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PubMed1979

The amino acid and energy requirements of broiler breeder hens.

Three trials, involving 1000 broiler breeder hens each, were conducted under rather uniform conditions in order to test the applicability of two models for calculating the amino acid requirements of broiler breeders, and to evaluate their energy requirements. The birds fed diets based on Model A (which assumes that all of the egg white and shell membrane proteins are synthesized during albumen formation and secretion at the expense of tissue proteins) produced at a rate greater than the planned target, whereas Model B (which assumes that only ovoglycoproteins and shell membranes are thus produced) supported a production close to the anticipated performance. This indicates the validity of Model B, developed for egg layers, to predict the requirements of the most limiting amino also for broiler breeder hens. The resulting practical diets contained considerably lower protein levels than customary. According to Model B, minimal amino acid requirements for broiler breeder hens producing a daily egg mass of 52.7 g. having a body weight of 3.5 kg and gaining weight at a rate of 4 g/day, calculated to be as follows (g/hen/day): methionine, .57; sulfur amino acids, .83; lysine, .76; arginine, 1.11; threonine, .72; valine, .92; isoleucine, .85; leucine, 1.25; tryptophane, .19; histidine,

Amino Acids↗

PubMed1980

Artificial insemination of individually caged broiler breeders. 1. Reproductive performance of males in relation to age and strain of females.

Studies were conducted to evaluate the reproductive capacity of male broiler breeders used for artificial insemination over an extended period and mated to females of six strains. Biweekly determinations were made of semen volume, semen concentration, and spermatozoal motility for each of the 47 males caged individually from their 39th to 63rd week of age. The percent fertility, duration of fertility, and percent hatchability were determined at five-week intervals (periods) using three young and three force-molted broiler female strains. With young female strains, the mean percent fertility for a 7-day collection of eggs following a single insemination (1 to 7 days) ranged from 95.7 to 81.1 over six consecutive periods. The mean duration of fertility (days) and the mean percent hatchability of fertile eggs was 13.3 and 13.0, and 92.5 and 84.9 respectively, for the first two periods. With force-molted hens, the mean percent fertility (1 to 7 days) ranged between 97.2 and 86.0 over the first three periods, and the mean duration of fertility and the mean percent hatchability was 13.2 and 12.8, and 91.5 and 84.1, respectively, for the first two periods. Fertility of eggs collected for 10 days following a single insemination was slightly but consistently lower than fertility over 7 days for both female groups. Significant differences among males and between periods existed for each semen trait. The effects of male, young female strain and period on fertility and duration of fertility were significant. Hatchability was significantly affected by period only. No male by female strain interaction existed for percent fertility or hatchability. A significant male by period interaction existed for percent fertility, semen volume and concentration. The results obtained are considered to support the feasibility of maintaining broiler breeders in cages and the use of artificial insemination (AI) to produce broiler hatching eggs.

Age Factors↗

PubMed1980

Strain variation in hematological response of broilers to dietary aflatoxin.

The response of clinical blood values to graded levels of dietary aflatoxin was studied in three populations of chickens. Male chicks of two commercial broiler strains, one color-sexed and the other feather-sexed, and a randombred strain were fed dietary aflatoxin at levels of 0, 1.25, 2.50 or 5.0 microgram/g of diet from 1 to 21 days of age. At the conclusion of the 21-day treatment period, all remaining birds were bled by cardiac puncture and packed cell volume (PCV), erythrocyte counts (RBC), hemoglobin concentration (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), total plasma protein, and total plasma cholesterol were determined. All strains of broilers were susceptible to aflatoxicosis as detected by total plasma protein and cholesterol. Anemia associated with aflatoxicosis was induced in the two commercial broiler lines, but not in the randombred line. The PCV, RBC, and Hb were diminished from control values in a dose-related fashion by graded levels of aflatoxin in the commercial broilers, but not in the randombred line. Decreases in MCV with no significant changes in MCHC were observed in all strains.

Aflatoxins↗

PubMed1981

Relationship of pen height to bone strength of broilers.

Broilers reared in cages have a high incidence of wing breakage during processing. Three trials were conducted to determine the effects of cage dimensions and floor types on bone breaking strength and wing breakage during processing. Broilers were fed commercial-type diets and processed through the pickers at a commercial processing plant or a research facility. Broken bones were detected by palpation, and humeri and tibia were removed. Breaking strength was determined for the humeri and tibia with a testing instrument. Incidence of breast blisters, crooked keels, follicle infection, fleshing downgrades, and slabsidedness were determined in one trial. Cage height was the major factor affecting wing breakage and humerus strength. Incidence of wing breakage for broilers on wire floors with cages .64 m high was not significantly different from that of control broilers reared on litter with ceiling 2.54 m high. Humerus breaking strength was significantly reduced in two of three trials by the .64-m-high ceiling. Cage rearing increased the incidence of crooked keels and feather follicle infections.

Animals↗

PubMed1982

Response of broilers to hyperthermic stress following treatment with a new cyclo-oxygenase inhibitor.

Two trials were conducted using broiler chickens to test the efficacy of pretreatment with Banamine, an inhibitor of prostaglandin synthesis, on various heat stress indices. Significant differences were found in peripheral prostaglandin F (PGF) levels between immature male and female broilers with pullets having a higher concentration. Females also had less mortality during the hyperthermic challenge, which was independent of medication treatment. Confinement and transport of male broilers resulted in elevated levels of PGF, which were markedly lowered near the time of heat stress death. All levels of Banamine appeared to give some measure of protection against heat stress in male broilers as evidenced by higher survival rates and longer survival times.

Administration, Oral↗

PubMed1982

Field trials with an oil emulsion infectious bursal disease vaccine in broiler breeder pullets.

Two independent field trials were undertaken with commercial broiler companies in separate sections of Alabama in order to test the efficacy of an experimental commercially prepared oil emulsion infectious bursal disease (IBD) vaccine in broiler breeder pullets. The IBD vaccine was tested both for safety and the production of neutralizing antibodies in pullets and their progeny as well as its ability to prevent early field exposure to virulent IBD virus (IBDV) in broiler progeny that may lead to immunosuppression resulting in poor performance. The following was demonstrated in both trials: 1) the IBD vaccine had no adverse effect on breeder performance, 2) the IBD antibody titers in breeders peaked at 10 weeks postvaccination (PV) and remained about 1.5 to 4 times higher than nonvaccinated breeders through 25 weeks (PV), 3) 1-day IBDV maternal titers in broilers were related to the parental titers, 4) the IBD vaccination in pullets prevented early infection to field IBDV in progeny as determined by antibody titers and various performance parameters.

Animals↗

PubMed1983

Lincomycin dose response for treatment of necrotic enteritis in broilers.

A dose response study was conducted to determine the appropriate (optimal) lincomycin concentration in drinking water for the treatment of necrotic enteritis (NE) in broilers. The study was replicated twice over time using a total of 2,895 broilers. Birds were raised in a facility containing a built-up litter from a source that experienced NE. They were commingled from 1 day of age until NE was observed. Lincomycin was mixed in drinking water at a rate of 0, .528, 2.114, 8.454, or 33.818 mg/liter for a period of 7 days. The study was terminated 3 weeks after initiation of therapy. Necrotic enteritis was diagnosed by mortality and pathological findings. The data on mortality were analyzed statistically using analysis of variance procedures. The Walker-Carmer technique was applied to estimate the appropriate lincomycin concentration. Lincomycin was effective for the treatment of NE in broilers at concentrations of greater than or equal to 2.114 mg/liter of drinking water. The minimal effective dose that would achieve maximal treatment response (optimal dose) against NE in broilers was estimated to be 16.9 mg lincomycin/liter of drinking water.

Animals↗

PubMed1983

The effect of sodium fluoride and sodium silicate on growth and bone strength of broilers.

Two experiments were conducted using 300 broilers each. Standard broiler diets were supplemented by adding to the drinking water either sodium fluoride or sodium meta-silicate. Sodium fluoride provided 120 ppm Na and 100 ppm F and 120 ppm Na and 74 ppm Si were provided by the sodium silicate. Control groups received tap water. All groups received a standard corn-soybean meal diet and drinking water ad libitum. All broilers were reared in floor pens, and hardwood shavings were used for bedding. Live weights and feed conversion were determined every 2 weeks. Growth rates, feed conversions, and mortality were not affected by the sodium salts in either experiment. Litter conditions in the pens were closely observed, and no differences were found resulting from the addition of either sodium salt to the drinking water. A significant decrease in humeri strength was observed when one wing of broilers in the control and sodium fluoride treated groups was immobilized with tape during the last 2 weeks of each experiment. This loss of strength was not significant in the sodium silicate group. In both experiments, breaking strength and ash content of humeri and tibiae were significantly increased in birds fed the sodium fluoride when compared to the control group. The sodium silicate group yielded intermediate results.

Animals↗

PubMed1983

Bone fragility in broilers as affected by pen height, sex, and a comparison of left and right humeri.

Humeri and tibiotarsi breaking strengths were determined for broilers raised in pens of varying heights. Five hundred forty-four broilers were reared in conventional floor pens or wire cages on the floor with overhead restrictions of 20, 30, 40, or 60 cm. No significant differences were noted on growth, feed conversion or tibiotarsi breaking strength. Height-restricted broilers had significantly weaker humeri than did the controls. A significant linear relationship (P less than .05) was noted in height-restricted broilers in that as pen height increased so did humeri strength. Further studies were conducted to test for significant differences between male and female humeri strength and between right and left humeri on the same bird. Forty-six pairs of female and male humeri were obtained, tagged for identity, and broken on the Instron Model 1122. Males had significantly stronger humeri than females and right humeri were significantly stronger than left humeri in both sexes.

Animals↗

PubMed1984

The efficacy of chlorine dioxide in controlling Salmonella contamination and its effect on product quality of chicken broiler carcasses.

A large spin-type chiller in an Ontario poultry processing plant was adapted so that the chill water could be treated with various levels of chlorine dioxide ( ClO2 ), increasing the concentration of ClO2 from 0 to 1.39 mg/liter resulting in reducing the bacteria count to the point where salmonellae could not be isolated from the chill water or the chilled broiler carcasses. In addition, coliform, psychrotroph , and aerobic plate counts were all greatly reduced (less than 1 log cycle) in chill water but were only slightly reduced (less than .5 log cycle) in macerated chicken broiler breast skin. Shelf-life was lengthened for broiler carcasses treated with 1.33 and 1.39 mg/liter ClO2 as compared to control carcasses. Sensory panelists reported no off flavors for any ClO2 concentration but rated broiler skin as being slightly lighter in color compared to control carcasses at all concentrations of ClO2 treatment.

Abattoirs↗

PubMed1984

Evaluation of nutrient specifications for broiler breeders.

Two experiments were conducted to determine if previously suggested nutrient requirements of broiler breeders (23 g protein, 850 mg sulfur amino acids, 4.5 g calcium, and 750 mg phosphorus/bird/day) are in excess and could be reduced during the laying period. In Experiment 1, Cobb color-sex broiler breeders were fed daily nutrient allowances that were 100.0, 96.3, 92.5, 89.4, and 86.6% of the suggested requirements. In Experiment 2, Cobb feather-sex breeders were fed daily allowances that were 92.5, 89.4, 86.6, 83.4, and 80.9% of the suggested requirements. Birds on all diets were fed the same energy level; however, energy varied with season to maintain body weight. Egg production, fertility, hatchability, egg weight, and shell quality were not significantly affected by the reductions in nutrient intake in either experiment. The diet with the lowest nutrient level (80.9% of the suggested requirement) was adequate, indicating a considerable margin of safety for the stated requirements. Body weight was quite variable but tended to decrease with nutrient restriction. Weights of broilers hatched from treated breeders were not significantly affected at 49 days of age by the breeder dietary treatments. These results indicate that broiler breeder diets formulated to meet presently suggested requirements have a large margin of safety and a reduction of specifications by approximately 10% is suggested. The revised daily intakes recommended are: 20.6 g protein, 754 mg sulfur amino acids, 400 mg methionine, 938 mg lysine, 1379 mg arginine, 256 mg tryptophan, 4.07 g calcium, 683 mg total phosphorus, and 170 mg sodium.

Amino Acids, Sulfur↗

PubMed1984

Utilization of energy for maintenance and gain in broilers and Leghorns at two ages.

Regression equations describing the relationship between energy gain and metabolizable energy intake per unit metabolic weight were derived for 8- to 22-day-old and 28- to 42-day-old broilers and 14- to 28-day-old and 28- to 42-day-old Leghorns. The estimated maintenance energy requirements were lower in the 28- to 42-day-old birds than in the younger birds, but the decreases were small. Maintenance energy requirements of Leghorns were 36% less than those of broilers. Age had no effect on the efficiency of energy utilization above maintenance in broilers. However, the efficiency of energy utilization above maintenance in Leghorns was 43% lower in the older birds. This was correlated with a lower percentage fat gain in the older Leghorns. The percentage fat gain in broilers was substantially higher in the older birds, but this was not correlated with changes in energetic efficiency.

Age Factors↗

PubMed1985

Duration of exposure--histological effects on broiler lungs, performance, and house environment with Mt. St. Helens' volcanic ash dust.

Fourteen hundred broilers were exposed to Mt. St. Helens' volcanic ash (VA) dust (D) from 28 to 49 days of age to correlate the duration of exposure time to histological effect on lungs and to determine the effects on broiler performance and house environment. Histological examinations of the lungs from birds exposed each day for 4 days to either VAD for 60 min (VAD 60) in the morning and afternoon (3276 g VA/day), or VAD after one direct application (DiAp) (20 kg/m2) on wood shaving litter revealed mild lymphoid hyperplasia and granuloma formation accompanied by phagocytized crystalline material seen in some alveolar macrophages; however, no effect was observed in lung tissues from broilers exposed each day for 4 days to VAD for 15 min (VAD 15) in the morning and afternoon (82 g VAD/day). Birds exposed to all VAD treatments and examined after 7 days had histological changes in the lungs, including giant cell granuloma formation, similar to those seen at 4 days. No significant histopathological changes were found in the turbinates with any VAD treatments. Levels of mean body weight, ammonia concentration, mortality, and respiratory dust (particles ranging in size from .5 to 10 micron) levels were not significantly different among the treatments. Significantly poorer mean feed conversion was observed with broilers exposed to VAD 60 than the VA DiAp exposure. No difference in feed conversion was observed between the control and either VAD 15 or VAD 60 treatments. From this experiment, the observed histological changes in the lungs occurred with 4 days or less exposure to VAD 60 (3276 g/day).

Air Pollutants↗

PubMed1985

The effect of maternal age on broiler performance on litter and a raised perforated floor.

The effect of maternal age and floor type on the performance of broiler chicks was studied. Hatching eggs were collected and hatched from the same Cobb commercial strain of broiler breeder hens at 27, 42, and 52 weeks of age. Chicks from each group were reared separately or intermingled on commercial diets. Maternal age had a significant effect (P less than .05) on live body weights of broilers reared either separately or intermingled. Weight differences found at day-old between chicks from 42- and 52-week-old dams were overcome by the age of 44 days. Chicks from the 27-week-old dams were not as heavy and consumed less feed than those from other parentage groups. Broilers on the perforated floors were heavier than their floor counterparts. Overall performance, except for body weight, was not affected by floor type or rearing condition.

Animals↗

PubMed1985

Effects of sorbic acid feed fungistat on the intestinal microflora of floor-reared broiler chickens.

The intestinal microflora of a group of broilers fed a diet containing .04% sorbic acid from Days 1 through 49 of their lives was compared with broilers given a diet without the fungistat. Four broilers from each group were killed at 7, 21, 35, and 49 days, and intestinal sections of the duodenum, the lower small intestine, and both ceca were removed aseptically. Samples of the contents of the intestinal sections were analyzed microbiologically. Groups of microorganisms analyzed included total aerobes, total anaerobes, coliforms, streptococci, lactobacilli, clostridia, Bacteroides, Bifidobacterium, yeasts, and molds. Generally, there was a large variation in viable counts of microorganisms for birds of the same treatment. Of the nine groups of microorganisms analyzed the highest counts obtained (greater than 10(6)/g) were for total aerobes, total anaerobes, lactobacilli, and Bifidobacterium. Coliforms, streptococci, and clostridia showed intermediate counts (greater than 10(3)/g), while yeasts and molds and Bacteroides showed the lowest counts (greater than 10(2)/g). Total microbial numbers, in most cases and irrespective of sorbic acid treatment, were highest in the ceca, lower in the small intestine, and still lower in the duodenum. There were no major trends of microbial population changes observed in a given treatment, intestinal location, or group of organisms with age and time on feed. Inclusion of sorbic acid in the feed did not influence total aerobes, total anaerobes, lactobacilli, streptococci, Bifidobacterium, and clostridia. However, broilers on sorbic acid-containing feed had, at 49 days of age, lower coliform counts in the duodenum, lower yeast and mold counts in the ceca, and higher Bacteroides counts in the ceca.

Animal Feed↗

PubMed1985

Effect of dietary fat supplementation on the carcass composition of three genetic lines of broilers.

Three genetic lines of broilers - a commercial line (Ross X Arbor-Acres), and lines selected for low abdominal fat (lean line), and high abdominal fat (fat line) were fed one of two isocaloric and isonitrogenous purified diets differing in total fat content (2 vs. 9%). Carcass composition (crude protein, ether-extract, ash, and total dry matter content) was determined on four broilers/line/diet at 21 days of age and at 1 kg body weight. Carcass protein and ether-extract were not significantly (P less than .05) affected by diet at 21 days of age or at 1 kg weight. Carcass ash was significantly (P less than .01) affected by diet at 21 days of age but not at 1 kg body weight. Genetic line of broiler significantly (P less than .05) affected carcass protein, ether-extract, and ash at 21 days of age and at 1 kg body weight. Lean line broilers had a significantly (P less than .05) higher percentage of carcass protein and a significantly (P less than .05) lower percentage of carcass ether-extract than the fat line or commercial broilers.

Adipose Tissue↗

PubMed1986

Evaluation of broiler breeder pullet vaccination programs for preventing clinical reovirus infections in the progeny.

The efficacy of various reovirus vaccination programs in commercial broiler breeder pullets for preventing clinical reovirus infections in broiler progeny was studied in three experiments. In each, 70 1-day-old broilers from each of four different commercial poultry companies that used various combinations of live and killed reovirus vaccines in breeder pullets were used. Broiler progeny from each company were bled and serum analyzed for neutralization antibody to the S1133 reovirus. Twenty chicks from each company were challenged by foot pad with a virulent reovirus (S1133) and 20 chicks challenged with another reovirus (81-B) isolate to determine their susceptibility. An additional 20 chicks from each of the four groups were maintained as unchallenged controls. Chicks were examined for morbidity, mortality, and weight gain for a 3-week period. Three weeks after challenge, all chickens were necropsied for gross lesions. There was a direct correlation between the number of doses of live inactivated reovirus vaccines that pullets received to antibody titer and resistance to challenge in the day-old progeny. Day-old progeny derived from breeder pullets that received one dose of live and two doses of inactivated reovirus vaccines had the highest numerical maternal antibody titer and best resistance to clinical infection following challenge.

Animals↗

PubMed1987

Processing yields and meat flavor of broilers fed a mixture of narasin and nicarbazin as an anticoccidial agent.

Processed yields (percent hot carcass) and cooked meat flavor of broilers fed 100 ppm of an anticoccidial agent (a mixture of 50 ppm narasin and 50 ppm nicarbazin) were compared with yields of birds fed a ration without the anticoccidial agent. Broilers were processed at 7 wk of age (49 days) after a 4-day withdrawal from the anticoccidial agent for the treated birds. The flavor of meat was evaluated by a 12-member sensory panel. Meat was either deep fat-fried or oven roasted. Sensory evaluations were made on freshly cooked samples and on cooked meat refrigerated for 24 h and reheated. The anticoccidial agent did not produce a difference (P greater than .05) in the hot carcass yields of the broilers as compared with control birds fed the nonmedicated diet. Analyses of triangle test data for flavor evaluations by two statistical methods indicated that there were no detectable differences (P greater than .05) in flavor between broilers fed the anticoccidial agent in the diet and those fed the control diet.

Animals↗