Influence of vitamin deficiency and level of dietary protein on the incidence of leg problems in broiler chicks

Leg disorders in broiler chickens: a review of current knowledge

Ensuring improved leg health is an important prerequisite for broilers to achieve optimal production performance and welfare status. Broiler leg disease is characterized by leg muscle weakness, leg bone deformation, joint cysts, arthritis, femoral head necrosis, and other symptoms that result in lameness or paralysis. These conditions significantly affect movement, feeding and broiler growth performance. Nowadays, the high incidence of leg abnormalities in broiler chickens has become an important issue that hampers the development of broiler farming. Therefore, it is imperative to prevent leg diseases and improve the health of broiler legs. This review mainly discusses the current prevalence of broiler leg diseases and describes the risk factors, diagnosis, and prevention of leg diseases to provide a scientific basis for addressing broiler leg health problems.

From Metabolism to Vitality: Uncovering Riboflavin's Importance in Poultry Nutrition

Riboflavin, or vitamin B2, is indispensable for poultry, profoundly impacting their metabolic equilibrium, growth, and overall health. In a climate of increasing demand for poultry products and heightened production intensity, grasping the multifaceted roles of riboflavin in domestic fowl nutrition becomes paramount. This essential vitamin serves as a precursor to two vital coenzymes, flavin mononucleotide and flavin adenine dinucleotide, integral players in pivotal redox reactions and energy metabolism. Inadequate riboflavin levels translate into stunted growth, skeletal deformities, and compromised feed conversion efficiency, thereby adversely affecting poultry performance and bottom-line profitability. Riboflavin goes beyond its fundamental role, ameliorating nutrient utilization, facilitating protein synthesis, and augmenting enzyme activity, rightfully earning its epithet as the "growth-promoting vitamin". Poultry's reproductive success intricately hinges on riboflavin levels, dictating egg production and hatchability. It is imperative to note that riboflavin requirements exhibit variations among poultry species and distinct production phases, emphasizing the importance of judicious and balanced supplementation strategies. Aligning dietary recommendations with genetic advancements holds the promise of fostering sustainable growth within the poultry sector. Exploring the multifaceted aspects of riboflavin empowers researchers, nutritionists, and producers to elevate poultry nutrition and overall well-being, harmonizing with the industry's evolving demands.

A theropod trackway providing evidence of a pathological foot from the exceptional locality of Las Hoyas (upper Barremian, Serranía de Cuenca, Spain)

We describe a trackway (LH-Mg-10-16) occurring in laminated carbonated limestones of the Las Hoyas locality, Serranía de Cuenca, Spain. It is unmistakably a large theropod dinosaur trackway encompassing two unusual aspects, namely, wide-steps, and a set of equally deformed left footprints (with a dislocated digit). The layer also preserves other vertebrate trails (fish Undichna) and different impressions in the sediment. To address these complex settings, we devised a multidisciplinary approach, including the ichnological and taphonomical descriptions, characterisation of the rock lithofacies using thin-sections, 3D structured-light digitalisation with a high precision of 200–400 μm, and a geometric morphometric comparison with a large sample of bipedal dinosaur trackways. Sedimentary analyses showed that the trackway was produced in a humid, benthonic microbial mat, the consistency and plasticity of which enabled the preservation of the details of the movement of the animal. The results of the geometric analysis indicate that the “wide-steps” of the trackway is not unusual compared to other trackways, providing evidence that it was made by a single individual with an estimated hip height approximately 2 m. Analogous pathologies in extant archosaurs that yield the combination of wide steps and deformed digits in the same trackway were considered. All results mutually support the hypothesis that a large theropod dinosaur, with a pathological foot, generated the trackway as it crossed an area of shallow water while slowly walking towards the main water source, thus stepping steadily over the benthonic mat over which multiple fish were swimming.

Integrative analysis of transcriptomic data related to the liver of laying hens: from physiological basics to newly identified functions

Background

At sexual maturity, the liver of laying hens undergoes many metabolic changes to support vitellogenesis. In published transcriptomic approaches, hundreds of genes were reported to be overexpressed in laying hens and functional gene annotation using gene ontology tools have essentially revealed an enrichment in lipid and protein metabolisms. We reanalyzed some data from a previously published article comparing 38-week old versus 10-week old hens to give a more integrative view of the functions stimulated in the liver at sexual maturity and to move beyond current physiological knowledge. Functions were defined based on information available in Uniprot database and published literature.

Results

Of the 516 genes previously shown to be overexpressed in the liver of laying hens, 475 were intracellular (1.23–50.72 fold changes), while only 36 were predicted to be secreted (1.35–66.93 fold changes) and 5 had no related information on their cellular location. Besides lipogenesis and protein metabolism, we demonstrated that the liver of laying hens overexpresses several clock genes (which supports the circadian control of liver metabolic functions) and was likely to be involved in a liver/brain/liver circuit (neurotransmitter transport), in thyroid and steroid hormones metabolisms. Many genes were associated with anatomical structure development, organ homeostasis but also regulation of blood pressure. As expected, several secreted proteins are incorporated in yolky follicles but we also evidenced that some proteins are likely participating in fertilization (ZP1, MFGE8, LINC00954, OVOCH1) and in thyroid hormone maturation (CPQ). We also proposed that secreted proteins (PHOSPHO1, FGF23, BMP7 but also vitamin-binding proteins) may contribute to the development of peripheral organs including the formation of medullar bones to provide labile calcium for eggshell formation. Thirteen genes are uniquely found in chicken/bird but not in human species, which strengthens that some of these genes may be specifically related to avian reproduction.

Conclusions

This study gives additional hypotheses on some molecular actors and mechanisms that are involved in basic physiological function of the liver at sexual maturity of hen. It also revealed some additional functions that accompany reproductive capacities of laying hens, and that are usually underestimated when using classical gene ontology approaches.

Effects of meal-time feeding and protein restriction on walking ability and some bone and carcass properties in broilers

This experiment was designed to investigate the effects of meal-time feeding and protein restriction on performance, gait score (GS) and carcass and bone traits in broilers. A total of 420 1-day-old chicks were wing banded and randomly distributed into 21 pens with 20 chicks each. At 7 days of age, chicks were weighed and randomly assigned to one of the three treatments: (1) control (C) feed (23.02% crude protein (CP)) was available ad libitum; (2) meal-time feeding (MF); control feed was available from 0100 to 0900 h and from 1500 to 2300 h. Food was withdrawn from 0900 to 1500 h and whole wheat (10 g/bird per day) was dispersed on the floor from 7 to 21 days; and (3) low-protein (LP) diet (19.71% CP) was fed to the chicks from 7 to 21 days. All of the groups were fed ad libitum from 1 to 7 days of age and from 21 to 45 days of age with a standard commercial diet. Individual body weight was measured on days 7, 21 and 45. Feed consumption was measured from 7 to 21 days and from 21 to 45 days. Forty-two chicks were humanly slaughtered and eviscerated for bone evaluation, on days 21 and 45. Also carcass characteristics were determined on day 45. Control group body weight was significantly higher (P < 0.05) at 21 and 45 days of age than the MF and LP groups, which did not differ. Feed intake was reduced by meal-time feeding and LP diet (P < 0.01). Feed efficiency was the best in the MF group during the period of 21 to 45 days of age (P < 0.01). In the control group, shank was significantly longer than that of the LP group and tibia breaking strength was higher than that of the MF group at 21 days (P < 0.05). However, shank width, tibia wet weight and tibia mid-diaphysis ash percentage of the MF group were significantly lower than those of the C and LP groups at 21 days of age (P < 0.05). GS, shank and carcass and tibia bone traits on day 45 were not significant among groups. No compensatory growth and walking ability improvement were observed at 45 days of age for broilers fed with MF and LP between 7 and 21 days of age.

Influence of dietary protein and sex on walking ability and bone parameters of broilers

1. The study was conducted to investigate the effect of dietary protein on the walking ability and bone parameters of broilers reared under summer temperatures which ranged from 26 degrees to 32 degrees C (+/- 2 degrees C). 2. Three different dietary protein combinations were used. The diets (per kg) were: low protein with 205 g crude protein and 12.94 MJ ME, 184 g crude protein and 12.75 MJ ME; medium protein with 219 g crude protein and 12.99 MJ ME, 201 g crude protein and 12.87 MJ ME; and high protein with 238 g crude protein and 12.99 MJ ME, 216 g crude protein and 12.96 MJ ME from 0 to 4 and 4 to 7 weeks of age, respectively. Body weights of birds were recorded and birds' walking ability (gait scoring) were scored for each bird, according to 3 categories (completely normal to immobile, at 4 and 7 weeks). Tibia parameters and tibia plateau angles were also determined at 7 weeks. 3. Birds fed on the low protein were lighter than those fed on the medium or high protein diets. At 7 weeks, birds with poor walking ability weighted 149 g less than birds with no walking difficulty. 4. Bone parameters were not affected by dietary protein, sex or gait score. There was a significantly positive correlation between bone strength and radiographic density. Bone strength was also significantly correlated with bone weight and length.

Effect of sodium bentonite or hydrated sodium calcium aluminosilicate on growth performance and tibia mineral concentrations in broiler chicks fed nutrient-deficient diets

An experiment was conducted to determine whether sodium bentonite (NaB) or hydrated sodium calcium aluminosilicate (HSCA) would affect growth performance and tibia mineral concentrations in chicks fed nutrient-deficient diets. Two identical trials were conducted; each using 240 5- to 19-d-old broiler chicks (4 replicates of 5 chicks each) in a completely random design. A factorial arrangement of treatments consisted of four types of nutrient deficiencies [nutritionally complete basal (C), macromineral-deficient (-MM), trace mineral- and vitamin-deficient (-TMV), and crude protein-deficient (-CP)], and three types of additive (none, .5% NaB, and .5% HSCA). The -MM and -TMV diets reduced (P < .01), gain, feed intake, and gain:feed. The -CP diet decreased (P < .01) gain and gain:feed but did not affect (P > .10) feed intake. Sodium bentonite increased feed intake (P < .01) of all diets; resulting in an increase in gain (P < .09). Sodium bentonite increased gain:feed in chicks fed the -MM diet but did not affect gain:feed in chicks fed the C, -TMV, or -CP diets (NaBx-MM interaction, P < .02). The -MM and -TMV diets decreased (P < .01) tibia ash, but the -CP diet increased (P < .01) tibia ash. The -MM diet decreased (P < .01) tibia Ca but increased (P < .01) tibia P. Neither NaB nor HSCA affected percentage of tibia ash, Ca, or P. Tibia Zn and Mn concentrations were increased (P < .01) by the -MM diet and decreased (P < .01) by the -TMV diet.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of early protein restriction (zero to eight weeks) on skeletal development in turkey toms from two to eighteen weeks

Turkey toms were fed protein- and lysine-deficient diets or protein- and lysine-adequate diets from 0 to 4 and 5 to 8 wk and similar diets from 9 to 18 wk. Beginning at 2 wk of age and at approximate 2-wk intervals thereafter, the length and width of the right tibia were measured in nine toms per treatment. The length and width of the femur were measured beginning at 8 wk. Three tibiae that were close to the average length for each age and treatment were selected for ashing. The top 25% (epiphyseal) and middle 10% (diaphyseal) segments from each of these bones were fat-extracted prior to ashing. Mean length of the tibia continued to increase throughout the experiment whereas tibia width reached a plateau at 16 wk. Femur length also continued to increase throughout the study whereas there were no significant changes in femur width after 16 wk. Compared with the control diet, the diet deficient in protein and lysine resulted in a significant decrease in tibia and femur width at all ages. There were no dietary effects on tibia length at 16 and 18 wk, however. There were no significant dietary effects on femur length after 14 wk. There were significant age effects but no significant dietary effects on epiphyseal or diaphyseal bone ash. Epiphyseal bone ash increased from 41 to 54% over the course of the study whereas diaphyseal bone ash increased only from 59 to 64%.

The effect of restrictive and compensatory growth on the incidence of leg abnormalities and performance of commercial male turkeys

To determine if excessive body weight and dietary protein and amino acid intake contribute to the incidence of leg deformities, the growth of male turkeys was restricted from 6 to 12 wk and from 6 to 20 wk of age by feeding diets for ad libitum intake that were low in dietary protein and amino acids (74% of controls). For those turkeys whose growth was restricted from 6 to 12 wk of age, a return to control diets (low compensatory plane) or to 20% above control diets (high compensatory plane) with respect to protein and amino acids resulted in live body weights comparable with controls at 20 wk of age. Feed to gain ratios (0 to 20 wk) were comparable between compensated and control birds, and protein efficiency was improved for birds fed the low compensatory plane diets. Restricting growth significantly lowered the incidence of leg abnormalities at 12 wk of age (P less than .05), as compared with controls, but by 20 wk, only birds fed the low compensatory plane diet showed a lowered incidence (P less than .06). These results on leg abnormalities (mainly valgus-varus deformities) suggest that rapid weight gains or dietary protein and amino acid intake may contribute to the leg weakness syndrome but is certainly not the only factor involved.