Evolution of complex flowering strategies: an age- and size-structured integral projection model

We explore the evolution of delayed age- and size-dependent flowering in the monocarpic perennial Carlina vulgaris, by extending the recently developed integral projection approach to include demographic rates that depend on size and age. The parameterized model has excellent descriptive properties both in terms of the population size and in terms of the distributions of sizes within each age class. In Carlina the probability of flowering depends on both plant size and age. We use the parameterized model to predict this relationship, using the evolutionarily stable strategy (ESS) approach. Despite accurately predicting the mean size of flowering individuals, the model predicts a step-function relationship between the probability of flowering and plant size, which has no age component. When the variance of the flowering-threshold distribution is constrained to the observed value, the ESS flowering function contains an age component, but underpredicts the mean flowering size. An analytical approximation is used to explore the effect of variation in the flowering strategy on the ESS predictions. Elasticity analysis is used to partition the agespecific contributions to the finite rate of increase (u) of the survival-growth and fecundity components of the model. We calculate the adaptive landscape that defines the ESS and generate a fitness landscape for invading phenotypes in the presence of the observed flowering strategy. The implications of these results for the patterns of genetic diversity in the flowering strategy and for testing evolutionary models are discussed. Results proving the existence of a dominant eigenvalue and its associated eigenvectors in general size- and age-dependent integral projection models are presented

Effect of wheat distillers dried grains with solubles and exogenous xylanase on laying hen performance and egg quality

Despite the rapid increase in the use of wheat distillers dried grains with solubles (DDGS) within the poultry sector, little information is available on how the long-term feeding of this by-product will affect the performance of laying hens. This experiment examined the effect of wheat DDGS, with and without exogenous xylanase on dietary apparent metabolizable energy (AME), total tract dry matter retention (DMR), nitrogen retention (NR), fat digestibility (FD) coefficients, feed intake (FI), bodyweight gain (BWG), eggs laid, mean egg weight, egg mass output, and egg quality characteristics including albumin height (AH), Haugh units (HU), yolk color, eggshell strength, and thickness. A total of 320 Hy-Line brown laying hens were randomly allocated to 80 enriched layer colonies (groups of 4). A total of 2 control wheat-soybean meal-based diets were formulated to contain 11.60 MJ/kg. One of the diets contained 300 g/kg wheat DDGS, while the other was DDGS free, with a respective crude protein content of 171.1 g/kg and 166.5 g/kg. Both diets were divided by 2 and half of them were supplemented with 2,500 U/kg of xylanase, resulting in 4 diets in total. Data was analyzed as a 2 × 2 factorial arrangement of treatments with analysis of variance (ANOVA). Diets were fed ad libitum from 17 to 43 wk of age and data was collected from 23 to 43 wk. The inclusion of wheat DDGS reduced (P < 0.001) dry matter retention (DMR), FI, BWG, eggs laid, mean egg weight, and egg mass. However, xylanase supplementation improved AME and NR in diets containing wheat DDGS and FD in diets without DDGS (DDGS × xylanase, P < 0.05) and tended to improve (P < 0.10) BWG and egg mass output. For egg quality measurements, the inclusion of DDGS improved (P = 0.046) HU values, eggshell strength (P < 0.001), and increased (P < 0.001) yolk color intensity. This experiment showed xylanase can be used to improve the AME and NR of DDGS-based diets. However, the long-term feeding of 300 g/kg wheat DDGS negatively impacts the productive performance of hens

Exogenous tannase improves feeding value of a diet containing field beans (Vicia faba) when fed to broilers

A total of 72 male Ross 308 broilers were used in a study to investigate the effect of dietary tannase on apparent metabolisable energy (AME), coefficients of dry matter retention (DMR) and nitrogen retention (NR) and fat digestibility (FD) of a diet containing 300 g/kg field beans (Vicia faba). Growth performance variables and gastrointestinal tract development were also measured. Two treatments were used in this study: control (C) and C + 3400 tannase units (TU) per kg feed. Diets were formulated to be nutritionally adequate with the exception that the AME was lower than recommended (12.65 vs 12.97 MJ/kg, respectively). Inclusion of tannase increased AME by 0.4 MJ/kg DM. Tannase supplementation improved dietary DMR, NR and FD by 2.8%, 3.2% and 6.5%, respectively. Birds given tannase had 4.4% reduction in feed intake and 2.6% improvement in gain to feed ratio (P < 0.05). Compared to control diet, birds given tannase had reduced relative to body weight (%BW) proventriculus and gizzard and pancreas weights, 3.29% vs 3.09% and 0.47% vs 0.44%, respectively. The mechanisms of action of the studied enzyme require further elucidation

Immune modulation, growth performance, and nutrient retention in broiler chickens fed a blend of phytogenic feed additives

his study aimed to assess the effect of a commercial blend of phytogenic feed additives (PA), comprising 5% carvacrol, 3% cinnamaldehyde, and 2% capsicum oleoresin on the modulation of immune biomarkers of broiler chickens, their growth performance, dietary energy, and nutrient retention. Four-hundred day-old birds were assigned to one of four dietary treatments. Two control diets based on either wheat (WC) or maize (MC) were each given with and without PA at 100 g/t. Growth performance variables including feed intake (FI), weight gain (WG), and feed conversion ratio (FCR) were recorded. Dietary N-corrected apparent metabolizable energy (MEn), dry matter (DMR), nitrogen (NR), and fat retention (FR) coefficients were also determined. Gene expression of immune biomarkers (cytokines) were determined in caecal tonsil tissue from 21 d old birds. Expression of IL2, IL18, IL10, and IL17C in the caecal tonsils were upregulated (P 0.05) change in expression levels in birds fed MC diets. Feeding MC diets gave greater FI (P 0.05) by cereal type. Supplementary PA improved FI (P < 0.05), WG (P < 0.001), FCR (P < 0.05), MEn (P < 0.05), MEn: GE ratio (P < 0.05), and FR (P < 0.05). In conclusion, dietary inclusion of PA improved overall growth performance variables, energy, and nutrient retention and intestinal cytokine expression

Short communication: Pelleting increases the metabolizable energy of de-hulled sunflower seed meal for broilers

The study examined the effects of two methods of processing de-hulled sunflower seed meal (SFM) from the same batch of sunflower seeds. Sunflower seed meal was fed to broilers as meal (MSFM) or after it had been pelleted (PSFM) at 75 °C and 360 kPa pressure to pass through a 3 mm mesh. Three diets were prepared, namely a balancer feed (BF) and two diets containing 200 g/kg MSFM or 200 g/kg PSFM. They were fed to 30 pens (two birds each) with male Ross 308 broilers, from 8 to 21 days old, following randomization. Data were analysed by ANOVA. Two pre-planned orthogonal contrast tests were performed to compare overall differences between the diets containing SFM and BF and between diets containing the MSFM and PSFM. The BF had a very different nutrient composition from the complete feeds containing SFM so, as expected, there were differences in growth performance and nutrient retention. The diet containing PSFM had greater apparent metabolizable energy corrected for N retention (AMEn) and dry matter retention (DMR) than that containing MSFM. The use of the substitution method showed the PSFM had AMEn that was 18% greater than the MSFM (8.79 vs 7.47 MJ/kg DM). Under the conditions of the current study, incorporating PSFM in a mash broiler feed increased dietary AMEn compared with the same feed containing MSFM. Further studies are needed to identify whether the benefits of pre-pelleting SFM remain after this product has been incorporated in complete pelleted broiler feeds

Nutritional value of raw and micronised field beans (Vicia fabaL. var.minor) with and without enzyme supplementation containing tannase for growing chickens

An experiment examined the effects of two field bean cultivar samples with different tannin contents, the effect of heat treatment (micronising) and the effect of dietary supplementation of a proprietary enzyme preparation containing tannase, pectinase, and xylanase activities on metabolisable energy (ME), total tract dry matter digestibility (DMD) and ether extract digestibility (EED), nitrogen retention (NR), tannin degradability, gastrointestinal tract (GIT) development, and endogenous mucin losses excretion in broiler chickens. The Control diet contained per kg 221 g crude protein and 12.83 MJ ME. Four additional diets contained 300 g/kg of each of the two untreated or micronised experimental field bean cultivar samples. Each diet was then split into two batches and one of them was supplemented with 3400 units tannase per kg diet resulting in 10 diets in total. Each diet was fed to seven pens with two randomly selected male broilers each. Birds fed the high tannin bean sample had a lower weight gain (p < 0.001), and a lower determined apparent ME (p < 0.05), and DMD (p < 0.001) but a higher tannin degradability (p < 0.001). Compared to the Control diet, feeding field beans increased (p < 0.001) the weights of the proventriculus and gizzard of the birds, and also increased endogenous mucin losses (p < 0.05). Supplementing diets with the tannase-containing enzyme preparation improved dietary ME (p < 0.001), DMD (p < 0.001), NR (p < 0.001) and DEE (p < 0.05), but did not change tannin degradability. Heat treatment of the beans reduced the degradability of condensed tannins and increased endogenous mucin losses (p < 0.05). The differences in the feeding value of the different field bean samples were not improved by heat treatment, but enzyme supplementation improved the feeding value of all diets regardless of the bean samples or heat treatment. Further research is warranted to study the effectiveness of tannase supplementation in poultry diet formulations by dose response trials with purified tannase preparations

The temperature of storage of a batch of wheat distillers dried grains with solubles samples on their nutritive value for broilers

A batch of wheat distillers dried grains with solubles (DDGS) was obtained immediately after production and was separated into 5 equal parts and placed in woven polypropylene sacks. The samples were stored under 5 different temperature conditions for one year as follows: kept at a constant -20ºC; kept at -20ºC for 24 h period and after that kept at a constant +4ºC; kept at a constant +4ºC only; kept at a constant +15ºC; stored at ambient temperature (range of weekly mean temperatures was from +4 to +22ºC). 2. Each of the 5 wheat DDGS samples was included (200 g/kg) in a nutritionally complete diet and fed to broiler chickens from 7 to 21 d of age. The chemical composition of the DDGS samples was determined at the beginning and at the end of the one year storage period. 3. The nitrogen corrected apparent metabolisable energy (AMEn) and the nutrient availability of each sample was measured using a total collection technique. The growth performance of birds was also determined. 4. The DDGS samples kept at a constant -20ºC had higher dry matter, lower oxidation value and lower antioxidant contents. The DDGS sample that was stored at ambient temperatures had a higher AMEn than the rest of the DDGS samples. 5. The results of this experiment have shown that there can be changes in the AMEn of wheat DDGS during storage at ambient temperatures. In general, there were no serious effects of storage of DDGS on its feeding value to broiler chickens

Dietary modelling of nutrient densities: Effect and response in different growing phases on growth performance, nutrient digestibility, litter quality and leg health in turkey production.

An experiment was conducted to explore the time bound (different growth phases) effect of different dietary nutrient densities i.e., different energy and protein concentration while maintaining the ratio between the two, all with the same ideal amino acid profile, on litter quality and leg health (footpad dermatitis (FPD) and hock burn (HB)), when fed to growing turkeys. The effects of dietary nutrient modelling on growth performance parameters, water intake and excretion, dry matter (DMD), organic matter (OMD), crude protein (CPD) digestibility coefficients and apparent metabolisable energy (AME) were also examined, when fed to growing turkeys invarying growth phases. At twenty-eight days of age one hundred and seventy five male turkeys (BUT 8) were transferred to 35 floor pens, using stratified randomisation on body weight, 5 birds in a pen, all pens were equipped with plastic feed hoppers and drinkers. The experiment was a randomized block design consisting of 5 treatments (5 levels of CP and ME concentrations and 4 feeding/ growth phases). Each dietary treatment was replicated 7 times with 5 birds in each replicate. Feed and water were offered ad libitum throughout the experiment. Five dietary treatments, containing either 77, 85, 100, 110 or 120% of the crude protein (CP) and metabolisable energy (ME) content recommended by the breed standard. The whole experimental period of 16 weeks starting from 4 weeks of age was divided into 4 weeks standard growth phases: 4-8, 8-12, 12-16 and 16-20 weeks, finishing at 20 weeks of turkey’s age, according to commercial management guide for BUT 8 (Aviagen Turkeys Ltd.). Nutrient density had a positive and linear effect (P<0.001) on weight gain, feed efficiency and dry matter digestibility (DMD) whereas the effect of nutrient density on dietary protein digestibility (CPD) only approached significance (P=0.081). As might be expected increasing nutrient density had a negative and linear effect on feed (P<0.001) and water (P<0.01) intake and did not affect the ratio between these two parameters. Increasing nutrient density had a positive effect on litter quality (linear (P 0.05) of treatment on FPD. The results suggest that an increase in nutrient concentration can reduce the moisture content of the litter and so improve overall litter quality. However, the incidence of hock burn increased with the high nutrient density diet s, suggesting that factors other than the litter moisture alone may contribute the occurrence of leg health problems in turkey production

Transcriptome analysis of hepatic gene expression and DNA methylation in methionine- and betaine-supplemented geese (Anser cygnoides domesticus)

Dietary methionine (Met) restriction produces a coordinated series of transcriptional responses in the liver that limits growth performance and amino acid metabolism. Methyl donor supplementation with betaine (Bet) may protect against this disturbance and affect the molecular basis of gene regulation. However, a lack of genetic information remains an obstacle to understand the mechanisms underlying the relationship between Met and Bet supplementation and its effects on genetic mechanisms. The goal of this study was to identify the effects of dietary supplementation of Met and Bet on growth performance, transcriptomic gene expression, and epigenetic mechanisms in geese on a Met-deficient diet. One hundred and fifty 21-day-old healthy male Yangzhou geese of similar body weight were randomly distributed into 3 groups with 5 replicates per treatment and 10 geese per replicate: Met-deficient diet (Control), Control+1.2 g/kg of Met (Met), and Control+0.6 g/kg of Bet (Bet). All geese had free access to the diet and water throughout rearing. Our results indicated that supplementation of 1.2 g/kg of Met in Met-deficient feed increased growth performance and plasma homocysteine (HCY) levels, indicating increased transsulfuration flux in the liver. Supplementation of 0.6 g/kg Bet had no apparent sparing effect on Met needs for growth performance in growing geese. The expression of many genes critical for Met metabolism is increased in Met supplementation group. In the Bet-supplemented group, genes involved in energy production and conversion were up-regulated. Dietary supplementation with Bet and Met also altered DNA methylation. We observed changes in the methylation of the LOC106032502 promoter and corresponding changes in mRNA expression. In conclusion, Met and Bet supplementation in geese affects the transcriptional regulatory network and alters the hepatic DNA methylation of LOC106032502

Variation in the chemical composition and the nutritive quality of different field bean UK grown cultivar samples for broiler chicks

1. The chemical composition and physical characteristics of 10 different UK grown field bean cultivar samples from the same harvest year were determined. 2. Diets included each bean sample at a level of 200 g/kg, and were used to compare broiler growth performance and determine N-corrected apparent metabolisable energy (AMEn) and nutrient utilisation. The AMEn and nutrient retention coefficients for the bean samples were obtained via the slope ratio method. The relationships were examined between variation in nutritive value for broilers and the laboratory analysis of the bean samples. 3. The data showed significant differences (P<0.05) among the bean cultivar samples for feed conversion ratio, AMEn and dry matter retention (DMR) coefficients. Further analysis showed that the feeding quality of different field bean cultivar samples, measured as AMEn, was highly correlated to crude protein (CP) (P<0.05) and colour (P<0.001) of the samples. Thus, beans with higher CP and pale colour had superior feeding value for broilers