1,721,068 research outputs found
Improving welfare conditions of broiler chicken in Italy. Effects on performances, carcass and meat quality
No full textA trial was carried out to evaluate the influence of improved housing conditions for broilers kept on litter on productivity, carcass and meat quality traits. A total of 33,000 Ross 508 female broiler chickens were divided into two groups Welfare (WLF) and Standard (STD) and reared under different stocking density (14 vs. 19 birds/sq m), litter (wood shaving) amount (3.5 vs. 2.5 kg/sq m) and light:dark regimen (18:6 vs. 23:1). Birds were slaughtered at 40 or 50 d of age. Environmental temperature and humidity as well as litter moisture did not change between the two housing conditions. WLF birds reached a higher body weight but had a slight worse feed efficiency, whereas no differences were found in carcass traits. Breast meat quality evaluation showed higher moisture content and poorer water holding capacity in WLF birds
Effect of dietary supplementation of lysophospholipids on productive performance, nutrient digestibility and carcass quality traits of broiler chickens
Full text linkAn experiment was carried out to evaluate productive performance, nutrient digestibility and carcass quality traits of broiler chickens fed diets supplemented with an exogenous emulsifier based on lysophospholipids prepared by enzymatic conversion of soy lecithin. One thousand seven-hundred and fifty-five one-day-old male Ross 308 chicks were randomly divided into three experimental groups of nine replications each: control group (CON) fed a corn–soybean basal diet, and two groups fed CON diet supplemented with constant (1 kg/ton) or variable (1–1.5 kg/ton) level of emulsifier (CONST and VARI, respectively). At the end of the trial (42 d), birds receiving the emulsifier had a statistically significant (p < 0.05) lower feed conversion rate compared to the control. Body weight and daily weight gain were only slightly influenced by lysophospholipids supplementation, while mortality and feed intake resulted similar among the groups. No statistically significant effect of the emulsifier was observed on nutrient digestibility as well as slaughtering yields, skin pigmentation and incidence of foot pad dermatitis. The results obtained in this study suggest that the use of an emulsifier based on lysophospholipids improves feed efficiency while showed limited effect on carcass quality traits
Effects of in ovo administration of betaine and choline on hatchability results, growth and carcass characteristics and immune response of broiler chickens
No full textThe effect of in ovo administration of different
levels of betaine and choline on egg hatchability,
immune response, growth and carcass
traits of broiler chickens was studied. Four
thousand hatching eggs from Ross 308 broiler
breeder layers, weighed individually, were incubated
for 21 days in a commercial hatchery. At
12th day of incubation, 3456 fertilized eggs were
randomly divided into 8 experimental groups of
3 replicates each (144 eggs per replicate): negative
control (NC) – not injected; positive control
(PC) – injected with 0.5 mL deionized water;
Bet 0.25 – injected with 0.5 mL deionized
water+0.25 mg soluble betaine; Bet 0.375 –
injected with 0.5 mL deionized water+0.375 mg
soluble betaine; Bet 0.50 – injected with 0.5 mL
deionized water+0.50 mg soluble betaine; Chol
0.25 – injected with 0.5 mL deionized
water+0.25 mg soluble choline; Chol 0.375 –
injected with 0.5 mL deionized water+0.375 mg
soluble choline; Chol 0.50 – injected with 0.5 mL
deionized water+0.50 mg soluble choline.
Among the hatched chickens, 360 males were
randomly chosen (45 for each group) and were
grown up to 42nd day of age. The embryo mortality,
pecked eggs, infected eggs and hatchability
percentages were similar among the experimental
groups. The betaine and choline treatments
improved hatching weight and final
weight of chickens, while reduced feed conversion
ratio and abdominal fat percentage. No
effect on carcass yield, and breast muscle, leg
and wings percentages, as well as on immunoglobulin
M (IgM), G (IgG), and total antibody (IgT) titers was observed. The treatments had
little effect on internal organs
Investigating differences of Pectoralis major muscle vimentin and desmin gene expression between broilers selected for different growth-rates
No full textInfluence of genotype and feeding on chemical composition of organi chicken meat
Full text linkThe aim of this study was to evaluate the effects of different genotypes and of feeding
on meat chemical composition, including fatty acid profile, of chickens reared under organic conditions.
Two meat–type fast-growing (FG) and medium-growing (MG), and one egg-type slow-growing (SG)
strains were assigned to 2 different diets differing for the protein source: soybean (SB) and faba bean
(FB) in partial substitution of soybean. Genotype markedly affected the meat chemical composition.
SG breast and thigh meat showed lower content of lipids (P<0.01) than FG. The highest proportions
of polyunsaturated fatty acids (PUFA) n-6 and n-3 and the lowest proportion of monounsaturated
(MUFA) (P<0.01), as well as the lowest ratio of PUFA n6/n3 (P<0.01) were found in SG breast and
thigh meat. MG showed always intermediate values. As for feeding, FB treatment produced only a
slight increment of protein in breast and a decrease of fat and ash in thigh meat. Total PUFA and
PUFA n-6 resulted lower in both thigh and breast meat of FB groups compared to SB (P<0.01)
Regeneration processes the Pectoralis major muscles of broiler chickens selected for different growth-rates: the importance of vimentin and desmin
No full textEffect of dietary arginine to lysine ratios on productive performance, meat quality, plasma and muscle metabolomics profile in fast-growing broiler chickens
Full text linkAbstract Background Due to the important functions of arginine in poultry, it should be questioned whether the currently adopted dietary Arg:Lys ratios are sufficient to meet the modern broiler requirement in arginine. The present study aimed, therefore, to evaluate the effects of the dietary supplementation of L-arginine in a commercial broiler diet on productive performance, breast meat quality attributes, incidence and severity of breast muscle myopathies and foot pad dermatitis (FPD), and plasma and muscle metabolomics profile in fast-growing broilers. Results A total of 1,170 1-day-old Ross 308 male chicks was divided into two experimental groups of 9 replicates each fed either a commercial basal diet (CON, digestible Arg:Lys ratio of 1.05, 1.05, 1.06 and 1.07 in each feeding phase, respectively) or the same basal diet supplemented on-top with crystalline L-arginine (ARG, digestible Arg:Lys ratio of 1.15, 1.15, 1.16 and 1.17, respectively). Productive parameters were determined at the end of each feeding phase (12, 22, 33, 43 d). At slaughter (43 d), incidence and severity of FPD and breast myopathies were assessed, while plasma and breast muscle samples were collected and analyzed by proton nuclear magnetic resonance-spectroscopy. The dietary supplementation of arginine significantly reduced cumulative feed conversion ratio compared to the control diet at 12 d (1.352 vs. 1.401, P < 0.05), 22 d (1.398 vs. 1.420; P < 0.01) and 33 d (1.494 vs. 1.524; P < 0.05), and also tended to improve it in the overall period of trial (1.646 vs. 1.675; P = 0.09). Body weight was significantly increased in ARG compared to CON group at 33 d (1,884 vs. 1,829 g; P < 0.05). No significant effect was observed on meat quality attributes, breast myopathies and FPD occurrence. ARG birds showed significantly higher plasma concentration of arginine and leucine, and lower of acetoacetate, glutamate, adenosine and proline. Arginine and acetate concentrations were higher, whereas acetone and inosine levels were lower in the breast of ARG birds (P < 0.05). Conclusions Taken together, these data showed that increased digestible Arg:Lys ratio had positive effects on feed efficiency in broiler chickens probably via modulation of metabolites that play key roles in energy and protein metabolism
Fatty acid composition of chicken breast meat is dependent on genotype-related variation of FADS1 and FADS2 gene expression and desaturating activity
Full text linkIn Western countries the dietary guidance emphasizes the need to decrease the intake of saturated fatty acids and to replace them with polyunsaturated fatty acids (PUFA), particularly long chain n-3 PUFA (LC-PUFA). The production of poultry meat having a lower fat content and healthier fatty acid (FA) profile is a hot topic for the poultry industry, and the possibility to identify genotypes able to produce meat with a higher LC-PUFA content deserves attention. The aims of the present study were to evidence in chicken (i) a genotype-related different expression of the desaturating enzymes delta-6 (Δ6, EC 1.14.99.25), delta-5 (Δ5, EC 1.14.19.) and delta-9 (Δ9, EC 1.14.19.1); (ii) the impact of the hypothesized different expression on the meat FA composition; (iii) the distribution of desaturase products in the different lipid classes. Slow (SG), medium (MG) and fast (FG) growing chickens fed the same diet were evaluated either for the relative expression of FADS1, FADS2 and SCD1 genes in liver (by q-PCR), or for the FA composition of breast meat. MG and particularly SG birds showed a greater expression of FADS2 and FADS1 genes, a higher Δ6 and Δ5 activity (estimated using desaturase indices), and consequently a higher LC-PUFA content in the breast meat than FG birds. The relationship between genotype and desaturating ability was demonstrated, with a significant impact on the PUFA content of breast meat. Due to the high consumption rate of avian meat, the identification of the best genotypes for meat production could represent an important goal not only for the food industry, but also for the improvement of human nutrition
Stress and Humoral Innate Immune Response of Gilthead Seabream Sparus aurata Cultured in Sea Cage
No full textInnate and acquired immune responses of Gilthead Seabream Sparus aurata was studied under normal culture and
short-term stressful conditions for 18 months in offshore sea cages inAlghero Bay, Italy.Every 45 d, 50 fish were sampled
and divided into two groups: fish in the first group (normal culture conditions) were bled after harvesting; fish in the
second group were put into a tank under stressful conditions (crowding and confinement) and bled after 2 h. Innate
humoral immunity, such as complement-like, hemagglutination, and lysozyme activities, was determined in the sera of
both groups. Pathogen challenge was not performed, but the specific humoral immune response was assessed against the
most common pathogens affecting cultured fish in Sardinia. Stressed fish, compared with the control, showed a lower
lysozyme activity against Vibrio (Listonella) anguillarum, which was not clearly correlated with temperatures.
Complement-like activity differed between the first and second half of the study and, at the end of the trial, a slightly
higher activity was recorded in the controls than in the stressed fish. Hemagglutination activity was mainly higher in the
stressed fish than in control fish. Confinement, crowding, and cold water temperature caused decreased lysozyme activity
in short-term stressed Gilthead Seabream compared with those reared normally. The specific humoral immune response,
against V. anguillarum, Tenacibaculum mesophilum, Enterococcus Seriolicida, and Aeromonas sobria, fluctuated during the
rearing period, particularly during the first year of culture
Effect of rearing techniques and feed composition on productive traits, bird welfare and quality of poultry products
No full textThe PhD project was focused on the study of the poultry welfare conditions and improvements. The project work was divided into 3 main research activities.
A) Field evaluation of chicken meat rearing conditions kept in intensive farms. Considering the lack of published reports concerning the overall Italian rearing
conditions of broiler chickens, a survey was carried out to assess the welfare conditions of broiler reared in the most important poultry companies in Italy to verify if they are in accordance with the advices given in the European proposal COM (2005) 221 final.
Chicken farm conditions, carcass lesions and meat quality were investigated.
1. The densities currently used in Italy are in accordance with the European proposal COM 221 final (2005) which suggests to keep broilers at a density lower than 30-32 kg
live weight/m2 and to not exceed 38-40 kg live weight/m2.
2. The mortality rates in summer and winter agree with the mortality score calculated following the formula reported in the EU Proposal COM 221 final (2005).
3. The incidence of damaged carcasses was very low and did not seem related to the stocking density.
4. The FPD scores were generally above the maximum limit advised by the EU proposal COM 221 final (2005), although the stocking densities were lower than 30-32 kg live
weight per m2.
5. It can be stated that the control of the environmental conditions, particularly litter quality, appears a key issue to control the onset of foot dermatitis.
B) Manipulation of several farm parameters, such litter material and depth, stocking density and light regimen to improve the chicken welfare conditions, in winter season.
1. Even though 2 different stocking densities were established in this study, the performances achieved from the chickens were almost identical among groups.
2. The FCR was significantly better in Standard conditions contrarily to birds reared in Welfare conditions with lower stocking density, more litter material and with a light
program of 16 hours light and 8 hours dark.
3. In our trial, in Standard groups we observed a higher content of moisture, nitrogen and ammonia released from the litter. Therefore it can be assumed that the environmental characteristics have been positively changed by the improvements of the rearing conditions adopted for Welfare groups.
4. In Welfare groups the exhausted litters of the pens were dryer and broilers showed a lower occurrence of FPD.
5. The prevalence of hock burn lesions, like FPD, is high with poor litter quality conditions.
6. The combined effect of a lower stocking density, a greater amount of litter material and a photoperiod similar to the natural one, have positively influenced the chickens
welfare status, as a matter of fact the occurrence of FPD in Welfare groups was the lowest keeping the score under the European threshold of the proposal COM 221 final(2005).
C) The purpose of the third research was to study the effect of high or low stocking density of broiler chickens, different types of litter and the adoption of short or long
lighting regimen on broiler welfare through the evaluation of their productivity and incidence of foot pad dermatitis during the hot season.
1. The feed efficiency was better for the Low Density than for High Density broilers.
2. The appearance of FPD was not influenced by stocking density.
3. The foot examination revealed that the lesions occurred more in birds maintained on chopped wheat straw than on wood shaving.
4. In conclusion, the adoptions of a short light regimen similar to that occurring in nature during summer reduces the feed intake without modify the growth rate thus improving the feed efficiency. Foot pad lesion were not affected neither by stocking densities nor by light regimens whereas wood shavings exerted a favourable effect in preserving foot pad in good condition.
D) A study was carried out to investigate more widely the possible role of 25-hydroxycholecalciferol supplemented in the diet of a laying hen commercial strain (Lohmann brown) in comparison of diets supplemented with D3 or with D3 + 25-
hydroxycholecalciferol. Egg traits during a productive cycle as well as the bone characteristics of the layers have been as well evaluated to determine if there the
vitamin D3 may enhance the welfare status of the birds.
1. The weight of the egg and of its components is often greater in hens fed a diet enriched with 25-hydroxycholecalciferol.
2. Since eggs of treated groups are heavier and a larger amount of shell is needed, a direct effect on shell strength is observed.
3. At 30 and at 50 wk of age hens fed 25 hydroxycholecalciferol exhibited greater values of bone breaking force.
4. Radiographic density values obtained in the trial are always higher in hens fed with 25-hydroxycholecalciferol of both treatments: supplemented for the whole laying cycle
(25D3) or from 40 weeks of age onward (D3+25D3)
- …
