Effects of two probiotic additives containing Bacillus spores on carcass characteristics, blood lipids and cecal volatile fatty acids in meat type chickens.

The objective of this study was to evaluate effects of two commercially available probiotic additives, containing Bacillus spores, on carcass and meat characteristics, serum lipids and concentration of cecal volatile fatty acids of meat type chickens. Birds were fed regular corn-soy meal based feed (control), supplemented with additive A, containing 1.6 × 10(6) spores per gram of feed of Bacillus subtilis and Bacillus licheniformis (group A) or additive B, containing the same concentration of Bacillus cereus var. toyoi spores (group B). One hundred and twenty birds (20 per replicate) were slaughtered at the age of 55 days. Results showed that birds in group B had higher (p < 0.05) final body weight compared to birds from group A and higher carcass weights and yield percentages compared with control. Breasts and whole legs were also heavier in group B, compared to control, but not the yield. Group A had higher yield of wings and lower abdominal fat weight compared to group B (p< 0.05), but not compared with control. Total cholesterol was not affected by the dietary treatment, on contrary both probiotics elevated the LDL (p < 0.05) and lowered HDL cholesterol, thus unfavourably changed animal's blood serum cholesterol profile. Both probiotics influenced the cecal fermentation, which was observed as decrease in cecal concentrations of propionic, butyric, n-butyric and n-valeric acids, but the differences compared to control group were statistically significant for group A only. It was established that probiotic additive B was more effective regarding carcass and meat part weights than additive A, however the animals from group B also had more abdominal fat and their meat had significantly higher conductivity than control group, which is not considered as beneficial.

Effects of divergent selection for 8-week body weight on postnatal enzyme activity pattern of 3 fiber types in fast muscles of male broilers (Gallus gallus domesticus).

A divergent selection experiment was conducted for 8-wk BW in chickens. At 3, 6, 9, and 12 wk of age, samples of pectoralis profundus (PP) and biceps femoris (BF) muscles from fast-growing and slow-growing lines were used to estimate the enzyme activities and muscle fiber diameter. Microphotometric measurements made in situ of succinate dehydrogenase (SDH, EC 1.3.99.1) and glycerol-3-phosphate dehydrogenase (GPDH, EC 1.1.99.5) were completed on serial sections of PP and BF muscles from male chickens, in order to examine the ratio of SDH:GPDH activity in single fibers. On the basis of the SDH:GPDH activity ratios, muscle fibers were divided using cluster analysis into 3 populations of different fiber types (O = oxidative, OG = oxidative-glycolytic, and G = glycolytic). Cockerels of the SGL attained an 8.1-fold increase and those of the FGL a 6.8-fold increase in BW at 12 wk compared with that at 3 wk of age. The O, OG, and G type fibers of the BF muscles of the SGL had significantly (P ≤ 0.001) lower SDH:GPDH activity ratios than those of the FGL. A step decrease in the SDH:GPDH activity of O, OG, and G fibers in the PP of both lines occurred, and this differed significantly between SGL and FGL (P ≤ 0.001). Age and line effects influenced the diameter of the 3 fiber types in the BF muscle only. In contrast to this response, all 3 fiber types of the PP muscles reached similar diameters in both lines during the growth process from wk 3 to 12. From the results of this study, we concluded that the activities of metabolic enzymes in skeletal muscle fibers are under the influence of muscle type, age, and selection pressure. Microphotometry is a suitable method for the evaluation of enzyme activity measured in a single muscle fiber. The method enables precise estimation of enzyme activities, especially in muscles composed of populations of different metabolic fiber types.

Identification of chromosomal regions associated with growth and carcass traits in an F(3) full sib intercross line originating from a cross of chicken lines divergently selected on body weight.

An F(3) resource population originating from a cross between two divergently selected lines for high (D+ line) or low (D- line) body weight at 8-weeks of age (BW55) was generated and used for Quantitative Trait Locus (QTL) mapping. From an initial cross of two founder F(0) animals from D(+) and D(-) lines, progeny were randomly intercrossed over two generations following a full sib intercross line (FSIL) design. One hundred and seventy-five genome-wide polymorphic markers were employed in the DNA pooling and selective genotyping of F(3) to identify markers with significant effects on BW55. Fifty-three markers on GGA2, 5 and 11 were then genotyped in the whole F(3) population of 503 birds, where interval mapping with GridQTL software was employed. Eighteen QTL for body weight, carcass traits and some internal organ weights were identified. On GGA2, a comparison between 2-QTL vs. 1-QTL analysis revealed two separate QTL regions for body, feet, breast muscle and carcass weight. Given co-localization of QTL for some highly correlated traits, we concluded that there were 11 distinct QTL mapped. Four QTL localized to already mapped QTL from other studies, but seven QTL have not been previously reported and are hence novel and unique to our selection line. This study provides a low resolution QTL map for various traits and establishes a genetic resource for future fine-mapping and positional cloning in the advanced FSIL generations.

Porous concrete block as an environmental enrichment device increases activity of laying hens in cages.

The purpose of this study was to consider the influence of simple and cheap environmental enrichment such as porous concrete on the behavior of laying hens in conventional cages. Forty brown laying hens were housed in individual wire mesh cages: 20 in experimental cages with porous concrete block provided for pecking and 20 in a control group without concrete block provided. Porous concrete block (5 cm length x 5 cm width x 5 cm height) was mounted on the side wall at the height of the hen's head. Behavior was studied from 42 to 48 wk of age. A group of 8 hens was filmed for 24 h, and the camera was moved each day so that all 40 hens were recorded over 5 d each wk. Videotaping was performed in wk 1, 3, 5, and 7 of the experiment. States (long-term behavior) were observed with 5-min interval recording (feeding, preening, resting, and remaining inactive), whereas events (short-term activities) were observed with instantaneous recording (drinking, pecking concrete, pecking neighbors, pecking cage, and attempting to escape). Data were analyzed with generalized linear mixed model with binomial distribution for states, and Poisson distribution for events. Monte Carlo Markov Chain methods were used to estimate model parameters. Because posterior distributions of quantities of interest were skewed, medians and standard errors are reported. Hens in experimental cages were more active in long-term behavior than controls (64.9 +/- 1.9 and 59.3 +/- 1.9% of the light period, respectively). Correspondingly, hens in the control group showed more long-term inactivity. In addition to pecking the porous concrete block, hens in experimental cages also showed other short-term activities with greater frequency (4.10 +/- 0.31 and 3.51 +/- 0.25 events per h, respectively). Our hypothesis that hens in enriched cages would have a greater level of activity was confirmed. Provision of a piece of porous concrete block as a pecking substrate enriched the environment of the birds at negligible cost.

Choice of nest types by hens of three lines of broiler breeders.

1. Choice of three different nest types by hens of broiler breeder lines was investigated: metal nests (26 x 29 x 33-45 cm, w x d x h) with inclined rubber mats, metal nests of the same size with litter, and larger wooden nests (30 x 40 x 38) with litter. Three lines were studied: line B (324 females + 36 males), line P (315 + 36), and line WM (306 + 32). Each line was housed in a pen 23.3 x 3.9 m (90.7 m2); half the area was concrete floor with litter, and the other half raised plastic slats, on which stood 84 nests, 28 of each type, in two-tier blocks. 2. Ninety-five per cent of eggs were laid in nests, with significant variation between types: 63% metal littered, 30% wooden littered, and 2.3% metal with inclined rubber mats. Choice between types was similar in the three lines. Hens of line B laid 66% of nest eggs in lower nests, P laid 57% and WM laid 64%. 3. The other 5.1% of eggs were laid on the floor: 1.2% on the litter and 3.9% on the slats in front of the nests. It is suggested that some subordinate hens were excluded from nests, and therefore laid on the floor.

The effect of dietary arsenic additions on the distribution of selenium and iodine in eggs and tissues of laying hens.

The aim of the work was to determine the short-term effect (19 days) of dietary As additions (30 microg As/g in the form As2O3) on the Se and I concentrations in eggs and tissues of 49-week-old Rhode Island Red laying hens. Se and I concentrations were determined in eggs collected from the 8th to the 10th and from the 17th to the 19th days of the experiment. After 19 days, blood was collected by anterior heart puncture, and after slaughter the liver, kidney, lung, muscle (musculus pectoralis superficialis) and feathers were collected. Se and I concentrations were determined by radiochemical neutron activation analysis and the results expressed on a dry matter basis. In the control and the exposed group, the highest Se concentrations were found in kidney, followed by liver, blood, lung, muscle, and feathers. In the control group the highest I concentration was found in feathers, followed by kidney, blood, lungs, liver, and muscle. In the trial group, the order was almost the same, except that blood concentration was lower than in liver. As2O3 added to the feed significantly increased the Se concentration in the lung (p = 0.0216), I concentration in muscle (p = 0.0112) and significantly decreased I concentration in blood (p = 0.0371). It had no effect on the concentrations of Se and I in egg yolk and white.

Arsenic residues in eggs from laying hens fed with a diet containing arsenic (III) oxide.

Three groups of six hens each were fed for twelve days with diets containing 7.5, 15.0, and 30.0 mg arsenic per kg in the form of As2O3. A control group was included in the trial. The hens from each group were formed into three subgroups. The eggs of two hens, laid in three days, formed a composite sample. The As concentration in the egg whites and yolks was determined in duplicate by radiochemical neutron activation analysis. With increasing As concentration in the poultry feedstuff, its concentration in egg yolk and white also increased, but a plateau appears to be reached quite rapidly. The ratio between the As concentration in yolk and in white is nearly constant (1:3) for all three groups of hens, irrespective of the level of As in the feed. The concentration of arsenic in dry matter of whites was significantly higher than in the dry matter of yolks, while the concentrations of arsenic in fresh samples of yolks were higher in the comparison with fresh samples of whites, but the differences were not significant.