scholarly journals Anatomical and biomechanical traits of broiler chickens across ontogeny. 1. Anatomy of the musculoskeletal respiratory apparatus and changes in organ size.

2014 ◽  
Author(s):  
Peter G Tickle ◽  
Heather Paxton ◽  
Jeffery W Rankin ◽  
John R. Hutchinson ◽  
Jonathan R Codd
Keyword(s):  
Body Mass ◽  
Rapid Growth ◽  
Broiler Chickens ◽  
Unintended Consequences ◽  
Oblique Muscle ◽  
Meat Production ◽  
Relative Reduction ◽  
Slaughter Weight ◽  
Respiratory Apparatus ◽  
Selection For

Genetic selection for improved meat yields, digestive efficiency and growth rates have transformed the biology of broiler chickens. Modern birds undergo a 50-fold multiplication in body mass in just six weeks, from hatching to slaughter weight. However, this selection for rapid growth and improvements in broiler productivity is also widely thought to be associated with increased welfare problems as many birds suffer from leg, circulatory and respiratory diseases. To understand growth-related changes in musculoskeletal and organ morphology and respiratory skeletal development over the standard six-week rearing period, we present data from post-hatch cadaveric commercial broiler chickens aged 0, 2, 4 and 6 weeks. The heart, lungs and intestines decreased in size for hatch to slaughter weight when considered as a proportion of body mass. Proportional liver size increased in the two weeks after hatch but decreased between 2 and 6 weeks. Breast muscle mass on the other hand displayed strong positive allometry, increasing in mass faster than the increase in body mass. Contrastingly, less rapid isometric growth was found in the external oblique muscle, a major respiratory muscle that moves the sternum dorsally during expiration. Considered together with the relatively slow ossification of elements of the respiratory skeleton, it seems that rapid growth of the breast muscles might compromise the efficacy of the respiratory apparatus. Furthermore, the relative reduction in size of the major organs indicates that selective breeding in meat-producing birds has unintended consequences that may bias these birds toward compromised welfare and could limit further improvements in meat-production and feed efficiency.

scholarly journals Anatomical and biomechanical traits of broiler chickens across ontogeny. 1. Anatomy of the musculoskeletal respiratory apparatus and changes in organ size.

2014 ◽  
Author(s):  
Peter G Tickle ◽  
Heather Paxton ◽  
Jeffery W Rankin ◽  
John R. Hutchinson ◽  
Jonathan R Codd
Keyword(s):  
Body Mass ◽  
Rapid Growth ◽  
Broiler Chickens ◽  
Unintended Consequences ◽  
Oblique Muscle ◽  
Meat Production ◽  
Relative Reduction ◽  
Slaughter Weight ◽  
Respiratory Apparatus ◽  
Selection For

Genetic selection for improved meat yields, digestive efficiency and growth rates have transformed the biology of broiler chickens. Modern birds undergo a 50-fold multiplication in body mass in just six weeks, from hatching to slaughter weight. However, this selection for rapid growth and improvements in broiler productivity is also widely thought to be associated with increased welfare problems as many birds suffer from leg, circulatory and respiratory diseases. To understand growth-related changes in musculoskeletal and organ morphology and respiratory skeletal development over the standard six-week rearing period, we present data from post-hatch cadaveric commercial broiler chickens aged 0, 2, 4 and 6 weeks. The heart, lungs and intestines decreased in size for hatch to slaughter weight when considered as a proportion of body mass. Proportional liver size increased in the two weeks after hatch but decreased between 2 and 6 weeks. Breast muscle mass on the other hand displayed strong positive allometry, increasing in mass faster than the increase in body mass. Contrastingly, less rapid isometric growth was found in the external oblique muscle, a major respiratory muscle that moves the sternum dorsally during expiration. Considered together with the relatively slow ossification of elements of the respiratory skeleton, it seems that rapid growth of the breast muscles might compromise the efficacy of the respiratory apparatus. Furthermore, the relative reduction in size of the major organs indicates that selective breeding in meat-producing birds has unintended consequences that may bias these birds toward compromised welfare and could limit further improvements in meat-production and feed efficiency.

scholarly journals In pursuit of a better broiler: A comparison of the inactivity, behavior, and enrichment use of fast- and slower-growing broiler chickens

2021 ◽  
Author(s):  
Lauren C Dawson ◽  
Tina M Widowski ◽  
Zhenzhen Liu ◽  
A. Michelle Edwards ◽  
Stephanie Torrey
Keyword(s):  
Growth Rates ◽  
Rapid Growth ◽  
Broiler Chickens ◽  
Specific Growth ◽  
General Activity ◽  
Behavioral Observations ◽  
Selection For ◽  
Motivated Behaviors ◽  
Slow Growing ◽  
Similar Growth

Selection for rapid growth has produced heavier, more efficient broiler chickens, but has also introduced health and welfare issues, which may cause or be caused by inactivity. Rapid growth may also limit the performance of motivated behaviors, whereas the provision of enrichment may increase these behaviors and general activity. This study aimed to evaluate the inactivity, behavior, and enrichment use of 2 fast- (CONV) and 12 slower-growing broiler strains [categorized as fastest (FAST), moderate (MOD) and slowest slow (SLOW), based on their growth rates]. To evaluate inactivity, one male and one female from 153 pens were outfitted with omni-directional accelerometers from day 21 until processing (14-24 birds/strain from 8-12 pens/strain). Additionally, to supplement inactivity data, five-minute continuous behavioral observations of four focal birds per pen (2 males, 2 females) were conducted on days 26, 42, and 56 (72-148 observations of 8-12 pens/strain) to quantify the duration and frequency of various behaviors; at the same time, 5-11 instantaneous scan samples were also performed for pen-based enrichment use. Inactivity peaked at 78-80% of the day for all strains; however, those with slower growth rates reached these levels at older ages. Compared to slower-growing strains at the same age, faster-growing strains were more inactive, spent more time sitting and feeding, spent less time standing and walking, and used enrichments less; these differences mostly occurred at younger ages. Generally, at the same age, strains with similar growth rates (within the same category) behaved similarly, with only a few exceptions. Results suggest that not all strains identified as 'slow-growing' broilers behave differently from fast-growing broilers, nor do they all behave similarly to each other. As such, results suggest that improved broiler welfare, particularly with respect to reduced inactivity, the performance of a wider range of normal, motivated behaviors, and/or increased enrichment use, is related to the broiler strain's specific growth rate.

The use of acidifying agents Aquasafe and Veleguard when rearing of broiler chickens

2020 ◽  
pp. 16-27
Author(s):  
L. Gamko ◽  
T. Tarinskaya
Keyword(s):  
Drinking Water ◽  
Organic Acids ◽  
Broiler Chickens ◽  
Positive Impact ◽  
The Body ◽  
Metabolic Energy ◽  
Control Group ◽  
Meat Production ◽  
Feed Conversion ◽  
Broiler Meat

It is known that necessary to replace the components of organic acids, which are part of acidifiers when drinking water to poultry in order to prevent the adaptation of microbes in the gastrointestinal tract. In the poultry industry organic acids are widely used, which are used as acidifiers to preserve the properties of water consumed. The purpose of this work was to evaluate the efficiency of broiler meat production when using acidifying agents of drinking water Aquasafe and Veleguard. The experimental part of the work has been performed in JSC “Kurinoe Tsarstvo-Bryansk” broiler area “Roshcha” in the Pochepsky district. The object of research was the livestock of broiler chickens cross Cobb 500 at floor housing. The effect of water acidifiers on meat productivity has been studied. Groups of chickens have been formed on the principle of pairs-analogues. Broiler chickens of experimental groups have been separated from the main livestock by a grid in the corner of the room for 100 heads in each group. It has been found by a result of research to be optimal dose usage of acidifying agents water Aquasafe and Veleguard to drink to broiler chickens. The positive effect of these acidifiers on the digestion of crude protein, crude fat, crude fiber, contributing to the effective use of nitrogen, which led to an increase in the intensity of growth, young animals’ livability and improved feed conversion. Slaughter yield in the control group was 55,1 %, and in the experimental group 57,2 and 58,4 %, which was by 2,1 and 3,3 % higher with the same level of metabolic energy and nutrients. In chickens that consumed acidifi ers more intensively used nutrients feed for deposition in the body of the components of the carcass, which affected the production. A positive impact of acidifying agents Aquasafe and Veleguard on meat quality in broiler chickens has been found.

The use of whole wheat grain in feeding of broiler chickens

2020 ◽  
pp. 3-8
Author(s):  
V. Khamitova ◽  
A. Osmanyan
Keyword(s):  
Broiler Chickens ◽  
Average Daily Gain ◽  
Live Weight ◽  
Economic Effectiveness ◽  
Metabolic Energy ◽  
Productivity Index ◽  
Feed Consumption ◽  
Meat Production ◽  
Wheat Grain ◽  
Whole Wheat

An experiment has been conducted to determine the effectiveness of growing broiler chickens when whole wheat grain has been included in the compound feed. The purpose of the research was to develop an appropriate scheme and dose for feeding whole wheat grain depending on the age of broilers, while observing the normative content of metabolic energy and nutrients in the diets, and to determine the economic effectiveness of rearing of broilers. To determine the effectiveness, data on live weight, growth rate, livability, uniformity of broiler population by live weight and variability of live weight of chickens have been studied. In the course of the work, the livability, average daily gain, feed conversion, homogeneity and variability coefficients, and the productivity index have been calculated. An increase in the live weight of broilers, as well as the rate of growth in pre-slaughter age when using whole grains in poultry diets, as well as a decrease in feed consumption per unit of live weight gain has been revealed. In conclusion, the economic effectiveness of broiler meat production has determined when whole grain has been included in diets. The use of whole wheat grain as an additive to the main diet in broiler feeding allowed to increase profits and increase the level of profitability. It has been found as a result of research that it is advisable to add whole wheat grain to the main diet for broilers at the age of 8–14 days in an amount of 5 % of the feed weight, at the age of 15–21 days – 15 %, at the age of 22–28 days – 20 %, at the age of 21–29 days – 30 % of grain without reducing the overall nutritional value of the diet.

Оrganic Meat Production of Broiler Chickens Hubbard Redbro Cross

2020 ◽  
Keyword(s):  
Broiler Chickens ◽  
Raw Materials ◽  
Animal Health ◽  
Meat Products ◽  
Poultry Meat ◽  
Meat Production ◽  
Significant Difference ◽  
Environmentally Safe ◽  
The Impact

This article presents the results of studying the impact of housing and feeding conditions on broiler chickens of Hubbard RedBro cross, as well as the quality of products obtained when using floor and cage content, in a farm. It established that when receiving a mixed feed of own production using feed raw materials grown on a farm without the use of pesticides, a statistically significant decrease in potentially dangerous substances for animal health is recorded. Compared with factory feed, it has reduced the content of pesticides by 14 times, and mercury and arsenic by 24 times, cadmium by five times, and lead by ten times. The results of the study of economic indicators of growing Hubbard RedBro cross broiler chickens, as well as the chemical composition and quality of carcasses, indicated that there was no significant difference between the floor and cell conditions of keeping. Still, the use of a diet based on eco-feeds contributed to a statistically significant decrease in the concentration of toxic metals in the muscles of the poultry of the experimental groups. As a result, it found that the use of the studied compound feed in the diets of broiler chickens increased the indicators of Biosafety and ensured the production of environmentally safe ("organic") poultry meat products.

scholarly journals Progress towards reduced-crude protein diets for broiler chickens and sustainable chicken-meat production

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sonia Yun Liu ◽  
Shemil P. Macelline ◽  
Peter V. Chrystal ◽  
Peter H. Selle
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Broiler Chickens ◽  
Crude Protein ◽  
Plasma Concentrations ◽  
Essential Amino Acids ◽  
Chicken Meat ◽  
Meat Production ◽  
Accurate Identification ◽  
Reduced Crude Protein

AbstractThe prime purpose of this review is to explore the pathways whereby progress towards reduced-crude protein (CP) diets and sustainable chicken-meat production may be best achieved. Reduced-CP broiler diets have the potential to attenuate environmental pollution from nitrogen and ammonia emissions; moreover, they have the capacity to diminish the global chicken-meat industry’s dependence on soybean meal to tangible extents. The variable impacts of reduced-CP broiler diets on apparent amino acid digestibility coefficients are addressed. The more accurate identification of amino acid requirements for broiler chickens offered reduced-CP diets is essential as this would diminish amino acid imbalances and the deamination of surplus amino acids. Deamination of amino acids increases the synthesis and excretion of uric acid for which there is a requirement for glycine, this emphasises the value of so-called “non-essential” amino acids. Starch digestive dynamics and their possible impact of glucose on pancreatic secretions of insulin are discussed, although the functions of insulin in avian species require clarification. Maize is probably a superior feed grain to wheat as the basis of reduced-CP diets; if so, the identification of the underlying reasons for this difference should be instructive. Moderating increases in starch concentrations and condensing dietary starch:protein ratios in reduced-CP diets may prove to be advantageous as expanding ratios appear to be aligned to inferior broiler performance. Threonine is specifically examined because elevated free threonine plasma concentrations in birds offered reduced-CP diets may be indicative of compromised performance. If progress in these directions can be realised, then the prospects of reduced-CP diets contributing to sustainable chicken-meat production are promising.

scholarly journals An elephant-sized Late Triassic synapsid with erect limbs

Science ◽  
2018 ◽  
Vol 363 (6422) ◽  
pp. 78-80 ◽  
Author(s):  
Tomasz Sulej ◽  
Grzegorz Niedźwiedzki
Keyword(s):  
Body Mass ◽  
Rapid Growth ◽  
Late Triassic ◽  
Mammalian Evolution ◽  
Limb Bones ◽  
Stem Group ◽  
Body Sizes ◽  
Latest Eocene

Here, we describe the dicynodontLisowicia bojani, from the Late Triassic of Poland, a gigantic synapsid with seemingly upright subcursorial limbs that reached an estimated length of more than 4.5 meters, height of 2.6 meters, and body mass of 9 tons.Lisowiciais the youngest undisputed dicynodont and the largest nondinosaurian terrestrial tetrapod from the Triassic. The lack of lines of arrested growth and the highly remodeled cortex of its limb bones suggest permanently rapid growth and recalls that of dinosaurs and mammals. The discovery ofLisowiciaoverturns the established picture of the Triassic megaherbivore radiation as a phenomenon restricted to dinosaurs and shows that stem-group mammals were capable of reaching body sizes that were not attained again in mammalian evolution until the latest Eocene.

Effects of ova transfer on the birthcoats of lambs

1972 ◽  
Vol 78 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Marca Burns
Keyword(s):  
Growth Rate ◽  
Meat Production ◽  
Transfer Experiment ◽  
Primary Follicle ◽  
Skin Expansion ◽  
Foetal Growth ◽  
Short Period ◽  
Selection For ◽  
Almost All ◽  
Size At Birth

SUMMARYBirthcoat samples from Lincoln and Welsh Mountain lambs born in an ova transfer experiment (Weiner & Slee, 1965) were examined to determine the fibre type arrays and any effect of ova transfer on manifestation of the prenatal check or the base (Dry, 1965).In the Lincoln breed arrays were Truncated Ravine or Truncated Valley thus showing central checking. Pre-curly tip fibres were mainly confined to central primary follicles. Post-natal medullation was plentiful, especially in peak curly-tips, but kemp was absent. In the Welsh lambs all identifiable arrays were either Plateau or Saddle, with the lateral primary fibres more checked than the centrals. Pre-curly tip fibres occupied almost all the primary follicles, with only a few curly-tips in primary laterals. Post-natal medullation was strongest in pre-curly tips and their successors.The effect of ova transfer was to decrease the manifestation of check in Lincoln-in-Welsh and increase it in Welsh-in-Lincoln, without affecting the base. Although this, in each case, changed the check of the lamb in the direction of that of the foster breed, it is suggested that this may not be due to any influence of maternal check on foetal check. The effect on pre-natal check may be due to foetal size, and in particular skin expansion, during a short period immediately following completion of primary follicle initiation. As compared to their respective controls, the Welsh transfer lambs had a higher S/P ratio at birth, whilst that of the transferred Lincolns was reduced.If increased prenatal fibre check is associated with increased foetal growth rate at the relevant period, it may also be correlated with increased lamb size at birth and therefore have been favoured in selection for meat production, at least in some breeds.

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