Intermittent light program impacts on reproductive performance, health and welfare of breeding hens.

The lighting regime significantly impacts poultry production, reproductive performance, health and welfare. This study aimed to test the effect of the intermittent light (IL) regime on reproductive organs and hormones, semen quality, and behavioral performance. Thus, 270 Rhode Island Red hens aged 20 weeks were distributed among three groups of six replicates and 15 birds each, housed in floor pens. The first group was used as a control (C) and was exposed to constant light for 16 h d-1, while birds in other groups were exposed to IL for 20 min h-1 (T20) and 40 min h-1 (T40) during the 16 h light period. The outcomes were that follicle number was higher for T20 compared to T40 but not the controls, while T40 is different from T20 but not the controls. The same is true for testosterone. The sperm concentration is lower for T40 compared to the controls, with no difference between T20 and the controls. Body temperature was not different among groups. Conversely, differences were not noticed for leg alterations; plumage conditions; and relative ovary, oviduct, and/or testes weight and hatchability. Thus, the IL T20 program should be further investigated as a lighting regimen for managing Rhode Island Red laying hens for stimulating follicle number and testosterone without negatively impacting the physiological response and health traits. From a practical point of view, the IL schedule of 20 min h-1 during 20-36 weeks of age can be economically viable due to saving 66 % of the light cost.

Wet feed and chilled water as stratigies to ameliorate heat stress impacts in growing turkeys during summer conditions.

The researchers investigated wet feed and chilled water effects on growth performance, carcass characteristics, and physiologic responses of native turkeys during the summer season. We hypothesized that the present treatments during the hot season would show different performances. A total of 180 four-week-old unsexed pullets were divided into six groups in a 3 × 2 factorial arrangement. Pullets were allocated regarding feed conditions to 3 groups (ad libitum dry feed, ad libitum wet feed, and diurnal wet feed). Each group was divided into 2 subgroups according to water temperature (ordinary or chilled water; 15-16 °C). Pullets fed diurnal wet feed and drank chilled water had the highest daily feed intake and the lowest feed conversion ratio during 4-16 weeks of age. Abdominal fat, IgG level and body temperature were low, whereas total antioxidant capacity and the meat quality scores for color, juiciness, and susceptibility were high in turkeys that drank chilled water. The interaction between wet feed and water temperature showed significant changes in glucose, cholesterol levels, and alanine transaminase activity. Pullets fed diurnal wet feed and drank chilled water had the lowest body temperatures. Wet feeding and chilled water may be the appropriate feeding method for native turkeys raised in hot weather.

Consequences of supplementing duck's diet with charcoal on carcass criteria, meat quality, nutritional composition, and bacterial load.

The influence of charcoal as feed additives on carcass and meat characteristics was studied in 144 four weeks old Muller ducks. The experimental ducklings were assigned to six groups of 24 birds (Eight per replicates each). The dietary treatments contained 0, 0.5, 1.0, 1.5, 2.0, and 2.5% charcoal for G1 (C), G2 (L1), G3 (L2), G4 (L3), G5 (L4) and G6 (L5), respectively. All experimental birds were raised under similar environmental and managerial conditions. Results indicated that charcoal did not affect most carcass traits significantly except for dressing percentage was higher (P < 0.05) in 1.5 and 2 % charcoal included ducks diets compared to control ducks. Charcoal supplementation significantly affected duck meat tenderness, juiciness and water holding capacity. Moreover, charcoal altered (P < 0.05) meat components such as crude protein, calcium components, desirable fatty acids, nutritional value and some bacterial counts. Thiobarbituric acid reactive substances reduced in birds fed charcoal at 1.5, 2, and 2.5%, with significant variation among treatments. No significant differences in the number of Escherichia coli and Staphylococcus aureus were detected among the ducks fed with charcoal and the control group. It could be concluded that charcoal could be included in ducks' diets at 1.5 and 2% with beneficial effects on carcass parameters.

Environmental heat stress in rabbits: implications and ameliorations.

Profitable production of rabbit meat requires comfortable environment for expression of good quality traits embedded in the genetic components of rabbits. One of the major problems facing rabbit production is heat stress, especially in hot regions of the world. This is further aggravated by global warming being experienced as a result of climate change. Rabbits have no or few sweat glands, complicating the problem of heat dissipation, thereby predisposing the animals to heat stress (HS). Heat stress adversely affect welfare and adaptation, feed consumption and utilization, immunity and health status, growth, reproduction, and milk production in rabbits. Rabbits are homoeothermic animals. They should be capable of body temperature regulation within a narrow range. Thermoregulation is extremely poor in rabbits because of lack of sweat glands. Rabbits are highly sensitive to high ambient temperature. The presence of thick insulator fur on the skin further impedes heat loss in rabbits. This review summarizes data available literatures in the last two decades (2000-2020). Short compilation on management techniques adopted in rearing rabbits under hot conditions is included.

Effects of lighting source as an environmental strategy for heat stress amelioration in growing Californian rabbits during summer season.

The current work investigated the influences of different light sources on growth performance, carcass characteristics, blood biochemicals, physiological status and health aspects. One hundred and twenty growing California rabbits were assigned into four empirical collections in an experiment of completely randomized design. Rabbits of the first collection were reared under incandescent light bulbs (control), while the second, third and fourth collections were reared under fluorescent, saving light and LED light bulbs, respectively. The results indicated that rabbits reared under incandescent and LED had the heaviest body weight at 16-weeks-old. Rabbits reared under LED recorded the greatest gain during 14-16 weeks of age and 6-16 weeks of age. The lowest feed conversion ratio was observed in rabbits reared under LED lighting, during 14-16 weeks of age, and during the whole period without significant variations. Fat percentage (%) was low in rabbits exposed to fluorescent and LED. Rabbits grown under LED showed the lowest albumin/globulin and the highest glucose concentration. Rabbits kept under LED showed the lowest rectal temperature, mortality and health risks %. Conclusively, LED lighting source might be appropriate for alteration of incandescent and fluorescent light sources in rabbit farms to improve growth performance without compromising rabbit's carcass and welfare.

Early heat acclimation during incubation improves Japanese quail performance under summer conditions.

Effects of exposing quail eggs to high temperature on the heat tolerance ability and productivity of birds were investigated. Four groups of 600 fertile eggs were randomly selected; the first group was incubated under 37.5 °C and the hatched chicks were reared under a gradual decrease in temperature from 35 to 24 °C (Control). The second group was exposed to 39.1 °C for 2 h/day during 4-14 days of embryogenesis and the hatched chicks were reared under a gradual decrease in temperature from 35 to 24 °C. The third group was incubated under 37.5 °C and the hatched chicks were exposed to 39 ± 1 °C for 2 h/day during 4-14 days of age. The fourth group was exposed to 39 ± 1 °C for 2 h during 4-14 days of embryogenesis and the hatched chicks were exposed to 39 ± 1 °C for 2 h/day during 4-14 days of age. The temperature applied changed (P < 0.01) embryo weight and incubation period. Birds exposed to high temperature during brooding had superior growth performance, dressed carcass, body temperature and health traits. Birds subjected to 39 ± 1 °C during brooding exhibited decreased feed consumption and body weight gain. Finally, this work suggests that thermal acclimation during embryogenesis might offer a practical method for easing heat stress.

Role of clay in detoxification of aflatoxin B1 in growing Japanese quail with reference to gender.

The present study investigated the influence of the quail diet polluted with aflatoxin B1 (AFB1) and its detoxification by using clay as a feed additive on the growth performance and some blood biochemical components of growing Japanese quail with reference to sex. A total number of 120 Japanese quail chicks (1 week old), was randomly divided into 10 groups (24 chicks/ group). A 5 × 2 factorial arrangement experiment was performed and included five levels of AFB1 (0 ppm, 1 mg/kg AFB1, 1 mg/kg AFB1 + 1% clay, 2 mg/kg AFB1 and 2 mg/kg AFB1 + 1% clay) and two sexes. Birds fed with aflatoxin free diet had significantly (P ≤ 0.05 and 0.01) higher final live body weight, weight gain and lower mortality rate than the other groups. Addition of 1% clay significantly (P ≤ 0.05 and 0.01) improved the growth performance traits and diminished aflatoxin effect when compared to groups without the addition of clay. Obtained results indicated significant (P ≤ 0.05) differences between the two sexes in their response to aflatoxicosis in the final live body weight and weight gain. Our results showed significant (P ≤ 0.01) changes in all blood biochemicals (total protein, albumin, globulin, total cholesterol, creatinine, uric acid) and activities of serum enzymes studied due to the toxicity of AFB1. Conclusively, the consumption of polluted diets with AFB1 caused deleterious effects on the growth performance and blood biochemicals components of Japanese quail, while dietary addition of natural clay to the diet of growing Japanese quail caused beneficial effects.

Lighting programs as an appliance to improve growing New Zealand white rabbit's performance.

Lighting regimes are possibly used as a strategy to improve rabbit production in tropical regions; on this background, this study was conducted to assess the possible role of different light (L):dark (D) regimes in improving growing New Zealand white rabbit's performance. Sixty-four growing rabbits were randomly divided into four groups. Rabbits of the first group (C) were exposed to 12 h of light (from 10.00 to 22.00 h). Rabbits of the second group (T1) were exposed to 12 h of light (from 22.00 to 10.00 h). The third group (T2) was exposed to 8 h of light (from 10.00 to 18.00 h), while the fourth group (T3) was exposed to 8 h of light (from 22.00 to 06.00 h). Temperature-humidity index values ranged between 27.00 and 28.87, indicating exposure of growing rabbits to very severe heat stress. Body weight (BW), body weight gain (BWG), feed consumption (FC), feed conversion ratio (FCR), carcass traits, blood parameters, and some physiological (rectum temperature, respiration rate) and health aspects (morbidity, mortality, and health risks %) were investigated. Rabbits of T1 showed the highest (P < 0.05) averages of BW and BWG in comparison with their counterparts. There were no significant differences in FC; however, rabbits of T1 had the lowest value of FCR at marketing. The percentages of dressed carcass, liver, and kidney in T1 and T3 were the highest. Non-significant changes were observed among the groups in most of the metabolic and hematology parameters of blood, except for ALT and N/L ratio. Further, rabbits of T1 showed the lowest rectal temperature and respiration rate in comparison with their counterparts. Conclusively, the utilization of photoperiod of afternoon program for over a short period of time in rabbitry brought in beneficial effects on growth performance and other productive and physiological parameters of growing rabbits.

Implementation of different feeding regimes and flashing light in broiler chicks.

A 3 × 2 factorial arrangement was implemented to determine the performance of 450 Cobb broilers subjected to different feeding regimes with and without lighting programs. The chicks were divided into 3 groups according to the feeding regime (ad libitum, restricted, or intermittent), and each group was reared under one of two lighting programs (100% continuous light or 50% continuous light and 50% flashing light). The results showed that the broilers under the ad libitum and intermittent feeding regimes had superior body weight (BW) and average daily gain (ADG) values and the lowest feed conversion ratio (FCR) at 3 and 6 wk of age. Broilers exposed to flashing light and an intermittent feeding regime had the highest BW and ADG values and the lowest FCR. Birds exposed to intermittent feeding had the highest dressed carcass weight and the lowest heart weight. Broilers reared with flashing light had higher tenderness and juiciness values than the other groups. Broilers subjected to a restricted feeding regime and flashing light had the lowest abdominal fat values of all the groups. Tenderness and juiciness were significantly higher in broilers subjected to the ad libitum feeding regime × flashing light and the intermittent feeding regime × flashing light. Broilers fed an intermittent regime had the lowest spleen %, heterophil, heterophil to lymphocyte (H/L) ratio and body temperature values of all the groups, and broilers reared under the intermittent regime × flashing light had the lowest spleen %, H/L ratio and body temperature values. Non-significant differences in all health aspects (shank length, keel bone length, foot pad burns, breast blisters score, hock discoloration, and mortality) were observed among the experimental groups. In conclusion, intermittent and restricted feeding regimes and a flashing lighting program improved the FCR and did not produce any adverse effects on performance or physiological parameters. The results of this work show that intermittent feeding and flashing lighting programs are more beneficial to broiler management.

Ameliorating deleterious effects of heat stress on growing Muscovy ducklings using feed withdrawal and cold water.

We studied the effect of feed withdrawal and cold water on the growth performance and health status of 180 Muscovy ducklings (28 days old) during the summer season. The experiment used a 3 × 2 factorial design consisting of 3 and 2 feeding and water systems, respectively. The birds were divided into 6 experimental groups of 30 birds each (10/replicate). The 3 feeding systems were ad libitum, full-feeding (AD); afternoon, feed withdrawn from 8 am to 2 pm daily (AF); and diurnal, feed withdrawn from 2 pm to 8 am daily (DI). The 2 water systems were tap water (TW) or cold water (CW). The results indicated that the different feeding systems with cold water positively affected the growth performance, dressed carcass, liver, gizzard, meat tenderness, juiciness, susceptibility, body temperature, tonic immobility, and blood biochemistry (glucose, aspartate aminotransferase, alanine aminotransferase, total antioxidant capacity, and malondialdehyde) of Muscovy ducklings. However, no differences in percentages of plumage, leg problems, breast blister scores, and most blood parameters were found among all groups. In conclusion, AF feeding of ducklings in combination with CW during hot conditions was more suitable than other feeding methods.

Use of some nutritional supplements in drinking water of growing turkeys during 1st month of age and their effect on performance, meat quality, blood profile and antioxidant status.

The management practices implemented by the poultry sector as using some nutritional additives in the early stage of a bird's life can potentially detect other challenges to production development in the poultry farms. Many potential supplements can be included in the early feeding as which are added to drinking water. In this study, 180 1-day-old chicks were randomly distributed into six groups to investigate the use of some nutritional supplements in drinking water of growing turkeys during 1st month of age and their effect on growth performance, carcass traits, meat quality, leg problems, blood profile and oxidative status. Birds that were supplied with tap water were considered the control group (C), whereas the birds that received the 1st, 2nd, 3rd, 4th and 5th treatments (T1, T2, T3, T4 and T5, respectively) were supplied with drinking water containing 10% sugar syrup, molasses, lemon juice, skim milk and fresh egg albumin respectively. The different water additives significantly (p < 0.05) affected the body weight (BW) and body weight gain (BWG) at all studied ages except for the BW at 4 weeks old and BWG at 0-4 weeks old and 8-12 weeks old. Significant effects of the treatments on the feed consumption (FC) and feed conversion ratio (FCR) were not observed during the experiment, and the treatments did not cause significant differences (p < 0.05) in the carcass cut-up traits, bone measurements, body temperature, plumage conditions, mortality rates and blood parameters except for IgA (p = 0.043). The activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) was improved in the treatment groups with 10% molasses and lemon juice respectively. The total antioxidant capacity (T-AOC) and catalase (CAT) activities were enhanced in the treatments compared with the control group. The plasma malondialdehyde (MDA) levels were decreased with the sugar syrup, molasses and lemon juice treatments compared with those in the control and other groups. Supplementation of molasses or lemon juice to drinking water of turkeys during the 1st month of age resulted in a higher profit margin in comparison with the control group. The results showed that birds supplied with water containing 10% molasses or lemon juice during the growing period presented an improved growth performance, immune response, antioxidant status and economic efficiency.

Sustainable floor type for managing turkey production in a hot climate.

Floor type management is an important factor in turkey production in hot climates exceeding 30°C. In this study, a total of 360 turkeys aged 4 wk were randomly distributed to investigate growth performance, carcass characteristics, certain health aspects (breast blisters score, footpad burns, hock discoloration, and plumage condition), and airborne conditions. Birds in the first group were raised on a littered floor (control; C), whereas birds in the other groups (T1, T2, T3, T4, and T5) were raised on cement, wire net, rubber mat, plastic and wooden slatted floors, respectively. The results indicated that growth performance and meat quality were improved, with increases in body weight, daily body weight gain, feed conversion ratio, and tenderness and juiciness values, when plastic and wooden slatted floors were used. Moreover, the use of plastic and wooden slatted floors attenuated body temperature, airborne dust particulates, and ammonia concentrations. In conclusion, placing plastic, wooden slatted, or wire floors reduced the incidence of health disorders and alleviated heat stress effects by decreasing body temperature and the heterophil to lymphocyte ratio. Thus, plastic and wooden slatted floors are suitable for growing turkeys under the conditions of this study.

Implementation of different feed withdrawal times and water temperatures in managing turkeys during heat stress.

This investigation studied the effects of different feed withdrawal times, water temperatures, and their interaction on growth performance, carcass traits, blood parameters, and health aspects of native turkeys (Egyptian local breed). We distributed native turkey poults (n = 180; 4 wk old) into 3 groups according to feed withdrawal time (ad libitum; feed withdrawal from 800 to 1,400 h, FW8 to 14; and feed withdrawal from 1,400 to 2,000 h, FW14 to 20). Each group was further divided into 2 subgroups corresponding to water temperature (ordinary and chilled water). Our results indicated that birds of FW14 to 20 exhibited the highest (P = 0.0001) body weight (BW) and average daily gain (ADG), whereas turkeys that drank chilled water displayed a higher BW than those that drank ordinary water. Turkeys that were kept under FW8 to 14 and drank chilled water displayed the highest BW at marketing and ADG from 4 to 16 wk of age. The lowest feed conversion ratio (FCR) was exhibited in turkeys kept off feed under the FW14 to 20 regime. Birds that were kept under FW14 to 20 and received chilled water showed the lowest FCR. The meat color scores of the birds that drank chilled water were higher than those that drank ordinary water, whereas birds kept off feed under the FW14 to 20 regime displayed the highest tenderness and juiciness, followed by those fed ad libitum. Turkeys reared under FW14 to 20 exhibited the highest albumin/globulin ratio and glucose content but the lowest globulin and aspartate transaminase (AST) values. Birds that were kept under FW14 to 20 and drank chilled water displayed the lowest corticosterone concentration. Turkeys reared under FW14 to 20 presented the lowest body temperature. Birds that drank chilled water exhibited a lower body temperature than those that drank ordinary water. Turkeys that were fed ad libitum and drank chilled water displayed the lowest body temperature. Conclusively, applying feed withdrawal and cold water had benefits in turkeys during heat stress. Applying these treatments as managerial alternatives for raising native turkeys during the summer season is highly recommended.

Effects of Dietary Supplementation of Zinc Oxide and Zinc Methionine on Layer Performance, Egg Quality, and Blood Serum Indices.

The objective of this study was to evaluate the effectiveness of dietary zinc oxide (ZnO) and zinc methionine (Zn-Met) supplementation on layer performance, quality of egg, some blood constituents, and oxidative status in blood of laying hens. A total of 120 laying hens (Hisex Brown) 22-week-old were indiscriminately allotted into five groups of 24 hens with six replications (four birds/replicate). A complete randomized design experiment was performed including control (basal diet), two levels of ZnO (50 and 100 mg/kg basal diet), and two levels of Zn-Met (50 and 100 mg/kg basal diet) through 22 to 34 weeks of age. Supplementation of 100 mg of Zn-Met significantly (P = 0.001) increased feed intake compared to other treatment groups. The groups supplemented with 50 mg of ZnO and 100 mg of Zn-Met reported the significantly higher egg production rate (P = 0.002) and egg mass (P < 0.001) compared to other treated groups. All traits of egg quality were not statistically (P < 0.05 or 0.01) affected by ZnO or Zn-Met supplementation except shell thickness, Haugh unit score, and yolk to albumin ratio. Dietary supplementation of either ZnO or Zn-Met did not affect the oxidative parameters in serum except the activity of Cu-Zn-SOD. Serum triglyceride, total cholesterol, and LDL cholesterol (low-density lipoprotein) were significantly (P < 0.05) affected by Zn supplementation, while HDL cholesterol (high-density lipoprotein) did not affect. Compared to the control group, supplementation of ZnO or Zn-Met increased serum content of zinc with no differences among supplemental zinc doses. It could be concluded that dietary inorganic (ZnO) and organic (Zn-Met) supplemented up to 50 and 100 mg/kg, respectively, can be used as effective supplements to improve productivity of laying hens, serum zinc level, lipid profile (triglyceride and LDL cholesterol), and activity of Cu-Zn-SOD.

Influence of swimming time in alleviating the deleterious effects of hot summer on growing Muscovy duck performance.

This experiment was conducted to observe the effects of varying swimming times (ST) of Muscovy ducks, raised in an open-sided house, in alleviating the deleterious effects of high temperature in hotter times of the day in the summer season on growth performance (body weight, average daily gain, feed consumption, and feed conversion ratio), carcass characteristics, body temperature, and some health aspects. We hypothesized that swimming times during the hottest periods of the day would show different performances. To test this hypothesis a total of 180 Muscovy ducklings were randomly distributed into 4 equal groups in a completely randomized design experiment. All groups were raised under similar housing conditions. Birds of the first group (C) were raised in the indoor system and had no access to a swimming pond. While all birds of the second, third, and fourth groups (T1, T2, and T3) had access to a swimming pond during 10:00 to 12:00 h, 12:00 to 14:00 h, and 14:00 to 16:00 h, respectively. The swimming pond (dimensions of 30 m length × 10 m width × 3 m depth with cement floor) was located in the front of the house. Vaccination and medical programs were undertaken according to the different ages under supervision of a licensed veterinarian. The obtained results indicated that swimming during 12:00 to 14:00 h improved (P < 0.05) growth performance, dressed carcass, meat tenderness, lymphocyte, heterophils/lymphocytes ratio, body temperature, and mortality rate of Muscovy ducks. However, bone measurement, plumage conditions, foot pad dermatitis, hock discoloration, breast blisters score, and blood hematocrit values were insignificantly better in the group with access to the swimming pond during 12:00 to 14:00 h. In conclusion, raising ducks during hot conditions in an open-sided house with access to a swimming pond at 12:00 to 14:00 h is highly recommended due to the high BW, better immunity, decreased mortality rate, and low body temperature of ducks which was positively reflected in the health condition.