Bursa Of Fabricius Weights Research Articles

Effect of Environmental Temperature During the First Week of Brooding Period on Broiler Chick Body Weight, Viscera and Bone Development

The objective of the present study was to assess the development of broiler chicks during the first week post-hatching when reared at three different environmental temperatures. A total of 480 day-old chicks were placed in three environmentally controlled rooms (20, 25 and 35°C) from 1 to 7 days of age. Body weight gain, feed and water intake, as well as liver, gizzard, heart, yolk sac and bursa of Fabricius weights were measured daily. Tibia and femur bones were weighed and their length and width (medial diameter) were also obtained. The chicks reared at 20º C had lower weight gain and ingested less food than chicks reared at 25°C and less water than chicks kept at 35°C. Relative weights of the liver, heart, and gizzard were affected by environmental temperature, whereas yolk sac and bursa of Fabricius relative weights were not. The data showed that all bone parameters increased with bird age. Environmental temperature did not affect tibia or femur width, however a significant increase in bone weight and length occurred with increasing environmental temperature. These results indicate that brooding temperature of 20°C during the first seven days post-hatching was stressful decreasing broiler bone development and reducing chicks body weight.

Influence of dietary arginine concentration on lymphoid organ growth in chickens

In vivo effects of graded dietary levels of arginine on the body and lymphoid organs were investigated using Cornell K strain chickens of the B15/B15 haplotype. Two-week-old birds were fed an arginine-deficient basal diet (0.53% arginine) supplemented with additional arginine (up to 1.0% L-arginine to the diet). At four weeks of age, body weight, lymphoid organ weight, and concentrations of amino acids in plasma were measured. Arginine supplementation produced significant increases in plasma arginine (from 200 nM in chicks fed the basal diet to 2,000 nM in chicks receiving the 1.5% arginine diet) and ornithine concentrations (from 17 nM in chicks fed the basal diet to 500 nM in chicks receiving the 1.5% arginine diet). The arginine-deficient diet reduced body weight gain (P < 0.0001) and thymus, spleen, and bursa of Fabricius weights (P < 0.05). In contrast to the bursa weight, the thymus and spleen weights, as percentages of body weight, were also decreased (P < 0.05). This study suggests that arginine markedly influences lymphoid organ development, with a more pronounced effect on the thymus and spleen than on the bursa of Fabricius.

Heterosis and developmental stability of body and organ weights at hatch for parental line broiler breeders and specific crosses among them

Body, yolk sac, left and right shanks with toes, empty left and right ceca, left and right lungs, heart, and bursa of Fabricius weights were obtained at hatch for 50 chicks from each of five commercial broiler parental lines (three sire and two dam) and three F1 crosses involving them. Differences among stocks and between sexes were inconsistent among mating combinations. Although correlation coefficients between yolk-free chick weight with organ weights were generally stock specific, they were high (> 0.75) with shank weight, intermediate with heart and lung weights, and low (< 0.25) with ceca and bursa weights. Heart:lung ratios of all F1 crosses were greater than those for their respective parental lines; however, the degree of heterosis differed among populations. Developmental stability, as measured by percentage relative asymmetry, was less in two of the sire parental lines than in their respective dam lines and F1 crosses.

Effect of Recombinant Human Insulin-Like Growth Factor-II on Weight Gain and Body Composition of Broiler Chickens

Osmotic minipumps containing either saline or recombinant human insulin-like growth factor-II (IGF-II) were implanted into 4-wk-old female broiler chickens such that the treated chickens received 0.5 mg IGF-II/kg body weight per d. At the end of the trial, no differences in body weight gain or bone length were detected between the treated and control groups. Similarly, there were no differences between the two treatments with respect to heart, spleen, liver, or bursa of Fabricius weight. The relative weight óf the abdominal fat pads was greater (P < 0.05) in the birds treated with IGF-II than in the controls, whereas the weight of breast muscle was reduced (P = 0.06) in the birds treated with IGF-II. There was no effect of IGF-II treatment on feed intake or feed conversion efficiency. Plasma growth hormone (GH) levels were acutely depressed by 15 min after IGF-II administration; and also after 2 wk of IGF-II treatment. Plasma triiodothyronine (T3) concentrations were significantly depressed by IGF-II treatment. These results suggest that IGF-II may not stimulate growth in chickens, but can act as a nutrient partitioning agent, either directly or indirectly through altering plasma GH or T3 concentrations.

Individual and Combined Toxicity of T-2 Toxin and Cyclopiazonic Acid in Broiler Chicks

The effects of feeding 6 mg T-2 toxin (T-2) and 34 mg cyclopiazonic acid (CPA)/kg of diet singly and in combination were characterized in male broiler chicks from 1 d to 3 wk of age. Body weights were depressed by T-2, CPA, and the combination of T-2 and CPA. There was a significant synergistic interaction between T-2 and CPA for relative liver and kidney weights and serum cholesterol and triglyceride concentrations and a significant interaction between T-2 and CPA for 3-wk body weights and relative bursa of Fabricius weights, which were less than additive. Neither the efficiency of feed utilization nor mortality was affected by dietary treatments. Oral lesions were present in a majority of the chicks fed diets containing T-2 with or without CPA. When compared with controls, other variables measured exhibited additive or less than additive toxicity. These data demonstrate that T-2 and CPA alone and in combination can cause reduced performance and adversely affect broiler health. The effects of these mycotoxins may be exacerbated by other factors when under field conditions; hence, the potential detrimental effects of these two mycotoxins when present alone or in combination cannot be dismissed.

Response of Broiler Breeder Females to Feed Restriction Below Recommended Levels.: 3.Characterizing the Onset of Sexual Maturity

The objective of this study was to characterize how the physical attributes associated with sexual maturity would be affected by feed allocation as female broiler breeders passed through the pullet-layer transition period. Treatments consisted of five feeding programs, or body weight goals, during the period of 0 to 20 wk of age. Those were 8% above breeder standard, standard (primary breeder recommended body weights), and 8, 16, and 24% below standard. The characteristics measured included body and fat pad weights, pubic spread, comb development, head score (comb and wattle appearance), shank length, total plasma lipid concentration, ovary weight, oviduct weight, bursa of Fabricius weight, and age at sexual maturity.The generalized effect of increased severity of the feed restriction programs was to delay the birds’ development without altering their ultimate physiological values. The exceptions to this were relative body weight and shank length after maturity, which were reduced in the most severely restricted birds. Measurements of pubic spread and comb growth and subjective scores of head appearance would be useful and easily obtained information when estimating the progression of a flock toward sexual maturity.

Effects of Androgen (Testosterone, 5α-Dihydrotestosterone, 19-Nortestosterone) Administration on Growth in Turkeys

The present studies examined the effect of three androgens, testosterone, a reduced form 5α-dihydrotestosterone (5α-DHT), and the readily aromatizable anabolic androgen, 19-nortestosterone, on growth in male and female turkeys. Growth (body weight, average daily gain, and right breast muscle weight) was increased by testosterone (females), 5α-DHT (males and females), and 19-nortestosterone (males and females). Moreover, both feed:gain ratio and the weight of abdominal adipose tissue was reduced in turkeys treated with testosterone (females), 5α-DHT (males and females), and 19-nortestosterone (females and males). Bursa of Fabricius weights were reduced in androgen-treated male or female turkeys with the decrease following 19-nortestosterone being greater than those observed with either testosterone or 5α-DHT. Androgen treatment had no effect on skeletal growth (as indicated by shank-toe length) or weights of the liver, spleen, or testes. In female turkeys, plasma concentrations of hormones were determined following androgen treatment. No effects were observed on plasma concentrations of insulin-like growth factor-I or luteinizing hormone after any androgen treatment. Testosterone administration was followed by a physiological increase in the plasma concentrations of testosterone. Plasma concentrations of growth hormone were unaffected by either 5α-DHT or 19-nortestosterone but reduced by the high dose of testosterone. The effect of castration on growth in the presence or absence of 19-nortestosterone was also examined. Castration did not depress growth compared with sham-operated controls, but increased adiposity. 19-Nortestosterone increased growth of castrated turkeys, increased muscle weight, and reduced abdominal adipose tissue weight.

Research Note: Effect of Electronic Treatment of Drinking Water on Growth Performance of Broiler Chickens

Three electronic devices used to treat drinking water were compared with untreated city well water in a broiler growth performance trial. In each treatment feed conversion and BW were measured in 16 replicate pens of 60 female broilers at 29, 42, and 49 days of age. Two of the devices increased dissolved oxygen content of the water and reduced conductivity and microorganism count. One of these reduced broiler mortality (P = .065), decreased pH (P = .062), and increased Fe and Mn concentration in the water. The other increased water temperature, Ti, and Mn but reduced the concentration of Cl, Al, Ca, Cr, Mg, and Sr in the water. Neither the third device, an electrostatic water treatment, nor the other devices affected BW (P = .586) or feed conversion (P = .564) at 49 days of age. No significant treatment differences (P≤.05) in hematocrit, bursa of Fabricius weight, or tibial ash weight were observed at 21 days of age.

Correlations of Organ Weights, Hematocrit, and Testosterone with Sexual Maturity of the Male Turkey

A study was conducted with Large White breeder male turkeys to determine changes in blood constituents and organ weights associated with sexual maturity. Testicular samples from 8- to 32-wk-old turkeys were histologically examined and the changes in the seminiferous tubule epithelium associated with sexual maturity were correlated with changes in blood constituents and organ weights. Spermatozoa were first found in the lumina of the seminiferous tubules at 15 wk, and semen containing mature spermatozoa was first observed in the ductus (d.) deferens at 26 wk. Testes weights increased significantly between 20 and 22 wk and continued to increase until 30 wk of age. Testosterone concentration in the blood was .2 ng/mL at 16 wk, and steadily increased to 1.3 ng/mL at 34 wk. The increase in testosterone paralleled the increase in testes weights. The bursa of Fabricius weight reached a maximum at 16 wk, began to regress at 22 wk, and was completely regressed at 32 wk. Hematocrit values started to increase at 16 wk and reached a plateau at 22 wk. The association of the increase in hematocrit with the functional maturation of the testes suggests that the increase in hematocrit could be used to predict maturation of testicular spermatozoa in the male breeder turkey. However, semen production (semen accumulation in the d. deferens) did not start until 10 wk after mature spermatozoa were found in the testes.

Suppression of Resistance to Salmonella typhimurium in Young Chickens Inoculated with Corynebacterium parvum

The effect of Corynebacterium parvum on resistance to Salmonella typhimurium infection was evaluated in young chickens. One-day-old chickens were inoculated subcutaneously (SC) or intraperitoneally (IP) with 1.4 mg killed C. parvum and challenged by IP injection with 5.0 X 10(7) S. typhimurium 4 days later. Spleen and bursa of Fabricius weights were not altered in the C. parvum-inoculated chickens. A transient increase in thymus weight occurred 3 days after inoculation with C. parvum. Phytohemagglutinin-elicited cutaneous hypersensitivity was significantly suppressed in the C. parvum-inoculated chickens. Morbidity due to Salmonella infection increased significantly from 15% and 21% in the control groups to 43% and 46% in the chickens inoculated IP or SC with C. parvum. The results indicated that inoculation of 1-day-old chickens with C. parvum suppressed cell-mediated immune responsiveness and decreased resistance to peritoneal infection with S. typhimurium.

A Comparison between the Effect of an Avian Reovirus and Infectious Bursal Disease Virus on Selected Aspects of the Immune System of the Chicken

Reovirus 81-176 was inoculated subcutaneously into day-old specific-pathogen-free leghorns and evaluated for its effects on the immune system over a 3-week period. Structural criteria included organ weights of the bursa of Fabricius (BF) and spleen (SP), scoring of histological lesions in the BF, SP, and thymus, and hematological analyses of the circulating leukocytes. Alterations in the functional capacity of the immune system were measured using the graft-versus-host reaction, the response of peripheral blood lymphocytes (PBLs) to mitogens, the ability of circulating monocytes to phagocytize latex beads, and the serological responses to Newcastle disease virus, sheep red blood cells, and Brucella abortus antigens. For comparison, infectious bursal disease virus (IBDV) was similarly evaluated by most of the same tests. Structurally, reovirus 81-176 altered BF and SP organ weights, the total numbers of white blood cells in circulation, and the degree of follicular atrophy in the BF. Functionally, reovirus inoculation reduced both the response of PBLs to the phytohemagglutinin-P stimulation and monocyte uptake of latex beads. According to the protocols used here, no significant alteration in B-cell function could be detected in reovirus-infected chicks. With the exception of leukocyte hematology, IBDV-infected chicks had significantly altered responses in all tests used. By way of comparison, the effects of IBDV were more persistent and pronounced than were those seen with reovirus. The graft-versus-host reaction indicated an elevated and/or uninhibited response of T-cells in the blood of IBDV-infected chicks.

Atmospheric Ammonia and Broiler Cockerel Performance

Effects of atmospheric ammonia at 0, 25, and 50 ppm in relation to time on broiler cockerels were studied. Average body weights, feed efficiencies, air sac scores, and paired-lung and bursa of Fabricius weights were determined from 10 birds per replicate at 28, 40, and 49 days of age. Carcass condemnations and USDA carcass grades were measured at 49 days of age.Feed efficiency at 49 days of age was significantly affected (P≤.01) by ammonia levels. Broilers subjected to 50 ppm ammonia from 1 through 49 days were least efficient. Broilers subjected to 50 and 25 ppm ammonia from 1 to 28 days and adjusted to 25 ppm ammonia from 29 to 49 days were next least efficient, followed by 50 and 25 ppm ammonia groups from 1 to 28 days and reduced to 0 ppm ammonia from 29 to 49 days. Control birds (0 ppm ammonia) from 1 to 49 days were most efficient.Average body weights, air sac scores, lung weights, and bursa of Fabricius weights as a percentage of live body weight, carcass grades, and condemnations were not significantly affected by treatment.The results indicated ammonia levels of 25 and 50 ppm from day of age in conjunction with Newcastle infectious bronchitis (Mass.) vaccination at 21 days of age can adversely affect feed efficiency of broiler cockerels and thereby increase cost of production.

Critical ages for responses to ACTH in chicks

Linear regression analyses of the responses of adrenal and bursa of Fabricius weights, and adrenal and plasma cholesterol concentrations on log doses of ACTH indicated that the optimal age for bioassay occurred during the third week following hatching. Optimum ages for the glycemic response were not as clearly defined.