E. D. Peebles

Effects of incubational humidity and hen age on embryo composition in broiler hatching eggs from young breeders.

There is a paucity of information regarding the influence of incubational humidity on the characteristics of broiler embryos from young hens that often produce chicks of marginal quality. Therefore, the effects of broiler breeder age (26, 28, and 30 wk) in young broiler breeders and incubator humidity (43, 53, and 63% RH) on embryonic growth between 16 and 21 d of incubation, hatching chick weight, and embryo and chick body compositions were evaluated. Hatching broiler chick BW at 21 d was lower for 26-wk-old breeders compared to those at 28 and 30 wk, and the lowest RH decreased relative wet embryo weight. Embryonic growth, on wet and DM bases, was increased in eggs from the youngest hens. Embryo moisture content (EM) was lower at 16, 17, and 19 d of incubation in eggs from breeders at 26 wk when compared to those at 28 wk of age. The effects of RH on embryo crude protein and fat composition were not consistent and varied with breeder age and length of incubation. It was demonstrated that broiler breeder age affects embryogenesis and hatching chick BW. Furthermore, EM was influenced by breeder age, and changes in incubational RH between 43 and 63% affected embryogenesis without having associated effects on EM or consistent effects on embryo crude fat and protein content. Nevertheless, a depression in embryogenesis with a reduction in incubational RH to 43% may accentuate poor posthatch performance of chicks from young breeders.

Effects of in ovo injection of carbohydrates on embryonic metabolism, hatchability, and subsequent somatic characteristics of broiler hatchlings

The effects of the in ovo injection of different carbohydrate solutions on the internal egg temperature (IT), hatchability, and time of hatch of embryonated Ross × Ross 708 broiler hatching eggs were determined. In addition, the BW, liver weight, yolk sac weight (YSW), and yolk-free BW (YFBW) of the embryos on d 19.5 of incubation and of the chicks on day of hatch were determined. Eggs containing live embryos were injected in the amnion on d 18.5 of incubation using an automated multiple-egg injector. Solution injections delivered 1.2 mL of physiological saline (0.85%) alone or with a supplemental carbohydrate. The following supplemental carbohydrates were separately dissolved in saline at a concentration of 0.3 g/mL: glucose, fructose, sucrose, maltose, and dextrin. Temperature transponders were implanted in the air cells of embryonated and nonembryonated eggs after in ovo injection for the detection of IT at 6, 14, and 22 h after injection. The IT of embryonated eggs was significantly greater than that of nonembryonated eggs at all 3 times after the treatment period. Eggs that were injected with saline with or without supplemental carbohydrates experienced a reduction in IT when compared with control eggs whose shells were perforated without solution delivery, and the decrease in IT was associated with a delay in hatch time. Liver weight was negatively related to YSW and positively related to YFBW, and YSW was negatively related to YFBW. Although the saline and carbohydrate solution injections increased chick BW compared with noninjected controls, chick YFBW was decreased in the maltose- and sucrose-injected groups. In conclusion, the injection of 1.2 mL of saline with or without supplemental carbohydrates lowered embryonic metabolism, as reflected by a lower IT and a delay in time of hatch. However, effects of the different carbohydrate solutions on yolk absorption and tissue deposition in yolk-free embryos varied. These results suggest that lower volumes for solutions containing maltose, sucrose, or fructose should be considered for in ovo injection.

Effects of in ovo injection of L-carnitine on hatchability and subsequent broiler performance and slaughter yield

Effects of in ovo injection of L-carnitine on the hatchability, grow-out performance, and slaughter yield of Ross x Ross 308 broilers from a young breeder flock were determined through 48 d of age. Fertilized eggs were injected in the amnion with L-carnitine (0.5, 2.0, or 8.0 mg dissolved in 100 microL of a commercial diluent) on d 18 of incubation using an automated egg injector. Three control groups (noninjected and injected with or without diluent) were also included. Hatchability and hatch rate of fertilized eggs were assessed. Furthermore, subsequent mortality, BW gain, feed intake per bird, and feed conversion were determined through 46 d posthatch. On d 47, live body, carcass, and abdominal fat pad weights, along with the weights of all major commercial cuts including the thigh, drumstick, wings, and breast muscles, were determined. Individual doses of supplemental L-carnitine had no significant effect on the hatchability or rate of hatch of fertilized eggs; however, significant trends were noted for increased hatchability and length of egg incubation in conjunction with increases in L-carnitine dose. Nevertheless, there were no significant treatment effects on any of the grow-out performance or slaughter yield parameters investigated. In conclusion, although increasing the levels of L-carnitine added to commercial vaccine diluent between 0.5 and 8.0 mg/100 microL for commercial in ovo injection did not significantly influence subsequent broiler grow-out performance or slaughter yield, L-carnitine dosages above those used in this study have the potential for significantly increasing incubation length and hatchability of broiler hatching eggs.

Effects of in ovo injection of l-carnitine on subsequent broiler chick tissue nutrient profiles

Effects of in ovo injection of L-carnitine on BW and the moisture and nutrient biochemical concentrations of various organs and muscles of Ross x Ross 308 broiler chicks, hatched from eggs laid by a 28-wk-old breeder flock, were determined through 48 d posthatch. Eggs containing live embryos were injected in the amnion with L-carnitine (0.5, 2.0, or 8.0 mg dissolved in 100 microL of a commercial diluent) on d 18 of incubation using an automated egg injector. Three control groups (noninjected and injected with or without diluent) were also included. On d 0, 3, 10, 28, and 48 posthatch, bird BW and the proportional weights and moisture concentrations of various organs and muscles were determined. Glycogen, glucose, protein, and fat concentrations were also determined in certain tissue samples. Bird BW; proportional liver weight; breast, thigh, and gastrocnemius muscle moisture; liver glycogen, glucose, and protein concentrations; and breast and thigh muscle fat and protein concentrations changed with posthatch bird age. Liver glucose on d 0 and pipping muscle moisture on d 3 posthatch were significantly affected by treatment. In comparison to eggs injected with commercial diluent with no added L-carnitine, liver glucose was reduced by the injection of diluent containing either 0.5 or 8.0 mg of L-carnitine, and pipping muscle moisture was increased by the injection of commercial diluent containing either 0.5 or 2.0 mg of L-carnitine. The modified concentrations of the 2 parameters in response to these treatments were not different from those in noninjected control eggs. In conclusion, L-carnitine added to commercial vaccine diluent at levels between 0.5 and 8.0 mg/100 microL for the commercial injection of broiler hatching eggs may decrease liver glucose and increase pipping muscle moisture concentrations of chicks on d 0 and 3 posthatch, respectively, so that their levels are commensurate with noninjected controls.

Effects of S6-Strain Mycoplasma gallisepticum Inoculation at 10, 22, or 45 Weeks of Age on the Digestive and Reproductive Organ Characteristics of Commercial Egg-Laying Hens

Experimental inoculation of commercial laying hens with the S6-strain of Mycoplasma gallisepticum (S6MG) at 20 wk of age, while being maintained under ideal conditions, has previously been shown to affect the lengths and weights of various portions of the reproductive tract. Two trials were conducted in the current study to compare the effects of S6MG inoculation prior to lay at 10 wk of age, during onset of lay at 22 wk of age, and during lay at 45 wk of age on the digestive and reproductive organs of commercial layers similarly housed and maintained under ideal conditions. In each trial, liver weight, liver moisture and lipid concentration, incidence of fatty liver hemorrhagic syndrome, ovary weight, ovarian mature follicle numbers, weights and lengths of the oviduct and oviductal regions, and weights and lengths of the small intestine and small intestinal regions were examined at 60 wk of hen age. At 60 wk, liver lipid concentration was depressed, and isthmus weight, as a percentage of total oviduct weight, was increased in birds that had been inoculated with S6MG at 45 wk. Alterations in liver lipid content and weight of the isthmal portion of the oviduct may occur in response to S6MG inoculation during the later stages of production in layers housed under ideal conditions.

Improvements in semen quality, sperm fatty acids, and reproductive performance in aged Cobb 500 breeder roosters fed diets containing dried ginger rhizomes (Zingiber officinale)

Exposure to high levels of polyunsaturated fatty acid predisposes spermatozoa to lipid peroxidation, resulting in their decreased fertility. Ginger powder (GP), which is high in antioxidative compounds, was fed to aged breeder roosters to improve their reproductive performance. Seventy-five 52-wk-old Cobb 500 breeder roosters randomly received either 0 (GP0), 15 (GP15), or 30 (GP30) g of GP/kg of diet for 14 consecutive wk, during which time their seminal characteristics were evaluated every 2 wk. At the end of the trial, semen samples were tested for determination of sperm fatty acid (FA) concentration and seminal plasma total antioxidant capacity. Furthermore, sperm penetration was assayed, and using 225 artificially inseminated hens, fertility and hatchability rates were determined. Dietary GP improved sperm forward motility, live sperm percentage, and sperm plasma membrane integrity. These were associated with a decrease in the percentage of abnormal sperm. The seminal TBA reactive species concentration was lower in birds belonging to the GP30 treatment in comparison with those in the GP15 and GP0 treatments. The feeding of GP resulted in overall decreases and increases in sperm saturated and unsaturated FA, respectively. The n-6:n-3 FA ratio of sperm was decreased in the GP30 group in comparison with controls. The highest levels of sperm C20:4(n-6) and C22:6(n-3) FA were recorded in the GP15 and GP30 treatments, respectively. A higher percentage of sperm C22:4(n-6) FA was found in GP-fed roosters. Seminal plasma total antioxidant capacity was considerably improved by the GP15 and GP30 treatments. Further, a higher number of perivitelline membrane sperm penetration holes was recorded for the GP30 treatment in comparison with the GP15 and GP0 treatments. Interestingly, although hatchability, chick quality, and embryonic mortality were not affected by dietary treatment, fertility rate was improved by the feeding of GP. In conclusion, dietary GP improved most of the seminal characteristics evaluated in aged roosters of this study, suggesting that it has potential for use in attenuating age-related subfertility in senescent male commercial broiler breeders.

Pipping muscle and liver metabolic profile changes and relationships in broiler embryos on days 15 and 19 of incubation

The relative proportions and relationships of pipping muscle and liver nutrients in broiler embryos on d 15 and 19 of incubation were determined. Ninety hatching eggs obtained from a 30-wk-old broiler breeder flock were incubated on 3 replicate tray levels (30 eggs per tray) for 19 d. On 15 and 19 d of incubation, 10 live embryos per tray level were necropsied to collect pipping muscle and liver samples. As the broiler embryo developed between d 15 and 19 of incubation, the glycogen and protein concentrations of the pipping muscle increased, whereas those of the liver decreased, and the fat concentration of the pipping muscle decreased, whereas that of the liver increased. Across d 15 and 19, pipping muscle glycogen was negatively correlated with liver fat, whereas on d 15, pipping muscle glucose was negatively correlated with liver fat, and pipping muscle glycogen was negatively correlated with liver glucose and glycogen. Pipping muscle fat was negatively correlated with liver glucose on d 15 but positively correlated with liver glycogen on d 19. In conclusion, in preparation for hatch between d 15 and 19 of incubation, weights of the liver and pipping muscle of broiler embryos increased relative to their BW. This occurred in association with the accumulation of glucose, glycogen, and protein and with the loss of fat in the pipping muscle. The carbohydrate stores in the pipping muscle were supported by the active metabolism of the liver before 19 d of incubation, which included the transfer of glucose and fatty acids to the pipping muscle via the circulation. Despite the livers active supply of these nutrient subunits for assimilation and oxidation by the pipping muscle, there was an overall accumulation of hepatic fat between d 15 and 19 of incubation. These data suggest that the integrated changes in the energy profiles of pipping muscle and liver between 15 and 19 d of embryogenesis are integral to the broiler embryos preparation for hatch.

Effects of the commercial in ovo injection of 25-hydroxycholecalciferol on the hatchability and hatching chick quality of broilers

The effects of the in ovo injection of commercial diluent containing various levels of 25-hydroxycholecalciferol [25(OH)D3] on hatchability and hatching chick quality variables in Ross × Ross 708 broilers were examined in 2 trials. All treatment groups, each containing 21 and 40 eggs in trials 1 and 2, respectively, were randomly represented on each of 10 replicate tray levels of a single-stage incubator. On 18 d of incubation (doi), eggs were subjected to 1 of 6 treatments using a commercial multi-egg injector. Treatments included noninjected and diluent-injected controls, along with those that received diluent containing 0.15, 0.30, 0.60, or 1.20 µg of 25(OH)D3 in trial 1 and 0.20, 0.60, 1.80, or 5.4 µg of 25(OH)D3 in trial 2. Hatchability of injected eggs (HI) was recorded on 20.5, 21.0, and 21.5 doi, and embryonic mortalities through 21.5 doi were determined. On 21.0 doi in each trial, the BW, body length, and weights and moisture concentrations of the livers and yolk sacs of male and female chicks in each replicate group were determined. In a preliminary trial, the in ovo injection of 0.60 µg of 25(OH)D3 on 18 doi significantly elevated its serum level concentrations in embryos on 19.25 doi. In both trials, the HI of noninjected controls through 21.0 doi was higher than that of diluent-injected controls. In trial 1, the HI of eggs on 21.0 doi after being injected with 0.30, 0.60, or 1.20 µg of 25(OH)D3 was higher compared with that of diluent-injected controls, and in trial 2, the HI of eggs on 21.0 and 21.5 doi after being injected with 0.60 µg of 25(OH)D3 was higher compared with that of diluent-injected controls. In conclusion, the in ovo injection of 0.60 µg of 25(OH)D3 may be used to alleviate depressions in HI in Ross × Ross 708 broiler hatching eggs that can occur in response to the in ovo injection of commercial diluent.

Effects of in ovo injection of carbohydrates on somatic characteristics and liver nutrient profiles of broiler embryos and hatchlings

Effects of the in ovo injection of commercial diluent supplemented with dextrin or with dextrin in combination with various other carbohydrates on the somatic characteristics and liver nutrient profiles of Ross × Ross 708 broiler embryos and chicks were investigated. Results include information concerning the gluconeogenic energy status of the liver before and after hatch. Eggs containing live embryos were injected in the amnion on d 18 of incubation using an automated multiple-egg injector for the delivery of the following carbohydrates dissolved in 0.4 mL of commercial diluent: 1) 6.25% glucose and 18.75% dextrin; 2) 6.25% sucrose and 18.75% dextrin; 3) 6.25% maltose and 18.75% dextrin; and 4) 25% dextrin. Also, a noninjected control and a 0.4-mL diluent-injected control were included. Body weight relative to set egg weight on d 19 of incubation (E19) was increased by the injection of all carbohydrate solutions, and on the day of hatch was increased by the injection of diluent, sucrose and dextrin, and maltose and dextrin solutions. Hatchability of the fertilized eggs, residual yolk sac weight, and liver weight were not affected by any injection treatment; however, as compared with the 0.4 mL diluent-injected group, all of the supplementary carbohydrates, except for the glucose and dextrin combination group, increased liver glycogen and glucose concentrations on E19. Furthermore, all carbohydrates, except for the 25% dextrin treatment, decreased liver fat concentration on E19. From E19 to the day of hatch, liver glycogen concentrations dropped dramatically from an average of 3.2 to 0.6%. Despite treatment differences observed on E19 for liver glycogen, glucose, and fat concentrations, these differences were lost by the day of hatch. Nevertheless, liver glycogen and glucose concentrations were positively correlated on the day of hatch. In conclusion, the in ovo injection of various supplemental carbohydrates dissolved in 0.4 mL of commercial diluent altered the liver nutrient profile of Ross × Ross 708 broiler embryos before hatch. However, the subsequent pattern of energy utilization during the hatching process modified these effects.

Effects of in ovo injection of electrolyte solutions on the pre- and posthatch physiological characteristics of broilers

Effects of the automated in ovo injection of various concentrations and volumes of physiological electrolyte solutions and a carbohydrate-electrolyte solution (CEN) on broiler embryo development and posthatch chick performance were investigated in 5 individual consecutive trials to test potential diluents for commercial injection. A 200-µL saline solution (117 mM) injection treatment and a noninjected control were included in all trials. For the first 4 trials, solutions were injected into the amnion of embryos on d 16 of incubation, and subsequent percentage incubational egg weight loss, embryo mortality, proportional embryo BW, embryo moisture content, proportional yolk sac weight, and yolk moisture content were evaluated on d 18. In trial 5, solutions were injected into the amnion on d 18, and subsequent hatchability and posthatch performance were investigated. In trial 1, a 200-μL injection of 5 mM tripotassium citrate (C(6)H(5)K(3)O(7)) and a 200-μL injection of CEN at 1:400 and 1:8,000 concentrations had no detrimental effect on proportional embryo BW. However, embryo moisture content was increased by the injection of either solution at all concentrations. In trial 2, 200-μL injections of saline, potassium chloride (KCl), or sodium dihydrogen phosphate (NaH(2)PO(4)) solution at various physiological concentrations did not affect any of the parameters examined. In trial 3, the injection of 2,000 µL of 117 mM saline reduced 0 to 18 d percentage egg weight loss. In trial 4, percentage egg weight loss was reduced and embryo moisture was increased by a 200-μL saline (117 mM) injection, but not by 200 μL of solutions of CEN (1:400), C(6)H(5)K(3)O(7) (5.0 mM), or NaH(2)PO(4) (1.0 mM) in 5.5 mM KCl. Compared with controls in trial 5, plasma refractive index was increased by CEN-KCl (1:400-5.5 mM) and saline (117 mM) injections, but not by C(6)H(5)K(3)O(7)-KCl (5 mM-5.5 mM). The current study indicated that 5.5 mM KCl and 5 mM C(6)H(5)K(3)O(7) have the greatest potential for use individually or in combination for the commercial injection of broiler hatching eggs.