- Informacje o czasopiśmie
- Pierwsze wydanie
- 25 Nov 2011
- Częstotliwość wydawania
- 4 razy w roku
- Otwarty dostęp
Sense of smell and volatile aroma compounds and their role in the evaluation of the quality of products of animal origin – a review
Zakres stron: 3 - 31
The aim of this article is to examine how the sense of smell and aroma compounds influence the quality of food of animal origin, and to review gas chromatography-olfactometry methods of volatile substances analysis that can help to promote regional animal products. Smell and smell-inducing compounds play an important role in human life. People have made use of aromatic herbs and spices for ages. The classification of smells was developed by, among others, Aristotle, Linnaeus, Zwaardemaker, as well as Amoore, the creator of the stereochemical theory of olfaction. Smell is also of exceptional importance in a consumer’s evaluation of food quality. Achievements in the area of chromatography, mass spectrometry and olfactometry have contributed to the development of tests for the content of volatile compounds in food materials, e.g. milk, cheese or meat. Analysis of these compounds is more and more often applied to regional products that are commonly characterised by different olfactory properties. The study’s results of raw meat of different animal species show that nutria meat and mutton differ the most from others. Apart from genetic factors, meat composition depends on feeding method, quality and type of fodder, method of cutting, meat seasoning, pH and temperature of processing. Chromatographic and olfactometric tests on animal products, in conjunction with chemometrics, can contribute to the development of reliable characteristics and help to identify the products’ origin. These tests are becoming an inseparable part of the policy of promotion of regional products with specific taste and olfactory properties.
- aroma compounds
- animal products
- Otwarty dostęp
Zakres stron: 33 - 51
The use of equid milk in human nutrition is a very interesting research topic in relation to the specific characteristics of this drink. Mare’s milk has a composition similar to human milk and is well digested, so it is a perfect alternative to cow’s milk in the feeding of children who are allergic to cow’s milk. Equid milk’s low content of α-lactalbumin and β-lactoglobulin makes it appropriate for such children. Its high concentration of lactose allows for a better growth of intestinal microflora. Mare’s milk is characterised by a high content of lysozyme, lactoferrin and lactadherin and has an inhibiting effect on the development of pathogenic bacteria. Research done so far indicates that it may be helpful in treating atopic dermatitis as well as in improving skin appearance. The high content of vitamin C in mare’s milk influences its antioxidant value. Due to its lower content of fat and cholesterol it can be used to lower cholesterol intake as well as to control cardiovascular diseases. Mare’s milk has been proved to play a role in curing Crohn’s disease, ulcerative colitis, as well as hepatitis and chronic gastric ulcers. The qualities of mare’s milk make it appropriate for use in children’s and elderly people’s nutrition in prophylaxis and as an aid to the process of curing various diseases.
- mare milk
- people’s health and nutrition
- Otwarty dostęp
Zakres stron: 53 - 64
Nanoparticles can be an alternative for currently used viral and non-viral systems of transporting exogenous DNA into cells, and furthermore, can be an effective way to produce transgenic animals. The possibility of linking them with proteins, lipids and of adding ligands enables improved transfection by making the crossing of membranes and the breaking of the endosomal barrier more efficient. Additionally, by the addition of magnetic particles it is possible to amend the intracellular kinetics of nanoparticle-DNA complexes. This review considers the use of nanoparticles to transfect cells and embryos and their possible application as a non-viral vector in animal transgenesis.
Animal genetics and breeding
- Otwarty dostęp
Sigmoid Models for the Growth Curves in Medium-Growing Meat Type Chickens, Raised under Semi-Confined Conditions
Zakres stron: 65 - 77
The study analyzed the growth of medium-growing chickens of the CCGP experimental line, using Gompertz, Logistic, and Richards models as well as body gain curves. The birds were reared until 9 wk of age. To fit BW values to the applied models, determination coefficients (R2
,Ř2) and standard error of the mean (±SE) were calculated for 487 male and 493 female chickens. The comparison of results obtained demonstrated the Gompertz model to be the most precise equation to describe the growth of both sexes of CCGP chickens, though in all examined models the determination coefficients were approximating 99%. According to the Gompertz model, the chickens may reach the maximum BW at the age of 16 wk (5900 g - males and 4000 g - females), whereas the maximum daily BW gain - on day 47 (69.0 g) in males and on day 41 (50.0 g) in females. Values achieved in the Logistic model were the most diverging from the values obtained with other models, whereas the Richards model may be successfully applied to estimate BW of chickens. Females were reaching the maximum BW gains earlier, but the curve of their BW gain was proceeding with two peaks (at ca. 4 wk - 313.09 g/wk and at 6 wk - 327.59 g/wk), which was probably due to partial growth deceleration as a result of allowing the birds to use free ranges on day 14. In the case of males, the maximum BW gain (727.35 g/wk) was reached at 6.2 wk.
- chickens growth models
- semi-confined conditions
- Otwarty dostęp
Zakres stron: 79 - 85
Sarcoid is the most common skin cancer in horses. The etiology of the tumor is associated with BPV infection (BPV-1, -2, -13), which is an inducer of malignant transformation. The comparative genomic hybridization (CGH) technique identifying the unbalanced chromosome aberrations was used to analyze the genome of equine sarcoid cells and to diagnose the chromosome rearrangements involving large deletions or amplification. The results were based on the analysis of 100 metaphases and their karyograms as well as the diagram showing the average ratio of the intensity of the green to red fluorescence, using MetaSystems software (Isis). Based on a comparison of the fluorescence intensity ratios we found duplication in the subtelomeric regions of chromosome pairs 1, 4, 7, 8 and 23. Duplicated region of chromosome pair 1 also included the coding region of the rDNA. In the chromosome 23 next to the duplication occurring in the centromeric region of q arm (23q11) we also found the presence of deletions involving 23q18-23q19 region. For the chromosome pairs 25 to 31 and the X chromosome the software failed to generate CGH diagram, but on the individual karyograms we were able to observe fluorescence signals characteristic of duplication (red), in rDNA regions of chromosome pairs 28 and 31. The study showed that duplications of DNA present in the sarcoid cells are found mainly in the telomeric and rDNA regions. The presence of the duplication of telomeric regions is associated with increased activity of the telomerase enzyme, which is a hallmark of cancer cells, affecting the immortality of these cells. Accordingly, duplications of rDNA coding regions increase activity of nucleolar organizer region which is a tumor marker.
- comparative genomic hybridization
The biology, physiology, reproduction, and health
- Otwarty dostęp
Zakres stron: 87 - 97
The aim of the study was to assess the effect of allowing racehorses to use paddocks, on the heart rate (HR). HR was used as a measure of horses’ psychosomatic response to environment effect. The study involved 90 Purebred Arabian horses divided into three groups of equal numbers of stallions and mares. The control group (C) was trained at the racetrack. The other two groups were trained in an off-the-racetrack centre and therefore, they were regularly transported to the races. One of those groups (T) was maintained in the same manner as horses at the racetrack, without access to paddocks. Horses from the other group (TP) were additionally released into a paddock every day. Each horse was examined within five three-week measuring periods, during one training season. HR was registered at rest, during saddling, and while walking with a rider. A multivariate analysis of variance (ANOVA, GLM) was used to compare HR. The significance of differences between means was determined using Tukey’s test. HR registered from 2nd to 5th measuring periods during saddling and walking was generally lower in TP than in C. For example, in stallions during saddling, HR amounted to: 54.4±14.7 vs 65.3±12.1, 53.2±13.5 vs 64.4±13.1, 55.4±12.2 vs 65.0±11.0 and 53.4±14.0 vs 66.5±13.8 beats/min, respectively. In T stallions and mares, HR tended to increase when the transportation began which was particularly pronounced at rest. The study revealed that the possibility of turnout into paddocks reduced HR in racehorses, in comparison to horses trained at racetrack. Training for horse racing in an off-the-racetrack centre with the use of paddocks was assessed as beneficial, provided the horses were used to being transported.
- heart rate
- Purebred Arabian racehorses
- Otwarty dostęp
Assessment of Geometric Parameters of Tibiotarsal Bones in White Kołuda Geese Using Peripheral Quantitative Computed Tomography
Zakres stron: 99 - 113
The aim of the study was to evaluate geometrical parameters of tibiotarsal bones in geese depending on age, sex and place in the bone and conditions of breeding. The inner structure of tibiotarsal bones of White Kołuda® geese (W31) subjected to intensive breeding was analyzed using peripheral quantitative computed tomography (pQCT ). The analyzed bones were derived from birds representing five age groups: one-day-old as well as birds of 2, 4, 6 and 8 wk of age. Bones of 10 males and 10 females were isolated from each group. The analysis was conducted at two levels of the bone: the area of the proximal metaphysis and at half the length of the diaphysis. The proximal metaphysis was selected for the research as it had higher content of the cancellous bone than the distal metaphysis. It was known that the cancellous bone was characterized by a higher rate of metabolic changes. The following geometric parameters were determined: total bone area (TOT _A), trabecular area (TRAB _A), cortical area (CRT _A), cortical thickness (CRT _TH K_C), periosteal circumference (PERI C), endocortical circumference (ENDO _C) and Strength Strain Index (SSI ). It was found that 6 wk of life may be considered as critical in the postnatal development of geese. In the group of 6 wk males in the shafts of the tibial bones, there was a decrease in the values of the following parameters: TOT _A, TRAB _A, PERI _C, ENDO _C. Whereas in 8 wk, an attenuation of the values of all geometric parameters of tibiotarsal bones was observed in both sexes (with the exception of CRT _TH K_C), which may have a negative influence on bone resistance to fractures. In this period, a significant decrease in the values of geometric parameters of tibiotarsal bones could be observed, negatively affecting the resistance of the bone to fractures in 8 wk. The values of SSI parameter at the proximal metaphysis of the tibiotarsal bone decreased in both males and females in 8 wk. In turn, at mid-diaphysis, the SSI values decreased only in males in 8 wk. The achieved results and observations justify the use of optimal environmental and nutritional conditions in geese in order to improve the quality of their skeletal system and to minimize the risk of the occurrence of deformities and fractures of the pelvic limb during the breeding.
- bone quality
- leg deformities
- Otwarty dostęp
Isolation, Characterization and Differentiation Potential of Chicken Spermatogonial Stem Cell Derived Embryoid Bodies
Zakres stron: 115 - 128
Human, murine and monkey spermatogonial stem cells (SSCs) have the capability to undergo self-renewal and differentiation into different body cell types in vitro, which are expected to serve as a powerful tool and resource for the developmental biology and regenerative medicine. We have successfully isolated and characterized the chicken SSCs from 3-day-old chicken testicular cells. The pluripotency was using Periodic Acid-Schiff (PAS ) staining or alkaline phosphatase staining, and antibodies to stage-specific embryonic antigens. In suspension culture conditions SSCs formed embryoid bodies (EBs) like embryonic stem (ES) cells. Subsequently EB differentiated into osteoblasts, adipocytes and most importantly into cardiomyocytes under induced differentiation conditions. The differentiation potential of EBs into cardiomyocyte-like cells was confirmed by using antibodies against sarcomeric α-actinin, cardiac troponin T and connexin 43. Cardiomyocytes-like cells were also confirmed by RT-PCR analysis for several cardiac cell genes like GATA-4, Nkx2-5, α-MHC, and ANF. We have successfully established an in vitro differentiation system for chicken SSCs into different body cells such as osteoblasts, adipocytes and cardiomyocytes. The most significant finding of this study is the differentiation potential of chicken SSCs into cardiomyocytes. Our findings may have implication in developmental biology and regenerative medicine by using chicken as the most potential animal model.
- chicken cardiomyocytes
- embryoid bodies
- spermatogonial stem cells
- Otwarty dostęp
The Effect of Body Condition Score on the Biochemical Blood Indices and Reproductive Performance of Dairy Cows
Zakres stron: 129 - 143
The aim of the study was to investigate the effect of BCS (Body Condition Score) on the calving day and its decrease during early lactation on the biochemical blood indices and reproductive performance. One hundred and thirty-one Polish Holstein-Friesian cows were divided into three groups according to the North-American body condition score on the calving day (AC≤3.5 point BCS; MID 3.51-3.75 point BCS; FAT>3.75 point BCS) and according to the decrease in BCS during early lactation (HG >0.49 point BCS; WEL 0.49-0.25 point BCS, L<0.25 point BCS). In current study, significant interaction between change of BCS during early lactation and time of blood sampling on BHBA concentration was observed. In the AC group (≤3.5 BCS), the highest concentrations of glucose on 3 and 5 d of lactation compared to the MID and FAT groups and of insulin on 28 d and also IGF-I on 5 and 28 d of lactation compared to the FAT group were recorded. In the FAT group, the highest concentration of NEFA on 3 and 5 d compared to the AC group and of BHBA on 28 d of lactation compared to the MID group was recorded. The body condition score on the parturition day affected the reproductive performance; in the FAT group (>3.75 BCS) the lowest conception rate of the first insemination, insemination index and thereby the longest days open were observed. The highest decreases in BCS (HG >0.49 points) resulted in increased concentrations of NEFA on 3 d and of BHBA on 3 and 5 d. Moreover, in the HG group, the lowest concentration of T3 on 3, 5 and 28 d as compared to the WEL group was recorded. We concluded that the BCS (>3.5 points) on the calving day had a significantly negative effect on the metabolic status of dairy cows in the postpartum period estimated by the concentration of biochemical blood indices characterising carbohydrates (IGF-I, insulin) and lipid (NEFA, BHBA) metabolism and also the reproductive performance such as the conception rate of the first insemination, insemination index, days open. We suggested that the blood serum concentrations of IGF-I and NEFA were the most sensitive biochemical markers of the metabolic status of dairy cows in our study.
- dairy cow
- body condition score
- metabolite and hormone indices
- Otwarty dostęp
Zakres stron: 145 - 154
The aim of this study was to investigate the effect of omega-3 supplementation on some haematological parameters like red blood cells (RBC), haemoglobin (Hgb), haematocrit (Hct), white blood cells (WBC), neutrophils (Neu) and lymphocytes (Lym) that may have a direct effect on the performance of athletic horses. Ten regularly trained Standardbred horses (6 geldings and 4 females, 4-5 years old, mean body weight 500 ± 25 kg) were used for the study. They were randomly divided into two groups. The experimental group received an omega-3 dietary supplementation every day for 30 days. The control group received no supplementation. Every 10 days, horses took part in a 1660 metre harness race and blood samples were collected from each horse: one in the morning before race (pre) and one after race (post). The application of one-way analysis of variance for repeated mesures (ANOVA) showed a statistically significant difference due to the race in the two different groups. The results obtained in the present study show a discordant effect of supplementation with omega-3 on RBC, HCT and Hgb, while omega-3 supplementation has been shown to have a better effect on WBC, Neu and Lym, but further studies should be performed to better evaluate the benefits of these on the performance of the athletic horse.
- physical exercise
- haematological parameters
- polyunsaturated fatty acid
- Otwarty dostęp
Physiological Threshold of Somatic Cell Count in Milk of Polish Heath Sheep and Polish Lowland Sheep
Zakres stron: 155 - 170
The study was conducted on 320 sheep of two breeds: Polish Heath Sheep (PHS) and Polish Lowland Sheep (PLS). Udder health status was assessed based on somatic cell count (SCC) and bacteriological examination of milk. Cells of the immune system (leukocyte populations and lymphocyte subpopulations) were identified in the blood and milk of sheep by flow cytometry, using a panel of specific monoclonal antibodies and fluorescent dyes. The study showed that the highest proportion of neutrophils and a lower percentage of lymphocytes (CD4+, CD8+, CD19+, WC1-N2+) in milk and blood occurred in sheep of both breeds in which milk SCC ranged between 201 and 300×103 cells/ml. In light of existing research, these results suggest that fluctuations in somatic cell count of ewe milk are physiologically determined up to 200×103cells/ml and result from udder health disturbances above this level.
Animal nutrition, and feedstuffs
- Otwarty dostęp
Influence of Oregano Essential Oil (Oeo) on Prevalence and Oocyst Shedding Dynamics of Naturally Acquired Eimeria Spp. Infection in Replacement Dairy Heifers
Zakres stron: 171 - 179
The administration of oregano essential oil (OEO) was tested in a dairy farm (Piacenza, Italy) with a history of sporadic cases of clinical coccidiosis in order to evaluate its influence on infection prevalence and oocyst excretion pattern in calves and replacement dairy heifers. Animals were recruited at 1 month of age and allocated to two groups of 25 animals, experimental (E) and control (C). OEO was added at a concentration of 100 ppm to the feedstuff administered to group E. Prevalence of infection and the number of oocysts per gram of feces (OPG) was evaluated monthly from 30 days of life (d30) till d150, with one extra sampling at d45, for a total of 6 time points. No significant differences were observed regarding the prevalence of infection between the two groups (83% general prevalence, 93% in group E, 72% in group C) although slightly higher prevalence was seen for Eimeria bovis and Eimeria alabamensis in group C, while the opposite was seen for Eimeria zuernii. OEO addition to the diet did not have any effect on the course of coccidial infections in calves and replacement dairy heifers. Other variables, in particular data on growth and production, should likely be tested before ruling out the potential role of OEO, alone or in combination with other control measures, to reduce infection pressure and therefore to improve animal welfare and performance.
- oregano essential oil
- dairy cattle
- Otwarty dostęp
Effect of Dietary Supplementation of Spirulina (Arthrospira Platensis) and Thyme (Thymus Vulgaris) on Serum Biochemistry, Immune Response and Antioxidant Status of Rabbits
Zakres stron: 181 - 195
Growing rabbits’ (42 rabbits/group, 3 rabbits/cage, 14 cages/treatment) diet was supplemented with 5% Spirulina (Arthrospira platensis) and 3% thyme (Thymus vulgaris L.) powder single (S or T) and in combination (ST) between 35 and 77 days of age. On day 0 (weaning at 35 days of age) 14 rabbits were vaccinated with 100 μg/animal ovalbumin to provoke immune response. Blood samples were taken on days 0, 14, 28 and 42 of the experimental period. Sampling dates significantly influenced total protein, albumin, glucose, cholesterol, urea, creatinine concentration and enzyme (AST, ALT, GGT) activities, with a significant age × diet interaction in the case of TP and CREA. There was a significant increase in ALT (+45 and 74%) and GGT (+87 and 102%) activity after immunisation. While Spirulina and thyme significantly ameliorated the rise in AST activity, their effect was inefficient in the case of GGT. Spirulina, both single and in combination showed a tendency in higher IgG level as compared to control (P<0.05). No significant effect of sampling date or treatment on phagocytic activity or secretory IgA was demonstrable (P>0.05). Higher MDA concentration was measured in the red blood cells of S, T and ST animals, while no other significant diet effect on the antioxidant parameters was detected, however, significant sampling date × diet interaction was found in the case of GPx activity. Plasma GGT (increase by 19-66%) was inversely associated with GSH (decrease by 66-113%) between days 0 to 42 of the experimental period (r=-0.57, P<0.05). It can be concluded that Spirulina supplementation alone resulted in higher IgG production, but none of the phytobiotics, at the dose used, affected significantly the antioxidant status of blood.
- serum biochemistry
- immune response
- antioxidant status
- Otwarty dostęp
Evaluation of the Nutritional Value of Yellow (Lupinus Luteus) and Blue Lupine (Lupinus Angustifolius) Cultivars as Protein Sources in Rats
Zakres stron: 197 - 207
The aim of this study was to determine the nutritional value of protein from the seeds of yellow lupine (Lupinus luteus) and blue lupine (Lupinus angustifolius) cultivars, contained in diets fed to rats. The experimental diets were based on the seeds of three yellow lupine (Mister, Markiz, Taper) or three blue lupine (Sonet, Boruta, Elf) cultivars as the only or main protein source. The nutritional value of the diets was determined based on their chemical composition and alkaloid and oligosaccharide concentrations. Lupine seeds were fed to male Wistar rats with initial body weight of approx. 112 g. Alkaloid concentrations in yellow lupine and blue lupine seeds were 0.07-0.09 g kg-1 DM and 0.26-0.39 g kg-1 DM, respectively. Oligosaccharide concentrations in yellow and blue lupine seeds were 108.0-108.9 and 65.4-67.6 g kg-1 DM, respectively. The inclusion of lupine seeds in rat diets increased fecal and urinary nitrogen losses, and decreased nitrogen retention by approx. 10%. The diets based on yellow or blue lupine seeds were characterized by lower nitrogen digestibility and lower biological value of protein than the control diet containing casein.
- protein value
- Otwarty dostęp
Effects of Two Enzyme Feed Additives on Digestion and Milk Production in Lactating Egyptian Buffaloes
Zakres stron: 209 - 222
The aim of this study was to evaluate the effect of two commercial enzyme products on milk production in Egyptian buffaloes. Twenty-one lactating buffaloes (570±15 kg BW) were divided into three groups (n=7) in a randomized block design for four months. Buffaloes were fed a total mixed ration containing 60% forage [rice straw and berseem hay (Trifolium alexandrinum)] and 40% concentrates with either no enzymes added (Control) or an addition of 40 g of Veta-Zyme Plus® (VET) or 40 g of Tomoko® (TOM ) enzyme product per day for each buffalo. Enzyme addition did not affect feed intake (P>0.05), but increased the digestibility of nutrients (P<0.05) and serum glucose concentration (P=0.011). Furthermore, the addition of VET increased milk (P=0.017) and fat corrected milk (P=0.021) yields, fat content (P=0.045), total unsaturated fatty acid (P=0.045) and total conjugated linoleic acid (P=0.031) contents in milk and decreased the content of total saturated fatty acids (P=0.046), while the addition of TOM increased milk total protein (P=0.023) and true protein (P=0.031) contents. The two enzyme products both resulted in higher concentrations of lysine (P=0.045) and total essential amino acids (P=0.036) in milk. It was concluded that addition of commercial fibrolytic enzyme products (i.e. Veta-Zyme Plus® and Tomoko®) to the diet of early lactating buffaloes enhanced nutrient digestibility and milk production and quality.
- fibrolytic enzyme
- milk composition
- milk production
- Otwarty dostęp
Influence of Protein Supply on Threonine Efficiency and Threonine Catabolism in Hepatic Mitochondria of Chicks and Rats
Zakres stron: 223 - 234
This research investigated the relationship between efficiency of threonine (Thr) utilization and Thr oxidation in hepatic mitochondria in chicks and rats fed with graded levels (5.5-33.0% CP for chicks, 6-24% CP for rats) of protein. Calculation of efficiency of Thr utilization was based on N-balance data and an exponential N-utilization model, and Thr dehydrogenase (TDG) activity was determined. According to the results, no significant effect on TDG activity was observed in the liver of chicks who received diets containing from 5.5 up to 16.5% CP. However, significantly elevated TDG activities were observed, despite limited supply of Thr in protein, with diets containing from 22.0 up to 33.0% CP. At the levels of CP content from 5.5 up to 27.5%, no significant change in efficiencies of Thr utilization was observed. However, a significant decrease in efficiency was observed with diets containing from 27.5 to 33.0% CP. In chicks, the relationship between oxidation of Thr and Thr efficiency was observed with graded CP levels. In addition, elevated TDG activities in rat liver were observed with diets containing from 6.0 to 12.0% CP. At the levels of CP content from 6.0 up to 24.0%, no significant effect on efficiency of Thr utilization was observed in rats. In addition, no relationship was observed between Thr oxidation and efficiency of Thr utilization with graded CP levels in rats. Taken together, reactions for TDG appear to be animal species-dependent.
- crude protein
- N-utilization model
- threonine dehydrogenase
- threonine efficiency
Behavior, well-being, production technology, and environment
- Otwarty dostęp
Effect of Broiler Breeders’ Age on Eggshell Temperature, Embryo Viability and Hatchability Parameters
Zakres stron: 235 - 243
The aim of the study was to analyze eggshell temperature, embryo viability, and hatchability parameters of broiler breeders at different ages (26-30, 31-35, 36-40, 41-45, and 46-64 weeks). A total of 33,150 eggs from Ross 308 broiler breeders collected from commercial flocks were used to analyze the following: egg weight and egg weight loss during 18 days of incubation; eggshell temperature controlled on days 3, 14, and 18 of incubation; number of infertile eggs including eggs with dead embryos at early stages of development, that is, in the oviduct or after oviposition; the total percentage of embryonic mortality and the percentage of embryonic mortality at different times of incubation; unhatched, dead after hatching, and culled chicks as well as hatchability percentage from fertilized eggs. The hatchability results of Ross 308 broiler breeders were high from the beginning of reproductive season till the 40th week. However, the study failed to reveal any relationships between hatchability and the egg weight, average temperature of the shell, and egg weight loss during incubation period. The oldest hens, over 45 weeks of age, had the highest mortality of chicks and the greatest share of unhatched chicks.
- broiler breeders
- egg incubation
- eggshell temperature
- Otwarty dostęp
Effect of Genotype, Sex and Age on Plumage Maturity, and Body Weight of Guinea Fowl (Numida Meleagris)
Zakres stron: 245 - 257
The objective of this study was to investigate the effect of genotype and sex on the degree of maturity of the plumage of guinea fowl. The experimental materials comprised 300 slow-growing (Label group) and 300 fast-growing (Standard group) gray guinea fowl. At 12, 14 and 16 weeks of age, 12 birds from each group (six ♂ and six ♀) were slaughtered. Dry feathers were collected from the dorsal area on both sides of the spine, in the interscapular and thoracic region, and from the outer side of the left thigh. The percentages of feathers at five stages of development were determined for each bird: I - pinfeathers covered in sheaths, II - beginning of vane development, III - feathers unsheathed by half of rachis length, IV - feathers unsheathed by more than half of rachis length, V - fully developed vanes and afterfeathers. Feather weight was determined and expressed as a percentage of a bird’s total body weight. At 12 weeks of age, guinea fowl were characterized by the lowest (68.23%) percentage of mature feathers. The percentage of mature feathers increased to 79.36% in week 14 and to 83.20% in week 16. In weeks 14 and 16, the proportion of feather weight in total body weight was significantly lower (9.95 and 10.20%, respectively) than in week 12 (11.88%). Genotype had no effect on feather development, but it influenced feather weight and percentage. Significant (P<0.05) genotype × sex × age interactions were observed in percentage of stage I feathers. Label group guinea fowl were characterized by higher feather weight and a higher proportion of feathers in total body weight than Standard group guinea fowl (267.0 g and 11.01%, 248.9 g and 10.34%, respectively). The percentage of feather weight was lower in females than in males.
- guinea fowl
Quality and safety of animal origin products
- Otwarty dostęp
Effect of Genotype and Slaughter Age on Carcass Traits and Meat Quality of the Celta Pig Breed in Extensive System
Zakres stron: 259 - 273
The objective of this study was to investigate the effects of genotype and slaughter age on carcass traits and meat quality of the Celta pig breed. Samples from 95 pigs of three lines (Barcina, Santiaguesa and Carballina) slaughtered at two different ages (12 and 16 months) were analysed. Pigs’ slaughter at 16 months showed significantly (P<0.001) higher live weight (157.2 vs. 178.9 kg), cold carcass weight (122.9 vs. 141.9 kg) and killing out percentage (77.7 vs. 79.5%; P<0.001) compared to those slaughtered at 12 months. Genotype also affected the live weight and cold carcass weight, both of which were highest in the Santiaguesa line. Changes in meat quality in relation to slaughter age and genotype were observed. The fat content increased with slaughter age, but did not vary with genotype. Regarding colour parameters, the L* values (48.53) were lower and a* values (11.55) were higher in samples of the Barcina line, indicating that the meat was darker and redder than in the other two lines. Both slaughter age and genotype had significant effects on texture parameters measured by the Warner Bratzler test, whereas textural profile analysis revealed significant differences mainly due to genotype.
- slaughter age
- carcass traits
- meat quality
- Celta pig breed
- Otwarty dostęp
Prediction of Carcass Meat Percentage in Young Pigs Using Linear Regression Models and Artificial Neural Networks
Zakres stron: 275 - 286
One of the approaches to improving performance testing of pigs is to look for mathematical solutions to increase the accuracy of calculations. This is mainly done through improvement of linear regression equations based on current data on performance tested pigs in Poland. The advances in computer technology and the improvements in mathematical analysis have made it possible to use artificial neural networks (ANNs) for prediction of carcass meat percentage in young pigs. The aim of the study was to compare the potential for live estimation of carcass meat percentage in pigs using two computational methods: linear regression equations and ANNs. The experiment used 654 gilts of six breeds, which were subjected to performance testing and slaughter analysis at the Pig Performance Testing Station (SKURTCh). The collected data were used to train ANNs to estimate carcass meat percentage in young pigs. Training was performed using the Levenberg- Marquardt algorithm. Next, meatiness estimated by ANNs was compared with the results obtained using linear modelling. It is concluded that based on the fattening and slaughter performance test results of live pigs, artificial neural networks (SSN23) are significantly more accurate in estimating carcass meat percentage in young pigs compared to the three-variable linear regression model 1. The difference in meatiness estimation between SSN23 and the four-variable linear regression model 2 was statistically non-significant in most of the breeds except Duroc and Pietrain, where the meatiness of young animals was estimated more accurately by the linear regression model.
- performance testing of animals
- carcass meat percentage
- regression equations
- artificial neural networks