Growth performance of Hubbard × Cobb 500 and Ross × Ross 708 male broilers fed diets varying in apparent metabolizable energy from 14 to 28 days of age

The cost of energy-contributing ingredients has increased over the last several years. Defining minimum dietary energy specifications for broilers is a strategy to mitigate high diet cost. Two experiments were conducted to evaluate the effects of diets with graded concentrations of AME_n fed to Hubbard × Cobb 500 (experiment 1) and Ross × Ross 708 (experiment 2) male broiler chicks from 14 to 28 d of age. Both experiments were identical in experimental procedures with the exception of genetic strain. Broilers were fed a common corn-soybean meal-based starter diet from 1 to 13 d of age. At 14 d of age, dietary treatments were provided with 1 of 6 concentrations of AME_n (3,000, 3,030, 3,060, 3,090, 3,120, and 3,150 kcal/kg). In experiment 1, BW gain, feed intake, and FCR of Hubbard × Cobb 500 broilers decreased linearly with increasing AME_n. Linear broken-line response of FCR was estimated at 3,062 kcal of AME_n/kg based on broken-line methodology. In experiment 2, Ross × Ross 708 broilers did not respond to graded concentrations of energy, as indicated by linear and quadratic regression of BW gain, feed intake, caloric conversion, and FCR data. Therefore, Hubbard × Cobb 500 male broilers respond to AME_n from 14 to 28 d of age and may be fed diets formulated at 3,062 kcal of AME_n/kg without loss of performance. Conversely, growth performance of Ross × Ross 708 male broilers was not affected by varying AME_n (3,000 to 3,150 kcal/kg) from 14 to 28 d of age. In addition, the response to AME_n may not be as pronounced with the modern broiler compared with broilers used in previous research.     

Growth and meat yield responses of Ross × Ross 708 male broilers fed diets formulated with distillers dried grains with solubles varying in ether extract content and inclusion rate from 1 to 49 days of age

An experiment was conducted to evaluate the effects of diets containing low-, moderate-, or high-oil dried distillers dried grains with solubles (DDGS) included at conventional- or increased-inclusion rates fed to 1,500 Ross × Ross 708 male broilers that were assigned to 60 floor pens from 1 to 49 d of age. Three sources of DDGS had ether extract composition of 6.06, 8.80, or 11.59%, on dry matter (DM) basis, representing low-oil, moderate-oil, or high-oil DDGS, respectively. Diets were formulated to contain corn, soybean meal, animal protein meal as the primary ingredients, and 1 of the 3 DDGS sources at either 5, 7, 9, or 11% (conventional-inclusion rate) and 8, 10, 12, or 14% (increased-inclusion rate) in the starter (1 to 14 d), grower (15 to 24 d), finisher 1 (25 to 34 d), and finisher 2 (35 to 49 d) periods, respectively. Apparent ME_n (low-oil:1,975, moderate-oil: 2,644, and high-oil: 3,137 kcal/kg) and digestible amino acid (AA) values of the 3 DDGS sources were determined from previous research. No differences were detected for cumulative BW gain and feed conversion 1 to 49 d of age or meat yields at 50 d of age. Feeding broilers diets containing the low-oil DDGS source increased feed cost per BW gain and breast meat weight of $0.025/kg and $0.004/kg compared with birds fed diets containing high-oil DDGS or moderate-oil and high-oil DDGS sources, respectively. These data indicated that DDGS source and inclusion rate did not affect cumulative growth and carcass characteristics of broilers from 1 to 50 d of age but demonstrate differences in feed cost/BW gain and feed cost/breast meat weight.     

Non-phytate phosphorus requirement for broilers from 8 to 21 days of age under heat stress conditions

Two trials were conducted to determine the non-phytate phosphorus (nPP) requirement for broiler under heat stress. In both trials, birds were distributed in a completely randomized 4 × 2 factorial design with four nPP concentrations: 0.25, 0.35, 0.45, and 0.55%, and two Ca supply techniques: Ca fixed at 0.899% (CaF) or varying along with nPP aiming a 2:1 Ca to nPP ratio (CaV). Both trials had eight pens/treatment, with nine and five birds/pen for exp. 1 and exp. 2, respectively. nPP concentration had no effect on feed intake (FI), body weight gain (BWG), feed conversion ratio (FCR), nor fat deposition ratio (FDR). nPP levels showed a linear effect on protein deposition ratio (PDR) only for CaF diets. The nPP levels had a significant effect, regardless the technique adopted, on tibia phosphorus (TibP), which varied quadratically, on tibia calcium (TibCa) that increased quadratically and linearly, respectively, on CaF and CaV diets, and on tibia ash (TibAsh) that showed a quadratic effect for both. No effect was observed on Ca to P ratio in the tibia (TibCa:TibP). The nPP levels showed a linear increase effect over phosphorus intake (PI), phosphorus excreted (PE), and phosphorus retained (PR), and a linear decrease effect on phosphorus retention coefficient (PRC). Therefore, the nPP requirement for broilers from 8 to 21 days of age that provided better performance and bone variables were 0.250 and 0.484%, respectively, for CaF diets and 0.250 and 0.511%, respectively, for CaV diets.     

Effect of dietary α -tocopherol concentration on performance and some immune responses in broiler chickens fed on diets containing oils from different sources

1. An investigation was carried out into the effects of dietary α-tocopherol (α-T) concentration and source of supplemental oil on performance, activity of anti-oxidative enzymes and some immune responses in broilers from day-old to 41 d of age. 2. Three dietary concentrations of α-T (10, 50 and 100 mg/kg) with three sources of supplemental oil (sunflower - SFO, palm - PMO and safflower - SAO) were provided using a 3 × 3 experimental design. 3. Body weight gain and food conversion efficiency were not affected by either interaction or concentrations of α-T and sources of oil in diet. 4. Concentrations of total protein, globulin, triglycerides and cholesterol in sera increased significantly with dietary α-T concentration irrespective of the source of oil. Significantly higher concentration of serum albumin was evident in broilers fed on the SFO-based diet and the concentration of globulin was higher in groups fed on those diets containing PMO and SAO. 5. The lipid peroxidation (LP), measured as MDA release, decreased with the concentration of α-T in a dose-related manner with SFO- and SAO-based diets, although not with the PMO-based diet. With different oil sources, LP was significantly lower with the PMO-based diet compared to the others. Activities of glutathione peroxidase and RBC catalase increased and heterophil: lymphocyte ratio was reduced with concentration of α-T for each source of oil tested. 6. Assays for humoral and cell-mediated immune responses indicated no effect of the source of dietary supplemental oil or interaction, although an increasing concentration of dietary α-T improved cell-mediated immune responses. 7. It is concluded that sunflower oil, palm oil and safflower oil can be used as sources of oil for broiler diets without having any effect on performance, immune responses or the activity of anti-oxidizing enzymes. Higher concentrations of dietary α-tocopherol (50 or 100 mg/kg) reduced lipid peroxidation activity and enhanced activities of anti-oxidative enzymes, they also improved the cell-mediated immune responses in commercial broilers.     

Effect of energy density of diet on growth performance of Thai indigenous (50% crossbred) Korat chickens from hatch to 42 days of age

The aim of the current study was to investigate the effect of the energy density of diet on the growth performance of Thai indigenous crossbred (50%) chickens known as Korat chicken (KRC). A total of 1440 mixed-sex KRC (720 birds in each phase) were randomly allocated to 4 dietary treatments containing 2750, 2900, 3050, or 3200 kcal ME/kg diet with 6 replicates of each treatment in a completely randomized design. The experimental diets were tested from hatch to 21 days and from 22 to 42 days of age. In both age groups, body weight gain was not affected (P >?0.05) by the ME density of the diets. Feed intake however decreased with increasing (metabolizable energy) ME (P <?0.05), thereby significantly improving the feed conversion ratio (FCR). Broken-line analysis was performed to estimate the ME content of feed to obtain minimum FCR and maximum protein efficiency ratio (PER) values. Minimum FCR and maximum PER values were found when the diet contained 3000 kcal ME/kg from hatch to 21 days of age and 3175 kcal ME/kg from 22 to 42 days of age, respectively, using diets containing 7.5 and 6.6 g of protein/100 kcal ME, respectively. In conclusion, we established that the ME requirements of KRC from hatch to 21 days and 22 to 42 days of age were 3000 and 3175 kcal/kg, respectively.     

Plasma alpha 1‐acid glycoprotein concentration in broilers: Influence of age,sex and injection of escherichia coli lipopolysaccharide

1. The influence of age, sex and injection of Escherichia coli lipopolysaccharide (LPS) on the plasma concentration of alpha‐1 acid glycoprotein (AGP) was determined in broilers using the single radial immunodiffusion method.

2. Plasma AGP concentration increased in the 3 d after hatching, and then stabilised at 240 ± 33 μg/ml up to 14 d of age.

3. No sex‐related differences in plasma AGP concentration were observed up to 6 weeks of age.

4. A single injection of 900 μg LPS per chick resulted in a 5‐fold increase in AGP concentration compared with that in saline‐injected chicks. Multiple injections of LPS (200 μg/chick every 2d for 14d) caused only a 50% increase in AGP concentration.     

Dietary calcium requirements of broilers fed a conventional corn-soybean meal diet from 1 to 21 days of ageOA

Background: The current calcium(Ca) recommendation for broilers is primarily based on studies conducted more than 30 years ago with birds of markedly different productive potentials from those which exist today. And the response indicators in these studies are mainly growth performance and bone ash percentage. Therefore, the present study was carried out to investigate the effect of dietary Ca level on growth performance, serum parameters, bone characteristics and Ca metabolism-related gene expr...     

Ultrasonography of the spleen,liver, gallbladder,caudal vena cava and portal vein in healthy calves from birth to 104?days of age

Background

Many of the ultrasonographic abdominal findings of adult cattle probably also apply to calves. However, significant changes associated with ruminal growth and transition from a milk to a roughage diet occur in young calves during the first few months, and it can be expected that ultrasonographic features of organs adjacent to the rumen such as spleen and liver also undergo significant changes. These have not been investigated to date and therefore the goal of this study was to describe ultrasonographic findings of the spleen, liver, gallbladder, caudal vena cava and portal vein in six healthy calves from birth to 104 days of age. Standing calves were examined ultrasonographically six times at three-week intervals starting on the first or second day of life using a 5.0-MHz transducer and techniques described previously.

Results

The spleen was imaged on the left at the 5th to 12th intercostal spaces. The dorsal and ventral visible limits ran from cranioventral to caudodorsal because of superimposition of the lungs. The size of the spleen was largest at the 7th and 8th intercostal spaces and the maximum thickness was measured at the 9th to 12th intercostal spaces. The liver was seen in all calves on the right and could be imaged at the 5th to 12th intercostal spaces and the area caudal to the last rib. Similar to the spleen, the dorsal visible margin of the liver ran parallel to the ventral border of the lungs. The visible size of the liver was largest at the 8th to 11th intercostal spaces and the maximum thickness was measured at the 8th and 9th intercostal spaces. The parenchymal pattern consisted of numerous fine echoes homogeneously distributed over the entire organ. The gallbladder was most commonly seen at the 9th intercostal space and was circular, oval or pear-shaped on ultrasonograms. It extended beyond the ventral border of the liver depending on the amount of bile. The caudal vena cava was triangular in cross section but sometimes had a round or oval profile and was always seen in at least one intercostal space. The maximum circumference was measured at the 10th and 11th intercostal spaces. The portal vein was circular or oval in cross section and was characterised by stellate ramifications branching into the liver parenchyma. The portal vein could always be imaged at the 7th to 11th intercostal spaces and its mean diameter at the 9th to 11th intercostal spaces ranged from 1.2 cm to 1.8 cm.

Conclusions

The ultrasonographic findings of the spleen, liver, gallbladder, caudal vena cava and portal vein in six healthy Holstein-Friesian calves from birth to 104 days of age serve as reference values for the examination of these anatomical structures in diseased calves.     

Applicability of major histocompatibility complex DRB1 alleles as markers to detect vertebrate hybridization: a case study from Iberian ibex × domestic goat in southern Spain

Background

Hybridization between closely related wild and domestic species is of great concern because it can alter the evolutionary integrity of the affected populations. The high allelic variability of Major Histocompatibility Complex (MHC) loci usually excludes them from being used in studies to detect hybridization events. However, if a) the parental species don’t share alleles, and b) one of the parental species possesses an exceptionally low number of alleles (to facilitate analysis), then even MHC loci have the potential to detect hybrids.

Results

By genotyping the exon2 of the MHC class II DRB1 locus, we were able to detect hybridization between domestic goats (Capra hircus) and free-ranging Iberian ibex (Capra pyrenaica hispanica) by molecular means.

Conclusions

This is the first documentation of a Capra pyrenaica × Capra hircus hybridization, which presented us the opportunity to test the applicability of MHC loci as new, simple, cost-effective, and time-saving approach to detect hybridization between wild species and their domesticated relatives, thus adding value to MHC genes role in animal conservation and management.     

Effect of supplementation with corn oil on postpartum ovarian activity,pregnancy rate,and serum concentration of progesterone and lipid metabolites in F<Subscript>1</Subscript> (<Emphasis Type="Italic">Bos taurus</Emphasis> × <Emphasis Type="Italic">Bos indicus</Emphasis>) cows

The aim was to evaluate the effect of corn oil supplementation during postpartum anoestrus on ovarian activity, pregnancy rate, progesterone (P₄), and lipid metabolites (cholesterol, CHO; low and high density lipoproteins; LDL and HDL, respectively) concentrations in blood of F₁ (Bos taurus × Bos indicus) grazing cows. Cows were randomly assigned to an experimental group, fed with a supplement containing 4% corn oil on dry matter basis (OG, n = 11), and a control group with the same supplement without corn oil (CG, n = 12). Both supplements contained equivalent amounts of crude protein and metabolizable energy and were fed for 34 days continuously. All cows were induced to estrous 12 days after beginning of supplementation by using a synthetic progestagen and artificially inseminated 56 h after retiring the implants. Pregnancy diagnosis was performed by transrectal palpation 45 days after insemination, evaluating simultaneously ovarian activity. P₄ and lipid metabolites (CHO, HDL, LDL) concentrations were determined in blood samples collected at 3-day intervals, from the beginning of corn oil supplementation and up to 10 days after artificial insemination. Ovarian activity was affected by treatment (p < 0.05), finding ovarian structures in 72.7% of OG cows and in 50% of CG cows. Concentration of P₄ and CHO was higher for OG with respect to CG (2.52 ± 0.65 vs 1.88 ± 0.62 ng/ml and 117.79 ± 11.57 vs 85.71 ± 12.11 mg/dl, respectively), whereas pregnancy rate and blood concentrations of HDL and LDL were not affected by treatment (p > 0.05). Addition of corn oil to the supplement stimulated ovarian activity and increased serum concentrations of progesterone and cholesterol in grazing B. taurus × B. indicus cows with low body condition score showing postpartum anoestrus.