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This study aimed to determine effects of diet density on growth performance, energy balance, and nitrogen (N) balance characteristics of broiler chickens during the first wk of life. Effects of diet density were studied using a dose-response design consisting of 5 dietary fat levels (3.5, 7.0, 10.5, 14.0, and 17.5%). The relative difference in dietary energy level was used to increase amino acid levels, mineral levels, and the premix inclusion level at the same ratio. Chickens were housed in open-circuit climate respiration chambers from d 0 to 7 after hatch. Body weight was measured on d 0 and 7, whereas feed intake was determined daily. For calculation of energy balances, O2 and CO2 exchange were measured continuously and all excreta from d 0 to 7 was collected and analyzed at d 7. Average daily gain (ADG) and average daily feed intake (ADFI) decreased linearly (P = 0.047 and P < 0.001, respectively), whereas gain to feed ratio increased (P < 0.001) with increasing diet density. Gross energy (GE) intake and metabolizable energy (ME) intake were not affected by diet density, but the ratio between ME and GE intake decreased linearly with increasing diet density (P = 0.006). Fat, N, and GE efficiencies (expressed as gain per unit of nutrient intake), heat production, and respiratory exchange ratio (CO2 to O2 ratio) decreased linearly (P < 0.001) as diet density increased. Energy retention, N intake, and N retention were not affected by diet density. We conclude that a higher diet density in the first wk of life of broiler chickens did not affect protein and fat retention, whereas the ME to GE ratio decreased linearly with increased diet density. This suggests that diet density appears to affect digestibility rather than utilization of nutrients. [ABSTRACT FROM AUTHOR]

A progressive selection for broiler live and processing performance traits has changed broiler growth patterns during the post hatch period. However, limited information is available to understand whether changes have also occurred during the embryonic stages. This study aims to examine influences of broiler strain on nutrient availability, embryonic development, and nutrient metabolism during incubation. Hatching eggs of Ross 308 and Cobb 500 fast feathering were selected from breeder flocks aged 43 to 46 weeks at an egg weight range of 60 to 63 g. Eggs were obtained in 2 batches, 120 eggs per strain per batch. For each batch, 20 eggs per strain were used to determine egg composition and nutrient availability. The remaining eggs were incubated separately in one of 2 climate respiration chambers at an eggshell temperature of 37.8°C. The results showed that Ross 308 eggs had a higher yolk:albumen ratio with 0.9 g more yolk and 0.7 g less albumen than Cobb 500. Albumen + yolk of Ross 308 eggs had a higher dry matter (Δ = 0.24 g) and crude fat (Δ = 0.23 g) than that of Cobb 500 eggs, but a similar amount of crude protein. Albumen and yolk of Ross 308 eggs had a higher energy content (Δ = 8.9 kJ) compared to Cobb 500 eggs. At 3 h after hatch, Ross 308 chicks were 0.2 cm longer and had a 0.6 g heavier yolk free body mass (YFBM) than Cobb 500 chicks. During incubation, Ross 308 embryos used 13.9 kJ more energy than Cobb 500, and the efficiency of converting energy used to YFBM (EYFB) was approximately 7.6% lower compared to Cobb 500. Ross 308 chicks hatched approximately 4 h later and had less hepatic glycogen (Δ = 5 mg) than Cobb 500 chicks. It can be concluded that, Cobb 500 and Ross 308 differ in egg nutrient availability and have different trajectories for embryonic development and nutrient metabolism during incubation. [ABSTRACT FROM AUTHOR]

Six broiler starter diets, based on wheat and soybean meal, were formulated to contain 1.1 2.0, 4.0, 6.0, 8.0 and 10.0 g calcium (Ca)/kg. All diets were equivalent in respect of total and non-phytate phosphorus contents (5.4 and 3.0 g/kg, respectively). The influence of dietary treatments on the growth performance, coefficient of apparent ileal digestibility (CAID) of nitrogen (N), starch, fat and phosphorus (P), Ca retention and apparent metabolisable energy (AME) in broiler starters was evaluated. A total of 288, one-day-old male broilers (Ross 308) were allocated to 36 cages (8 birds/cage), and cages were randomly assigned to 6 dietary treatments. Birds were also provided with a source of Ca in a separate feed trough. Birds fed the diet with 1.1 g Ca/kg gained more (P<0.05) weight and tended (P=0.08) to have higher feed intake than those fed the diets with 8.0 and 10.0 g Ca/kg. Increasing dietary Ca concentrations from 1.1 to 8.0 g/kg increased (P<0.05) feed per unit gain, but diets with 1.1 and 10.0 g/kg Ca resulted in similar (P>0.05) feed per unit gain. During d 8 to 14, d 15 to 21, and over the entire trial period of 21 d, birds fed Ca-deficient (6.0 g Ca/kg and less) diets consumed more (P<0.001) of the separate Ca source. During the third week and over the 21 d trial period, total Ca intake (Ca from feed plus Ca from separate source) of birds fed Ca-insufficient diets was higher (P<0.05) than those fed diets with higher dietary Ca concentrations. Diets with 1.1 g Ca/kg resulted in the highest (P<0.05) CAID of P. There was no effect (P>0.05) of dietary Ca on the retention of Ca and ash, AME and toe ash. The present data suggest that feeding broilers low Ca diets with access to a separate Ca source, is advantageous in terms of broiler performance, while maintaining bone mineralisation. The data also demonstrate that the provision of separate Ca source may hold promise for reducing the dietary P contents. [ABSTRACT FROM AUTHOR]

Effect of cashew nut shell liquid ( CNSL), a methane inhibitor, on bovine rumen fermentation was investigated through analysis of the metabolic hydrogen flow estimated from concentrations of short-chain fatty acids ( SCFA) and methane. Three cows were fed a concentrate and hay diet without or with a CNSL-containing pellet. Two trials were conducted using CNSL pellets blended with only silica (trial 1) or with several other ingredients (trial 2). Methane production was measured in a respiration chamber system, and energy balance and nutrient digestibility were monitored. The estimated flow of metabolic hydrogen demonstrated that a part of metabolic hydrogen was used for hydrogen gas production, and a large amount of it flowed into production of methane and SCFA in both trial 1 and 2, when CNSL was administered to the bovine rumen. The results obtained by regression analyses showed that the effect of CNSL supply on methane reduction was coupled with a significant ( P < 0.01) decrease of acetate and a significant ( P < 0.01) increase of propionate and hydrogen gas. These findings reveal that CNSL is able to reduce methane and acetate production, and to increase hydrogen gas and propionate production in vivo. [ABSTRACT FROM AUTHOR]

An experiment was conducted in a 4 x 4 LSD trial using adult Labrador dogs (live weight 18.25 ± 0.25 kg, 380.75 ± 2.81 days of age) to find out the effect of incorporation of different levels of poultry slaughter waste (PSW) in dog diets on dry matter (DM) intake, palatability and digestibility of nutrients. The treatment diets were No PSW (CON; n = 6); 5% PSW (PSW5; n =6); 10% PSW (PSW10; n =6) and 15% PSW (PSW15; n =6). The test diets were prepared by extrusion cooking process and fed in the form of differently shaped dry extruded type dog biscuits. The experiment lasted for 60 days. DM intake, DM intake as % body weight (P<0.05) and DM intake per kg metabolic body weight were significantly higher (P<0.01) for the PSW5 group than other two PSW and CON groups. The adult dogs consumed all test diets with equal preference to the control diet indicating, palatability of the PSW based dog diet biscuits was good and extrusion cooking of the diets had positive impact on the intake of the diets, while shape of the biscuit had no effect on the palatability. Digestibility of OM, CP, CF (P<0.01) and EE were significantly (P<0.05) higher on PSW5 diet compared to CON diet, while PSW10 and PSW15 diets were intermediate, indicating incorporation of PSW at 5% level in dog diet biscuits prepared by extrusion cooking had positive impact on digestibility of nutrients. The cost incurred on test diet PSW15 was 11% lesser when compared to CON diet. It is concluded that, inclusion of PSW in the extruded dog diets improved palatability, DM intake and nutrient utilization and PSW could be incorporated in the adult dog diets at 15% level without any adverse effect on health of the animal while being cost effective. [ABSTRACT FROM AUTHOR]

During critical prenatal periods nutrient supply programs central control of energy balance, feed intake and body weight. In mammals as well in birds, prenatal glucose oversupply, for instance, may increases the offspring risk for metabolic disorders and related diseases throughout life. We investigated the long-lasting influence of temporary inovo hyperglycemia in chickens on neuronal mechanisms of the nucleus infundibuli hypothalami (NI), the 'critical' centre regulation metabolism, feed intake and body weight as well as on related peripheral parameters. Experiments were carried out in Lohmann White Leghorn chickens starting in embryos in three experimental groups: one untreated control group, one in-ovo injection control (daily single injection of 0.5 ml NaCl-solution) and one group prenatally experienced with temporary hyperglycemia by daily single injection of 0.5 ml glucose solution (30 mmol/l) from days 14 to 17 of incubation. After three weeks post-hatching in the untreated control group for the first time the avian neuronal glucose and leptin sensitivity was investigated using extracellular recordings in brain slices. Human recombinant leptin was also tested in combination with GABAB-receptor agonist and antagonist. The longlasting effect of temporary in-ovo hyperglycemia was examined on neuronal glucose sensitivity, the glucose transporter GLUT1 and 3, the leptin and insulin receptor expression as well as on the total body fat and blood glucose level. Additional, in male and female chickens the body weight development was recorded in all experimental groups during the total 3-weeks growing period. Results can be summarized as follows (RANCOURT et al., 2015; TZSCHENTKE et al., 2015; BOGATYREV et al., 2017): 1) NI-neurons show mammalian-like responsiveness after acute glucose, leptin and GABA application. GABAB-mechanisms involved in GABA release play a likely important role in the leptin mediated effects on NI neurons via functional leptin receptors. 4) Temporary late prenatal hyperglycemia induces lasting hypothalamic 'glucose-resistance' via strongly decreased neuronal glucose sensitivity as well glucose transporter, insulin- and leptin receptor expression. 3) After 3 weeks post-hatching the strong changes in the neuronal mechanisms were not accompanied by changes in related peripheral metabolic parameters as well in the body weight in male and female chickens. In conclusion, although in 3 weeks old chickens no changes in peripheral metabolic parameters and body weight development could be observed, just temporary hyperglycemia during the second half of incubation, may leading to persistent malprogramming in central control of energy balance, feed intake and body weight as predisposition for the development of metabolic disorders. It shows a risk of in-ovo feeding. Further, the chicken embryo provides a valuable new model for investigating early central nervous origins of 'diabesity' and related diseases. [ABSTRACT FROM AUTHOR]