Voluntary Intake Research Articles

Effect of Palm Kernel Cake Supplementation on Voluntary Feed Intake, In Situ Rumen Degradability and Performance in Buffaloes in the Eastern Amazon

The objective was to evaluate the effects of palm kernel cake (PKC) supplementation on voluntary feed intake, in situ rumen degradability and performance in the wettest (WS-January to June) and less rainy seasons (LR-July to December) in the eastern Amazon. A total of 52 crossbred buffaloes that were neither lactating nor gestating were used, with 24 for the LR, aged 34 ± 04 months and an initial average weight of 503 ± 48 kg, and 24 for the WS aged 40 ± 04 months with an average weight of 605 ± 56 kg. The four treatments (levels of PKC in relation to body weight) were distributed in a completely randomized design, with 0% (PKC0), 0.25% (PKC0.2), 0.5% (PKC0.5) and 1% (PKC1) with six repetitions. The animals were housed in Marandu grass paddocks, intermittently, with access to water and mineral mixture ad libitum. Degradability was evaluated by the in situ bag technique in four other crossbred buffaloes with rumen cannulae, in a 4 × 4 Latin square (four periods and four treatments). The inclusion of PKC increased supplement consumption and production of ether extracts and reduced the intake of forage and non-fibrous carbohydrates. The dry matter degradability of Marandu grass was not affected; however, the fermentation kinetics in neutral detergent fiber (NDF) differed between the treatments. The co-product dry matter colonization time was greater in PKC1 and the highest effective degradability rates were from PKC0, but the productive performance of the animals was not influenced. Supplementation of buffaloes with PKC is recommended for up to 1% of body weight.

Mu-opioid receptor-expressing neurons in the paraventricular thalamus modulate chronic morphine-induced wake alterations

Disrupted sleep is a symptom of many psychiatric disorders, including substance use disorders. Most drugs of abuse, including opioids, disrupt sleep. However, the extent and consequence of opioid-induced sleep disturbance, especially during chronic drug exposure, is understudied. We have previously shown that sleep disturbance alters voluntary morphine intake. Here, we examine the effects of acute and chronic morphine exposure on sleep. Using an oral self-administration paradigm, we show that morphine disrupts sleep, most significantly during the dark cycle in chronic morphine, with a concomitant sustained increase in neural activity in the Paraventricular Nucleus of the Thalamus (PVT). Morphine binds primarily to Mu Opioid Receptors (MORs), which are highly expressed in the PVT. Translating Ribosome Affinity Purification (TRAP)-Sequencing of PVT neurons that express MORs showed significant enrichment of the circadian entrainment pathway. To determine whether MOR + cells in the PVT mediate morphine-induced sleep/wake properties, we inhibited these neurons during the dark cycle while mice were self-administering morphine. This inhibition decreased morphine-induced wakefulness but not general wakefulness, indicating that MORs in the PVT contribute to opioid-specific wake alterations. Overall, our results suggest an important role for PVT neurons that express MORs in mediating morphine-induced sleep disturbance.

Dietary Tryptophan Supplementation Implications on Performance, Plasma Metabolites, and Amino Acid Catabolism Enzymes in Meagre (Argyrosomus regius)

Tryptophan (Trp) is an essential amino acid, commercially available as a feed-grade product, and is a precursor to serotonin and melatonin, which are both important molecules in stress mitigation. Meagre have a high potential for marine aquaculture diversification but are highly susceptible to stressful conditions. This study aimed to assess the potential role of dietary tryptophan supplementation in meagre juveniles in order to minimize the deleterious effect of potential stress conditions. For this, a growth trial was performed wherein meagre juveniles were fed four isoproteic (45%DM) and isolipidic (16%DM) diets; namely, a control diet, and three diets similar to the control diet but supplemented with varying levels of tryptophan, graded according to the resulting percentage in each diet’s dry matter (Control, 0.25%Trp, 0.5%Trp, and 1%Trp), corresponding to a total dietary tryptophan of 1.06, 1.70, 2.08, and 3.24 g 16 g−1 N, respectively. Diets were tested in triplicate, and fish were fed twice a day, six days a week, for eight weeks. Five days after the end of the growth trial, a time-course blood sampling was performed at 0 h, 1 h, 3 h, 6 h, and 12 h after feeding. At the 6 h sampling point, the liver was also collected. Overall, our results indicate that 1Trp supplementation (total dietary Trp 3.24 g 16 g−1 N) may be harmful to fish, decreasing growth performance and feed utilization, although doses up to 0.5Trp do not influence these parameters. Voluntary feed intake lineally decreased with the increase in the level of dietary Trp. Whole-body lipid content decreased at the highest tryptophan inclusion, whereas no changes were observed in protein levels. After 12 h from feeding, plasma glucose levels were lower in all dietary treatments supplemented with tryptophan compared to those observed in the control. Hepatic enzyme activity of protein catabolism decreased with dietary Trp inclusion. Overall, our results suggested that while a dietary Trp level increase of up to 2.08 g 16 g−1 N did not affect growth performance and feed efficiency, both these parameters were severely compromised with a Trp level of 3.24 g 16 g−1 N.

Effects of hindgut acidosis on inflammation, metabolism, and productivity in lactating dairy cows fed a high-fiber diet

Hindgut acidosis (HGA) may cause or contribute to the inflammatory state of transition dairy cows by compromising the intestinal barrier. Previous experiments isolating the effects of HGA on inflammatory metrics have generated inconsistent results, which may be explained by acclimation to low- versus high-starch diets. Thus, study objectives were to evaluate the effects of HGA in cows acclimated to a high-fiber diet. Ten rumen-cannulated Holstein cows (38 ± 5 kg/d milk yield; 243 ± 62 d in milk; 1.6 ± 1.1 parity; 663 ± 57 kg of body weight) were enrolled in a study with 2 experimental periods (P). Before P1, all cows were acclimated to a high-fiber, low-starch diet (50% neutral detergent fiber, 15% starch) for 17 d. During P1 (4 d), baseline data were collected for use as covariates. During P2 (7 d), cows were assigned to 1 of 2 abomasal infusion treatments: (1) control (CON; 1.5 L of H2O/infusion; n = 4) or (2) starch infused (ST; 1 kg of corn starch + 1.5 L of H2O/infusion; n = 6). All cows were infused with their respective treatments every 6 h daily at 0000, 0600, 1200, and 1800 h, such that ST cows received a total of 4 kg of corn starch/d. Starch infusions successfully induced HGA, as indicated by a marked decrease in fecal pH (1.2 units) relative to CON. However, in contrast to our assumptions, infusing starch had no deleterious effects on milk yield, energy-corrected milk, or voluntary dry matter intake during P2. Milk protein, lactose, their yields, fat yield, and somatic cell score remained unaffected by starch infusions, whereas milk fat content and urea nitrogen were decreased in ST relative to CON (8 and 17%, respectively). Overall, circulating glucose and β-hydroxybutyrate concentrations remained similar between treatments, but starch infusions decreased nonesterified fatty acids on d 3 relative to CON. Blood urea nitrogen decreased throughout P2 in ST (38%) relative to CON. In contrast to our hypothesis, HGA did not alter circulating serum amyloid A or lipopolysaccharide binding protein, nor did it affect rectal temperature. In summary, HGA moderately altered metabolism but did not affect production or elicit an inflammatory response in lactating dairy cows previously acclimated to a high-fiber diet.

Gastrojejunal Fistula Following Gastrostomy Tube.

Gastrostomy tubes are often placed in patients with poor voluntary intake, oropharyngeal dysphagia, or chronic illness to provide definitive nutritional access. Despite the widespread use of gastrostomy tubes, some patients can experience complications associated with this procedure including gastrocolic-cutaneous fistula and dislodgement of gastrostomy tube. This case discusses an instance of gastrojejunal fistula formation over one year after gastrostomy tube placement likely due to tube dislodgement. Imaging showed gastrostomy tube traversing the posterior wall of the stomach and creating a fistula into the jejunum, with the balloon inflated within the jejunum. Gastrostomy tube was removed and replaced, with gastrostomy tube study showing no extravasation of contrast. Patient is now doing well-tolerating tube feeds at goal.

Statistical modelling of voluntary feed intake in individual Atlantic salmon (Salmo salar L.)

Precision feeding aims to provide the correct amount of feed to farmed animals for optimal growth and performance and to avoid feed waste. However, knowledge underlying the meal-to-meal variability in voluntary feed intake of farmed species is still limited. This study examined the relationship between meals, feed deprivation time and the feed (pellets) consumed by Atlantic salmon post smolts. The data was collected from individual fish handfed to satiety without social interaction in three independent short-term (6-12 days) experiments. The fixed variables of our model (feed deprivation time (i.e., time between meals), number of pellets provided, day, previous meal size, and fish growth) explained most of the feed intake (number of pellets ingested) (R2 0.68). Results show that fish ingested more pellets over the course of the trials as they grew, resulting in a positive correlation between feed intake and fish growth (final minus initial fish weight). The time between meals and prior meal size (the number of pellets ingested in the previous meal) significantly affected feed intake in the following meal. Our results suggest that it is possible to optimise meal size by considering the size of the previous meal and the time since it was given.

Effects of the inclusion of coffee pulp silage in the diet on the performance and profitability of crossbred milk cows in the middle tropics

The objective of this study was to evaluate the inclusion of coffee pulp silage (CPS) on the performance and profitability of crossbred cows in the middle tropics. The research took place at the Villa Marina Experimental Farm of the University of Pamplona, Pamplonita, Colombia. Four lactating multiparous bovines with a body weight of 380 ± 10 kg, 6 ± 0.03 years of age and a body condition of 3.8 on a scale of 1 to 5. The animals were distributed in a balanced 4 × 4 Latin square for residual effect. The experiment consisted of four subperiods of 21 days each, being the first 14 days of adaptation to the experimental diet and 7 days for taking samples. The base diet consisted of Pennisetum sp. forage, concentrated in a proportion of 0.2% of body weight, water, and mineralized salt at will. The inclusion of the CPS was included in levels of 4, 8, and 12% of the dry matter (DM) intake. DM intake parameters, nutrient digestibility, milk production and composition, blood parameters, and economic analysis were evaluated. Treatments were compared using orthogonal contrasts; contrasts were constructed in order to evaluate the effects of inclusion of CPS, and the linear and quadratic effects of level inclusion in the DM of the diet. For the variables which did not present inclusion of CPS effect but a linear or quadratic effect was significant, a Dunnett’s test was performed to identify whether a supplemented treatment differed from the control. Significance was considered at P < 0.05 and tendencies when 0.05 < P ≤ 0.10. The inclusion of CPS in the diet increases (P < 0.05) the voluntary intake in kg day−1 of DM, organic matter (OM), CP, ethereal extract (EE), non-fiber carbohydrates (NFC), digested OM (DM), neutral detergent fiber corrected for ash and protein (NDFap), DNDF and dietary NTD concentration, the total digestibility of DM and OM, and dietary DOM content. The production and chemical composition of milk was not affected (P > 0.10) by the inclusion of EPC in the diet. The inclusion of CPS increased (P < 0.05) the concentration of albumin and globulins in the blood. The inclusion of CPS in the diet improved the productive efficiency of dairy cattle. The inclusion of 4% CPS in the DM of the diet is a nutritional strategy, which improves the nutritional characteristics and the concentration of albumin and globulins in the blood of crossed dairy cows in the middle tropics and benefit: cost ratio without affecting milk production.

Investigation of Chinese Herbal Decoctions with Enzymatic Hydrolysis and Sequential Fermentation as Potential Nutrient Supplements

Chinese herbal medicine has attracted increasing attention due to its therapeutic effects. It demands increasing understanding of the processing methods and the generated changes to control quality and offer better final products. In this study, extraction differences were compared among direct plant extracts (DE), standard decoction (SD), spontaneous fermentation (SF) and inoculated sequential fermentation (IF). Results showed that the extraction with the transformation of probiotics positively contributed to the release of functional compounds from Chinese herbs. It provided the strongest antioxidant capacity and the best amino acid profile. The flavor and the compositions of the herbal decoctions were further characterized. Distinctive volatile differences were found, indicating that the different treatments profoundly altered the spectrum of volatile components. The most aromatic changes were in the IF group, which corresponded with the greatest number of upregulated and the lowest number of downregulated differential compounds. Beneficial intestinal microbiota with voluntary intake of herbal tea suggested a possible positive metabolism shift in the healthy host. In conclusion, the combination of enzymatic hydrolysis and sequential fermentation provided better extraction efficiency than direct plant extraction and traditional herbal decoction. It may enable a broader utilization of traditional Chinese herbs as potential nutrient supplements, such as antibiotic alternatives in animal husbandry.

Strategies of energy supplementation for cattle fed tropical forage and infrequently supplemented with protein

Our objective was to evaluate the effects of different energy supplementation strategies in Nellore heifers fed tropical grass forage and infrequently supplemented with nitrogen (N) compounds on voluntary intake, digestion, ruminal fermentation and fibre dynamics, urinary excretion characteristics, N balance, and hormonal and blood metabolic profile. Five rumen and abomasum fistulated Nellore heifers, averaging 332 kg of body weight, were used in a 5 × 5 Latin square design. The five treatments were: control, without supplementation; supplementation of 660 g of crude protein (CP) every 3 days; supplementation of 660 g of CP every 3 days and daily supplementation with 440 g of starch; supplementation of 660 g of CP and 1320 g of starch every 3 days; and supplementation of 660 g of CP and 1320 g of starch every 3 days, but starch supplementation was performed one day after CP supplementation. On average, treatments did not affect (P > 0.44) voluntary forage intake. However, the forage intake varied over the three-day supplementation cycle. Forage intake was depressed (P < 0.05) by protein supplementation alone on the first two days of the supplementation cycle, but increased on the third day. Only the concomitant supplementation with protein and starch caused a constant intake over the days. Ruminal fibre digestibility and the ruminal N balance were improved by supplementation (P < 0.05). A concomitant evaluation of serum urea N, rumen ammonia N, blood transaminases, and urinary excretion indicated that protein supplementation alone caused a hepatic N overload, which was improved when starch was concomitantly provided with protein. We concluded that infrequent protein supplementation causes negative impacts on hepatic metabolism and depresses voluntary forage intake, remarkably on the day the supplementation occurs. However, these negative effects on intake can be eliminated with adequate energy provision concomitantly with protein supplementation.

Voluntary intake and in vivo digestibility of four groundnut haulms varieties measured on Djallonké sheep in Benin

Voluntary intake and in vivo digestibility of four groundnut haulms varieties measured on Djallonké sheep in Benin

Comparative evaluation of voluntary feed intake (VFI) and average daily gain (ADG) of Flemish Giant, New Zealand White and California black growing rabbit breeds fed soya bean (Glycine max), Cowpea (Vigna unguiculata) and Pigeon pea (Cajanus cajan

Voluntary Feed Intake (VFI) and Average Daily Gain (ADG) of three rabbit breeds fed on pigeon pea (PP), cowpea (CoP) and soybean (SB) as sources of protein for growing rabbits were determined. Flemish Giant (FG), California Black (CB) and New Zealand White (NZW)) were fed soybean (Glycine max), pigeon pea (Cajunus cajan) and cowpea (Vigna unguiculata) as protein sources in the ration. Eighteen rabbits weaned at six weeks of age were used for each breed (a total of 54 rabbits) out of which six of them were assigned to Ration 1 (containing 31.6% SB), six rabbits to ration 2 (containing 72% CoP) and the last six to Ration 3 (containing 70.18% PP). The rabbits were randomly assigned to fifty four cages in a 3 x 3 factorial experiment. The three legume grains were roasted before rations were compounded. Raw Legume Grains (RaLG), Roasted Legume Grains (RoLG) and the three Rations (1, 2 and 3) were analyzed for tannin content (TC). TC was significantly (p&lt;0.05) higher in CoP and Ration 3. Average daily feed intake (ADFI) was significantly (p&lt;0.05) higher for FG. Rabbits fed SB based ration had significantly (p&lt;0.05) higher growth rate than rabbits fed either CoP or PP based rations. Rabbits offered PP based ration demonstrated a significantly (p&lt;0.05) higher growth rate than rabbits consuming the CoP based ration. Dressing-out percentage was significantly (p&lt;0.05) higher for the FG than for either NZW or CB. The study revealed that SB and FG were superior legume and breed in terms of VFI and ADG, respectively. The study also showed that PP could successfully replace SB in rabbit rations without adversely affecting the VFI and ADG of rabbits.

Estimation of dry matter intake by lambs managed on different leaves allowance of Brachiaria-grass using internal and external markers

ABSTRACT It aimed to estimate the forage intake by lambs managed in different leaf allowances on Brachiaria-grass using internal and external markers. Forty-eight Texel lambs with 17.52 ± 3.48 kg were evaluated which were 12 testers and 36 regulators. The lambs were kept in twelve paddocks, subdivided into four treatments based on green leaf allowance (60, 75, 90, and 105 g/kg of BW). The experimental design was completely randomised. To estimate dry matter intake (DMI), the following markers were used: indigestible dry matter (iDM); indigestible neutral detergent fibre (iNDF); indigestible acid detergent fibre (iADF); lignin in indigestible acid detergent (iADL) and titanium dioxide (TiO2). Comparisons between intake markers were made using Chromic Oxide (Cr2O3) as a control marker. The leaves allowance tested did not alter the voluntary intake by lambs kept in Brachiaria-grass pasture. Comparison between the control intake marker (Cr2O3) and the other markers by Dunnett's test showed that, regardless of green leaf allowance, the Cr2O3, TiO2 and iADL markers provided similar estimates of DMI, but with lower values than the other markers. External marker TiO2 and the internal iADL were demonstrated to be more suitable for estimating the dry matter intake in grazing lambs regardless of the leaf allowance.

Chronic MAP4343 reverses escalated alcohol drinking in a mouse model of alcohol use disorder

Alcohol use disorders can be driven by negative reinforcement. Alterations of the microtubule cytoskeleton have been associated with mood regulation in the context of depression. Notably, MAP4343, a pregnenolone derivative known to promote tubulin assembly, has antidepressant properties. In the present study, we tested the hypothesis that MAP4343 may reduce excessive alcohol drinking in a mouse model of alcohol dependence by normalizing affect during withdrawal. Adult male C57BL/6J mice were given limited access to voluntary alcohol drinking and ethanol intake escalation was induced by chronic intermittent ethanol (CIE) vapor inhalation. Chronic, but not acute, administration of MAP4343 reduced ethanol intake and this effect was more pronounced in CIE-exposed mice. There was a complex interaction between the effects of MAP4343 and alcohol on affective behaviors. In the elevated plus maze, chronic MAP4343 tended to increase open-arm exploration in alcohol-naive mice but reduced it in alcohol-withdrawn mice. In the tail suspension test, chronic MAP4343 reduced immobility selectively in Air-exposed alcohol-drinking mice. Finally, chronic MAP4343 countered the plasma corticosterone reduction induced by CIE. Parallel analysis of tubulin post-translational modifications revealed lower α-tubulin acetylation in the medial prefrontal cortex of CIE-withdrawn mice. Altogether, these data support the relevance of microtubules as a therapeutic target for the treatment of AUD.

Effect of different levels of concentrate supplementation on feed intake, growth performance, carcass traits and composition in finisher Barbari kids reared under intensive system

Thirty-two weaned male Barbari kids (av. age, 144.65 days; weight, 9.43±0.24 kg), reared under intensive system of feeding, were divided equally into four groups (T1, T2, T3 and T4) to investigate the effect of supplementation of different levels of concentrate mixture on voluntary intake, growth performance, carcass traits and quality. All kids were fed with Bengal gram straw ad lib. + green fodder ad lib. as basal ration and supplemented with barley grain @ 0.7% of body weight in T1 and concentrate mixture @ 0.7, 1.4, and 2.1% of body weight in T2, T3, and T4, respectively. Dry Matter Intake (DMI, g)/kg W0.75 increased significantly in T1 and T4 than T2 and T3. Average daily weight gain (ADG) (g/d/kid) was enhanced significantly with each gradual increase in concentrate level. Slaughter weight and empty body weight were greatest in T4 compared with other treatments. Significantly greater dressing percentage and yield of separated lean meat was observed in kids under T3 and T4 than other two groups. But, meat:bone ratio and separated carcass fat yield was significantly higher only in kids under T4. Meat protein content (%) increased in T2, T3, and T4 as compared to control T1. Meat fat content increased linearly due to a gradual increase in the level of concentrate mixture supplementation to the finisher kids. Whereas, meat moisture and ash per cent remained unaltered due to different levels of concentrate supplementation to kids. Therefore, it may be concluded that supplementation of concentrate mixture @ 2.1% of the body weight in the roughage-based diet increased DMI in finisher Barbari kids with greater energy and protein values, which attributed to enhanced ADG in such kids by 408.3% over the control (supplemented with barley grain only), and also improved feed conversion ratio, carcass yield, carcass traits, and meat quality.

Sheep Preference for Fresh Leaf and Stem of Seven Accessions of Tedera Was Not Influenced by Prior Grazing Experience and Wilting Made No Difference

Tedera is a valuable high-quality forage for sheep during summer–autumn. There is evidence that prior grazing experience of novel forages influences preference and haymaking of tedera improves preference by goats. In the first experiment, it was hypothesised that the voluntary feed intake (VFI) of fresh leaves and stems of tedera by sheep would be greater for experienced vs. naïve sheep. In the second experiment, it was hypothesised that the VFI of naïve sheep fed wilted leaves and stems of tedera would be greater than fresh leaves and stems of tedera. To test these hypotheses, adult Merino sheep were fed seven accessions of tedera, in two outdoor pen feeding experiments conducted consecutively. Each of six pens had 14 feeders, two for each accession, and two sheep. In experiment 1, three pens had sheep that had previously grazed tedera (experienced) and three pens had sheep with no experience (naïve), and all were fed fresh leaves and stems of the seven tedera accessions. Experiment 2 involved only naïve sheep, with three pens fed fresh leaves and stems and three pens fed wilted leaves and stems of the seven tedera accessions. Preference was measured each day for six days in experiment 1; and for five days in experiment 2 by calculating the average differences of feed offered and feed remaining from the feeders. In experiment 1, experienced sheep showed no difference in preference (average percentage eaten) in the first hour of each day compared to naïve sheep (70% vs. 56% DM intake (kg), p = 0.27). There was an increase in the amount eaten from the first to the last day for both groups, except for the intake of one accession that was reduced for the experienced sheep. In experiment 2, there was no statistical difference in preference between accessions. However, when the average percentage eaten by the experienced and naïve groups are combined, they are strongly correlated, with significant differences between accessions. Sheep did not eat more wilted tedera compared to fresh, which did not support our hypothesis. The only differences we found in sheep preference for tedera accessions occurred in experiment 1. Further studies to investigate seasonal differences in sheep preference between accessions is required and increased replication is needed to better determine the effect of prior grazing experience on the preference for tedera accessions.

Effect of exogenous fibrolytic enzymes supplementation on voluntary intake, availability of nutrients and growth performance in Black Bengal kids (Capra hircus)

A Growth experiment was conducted on fifteen weaned Black Bengal kids divided into three groups. Kids under control (T0) group were fed ad libitum Total Mixed Ration (TMR) prepared from concentrate mixture and green fodder @ 40: 60 (on a DM basis). Kids under T1 and T2 groups were supplemented with two levels of EFE (T1 with cellulase and xylanase @ 8000 and 16,000IU/kg TMR DM and T2 with 12,000 and 24,000IU/kg TMR DM). A digestion trial was also conducted during the last phase of the growth trial. The intake of nutrients, like DM, OM, CP, TDN, and DCP (g/kg W0.75) were significantly (P < 0.001) higher in enzyme-supplemented treatments. Supplementation of EFE also increased (P < 0.001) intake of DE and ME (Mcal/ kg W0.75) in Black Bengal kids. The differences in all the blood biochemical parameters and enzymes (glucose, total protein, globulin, albumin, urea, AST, and ALT) were non-significant (P > 0.05) among the three treatment groups. Average daily body weight gain (ADG, g/d/kid) was increased significantly (P < 0.05) by 7.00 % in T1 and 7.19 % in T2 over the control group (T0). The FCE (feed conversion efficiency) was also greater (P < 0.05) in both enzyme-supplemented (T1 and T2) groups compared to the control. The results depicted no additional advantage due to the supplementation of a higher level of an enzyme mixture. Therefore, it may be concluded that the supplementation of EFE @ cellulase 8000 and xylanase 16,000IU/kg diet DM increased the intake of different nutrients and growth performance in weaned Black Bengal kids.

Effects of the central melanocortin system on feed intake, metabolic hormones and insulin action in the sheep.

Voluntary feed intake is insufficient to meet the nutrient demands associated with late pregnancy in prolific ewes and early lactation in high-yielding dairy cows. Under these conditions, peripheral signals such as growth hormone and ceramides trigger adaptations aimed at preserving metabolic well-being. Recent work in rodents has shown that the central nervous system-melanocortin (CNS-MC) system, consisting of alpha-melanocyte-stimulating hormone (α-MSH) and agouti-related peptide (AGRP) acting respectively as agonist and antagonist on central MC receptors, contributes to the regulation of some of the same adaptations. To assess the effects of the CNC-MC on peripheral adaptations in ruminants, ewes were implanted with an intracerebroventricular cannula in the third ventricle and infused over days with artificial cerebrospinal fluid (aCSF), the α-MSH analog melanotan-I (MTI), or AGRP. Infusion of MTI at 0.03 nmol/h reduced intake, expressed as a fold of maintenance energy requirement (M), from 1.8 to 1.1 M (P < 0.0001), whereas AGRP at 0.3 nmol/h increased intake from 1.8 to 2.0 M (P < 0.01); these doses were used in all subsequent experiments. To assess the effect of MTI on plasma variables, sheep were fed ad libitum and infused with aCSF or MTI or pair-fed to MTI-treated sheep and infused with aCSF (aCSFPF). Feed intake of the MTI and aCSFPF groups was 40% lower than the aCSF group (P < 0.0001). MTI increased plasma triiodothyronine and thyroxine in an intake-independent manner (P < 0.05 or less) but was devoid of effects on plasma glucose, insulin, and cortisol. None of these variables were altered by AGRP infusion in sheep fed at a fixed intake of 1.6 M. To assess the effect of CNS-MC activation on insulin action, ewes were infused with aCSF or MTI over the last 3 d of a 14-d period when energy intake was limited to 0.3 M and studied under basal conditions and during hyperinsulinemic-euglycemic clamps. MTI had no effect on plasma glucose, plasma insulin, or glucose entry rate under basal conditions but blunted the ability of insulin to inhibit endogenous glucose production during hyperinsulinemic-euglycemic clamps (P < 0.0001). Finally, MTI tended to reduce plasma leptin in sheep fed at 0.3 M (P < 0.08), and this effect became significant at 0.6 M (P < 0.05); MTI had no effect on plasma adiponectin irrespective of feeding level. These data suggest a role for the CNC-MC in regulating metabolic efficiency and peripheral insulin action.

A comparison of post-ruminal provision of Ca-gluconate and Ca-butyrate on growth performance, gastrointestinal barrier function, short-chain fatty acid absorption, intestinal histology, and brush-border enzyme activity in beef heifers.

The objective of this study was to compare the effects of post-ruminal provision of Ca-butyrate (CaB) when delivered via abomasal dosing, and Ca-gluconate (CaG) when provided ruminally using a rumen protected form or using an unprotected form via abomasal dosing on short-chain fatty acid (SCFA) concentration throughout the GIT, nutrient digestibility, GIT barrier function, ruminal SCFA absorption, ruminal morphometrics, intestinal brush border enzyme activity, and blood parameters for beef heifers. Thirty-two beef heifers fitted with ruminal cannulas were used in a randomized complete block design and assigned to one of four treatments: 1) negative control (ruminal infusion of double-distilled water; CON); 2) abomasal infusion of CaB (AB; 0.0029% of BW); 3) abomasal infusion of CaG (AG; 0.0077% of BW); and 4) ruminal infusion of a hydrogenated fat-embedded CaG (RG; 0.0192% of BW) to provide ruminal protection. Excluding CON, treatments were designed to deliver the same amount of butyrate in the small intestine. Heifers were housed in individual pens and DMI was limited to 95% of voluntary intake to minimize a potential confounding effect of DMI on treatment responses. Total GIT barrier function was assessed on day 17 and SCFA disappearance was evaluated on day 21 using the temporarily isolated and washed reticulo-rumen technique. On day 28, heifers were slaughtered, and ruminal and colonic digesta were collected to assess SCFA concentration. Additionally, ruminal, jejunal, and colonic tissues were collected to assess SCFA fluxes and regional barrier function ex vivo using the Ussing chamber technique. For colonic digesta, both AB and CaG treatments reduced the proportion of acetate (P < 0.05) and increased the proportion on propionate (P < 0.05) compared to CON. Relative to CON, AB but not CaG treatments increased in vivo ruminal disappearance of total SCFA (P = 0.01), acetate (P = 0.03), propionate (P = 0.01), and butyrate (P > 0.01). Treatments did not affect (P ≥ 0.10) acetate and butyrate fluxes in the ruminal and colonic tissues when measured ex vivo; however, when compared with CON, AB tended to decrease (P = 0.09) mannitol flux across ruminal tissue. In addition, mannitol flux was affected (P < 0.01) by region, with greater mannitol flux across the jejunum than rumen and colon. We conclude that while both abomasal infusion of CaB and CaG affect the molar proportion of acetate and propionate in the colon, only abomasal CaB stimulated ruminal SCFA absorption for growing beef heifers.

Effects of supplementing rice straw with two fodder tree leaves and their combinations on voluntary feed intake, growth, and nitrogen utilization in sheep.

Fodder tree leaves (FTL) are limitless nutrient resources that provide high-quality feed, particularly during the dry season, improving animal diets, and reducing the use of concentrates in ruminant livestock farming. In order to determine the benefits of FTL, two experiments were conducted to measure the voluntary feed intake, growth performance, and nitrogen utilization of forest-type (FT) sheep fed rice straw (RS) and supplemented with either Leucaena leucocephala (LEU) or Samanea saman (SAM) or their equal combination (LS). For the growth trial (Experiment 1), 12 male FT sheep with mean initial body weight (BW) of 17.0 ± 1.0 kg (mean ± SD) were randomly assigned to one of four dietary treatments in a Completely Randomized Design. The diets were Urea-treated RS (UTS) (Control), RS + L (LEU), RS + S (SAM), and RS + 50% L + 50% S (LS). After 14 d of adjustment period, feed intakes and refusals were recorded daily, whereas BW was recorded bi-weekly for 12 wk. Four rams weighing 17.0 ± 1.0 kg BW were randomly assigned to the four treatments over a four period in a repeated (4 × 4) Latin square design to estimate the nitrogen (N) balance study (Experiment 2). Treatment diets were the same as that of Experiment 1. Dry matter intake of straw was highest (P = 0.0001) for sheep fed UTS. However, combining L with S increased (P = 0.0001) straw DM intake compared to feeding L or S alone. There was no significant difference (P > 0.05) in total feed intake between sheep offered UTS and LS, but both were significantly higher (P = 0.0001) than those offered LEU and SAM. Body weight gain (3.70 kg) and growth rate (196.15 g/d) were highest (P = 0.0001) for sheep offered LS compared to the other treatment groups. Values for N balance differed (P = 0.0001) among treatment diets. N balance for LUE and LS supplemented diets were higher than that of SAM but all were higher (P = 0.0001) than those offered UTS. Leucaena and Samanea leaves could, therefore, be utilized as supplement to poor-quality straws to improve the productivity of small ruminants especially during the long dry seasons in the tropics.

Effects of breed on preferential intake of hydroxychloride and sulfate sources of trace minerals in growing beef heifers

Abstract This study evaluated the effects of breed on voluntary preferential intake of two sources of Cu, Mn, and Zn when added to white salt-based trace mineral supplement (days 0 to 55; experiment 1) and protein supplement (days 56 to 112; experiment 2). On day 0, Nelore and ½ Angus × ½ Nelore heifers (n = 20/breed) were stratified by breed, body weight (BW = 347 ± 82 kg), and age (12 to 30 mo), and randomly allocated into 1 of the 40 drylot pens (1 heifer/pen). Both experiments were divided into washout (days 0 to 27 in experiment 1 and days 56 to 83 in experiment 2) and preferential intake periods (days 28 to 55 in experiment 1 and days 84 to 112 in experiment 2). During the respective preferential intake period, heifers were provided simultaneous free-choice access to sulfate (SUL) and hydroxychloride (HYD) sources of Cu, Mn, and Zn mixed into salt-based trace mineral supplements from days 28 to 55 (experiment 1) and then protein supplements from days 84 to 112 (experiment 2). Heifers were provided free-choice access to Tifton 85 (Cynodon sp.) hay from days 0 to 112. Effects of breed × source × day of the study were detected (P ≤ 0.05) for daily trace mineral intake from days 28 to 56 and days 84 to 112. Angus × Nelore heifers consumed a greater amount of SUL vs. HYD supplements on days 31 to 33 (P = 0.02) and HYD vs. SUL supplements on days 37 to 42 (P ≤ 0.02), whereas Nelore heifers consumed more HYD vs. SUL supplements on days 31 to 33 and 43 to 51 (P ≤ 0.05). Both breeds consumed (P ≤ 0.05) a greater amount of protein supplement containing HYD vs. SUL from days 84 to 112, but the differences in protein supplement intake increased (P ≤ 0.04) in greater magnitude for Nelore vs. Angus × Nelore heifers. Supplement intake coefficient of variation (CV) from days 28 to 41 and days 84 to 97 tended (P = 0.06) to be greater for Nelore vs. Angus × Nelore heifers. Effects of breed × source were detected (P = 0.02) for supplement intake CV from days 84 to 112. Intake CV of supplements added with HYD did not differ (P ≥ 0.40) between Nelore vs. Angus × Nelore heifers but was greater (P &amp;lt; 0.01) for Nelore vs. Angus × Nelore heifers fed SUL supplements. Overall, Nelore heifers had greater preferential intake for mineral and protein supplements containing hydroxychloride vs. sulfate sources compared to Angus × Nelore heifers. Hydroxychloride sources encouraged voluntary intake and reduced variation in supplement consumption compared to SUL sources of the same metals.