Effects Of Feeding Regimen Research Articles

The effects of follicle stimulating hormone (FSH)-induced controlled ovarian hyperstimulation and nutrition on implantation-related gene expression in caruncular tissues of non-pregnant sheep

Disturbances at the conceptus-maternal interface can have detrimental effects on pregnancy outcome. Additionally, changes in body condition and exogenously administered gonadotropins could affect ovarian and uterine function, including cell proliferation and ovulation rates, and alter endometrial receptivity. In ruminants, endometrial caruncles maintain placental function via interaction with fetal chorionic cotyledons. Here, the effects of feeding regimens on the expression of selected genes known to be involved in uterine receptivity were investigated in the caruncles of control and FSH-superovulated ewes. Sheep were grouped according to their diet: control fed (CF), overfed (OF) or underfed (UF), and were either superovulated with FSH (SOV) or untreated (CON, naturally cycling) (n = 3–5/group). Caruncular samples for the assessment of the transcript levels of 11 target genes were collected at either the early (day 5) or mid-luteal (day 10) phases of the luteal lifespan, resulting in 12 groups of animals. The day of the estrous cycle affected the expression of ITGAV, ITGB3, FGF10 and IGFBP3 mRNA. There was lower expression of MUC1, and higher expression of FGF10, ITGB3 and FN1, on day 10 in CF_SOV animals. Compared with CF, expression of integrins (ITGB3, ITGA5 and ITGA4) was higher in OF and UF, and higher transcript levels of HGF and IGFBP3 in UF animals on day 10. Expression of ITGA5, ITGB1, -3, -5 and MUC1 was greater in OF_SOV than CF_SOV at day 10. In conclusion, it appears that imbalanced nutrition, by altering the expression of genes responsible for intercellular communication, cell adhesion, and encoding for growth factors, could affect the uterine responsiveness to exogenously applied hormonal stimulation and, likely, uterine receptivity.

Effects of time-restricted feeding and type of food on fertility competence in female mice

We assessed the effects of feeding regimen (ad libitum vs. time-restricted food access) and type of food (normal chow (NC: 12% fat) vs. moderately high calorie diet (mHCD: 31% fat)) on fertility competence of female mice. Mice fed mHCD had higher number of oocytes than mice fed NC. On the other hand, when mice were fed NC under time-restricted access to food (NT), the developmental rate to the blastocyst per number of normally fertilized ova was significantly decreased compared to others. The reactive oxygen species (ROS) level in oocytes increased in time-restricted food access and NC group. Transcriptome analysis of whole ovarian tissues from these mice showed a change in the cholesterol metabolism among the four groups. Time-restricted food access decreased serum LDL cholesterol level in both NC and mHCD groups. Moreover, the number of atretic follicles increased in NT mice compared to ad libitum food access mice. The present study shows that mHCD feeding increases the number of ovulated oocytes and that time-restricted feeding of NC impairs the developmental competence of oocytes after fertilization, probably due to the changes in serum cholesterol levels and an increase in the ROS content in oocytes.

Intermittent fasting induces chronic changes in the hepatic gene expression of Red Jungle Fowl (Gallus gallus)

BackgroundIntermittent fasting (IF), the implementation of fasting periods of at least 12 consecutive hours on a daily to weekly basis, has received a lot of attention in recent years for imparting the life-prolonging and health-promoting effects of caloric restriction with no or only moderate actual restriction of caloric intake. IF is also widely practiced in the rearing of broiler breeders, the parent stock of meat-type chickens, who require strict feed restriction regimens to prevent the serious health problems associated with their intense appetites. Although intermittent fasting has been extensively used in this context to reduce feed competition and its resulting stress, the potential of IF in chickens as an alternative and complementary model to rodents has received less investigation. In both mammals and birds, the liver is a key component of the metabolic response to IF, responding to variations in energy balance. Here we use a microarray analysis to examine the liver transcriptomics of wild-type Red Jungle Fowl chickens fed either ad libitum, chronically restricted to around 70% of ad libitum daily or intermittently fasted (IF) on a 2:1 (2 days fed, 1 day fasted) schedule without actual caloric restriction. As red junglefowl are ancestral to domestic chicken breeds, these data serve as a baseline to which existing and future transcriptomic results from farmed birds such as broiler breeders can be compared.ResultsWe find large effects of feeding regimen on liver transcriptomics, with most of the affected genes relating to energy metabolism. A cluster analysis shows that IF is associated with large and reciprocal changes in genes related to lipid and carbohydrate metabolism, but also chronic changes in genes related to amino acid metabolism (generally down-regulated) and cell cycle progression (generally up-regulated). The overall transcription pattern appears to be one of promoting high proliferative plasticity in response to fluctuations in available energy substrates. A small number of inflammation-related genes also show chronically changed expression profiles, as does one circadian rhythm gene.ConclusionsThe increase in proliferative potential suggested by the gene expression changes reported here indicates that birds and mammals respond similarly to intermittent fasting practices. Our findings therefore suggest that the health benefits of periodic caloric restriction are ubiquitous and not restricted to mammals alone. Whether a common fundamental mechanism, for example involving leptin, underpins these benefits remains to be elucidated.

143. Effect of feeding regimen, strain and sex on growth characteristics of four strains of broilers

143. Effect of feeding regimen, strain and sex on growth characteristics of four strains of broilers

Effect of feeding regimen on circadian activity rhythms of food anticipatory by ghrelin hormone in a pig model

ABSTRACT Increasingly diverse meal patterns affect the internal body clock. Ghrelin secretion is closely associated with the anticipation of a regularly scheduled mealtime, leading ghrelin to be a putative candidate for food-related entraining signals that drive activity rhythms. Here, growing pigs with different meal frequencies were used to construct an irregular eating pattern model. We found that irregular eating patterns changed central ghrelin levels of pigs, affected the circadian entrainment and circadian rhythm pathways in hypothalamus tissue, and altered the daily behavior and food anticipatory activity (FAA). To determine whether ghrelin exerts an effect, growing pigs were intravenously injected with ghrelin antagonist [D-Lys3]-GHRP-6 for 7 days. We showed here that [D-Lys3]-GHRP-6 administration decreased locomotor activity of growing pigs in the 4-h window preceding onset of food availability. In addition, we also confirmed that the direct role of ghrelin in molecular mechanism of regulating clock genes expression via calcium mobilization through intracellular PKC/PLC and AC/PKA pathways in vitro. Collectively, irregular eating patterns affect the central circadian system by ghrelin, supporting ghrelin as a temporal messenger of food-entrainment in hypothalamic circadian functions.

The daytime feeding frequency affects appetite-regulating hormones, amino acids, physical activity, and respiratory quotient, but not energy expenditure, in adult cats fed regimens for 21 days.

The effects of feeding frequency on postprandial response of circulating appetite-regulating hormones, insulin, glucose and amino acids, and on physical activity, energy expenditure, and respiratory quotient were studied in healthy adult cats. Two experiments were designed as a 2 x 3 replicated incomplete Latin square design. Eight cats, with an average body weight (BW) of 4.34 kg ± 0.04 and body condition score (BCS) of 5.4 ± 1.4 (9 point scale), were fed isocaloric amounts of a commercial adult maintenance canned cat food either once (0800 h) or four times daily (0800 h, 1130 h, 1500 h, 1830 h). Study 1 consisted of three 21-d periods. On day 14, two fasted and 11 postprandial blood samples were collected over 24 hours to measure plasma concentrations of ghrelin, GLP-1, GIP, leptin, PYY, insulin and amino acids, and whole blood glucose. Physical activity was monitored from day 15 to 21 of each period. In Study 2 indirect calorimetry was performed on the last day of each period. Body weight was measured weekly and feed intake recorded daily in both experiments. No effect of feeding regimen on BW was detected. Cats eating four times daily had lesser plasma concentrations of GIP and GLP-1 (P<0.05) and tended to have lesser plasma PYY concentrations (P<0.1). Plasma leptin and whole blood glucose concentrations did not differ between regimens (P>0.1). Cats fed once daily had a greater postprandial plasma amino acid response, and greater plasma ghrelin and insulin concentrations (P<0.05). Physical activity was greater in cats fed four times (P<0.05), though energy expenditure was similar between treatments at fasting and in postprandial phases. Finally, cats eating one meal had a lower fasting respiratory quotient (P<0.05). Overall, these data indicate that feeding once a day may be a beneficial feeding management strategy for indoor cats to promote satiation and lean body mass.

Effect of feeding regimen on meat quality, MyHC isoforms, AMPK, and PGC-1α genes expression in the biceps femoris muscle of Mongolia sheep.

The effects of two feeding regimens on meat quality, myosin heavy chain (MyHC) types, and key factors regulating muscle fiber type (AMP‐activated protein kinase [AMPK] and peroxisome proliferator‐activated receptor‐coactivator‐1α [PGC‐1α]) in the biceps femoris muscle of Mongolia sheep were investigated. A total of 20 Mongolia sheep were weaning for 90 days and divided into two groups (pasture group (P) and confinement group (C)) at 10.36 ± 0.35 kg of weaning weight. After weaning, sheep were pasture fed or confinement fed for 9 months. The results showed that live weights, carcass weight, intramuscular fat (IMF), and Warner–Bratzler shear force (WBSF) in P group were significantly lower (p < .05) than that in C group. Compared with P group, color evaluations with respect to L* and b* values were significantly higher (p < .05) in C group. Expression of the MyHC I gene in the P group was significantly higher, while MyHC IIa and MyHC IIb genes expression was significantly lower (p < .05) than that in C group. Also, AMPK activity and expression of AMPKα2 and PGC‐1α genes were significantly higher (p < .05) in P group compared with C group. The present study indicated that muscle fiber composition was one of the key differences leading to the differences of meat quality in different feeding regimens. AMPK, particularly AMPKα2, and PGC‐1α were considered to be two key factors regulating muscle fiber types in Mongolia sheep. The results support that AMPK activity and the expression of AMPKα2 and PGC‐1α genes may affect the composition of muscle fibers; thus, AMPK activity and the expression of AMPKα2 and PGC‐1α genes had an effect on meat quality by changed composition of muscle fibers.

Hypoenergetic feeding does not improve outcomes in critically ill patients with premorbid obesity: a post hoc analysis of a randomized controlled trial

Optimal energy goals for adult, obese critically ill surgical patients are unclear. To date, there has been little data comparing feeding regimens for obese and non-obese critically ill surgical patients and the effect on outcomes. The objective was to compare the effect of hypoenergetic and euenergetic feeding goals in critically ill obese patients on outcomes, including infection, intensive care unit length of stay, and mortality. We hypothesized that hypoenergetic feeding of patients with premorbid obesity (body mass index ≥ 30 kg•m−2) during critical illness does not affect clinical outcomes. Post hoc analyses were performed on critically ill surgical patients enrolled in a randomized controlled trial. Patients were randomized to receive 25-30 kcal•kg−1•d−1 (105-126 kJ.kg−1•d−1, euenergetic) or 12.5-15 kcal•kg−1•d−1 (52-63 kJ.kg−1 •d−1, hypoenergetic), with equal protein allocation (1.5 g•kg−1•d−1). The effect of feeding regimen on outcomes in obese and nonobese patients were assessed. Of the 83 patients, 30 (36.1%) were obese (body mass index ≥ 30 kg•m−2). Average energy intake differed based on feeding regimen (hypoenergetic: 982±61 vs euenergetic: 1338±92 kcal•d−1, P = .02). Comparing obese and nonobese patients, there was no difference in the percentage acquiring an infection (66.7% [20/30] vs 77.4% [41/53], P = .29), intensive care unit length of stay (16.4±3.7 vs 14.3±0.9 days, P = .39), or mortality (10% [3/30] vs 7.6% [4/53], P = .7). Within the subset of obese patients, the percentage acquiring an infection (hypoenergetic: 78.9% [15/19] vs euenergetic: 45.5% [5/11], P = .11) was not affected by the feeding regimen. Within the subset of nonobese patients, there was a trend toward more infections in the euenergetic group (hypoenergetic: 63.6% [14/22] vs euenergetic: 87.1% [27/31], P = .05). Hypoenergetic feeding does not appear to affect clinical outcomes positively or negatively in critically ill patients with premorbid obesity.

Effects of feeding regimens on meat quality, fatty acid composition and metabolism as related to gene expression in Chinese Sunit sheep

The present study investigated the effects of two feeding regimens on meat quality, fatty acid profile and metabolism as it relates to gene expression in Sunit sheep. Two feeding regimens were used (pasture feeding and barn feeding, PF and BF) each containing 10 Sunit sheep. Results of this study indicated that PF sheep had significantly (P < 0.05) higher L* and b* values in their muscle compared to BF sheep. Also, the fatty acid composition of longissimus dorsi muscle and subcutaneous adipose tissues differed between feeding regimens. In this respect, concentrations of palmitic acid (C16:0) in the subcutaneous adipose tissue were significantly (P < 0.05) higher in BF sheep. Pastured sheep exhibited greater concentrations of polyunsaturated fatty acids (PUFA) including: linolenic acid (C18:3) (P < 0.001), DHA (P < 0.05), EPA (P < 0.001) and CLA cis-9, trans-11(P < 0.05) in their muscle compared to BF sheep. The expression of nine candidate genes related to fatty acid metabolism were analyzed by qPCR. In longissimus dorsi muscle, expression of acetyl CoA carboxylase (ACACA; P < 0.05) was up-regulated in BF sheep. Expression of the peroxisome proliferator activated receptor (PPARγ) (P < 0.05), stearoyl CoA desaturase (SCD) (P < 0.01), fatty acid desaturase1 (FADS1) (P < 0.05) and fatty acid desaturase 2 (FADS2) (P < 0.05) were up-regulated in PF sheep. Pasture feeding also increased (P < 0.05) expression of lipoprotein lipase (LPL), PPARγ, SCD, FADS1and fatty acid elongase 5 (Elove5) in the subcutaneous adipose tissue, however, the feeding regimens did not change expression of fatty acid synthase (FASN) and carnitine palmitoyl transferase I (CPT1). The results of this study indicated that the feeding regimen could be an important tool in manipulating the fatty acid profile of animal adipose tissue by altering the gene expression of enzymes involved in fat metabolism.

Effect of feeding regimen on the fatty acid profile of sheep bulk tank milk

The quality of dairy products is affected by the fatty acid (FA) profile of the milk. The aim of this study was to determine whether the feeding regimen and lactation stage of the sheep produced a healthier FA profile of milk. The study was carried out on 30 commercial farms, and the feeding regimens studied were different grazing allowances (50%, G1; 25%, G2; 0%, G3). The variance explained by the lactation stage for the FAs was below 4.18%. The milk from the grazing allowance G1 (50% grazing time per day plus alfalfa silage and barley grains) showed a higher conjugated linoleic acid (1.16%) proportion, followed by the grazing allowances G2 (0.90%) and G3 (0.79%), which showed that grazing improved the nutritional quality of milk fat.

Effect of Feeding Regimen on Relationship between Carcass Measurements, Slaughter Weight and Hot Carcass Weight of Sudanese Desert Goats

The study was conducted to determine the effect of feeding diets, on growth performance and relationship between carcass measurements, slaughter weight and hot carcass weight, of 72 intact male desert bucks divided randomly into three groups; each group (24 males), the animals were slaughtered according to halal standard procedures. The results obtained indicated that correlation coefficients between slaughters weight and carcass measurements were significantly higher (P &lt;0.01) and positive. In free grazing group correlation coefficients between hot carcass weight and carcass measurements were significantly (P &lt;0.01) and positive. Also the relationship between slaughters weight and carcass measurements was significant and positive except internal chest length. In the group that grazing and supplemented with diets showed positive and significantly (P &lt;0.01) correlation coefficients between hot carcass weight and carcass measurements and between slaughters weight and carcass measurements were significant and positive except carcass length. The zero grazing groups obtained non not significant correlation coefficients between hot carcass weight and carcass measurements except slaughter weight and external chest length.

Biological implications of longevity in dairy cows: 1. Changes in feed intake, feeding behavior, and digestion with age

Milk production strategies focusing on longevity and limited use of concentrate are receiving increasing attention. To evaluate such strategies, knowledge of the development with age of animal characteristics, particularly digestion, is indispensable. We therefore investigated the development of feed intake, chewing activity, and digestion in 30 lactating Brown Swiss cows (876–3,648 d old) and 12 heifers (199–778 d old). We also studied whether age effects were exhibited differently in animals selected from herds subjected for 11 yr either to a forage-only or to a forage-concentrate feeding regimen. Forages consisted of grass hay (the only feed for heifers), corn silage, and grass pellets. Measurements lasted for 8 d, where amounts and composition of feeds, feces, and milk were recorded and analyzed. Ruminal pH data and eating and rumination activity were assessed by pH sensors put into the rumen and halter-mounted noseband sensors. The mean retention time of feed particles was assessed using Cr-mordanted fiber and data were used to calculate dry matter gut fill. Data were subjected to regression analyses with age and feeding regimen as explanatory variables, and body weight, milk yield, and proportion of hay in forage as covariates. This allowed separating age-related changes of body weight and milk yield from independent age effects and correcting for differences in preference for individual forages. In cows, organic matter intake increased with age (from slightly below to above 20kg/d), as did mean retention time and gut fill. Digestibility of organic matter did not show a clear age dependency, but fiber digestibility had a maximum in cows of around 4 to 6 yr of age. Ruminal pH and absolute eating and rumination times did not vary with cow age. Young and old cows chewed regurgitated boluses more intensively (60–70 times) than middle-aged cows (about 50 times). Effects of feeding regimen were small, except for fiber intake and rumination time per unit of intake, owing to the different fiber content of the diets. No significant interactions between age and feeding regimen were found. Heifers spent more time eating and ruminating per unit of feed than cows, which resulted in a high fiber digestibility. Irrespective of the feeding regimen tested, older cows maintained intake and digestion efficiency with longer retention times and chewing rumination boluses more intensively. The results support efforts to extend the length of productive life in dairy cows.

Response of two broiler strains to four feeding regimens under hot climate

In total, 392 male broilers were randomly distributed in a factorial arrangement of 2 × 4, with two commercial broiler strains (Arbor Acres (AA) and Hubbard (Hub)) and four (NRC, Degussa, CVB, and strain guides) different feeding regimens (FR), totaling eight treatments and seven replicates, with seven broilers in each one. The following parameters were evaluated: bodyweight gain (BWG), feed intake (FI), feed conversion ratio (FCR), carcass yield, meat quality, nutrient intake, and its correlation with BWG. Interaction strain type × FR was significant for BWG, FI, and FCR, with the AA broilers showing higher BWG and FI and lower FCR than the Hub broilers. There was no difference in BWG, FI, and FCR of the AA broilers regardless of FR they were on, but the Hub broilers had lower BWG when they were fed according to the Degussa and CVB regimens; BWG and FCR were negatively affected. During the starter phase, BWG of the AA broilers was significantly correlated with feed, metabolisable energy (ME), lysine, and sulfur amino acids (SAA) intake. However, BWG was correlated with feed and ME intake and feed intake from 1 to 31 and from 1 to 42 days of age, respectively. In the Hub chicks, ME and crude protein intake and lysine and SAA intake were inversely correlated with BWG from 1 to 31 days and from 1 to 42 days of age, respectively. There was no significant effect of FR on dressed carcass weight or relative gizzard, pancreas, and liver weights and on intestinal weight; however, abdominal fat and spleen differed significantly with FR. Strain type significantly affected the relative weight of the intestines. There was no significant effect of FR and/or strain type on meat moisture, crude protein, lipid and ash content, or pH, colour, meat juiciness and tenderness (meat softness). In conclusion, AA strain of broiler performed better than the Hub strain under the different FR in all the evaluated production phases, but neither FR nor strain type affected carcass characteristics.

PIH1 - Mothers’ Own Milk for the Feeding of Preterm Infants: A Systematic Literature Review

To conduct a systematic review to examine the incremental benefits of mothers’ own milk (MM), with or without fortification, compared with donor milk (DM) and/or preterm formula (PF) for the nutritional support of preterm infants both in the neonatal intensive care unit (NICU) and following hospital discharge. English-language studies published post-1990 were identified from electronic databases (Medline, EMBASE and Cochrane Library) and conference proceedings. Eligible studies enrolled infants with mean gestational age less than 35 weeks with no restriction on geographical location. Thirty-three unique studies met eligibility criteria: United States (n=12), Canada (n=2), Australia (n=2), Mexico (n=1), Israel (n=2), Europe (n=13) or multinational (n=1). There was a paucity of both RCT data (n=7) and studies which reported exclusive use of MM feeding (n=3). In addition, there was considerable heterogeneity between studies with regard to study design, duration of follow up and amounts of MM ingested, and a robust meta-analysis was therefore not feasible. However, a significant beneficial effect for MM over DM and/or PF for the incidence of sepsis, necrotizing enterocolitis (NEC) and longer-term neurodevelopment was reported in a number of individual studies. With regard to anthropomorphic outcomes of body weight, length and head circumference, there was no clear consensus on the effect of feeding regimen. Sixteen studies reported the relationship between the dose of MM received and outcomes; increased MM dosages in the feeding regimen were associated with significantly lower rates of sepsis, NEC, and hospital readmissions, reduced NICU costs, and improved neurodevelopment. Exclusive or high-dose MM with or without fortification is associated with short- and long-term beneficial effects in preterm infants. These results confirm MM to be the optimal nutrition for preterm infants and stress the importance of developing comprehensive strategies to overcome the challenges of providing MM and improving breastfeeding rates in preterm infants in the NICU.

Experimentally induced hyperchloremic and dl-lactic acidosis in calves: An attempt to study the effects of oral rehydration on acid-base status

Many diarrheic calves suffer from metabolic acidosis, which is commonly treated by oral rehydration therapy. Oral rehydration solutions can be prepared in water, milk, or milk replacer. Therefore, the aim of the study was to verify dietary effects of water- or milk replacer-based oral rehydration solutions on parameters of acid-base balance in calves with experimentally induced hyperchloremic and dl-lactate acidosis. In 12 calves, hyperchloremic or dl-lactate acidosis was induced by HCl or dl-lactic acid infusions according to protocols outlined in previous literature. Immediately after induction, the calves were fed with milk replacer or water- or milk replacer-based oral rehydration solutions, or remained fasting, respectively. Blood samples were taken to monitor acid-base status over an experimental period of 4h. Using the protocols, all calves revealed a manifest hyperchloremic or dl-lactate acidosis. Because of high infusion volumes, plasma volume was expanded and effects of feeding regimens on blood parameters were rare. Unexpected clinical aberrations occurred after repeated induction of dl-lactate acidosis: all calves developed a thrombophlebitis of the jugular vein, whereas HCl infusion had no effect on endothelium. Induction of acidosis via infusion is not suitable to study dietary effects. A protocol to induce acidosis and dehydration simultaneously is required to duplicate the metabolic conditions of diarrheic calves. In further investigations, attention should be focused on effects of d-lactate or its metabolites on endothelial tissue.

Effect of feeding regimens on polyhydroxybutyrate production from food wastes by Cupriavidus necator

We investigated the effects of different feeding regimens (1-pulse, stepwise, and continuous) of fermented food-waste liquid on polyhydroxybutyrate (PHB) production. The fermentation liquid was filtered with a membrane filter (pore size, 0.45 μm) to remove anaerobic microorganisms and solids and used as a carbon source for Cupriavidus necator. One-pulse feeding yielded the highest cell concentration of C. necator. However, the PHB concentration was higher in the stepwise- and continuous-feeding regimens. Therefore, the continuous-feeding regimen was used for continuous PHB production. PHB could be produced over 259 h (8 draw-fill cycles) with a maximal PHB content of 87%, but the PHB concentration and content decreased with an increase in the operation time.

Effect of feeding regimens on circadian rhythms: Implications for agingand longevity

Increased longevity and improved health can be achieved in mammals by two feeding regimens, caloric restriction (CR), which limits the amount of daily calorie intake, and intermittent fasting (IF), which allows the food to be available ad libitum every other day. The precise mechanisms mediating these beneficial effects are still unresolved. Resetting the circadian clock is another intervention that can lead to increased life span and well being, while clock disruption is associated with aging and morbidity. Currently, a large body of evidence links circadian rhythms with metabolism and feeding regimens. In particular, CR, and possibly also IF, can entrain the master clock located in the suprachiasmatic nuclei (SCN) of the brain hypothalamus. These findings raise the hypothesis that the beneficial effects exerted by these feeding regimens could be mediated, at least in part, through resetting of the circadian clock, thus leading to synchrony in metabolism and physiology. This hypothesis is reinforced by a transgenic mouse model showing spontaneously reduced eating alongside robust circadian rhythms and increased life span. This review will summarize recent findings concerning the relationships between feeding regimens, circadian rhythms, and metabolism with implications for ageing attenuation and life span extension.

Effects of feeding regimen and chilled storage on water‐holding capacity, colour stability, pigment content and oxidation in red deer (Cervus elaphus) meat

AbstractThe effects of feeding regimen on carcass characteristics, meat colour and lipid stability, pigment content and water‐holding capacity of M. longissimus were studied in 16 male red deer. All animals were farm raised; eight were grazing pasture and eight were fed a pelleted commercial feed mixture for 10 weeks prior to slaughter. The pellet‐fed deer had significantly higher live weight, carcass weight, dressing yield (g kg−1) and fat content than the pasture group. Carcasses from the pellet‐fed deer had higher temperatures over 0–10 h post mortem than carcasses from the grazing animals, probably due to an insulating fat cover. Ultimate pH values were lowest in meat from the pellet‐fed deer. The meat from the grazing deer had significantly better colour stability at 1 day post‐slaughter and after 1, 3 and 6 weeks of refrigerated storage (−1.5 °C) in vacuum bags. After 3, 6 and 12 weeks of refrigerated storage the meat from the pellet‐fed deer had significantly higher drip loss. No difference was found in the amount of oxidation products (thiobarbituric reactive substances, TBARS) when comparing the treatment groups, although the amount of TBARS increased during storage. Muscle pigment content was significantly higher in grazing deer than in the pellet‐fed group. It was not possible to confirm a correlation between lipid and pigment oxidation in the meat, and the pigment content of the meat samples did not seem to have an influence on colour stability or oxidation product formation. Copyright © 2005 Society of Chemical Industry

Fatty liver in dairy cows post partum is associated with decreased concentration of plasma triacylglycerols and decreased activity of lipoprotein lipase in adipocytes

Cholesterol and phospholipid concentrations in serum lipoproteins, plasma activities of lecithin:cholesterol acyltransferase (LCAT) and phospholipid transfer protein (PLTP) and lipoprotein lipase (LPL) activity in adipose tissue biopsies were measured ante and post partum in dairy cows given either free or restricted access to feed during the dry period. After parturition, all cows were fed ad libitum. The purpose of this study was to try to understand the earlier observed marked drop post partum in plasma triacylglycerol (TAG) in terms of lipoprotein metabolism in cows developing fatty liver post partum. As would be expected, free access to feed during the dry period induced a rise of hepatic TAG concentrations post partum associated with a decrease in plasma TAG levels. Total and free cholesterol concentrations in the VLDL, IDL, LDL and HDL2 fractions fell immediately after parturition. VLDL and IDL cholesterol concentrations remained at a constant, low level during the entire sampling period post partum, whereas the drop in LDL and HDL2 cholesterol post partum was followed by a rebound rise. Plasma LCAT and PLTP activities decreased by on average 19% and 33%, respectively, after parturition and then rose to values seen before parturition, but there was no effect of feeding regimen during the dry period. Activities of LCAT and PLTP were significantly correlated with cholesterol and phospholipid concentrations in LDL and HDL2. Plasma LCAT activity, as measured with exogenous substrate, and PLTP activity were both positively correlated with HDL3 phospholipid levels. LPL activity in adipose tissue dropped after parturition, the drop being smaller after feeding ad libitum during the dry period. It is concluded that the drop in adipose tissue LPL activity post partum is at variance with the simultaneous fall in plasma TAG. Possibly, the decrease in adipose tissue LPL activity helps to channel fatty acids away from adipose tissue into the udder. The post-partum changes in lipid transfer proteins in the blood are in line with the changes observed in the levels of the lipoproteins.

The Effect of Feeding Regimen on Mixed-Size Pond-Grown Channel Catfish, Ictalurus punctatus

The culture of channel catfish, Ictalurus punctatus, is an established industry in many areas of the southern United States. Improvements in feeding regimens would economically benefit producers. The present research was designed to evaluate the effect of feeding time (AM vs. PM), feeding frequency (one vs. two times a day) and intermittent fasting (6 days of feeding, 1 day of fasting) on production, feed conversion ratio (FCR), survival, weight-length relationship, percent dressout (headed and gutted carcass per unit live weight), and body composition of channel catfish reared in earthen ponds. Treatments consisted of: (1) feeding catfish once daily to satiation at 0800; (2) feeding catfish once daily to satiation at 1800; (3) feeding catfish twice daily at 0800 and 1800; and (4) feeding catfish once daily at 0800 for six consecutive days followed by one day of fasting. Twenty 0.04-ha ponds were stocked with 135 sub-market (average size: 182.6 g/fish) catfish and 600 fingerlings (average size: 18.2 g/fish), resulting in a total density of 18,375 fish/ha. Each treatment was assigned to five ponds at random. Fish in all treatments were offered a commercial floating catfish diet. A portion of the marketable catfish were harvested in mid-summer and the ponds completely harvested in the fall. Production parameters (e.g., bio-mass, weight gain, FCR, and survival), percent dressout, and weight-length relationship of catfish did not differ among the four treatments (P > 0.05). Percent dry matter and percent lipid of the fillet offish fed once daily at 0800 seven days a week were significantly higher than those of fish in all other treatments (P ⁁ 0.05). The percent crude protein of the fillet offish fed once daily at 1800 seven days a week was significantly higher than fish fasted one day a week (P >0.05). These results indicate that as long as the fish are fed to apparent satiation there is no advantage to multiple feedings, to feeding at a specific time of day, or to intermittent fasting in earthen ponds.