Global waterfowl production: stocking rate is a key factor for improving productivity and well-being-a review.

Waterfowl is an important animal-protein source, which has the potential to get a bigger share in the animal production sector. However, waterfowl farming practices and welfare standards are not well established yet. Stocking rate is one of the farming standards that can enhance the productivity, behavior, and well-being of birds; however, rare studies are available in this area. Thus, this article (1) gives an overview of the recent global waterfowls' meat and egg production and their population distribution, (2) reviews the effects of stocking rate on social, feeding, and sexual behaviors, (3) shows the effects of stocking rate on growth performance, carcass weight, and meat quality of ducks and geese, and (4) declares the relationship between the stocking rate and egg production. Conclusively, an optimal stocking rate standard can improve behaviors, productivity (meat-egg), and meat quality. Moreover, using weight (kg)/m2 will help in affording the required space allowance for different ducks and geese under various housing systems. The fish-waterfowl production system could be a promising and sustainable solution for increasing waterfowl production, maintaining the welfare of birds, saving energy, and reducing the water footprint of waterfowl meat. Based on prior research findings, we recommended adopting the stocking rate (SR) standard for specific duck and goose breeds to achieve an optimal production-welfare balance.

Quantitative and molecular aspects of water intake in meat-type chickens.

Even though water is the most essential nutrient for poultry production, adequate data on individual water intake in broiler chickens and its relationship with other traits of economic importance is scant. Water is provided to chickens in an unrestricted manner in spite of being a finite resource. Climate change continues to affect water sources and efficient bird use of water is long overdue. Understanding the biological basis of water intake is essential for sustainability of the poultry industry. Individual water and feed intake, and growth data was collected on 520 commercial broilers aged 14 to 42 days. We introduced the concepts of water conversion ratio (WCR) and residual water intake (RWI) as parameters that can be used to assess water intake efficiency. Water conversion ratio was defined as the amount of water consumed per unit of body weight gain, and RWI was defined as the difference between the actual water intake (WI) of a given bird and the expected WI by an average bird from the population with the same metabolic body weight, feed intake (FI) and body weight gain (BWG). The correlation between WI and FI was positive (r=0.77; P<0.0001), and the correlation between WI and BWG was positive (r=0.80; P<0.0001). Based on the distribution of RWI, the bottom 5 birds (LRWI) and the top 5 birds (HRWI) for RWI were selected for mRNA expression differences. The average broiler consumed about 7.8 L (± 1L) of water from 14 to 42 days of age. The mRNA expression of arginine vasopressin (AVP) antidiuretic hormone, calcium sensing receptor (CasR), sodium channel epithelial 1 subunit alpha (SCNN1A) and SCNN1D in the hypothalamus was upregulated in the LRWI group compared to the HRWI group. Similarly, kidney aquaporins (AQP) 2, 3, and 4 were upregulated in the LRWI group compared with the HRWI group. Given that water was provided ad libitum, the up-regulation of AVP and AQP gene mRNA expressions seem to indicate that the LRWI birds were more efficient in water reabsorption in the kidney compared to their HRWI counterparts. Increased water reabsorption will reduce the amount of water consumed to attain hydration. The water reabsorption potential was reflected in the excreta moisture levels as the LRWI birds had significantly lower excreta moisture than the HRWI birds. Excreta moisture level require further studies and could be considered as a potential proxy trait for water intake.

Factors influencing the development of gastrointestinal tract and nutrient transporters' function during the embryonic life of chickens-A review.

Intestinal morphology and regulation of nutrient transportation genes during the embryonic and early life of chicks influence their body weight and feed conversion ratio through the growing period. The intestine development can be monitored by measuring villus morphology and enzymatic activity and determining the expression of nutrient transporters genes. With the increasing importance of gut development and health in broiler production, considerable research has been directed towards factors affecting intestine development. Thus, this article reviews (1) intestinal development during embryogenesis, and (2) maternal factors, in ovo administration, and incubation conditions that influence intestinal development during embryogenesis. Conclusively, (1) chicks from heavier eggs may have a better-developed intestine than chicks from younger ones, (2) in ovo supplementation with amino acids, minerals, vitamins or a combination of several probiotics and prebiotics stimulates intestine development and increases the expression of intestine mucosal-related genes and (3) the long storage period, improper incubation temperature and imbalanced ventilation can negatively influence intestinal morphology and nutrient transporters gene expression. Finally, understanding the intestine development during embryonic life will enable us to enhance the productivity of broilers.

Stocking density, ambient temperature, and group size affectsocial behavior, productivity and reproductivity of goats- A review.

The stocking density (animal/area, SD) is one of the significant factors that influence the welfare and performance of animals. However, there are discrepancies in the recommended SD for fiber, meat, and dairy goats, which means farming practices and welfare standards for goats should be better defined. Therefore, this review article sheds light on 1) some differences between goats and sheep. 2) the geographical distribution of fiber, meat type, and dairy goat populations. 3) effects of interaction between SD and group size on social, feeding, and aggressive behaviors. 4) the effects of SD on meat and milk production. 5) the relationship between SD and reproductive performance. In conclusion, the larger space allowance with access to an outdoor yard can improve species-specific behaviors and meat and milk yield. Moreover, goats are more sensitive to high SD (less than 3 m2/ goat), especially during the last stage of the gestation period. Allowing optimal floor space for each breed is important to avoid the undesired behavioral response. Conclusively, improving the housing aspects, including floor space and enrichment tools, would assist in implementing welfare-economic production standards for goats.

Space allowance impacts behavior, productivity, reproductivity and immunity of sheep-a review.

Sheep is an important producing animal in subtropical and arid regions; however, sheep farming practices and welfare standards are still not well established. To move to either intensive or intensive sheep production, stocking density (animal/area, SD) is a significant factor that influencing the welfare and productivity of animals. However, there are discrepancies in space allowance standards for wool, meat, and dairy sheep at different stages. Thus, this review article sheds light on (1) the geographical distribution of wool, meat-type, and dairy sheep populations; (2) the effects of interaction among space allowances, housing systems, and group size on the social, feeding, and aggressive behaviors and human-sheep contact; (3) the effects of space allowance on wool, growth performance, and milk production of sheep; (4) the relationship between space allowance and reproductive performance; (5) the effects of stocking rate on immunity; and (6) suggestions to mitigate the stress and deleterious influences of SD on the productivity of sheep. In conclusion, the larger space allowance with access to an outdoor yard can improve social and feeding behaviors, meat and milk yield, and wool quality. Moreover, ewes are more sensitive to SD, so they should receive an adequate space allowance at each stage. The changes in behavioral responses of each sheep breed refer to their different requirements. Therefore, there is a need to determine the impact of housing aspects, especially space allowance and enrichment tools on the productive performance and welfare indices of sheep for implementing welfare-economic standards for sheep production.

Water scarcity can be a critical limitation for the poultry industry.

Water is essential for various physiological functions and the productive performance of animals. However, with climatic uncertainties exacerbated by climatic changes, water could become a scarce nutrient shortly. This is already the case in one-third of the world's countries, which are under medium to high levels of water stress. Accordingly, with the growth of poultry production, the availability of water at ad libitum level may not be guaranteed, and birds can be under water restriction for variable periods. Thus, this article aims at attracting the attention of animal scientists to the freshwater shortage challenge, as well as shedding light on (1) the effects of climate change on the freshwater resources; (2) the effects of limited access to water, either by water restriction (WR) or water deprivation (WD), on the growth, feed efficiency, and meat quality of broilers; (3) the effects of different levels of WR or WD on egg production and egg quality traits; (4) the effects of limited access to water on the health, behavior, and welfare status of chickens; and (5) suggested solutions to overcome future water shortage challenges. In conclusion, severe water shortage/restriction might negatively influence the productivity, behavior, and welfare status of the chickens. Genetic background and environmental conditions may interact with the WR effects. The tolerance level of indigenous chicken breeds to limited water access could provide the knowhow to potential solutions to overcome water shortage problems. Selection of chicken strains with high tolerance capacity to thirst and limited water access regimens may be a sustainable solution for solving water scarcity problems.

The impact of magnetized drinking water on semen quality, fertility and hatchability rates of Fayoumi chicken.

The present study was conducted to interpret the effect of magnetic field on water pH and calcium form, and evaluate semen quality, fertility and hatchability rates of Fayoumi chickens receiving magnetized drinking water (MDW). A total of 180 Fayoumi chickens (20 roosters + 160 hens), 54 weeks of age, were divided into two groups. The first group served as control, which received regular drinking water, and the second group was treated with MDW. Semen was collected twice (at day 15 and day 30 of the experiment) to determine semen quality. Fertility and hatchability were determined in two patches of hatching eggs through 1-15 and 16-30 days of the experiment. Results showed that the roosters of MDW group had higher live sperm and sperm motility ratios than those of the control group throughout the experimental period (1-30 days). The abnormal sperm ratio and methylene blue reaction time of MDW-received roosters were significantly lower than those of control roosters. Fertility and hatchability percentages of MDW group were greater compared to those of regular drinking water. Conclusively, alterations in the physiochemical characteristics of MDW and the calcium form can play a role in improving semen quality, fertility, and hatchability percentages during the late laying phase.

Performance traits and selected blood constituents of broiler chicks as influenced by early access to feed post-hatch.

The present study aimed to investigate the effect of early access to feed and water post-hatch on broiler chicks' performance. One hundred and twenty chicks were transferred from the hatchery to the rearing house and randomly divided into two groups. The first group: chicks were immediately access to feed and water (F-time 0). The second group: was held without feed and water for 24 h (F-time 24). Then, feed and water were provided ad-libitum, for both groups until 35 days of age. Results indicated that F-time 0 increased body weight and body weight gain throughout the experimental period. It increased feed intake during all experimental periods except from (22-28 days). Additionally, the F-time 0 enhanced the European production efficiency factor index. The F-time 24, increased red blood cells (RBCs) count, hemoglobin (HGB), and packed cell volume (PCV) percentage after 24 h. However, the F-time 0 had a higher RBCs count, HGB, and PCV at 35 days of age. F-time 24 increased total plasma protein, albumin, cholesterol, and triglycerides, after 24 h. In conclusion, early access to feed and water post-hatch enhances broiler chicks' performance and productivity and increases producers' revenue.

Space allowance: a tool for improving behavior, milk and meat production, and reproduction performance of buffalo in different housing systems-a review.

Buffalo population has dramatically increased during the last two decades, especially in tropical and subtropical regions. Although buffalo are important milk and meat-producing animal, still practices of buffalo farming and welfare aspects are not well established. Housing system and stocking density are significant factors that affect the welfare and production of animals; however, no space allowance standards have been demonstrated for buffalo at different ages. This review article presents the following: (1) an overview of buffalo subtypes and their geographical distribution of buffalo populations and their production; (2) the effect of housing systems and space allowance on the social behavior and welfare indices; (3) the effects of space allowance on milk production and growth performance of buffalo; and (4) the relationship between space allowance and reproductive performance. Although the limited data in this area of research, it can be driven that a larger space allowance with access to a pool, especially during the hot season, maintains buffalo production at optimal levels. Moreover, optimal floor space improves the welfare and social indices of buffalo; however, there are discrepancies in aggressive and agonistic behavior results. Surprisingly, the reproductive performance of buffalo was not affected by space allowance. Therefore, further research is needed to identify the impact of the housing aspects, including space allowance and enrichment tools. on the productive performance, and welfare indices of buffalo. This would assist in implementing welfare-economic standards for buffalo production and reveal the potentiality of this eco-friendly animal.

Effect of Organic Selenium-Enriched Yeast on Relieving the Deterioration of Layer Performance, Immune Function, and Physiological Indicators Induced by Heat Stress.

Heat stress (HS) induces deleterious effects on the performance of laying hens and causes economic losses for poultry industry. This study was carried out to investigate the organic effect of selenium-enriched yeast (SY) on relieving the performance, immunity and physiological deterioration induced by heat stress in laying hens. A total of 324, 28-week-old, Hy-Line Brown commercial chicken layers were randomly distributed into 4 treatments according to a 2 × 2 factorial design, with 9 hens × 9 replicates per treatment (n = 81). From 30 to 34 weeks of age, layers were exposed to 2 temperature treatments (the HS treatment groups): a thermoneutral temperature at 24°C and a heat stress at 35°C. Layers were further assigned into the 2 subgroups according to dietary supplementation with organic selenium-enriched yeast (the SY treatment groups) at either 0 or 0.4 mg/kg diet. Results indicated that all the aspects of the layer performance during the experimental period were impaired by exposure to HS, while SY supplementation improved the layer performance in both the HS and non-HS layers. Intestinal villi disruptions and liver necrotic hepatocytes were observed in the layers exposed to HS, while villi integrity and hepatocytic normality were enhanced by SY treatment. A significant (P < 0.05) decrease in the total leukocyte count, sheep red blood cell (SRBC) antibody titer, and T- and B-lymphocyte proliferation along with an increase in the heterophils/lymphocytes (H/L) ratio were observed in the HS layers compared to non-HS layers. On the contrary, SY treatment significantly (P < 0.05) improved the immune function traits in both the HS layers and non-HS layers. Furthermore, the SY treatment plays an important role in mitigating the oxidative stress and inflammation induced by HS, displaying lower levels of plasma corticosterone, lipid peroxidation, interleukin-1ß, and tumor necrosis factor-α in HS layers supplemented with SY compared to HS layers without SY supplementation. These results conclude that addition of SY to the diet of laying hens could be applied as a potential nutritional approach to relieve the deterioration effects of heat stress on the immunity, physiological status, and productive performance of laying hens.

Stocking density: a clue for improving social behavior, welfare, health indices along with productivity performances of quail (Coturnix coturnix)-a review.

The quail populations are considered to be one of the largest among the poultry species. Although quail egg and meat production are growing rapidly, still, quail farming practices and welfare aspects are not well established. Stocking density is one of the factors that can significantly affect the welfare, health, and performance of birds, but according to The Expert Group for Technical Advice on Organic Production, no allowed space standards have been reported for new hybrids and different breeds of quail. This review presents an overview of 1) the benefits of egg and meat of quail, 2) the global market of quail products, 3) the factors affecting the stocking density rate, and 4) the effects of stocking density rates and housing systems on the social behavior, welfare, physiological indices, and performance parameters of broiler and laying quail. Conclusively, larger space and enriched aviaries reduce aggressive behavior, and improve the quail welfare and immunological indices. However, the effect of stocking density on some blood biochemical indices and growth performance parameters showed mixed results. A better understanding of the relationship between housing, health, growth performance, and welfare aspects would assist in the implementation of welfare-economic standards for quail production. According to available data, stocking density ranges for broiler and laying Japanese quail are suggested; however, these stocking rates should be tested under different conditions.

Copper: benefits and risks for poultry, livestock, and fish production.

Protein production from animal origin should increase to meet the needs of a growing global population. This article presents an overview on copper (Cu) forms and their importance for animals' physiological functions. Moreover, it will focus on the current and promising nano-Cu applications in poultry, livestock, and fish production systems. Use of Cu as a feed additive directly or indirectly impacts the human food chain and may affect the safety and/or quality of food. Finally, the expected risks and hazards related to the use of nano-Cu that can affect animals, humans, and the environment are described. It is concluded that nano-Cu applications have the potential to provide an efficient solution for reducing the Cu amount in the poultry, livestock, and fish diets, which can help in reducing costs and environmental contamination and increasing animals' productivity. However, concerns over the safety of nano-Cu applications hamper their immediate implementation. Thus, rigorous risk assessments should be conducted to ensure the safety of animal-origin products in the case of supplementation animal diets with nano-copper.