Reflux of N-labeled uric acid after intracloacal infusion in broiler chickens fed low- or high-protein diets.

Reflux of urine from the cloaca into the ceca provides chickens with a mechanism for recycling of urinary-Nitrogen (N) in a way analogous to urea recycling in mammals. However, it is unknown if reflux has substantial relevance in current poultry husbandry, where birds are fed ad libitum and have high protein intake. To evaluate the fate of urinary-N in ad libitum-fed broiler chickens, 15-day-old broilers were assigned to a high (21.

Dietary Protein Intake and Distribution Patterns of Well-Trained Dutch Athletes.

Dietary protein intake should be optimized in all athletes to ensure proper recovery and enhance the skeletal muscle adaptive response to exercise training. In addition to total protein intake, the use of specific proteincontaining food sources and the distribution of protein throughout the day are relevant for optimizing protein intake in athletes. In the present study, we examined the daily intake and distribution of various proteincontaining food sources in a large cohort of strength, endurance and team-sport athletes.

Dietary Amino Acid Deficiency Reduces the Utilization of Amino Acids for Growth in Growing Pigs after a Period of Poor Health.

Background: During immune system activation, partitioning of amino acids (AAs) changes between protein gain and use by the immune system.

Objective: We determined the effects of health status and dietary AA deficiency on nitrogen retention and AA utilization in pigs.

Methods: Barrows (55 d of age) were obtained from good health (GH, n = 14) or poor health (PH, n = 14) status farms and allocated to a diet either adequate in essential amino acids (Adq) or 25% deficient in Met + Cys, Thr, and Trp (Def).

Fermentation in the small intestine contributes substantially to intestinal starch disappearance in calves.

Background: The proportion of starch disappearing from the small intestinal lumen is generally lower in ruminants than in monogastric animals, and there are indications that the starch digestion capacity in ruminants is limited.

Objectives: Milk-fed calves were used to study the rate-limiting enzyme in starch hydrolysis and to quantify starch fermentation in ruminants.

Methods: Forty male Holstein-Friesian calves were fed milk replacer containing either lactose (control) or 1 of 4 corn starch products.

Induced lung inflammation and dietary protein supply affect nitrogen retention and amino acid metabolism in growing pigs.

It is hypothesised that during immune system activation, there is a competition for amino acids (AA) between body protein deposition and immune system functioning. The aim of the present study was to quantify the effect of immune system activation on N retention and AA metabolism in growing pigs, depending on dietary protein supply. A total of sixteen barrows received an adequate (Ad) or restricted (Res) amount of dietary protein, and were challenged at day 0 with intravenous complete Freund's adjuvant (CFA).

Urea recycling contributes to nitrogen retention in calves fed milk replacer and low-protein solid feed.

Urea recycling, with urea originating from catabolism of amino acids and hepatic detoxification of ammonia, is particularly relevant for ruminant animals, in which microbial protein contributes substantially to the metabolizable protein supply. However, the quantitative contribution of urea recycling to protein anabolism in calves during the transition from preruminants (milk-fed calves) to ruminants [solid feed (SF)-fed calves] is unknown. The aim of this study was to quantify urea recycling in milk-fed calves when provided with low-protein SF.

High environmental temperature increases glucose requirement in the developing chicken embryo.

Environmental conditions during the perinatal period influence metabolic and developmental processes in mammals and avian species, which could impact pre- and postnatal survival and development. The current study investigated the effect of eggshell temperature (EST) on glucose metabolism in broiler chicken embryos. Broiler eggs were incubated at a high (38.

A diet high in resistant starch modulates microbiota composition, SCFA concentrations, and gene expression in pig intestine.

Resistant starch (RS) is highly fermentable by microbiota in the colon, resulting in the production of SCFAs. RS is thought to mediate a large proportion of its health benefits, including increased satiety, through the actions of SCFAs. The aim of this study was to investigate the effects of a diet high in RS on luminal microbiota composition, luminal SCFA concentrations, and the expression of host genes involved in SCFA uptake, SCFA signaling, and satiety regulation in mucosal tissue obtained from small intestine, cecum, and colon.

Effects of dietary fibers with different fermentation characteristics on feeding motivation in adult female pigs.

Dietary fibers can be fermented in the colon, resulting in production of short-chain fatty acids (SCFA) and secretion of satiety-related peptides. Fermentation characteristics (fermentation kinetics and SCFA-profile) differ between fibers and could impact their satiating potential. We investigated the effects of fibers with varying fermentation characteristics on feeding motivation in adult female pigs.

Asynchronous supply of indispensable amino acids reduces protein deposition in milk-fed calves.

A balanced supply of indispensable amino acids (AA) is required for efficient protein synthesis. Different absorption kinetics (e.g.

Effects of pretreatment of wheat bran on the quality of protein-rich residue for animal feeding and on monosaccharide release for ethanol production.

The effects of hydrothermal conditions for pretreating wheat bran on the quality of residual protein for animal feeding, and on monosaccharide release for ethanol production were studied according to a 4×2×2 design with the factors, temperature (120, 140, 160, and 180°C), acidity (pH 2.3 and 3.9), and retention time (5 and 10 min).

The effects of bulking, viscous and gel-forming dietary fibres on satiation.

The objective was to determine the effects of dietary fibre with bulking, viscous and gel-forming properties on satiation, and to identify the underlying mechanisms. We conducted a randomised crossover study with 121 men and women. Subjects were healthy, non-restrained eaters, aged 18-50 years and with normal BMI (18.

Effects of dietary fibers with different physicochemical properties on feeding motivation in adult female pigs.

The satiating effects of dietary fiber may depend more on physicochemical properties of the fiber than on total fiber intake. These properties are expected to affect satiety feelings and feeding motivation due to different effects in the gastrointestinal tract. The aim of the current study was to assess the effects of fibers with varying physicochemical properties (bulkiness, viscosity and fermentability) on feeding motivation in adult female pigs.

Quantifying resistant starch using novel, in vivo methodology and the energetic utilization of fermented starch in pigs.

To quantify the energy value of fermentable starch, 10 groups of 14 pigs were assigned to one of two dietary treatments comprising diets containing 45% of either pregelatinized (P) or retrograded (R) corn starch. In both diets, a contrast in natural ¹³C enrichment between the starch and nonstarch components of the diet was created to partition between enzymatic digestion and fermentation of the corn starch. Energy and protein retention were measured using indirect calorimetry after adapting the pigs to the diets for 3 wk.

Oxidation of dietary stearic, oleic, and linoleic acids in growing pigs follows a biphasic pattern.

We used the pig as a model to assess the effects of dietary fat content and composition on nutrient oxidation and energy partitioning in positive energy balance. Pigs weighing 25 kg were assigned to either: 1) a low fat-high starch diet, or 2) a high saturated-fat diet, or 3) a high unsaturated-fat diet. In the high-fat treatments, 20% starch was iso-energetically replaced by 10.

Tissue methionine cycle activity and homocysteine metabolism in female rats: impact of dietary methionine and folate plus choline.

Impaired transfer of methyl groups via the methionine cycle leads to plasma hyperhomocysteinemia. The tissue sources of plasma homocysteine in vivo have not been quantified nor whether hyperhomocysteinemia is due to increased entry or decreased removal. These issues were addressed in female rats offered diets with either adequate or excess methionine (additional methyl groups) with or without folate and choline (impaired methyl group transfer) for 5 wk.

Body fat deposition does not originate from carbohydrates in milk-fed calves.

Milk-fed heavy calves utilize dietary protein with a low efficiency and often develop hyperglycemia and insulin resistance. Distributing the daily nutrient intake over an increasing number of meals increases protein deposition and improves glucose homeostasis. Therefore, we examined effects of feeding frequency (FF) and feeding level (FL) on the diurnal pattern of substrate oxidation and on the fate of dietary carbohydrates in milk-fed heavy calves.

Whole body and muscle energy metabolism in preruminant calves: effects of nutrient synchrony and physical activity.

The effects of asynchronous availability of amino acids and glucose on muscle composition and enzyme activities in skeletal muscle were studied in preruminant calves. It was hypothesized that decreased oxidative enzyme activities in muscle would explain a decreased whole body heat production with decreasing nutrient synchrony. Preruminant calves were assigned to one of six degrees of nutrient synchrony, step-wise separating the intake of protein and lactose over the two daily meals.

Synchronizing the availability of amino acids and glucose decreases fat retention in heavy preruminant calves.

Effects of synchronizing the availability of amino acids and glucose within a day on protein and energy metabolism were studied in heavy preruminant calves. Thirty-six preruminant calves (148 +/- 1.6 kg body weight) were assigned to 1 of 6 degrees of nutrient synchrony (SYN, 1-6) and to 1 of 2 meal sequences (i.

Reviewing the low efficiency of protein utilization in heavy preruminant calves--a reductionist approach.

The efficiency of protein utilization for growth in preruminant calves is decreasing with increasing body weight. In contrast to calves weighing less than 100 kg of body weight, heavy preruminant calves do not respond in protein retention to an increased intake of indispensable amino acids in dose-response studies. The marginal efficiency of protein utilization is low compared with pigs and milk-fed lambs at a similar stage of maturity.