF and starch concentration, with high-fiber, low-starch diets causing greater rumination overnight but not midday. High-starch diets decreased total daily rumen pH equally across the day, but did not change the daily pattern. Type of corn silage did not affect the daily patterns of rumination or rumen pH, but pH was reduced throughout the day in brown midrib diets. In the third experiment, no interactions between fatty acid supplement and time of day were observed for intake, rumination, or rumen pH. Within all experiments, rumination fit or tended to fit a 24-h rhythm regardless of diet, with the amplitude of the rumination being reduced in low-starch diets and diets containing saturated FA or a mixture of saturated and unsaturated FA. Overall, intake, rumination, and rumen pH follow a daily pattern that was minimally modified by dietary fiber and starch type and level or fat level and fatty acid profile.

Effects of chromium supplementation on weight gain, feeding behaviour, health and metabolic criteria of environmentally heat-loaded Holstein dairy calves from birth to weaning

ABSTRACTThe objectives of this study were to investigate the effects of chromium (Cr) supplementation on feed intake and meal pattern, weight gain and skeletal growth, and health and metabolic criteria of environmentally heat-loaded dairy calves during the pre-weaning period. Forty-eight newborn female calves were allotted randomly to a control group (no Cr supplement; Cr−) or a Cr group (Cr+) receiving 0.05 mg Cr (as Cr-methionine)/kg BW0.75. Cr was provided in the liquid feed (colostrum and milk) during the pre-weaning period. The average maximum temperature–humidity index was 83.7 U, indicating severe environmental heat load. Despite reduced meal frequency and increased in inter-meal interval, Cr supplementation tended to increase starter feed intake and total dry matter intake as a result of increased meal size and duration. Respiration rate was lower in Cr+ calves. Calf growth, rectal temperature, faecal score and incidence of diarrhoea or pneumonia were not affected by Cr supplementation, but number of days with diarrhoea and treatment duration decreased during the pre-weaning period. Cr supplementation tended to increase resting time and decreased time devoted to non-nutritive oral behaviours. At weaning, serum concentration of glucose was lower but total protein and globulin concentrations were higher in Cr+ calves. In Cr+ calves, the activity of glutathione peroxidase was higher and lower on d 49 and 63 of the study, respectively, compared to the control calves. Activity of catalase was increased on d 21 and tended to decrease on d 35 in Cr+ calves. In general, Cr supplementation to environmentally heat-loaded dairy calves decreased non-nutritive oral behaviours, improved feed intake and decreased days with diarrhoea and treatment duration, but had minimal effects on weight gain, metabolism and indicators of oxidative stress or insulin function.

Evaluation of three different patterns of feed intake during early lactation in lactating sows.

Forty-five multiparous sows (Landrace×Yorkshire; parity: 3.58±1.30) were used to determine the effects of three patterns of feed intake during early lactation on the performance of lactating sows. Experimental treatments were as follows: IFI-1.4, the amount of feed increased by 1.4kg per day for the first 5days post-farrowing, followed by adlibitum feeding until weaning; IFI-1.0, the amount of feed increased by 1.0kg per day for the first 7days post-farrowing, followed by adlibitum feeding until weaning; IFI-0.7, the amount of feed increased by 0.7kg per day for the first 10days post-farrowing, followed by adlibitum feeding until weaning. The number of live piglets at birth/litter in three dietary treatments was 11.50, 10.07, and 10.85, respectively. Sows in the IFI-1.4 treatment had lower backfat loss during lactation, greater daily feed intake during days 1-6, 7-12, and 1-24 compared with those in the IFI-0.7 treatment (p<.05). The litter weaning weight, litter weight gain, and average litter daily gain in the IFI-1.4 treatment were greater compared with thosein the IFI-0.7 treatment (p<.05). In conclusion, the results indicated that the IFI-1.4 feed intake pattern allowed lactating sows and their litters to obtain optimal performance.