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PubMed2003

Components of feed efficiency in broiler breeding stock: is improved feed conversion associated with increased docility and lethargy in broilers?.

Two trials were conducted to test the hypothesis that broilers classified as good rather than poor feed converters (low vs. high feed-to-gain ratios, respectively) would show decreased activity (increased lethargy) and reduced fear of human caretakers. In both trials birds were reared to juvenile selection age when the 192 males with the "best" breast and leg conformation were placed into individual bird cages (46 x 60 cm), and their feed conversion ratio (FCR) was measured. In trial 1, birds remained in the cages for 7 d for assessment of feed conversion. During the feed conversion testing period, the birds were subjected to three behavioral tests. First, approach-avoidance responses to a novel object placed in the feeder were observed when feeding would be expected. Second, behavior patterns of individual birds were assessed by recording feeding, drinking, walking pecking, preening, standing, and resting. Third, the 20 birds showing the best FCR and the 20 showing the worst were induced into tonic immobility (TI). Feed conversion was not related to either the novel object or the TI measures of fearfulness. Neither was FCR related to feeding, drinking, walking, or pecking. However, FCR was positively correlated with both standing and preening and negatively correlated with resting behavior. In trial 2, the FCR test lasted for 11 d. The birds were assessed for behavioral patterns (feeding, drinking, walking, pecking, preening, standing, and resting) as in the previous trial. As in trial 1, FCR was positively correlated with standing and negatively correlated with resting behavior. Contrary to expectations, the results of these two studies suggest that broilers with good FCR were actually less lethargic and no more fearful than those that showed poor FCR values.

Animal Feed↗
PubMed1989

Control, prevention and eradication of Salmonella enteritidis infection in broiler and broiler breeder flocks.

Salmonella enteritidis was identified by serological and bacteriological techniques in two clinically normal breeder flocks in an integrated broiler organisation in Northern Ireland. The organism was transmitted vertically to clinically affected progeny flocks. The infected breeder flocks were slaughtered and the infection throughout the organisation controlled and subsequently eradicated. A working group, consisting of the senior management of the broiler organisation and veterinary staff from the Veterinary Research Laboratories at Stormont, was formed to establish procedures to minimise the risk of the reintroduction of salmonella infection, by preventing vertical transmission from grandparent flocks, or lateral transmission from personnel, other animal species and fomites, or transmission through the feed. All feed was heated to a minimum of 70 degrees C for 12 minutes immediately before it was pelleted and subsequently transported to the flocks through a dedicated system of conveyor belts, bins and lorries. A comprehensive system for monitoring the efficacy of the preventive procedures was established and is now used throughout the poultry industry of Northern Ireland.

Animals↗
PubMed1989

Observations on swollen head syndrome in broiler and broiler breeder chickens.

Chickens on 14 broiler breeder farms were examined at various times throughout their laying cycle. Antibodies to the turkey rhinotracheitis virus were common although they were not always accompanied by clinical signs of the swollen head syndrome. Ninety-nine broiler flocks were tested of which only 20 were serologically positive to the virus. Some of these infections were subclinical. On nine farms where swollen head syndrome occurred several successive flocks were sampled; the syndrome occurred intermittently.

Animals↗
PubMedDate not supplied

Chicken anemia virus in broilers: dynamics of the infection in two commercial broiler flocks.

Chicken anemia virus (CAV) can cause a disease syndrome characterized by severe anemia, bone marrow atrophy, and severe immunosuppression in young chicks. Maternal antibodies prevent these clinical signs but do not prevent infection, transmission of the virus, or immunosuppression. The clinical disease is rare today because of the widespread practice of vaccinating breeders, but the subclinical form of the disease is ubiquitous. The dynamics of CAV infection, CAV antibody responses, relative lymphoid organ weights, and associated lesions were studied in two broiler flocks from a commercial producer. Both groups had detectable CAV antibodies at hatch, which waned over the first 3 wk of life. Both groups had detectable CAV DNA in both thymi and bursae over the same period. At 35 days of age, virus was detectable by polymerase chain reaction in 16 of 20 chickens, and 7 of 20 had detectable antibodies. By 42 days of age, virus was detectable in 18 of 20 chickens, and 18 of 20 had antibodies to CAV. We observed a decrease in relative thymic weights beginning at 35 days of age, coincidental withthe detection of CAV in the thymus. Bursal sizes began to decrease at 28 days of age, coincidental with a rise in antibody titers to infectious bursal disease virus. In this study, we demonstrated that under typical field conditions CAV infections in broilers have unique dynamics unlike those reported in egg laying strains of chickens managed under specific-pathogen-free conditions.

Animals↗
PubMed1983

Calcium metabolism in broiler breeder hens. 1. Calcium status of the digestive tract of broiler breeders throughout a 24-hour period.

Dry matter and calcium content of the digestive tract were determined on two groups of broiler breeders during a 24-hr period. The individually caged hens were fed either ad lib or restricted to 122 g of feed during a 4-hr feeding period each day from 0700 to 1100 hr. The hens received artificial light from 0700 to 2300 hr. On Day 14 of the feeding program a total of 100 hens, 10 from each group, were necropsied at selected intervals (0700, 1100, 1900, 2300, 0300 hr), and the contents of the various segments of the digestive tract and feces were collected and analyzed for dry matter and calcium. The calcium analysis also included any endogenous excretions and, therefore, absorption values are apparent. Hens restricted to 122 g feed per day had only 51.7% of the dry matter and 64.2% of the calcium consumed during the 4-hr feeding period remaining in the digestive tract at 1100 hr. By 2300 hr only 20.6% of the feed and 28.1% of the calcium remained. Hens had only approximately 14% (14.2 g) of their total dry matter intake and 16% (.70 g) of the calcium available for absorption from 0300 hr. The ad lib group, with an average intake of 171 g feed per day, had consumed only 26% of their daily feed intake by 1100 hr. Fifty-five percent of the dry matter consumed and 22% of the calcium remained in the digestive tract at 1100 hr. It was concluded that broiler hens restricted to morning feeding do not maintain a constant and equal metering of dry matter or calcium from the crop into the digestive tract throughout a 24-hr period.

Animals↗
PubMed1983

Calcium metabolism in broiler breeder hens. 2. The influence of the time of feeding on calcium status of the digestive system and eggshell quality in broiler breeders.

Experiments were conducted to determine the influence of time of dietary calcium intake on eggshell quality in broiler breeder hens. In Experiment 1, 60 hens were randomly divided among three treatment groups. The control group received 155 g feed (3.1% calcium) per day at 0800 hr whereas the morning- (a.m.) and evening-fed (p.m.) treatments received a .42% calcium diet (155 g/bird) and were intubated with 4.2 g calcium at 0800 or 1600 hr, respectively. Egg weight, shell weight, and specific gravity were determined at 3-day intervals for 15 days. In Experiment 2, 150 breeder hens were randomly divided among two treatment groups. They were fed 122 g per hen during a 2.5-hr feeding time at 0700 to 0930 or 1530 to 1800 hr. Eggs were collected for egg weight, shell weight, and specific gravity determinations. At the end of the 5th week, 10 hens from each treatment group were sacrificed at various times throughout a 24-hr period and the contents of each segment of the GI tract and feces were analyzed for moisture, dry matter, and calcium. In Experiment 3, two commercial broiler-breeder houses with 5,000 hens each were used. They were fed 132 g/hen per day at 0530 hr daily with water provided ad lib. The feeding time of one house was moved forward by 2 or 2.5 hr per day until the feeding time was 1600 hr. Eggs were collected for 2 weeks following pretreatment data and values determined for specific gravity. Eggs were also candled at 7 days incubation to determine embryonic mortality and fertility. Hens intubated at 0800 hr with their daily supply of calcium did not maintain shell quality equivalent to controls (Experiment 1). However, hens intubated at 1600 hr had no difficulty maintaining shell quality. Hens fed at 1530 hr had significantly better shell quality during all weeks tested compared to hens fed at 0700 hr (Experiment 2). The p.m.-fed hens had 66.9% more calcium available at 1800 hr (2.07 vs. 1.24 g) compared to a.m.-fed hens. Hens fed at 1600 hr in the commercial houses (Experiment 3) had significantly better eggshell quality (specific gravity) than hens fed at 0530 hr. There was no significant difference in percent embryonic mortality or percent fertility when eggs were candled after 7 days of incubation. It was concluded that p.m.-fed hens had significantly more calcium available during the stages of eggshell calcification. The result was significantly better eggshell quality.

Animals↗
PubMed1983

The influence of cage versus floor pen management of broiler breeder hens on subsequent performance of cage reared broilers.

Chicks from breeder hens maintained in cages or floor pens were reared in Lohman battery cages in three separate trials. The ages of the breeder flock at the time of egg collection were 29, 36, and 54 weeks, respectively. The fertility of the artificially inseminated caged hens was significantly (P less than .05) lower than that of the naturally mated hens. The source of hatching eggs had no effect on early embryonic mortality, feed conversion, or growing period mortality in any broiler trials. Hatchability of all eggs set was significantly (P less than .05) lower for caged breeders in Trials 2 and 3. In all trials, eggs from caged hens produced significantly (P less than .05) larger day-old chicks than their floor-housed counterparts; however, these chicks were significantly (P less than .05) heavier at slaughter only in Trial 2. Carcass evaluations for breast blisters, keel malformations, and leg abnormalities revealed that the severity of each condition was associated with the sex of the broiler and that, within sexes, maternal housing management had no effect.

Animal Husbandry↗
PubMedDate not supplied

Effect of used litter from floor pens of adult broilers on Salmonella colonization of broiler chicks.

The effect of used pine-shaving litter from broiler floor pens on Salmonella colonization resistance was evaluated in broiler chicks. One-day-old chicks were placed in floor pens on fresh unused litter or on used litter. All chicks were challenged orally with 10(4) S. typhimurium at 3 days of age. The study was replicated in three trials with used litter that was collected and stored for 1 day (Trial 1), 4 days (Trial 2), or 50 days (Trial 3) before the start of each trial. Cecal concentrations of volatile fatty acids (VFAs) were significantly higher (P < 0.05) in chicks placed on used litter than in chicks on new litter. In all three trials, the number of Salmonella in the cecal contents and the number of Salmonella cecal-culture-positive chicks was significantly lower (P < 0.01) at 10 days and 20 days of age in the chicks on used litter than in the chicks on new litter. The results indicated that newly hatched chicks reared on used litter had higher cecal VFA concentrations and higher resistance to Salmonella colonization than chicks reared on new litter.

Animals↗
PubMed1989

Protein and energy relations in the broiler chicken. Chronic or acute effects of alternating protein or intermittent feeding regimens on broiler lipid metabolism.

1. Broiler chickens growing from 7 to 28 d of age were given: (1) a 210 g protein/kg control diet for the entire experimental period, (2) an intermittent feeding regimen (210 g protein/kg diet for either 1 or 2 d followed by a 1 d fast), or (3) a daily change in the dietary protein level from 120 to 300 g/kg diet. Treatment variables examined were lipogenesis and glucose production in vitro, and circulating concentrations of insulin, triiodothyronine (T3) and thyroxine (T4) to determine the effects of chronic or acute dietary treatments. 2. Giving the 300 g protein/kg diet or withholding feed for 1 d decreased (P less than 0.05) lipogenesis in vitro compared with controls. 3. Giving the 120 g protein/kg diet or refeeding with a 210 g protein/kg diet for 1 or 2 d increased (P less than 0.05) lipogenesis in vitro compared with controls. Glucose production was affected in the same manner. 4. Fasting decreased (P less than 0.05) plasma insulin and T3 and increased T4. Both refeeding and a low-protein diet increased T3. Refeeding increased and a low-protein diet decreased insulin. 5. Chronic use (7-28 d of age) of either an alternating protein or intermittent feeding regimen caused greater responses compared with acute bouts (single cycle) of either of the regimens.

Animals↗
PubMed1994

Weight of internal organs and carcase yield of early food restricted broilers broilers.

1. Effects of food restriction on growth rate and relative growth rates of supply organs (liver, heart, lungs and kidneys, digestive tract) and demand organs (breast, back, thighs, abdominal fat) of broiler chickens were studied. 2. Birds were restricted in intake to 50% (group FI 50) or 75% (group FI 75) of ad libitum from 5 to 11 d of age; all birds were fed ad libitum from 12 to 39 d of age. 3. Relative growth rates from 12 to 39 d of age of group FI 50 were higher (P < 0.05) than group FI 75 and control group. 4. No significant differences in food conversion ratio, carcase fat and abdominal fat between groups were observed. 5. At 12 d of age, relative weight of the empty digestive tract of group FI 50 was higher (P < 0.05) than that of the control group and group FI 75. 6. The increased weight of the empty digestive tract may have contributed to the ability of the chickens to achieve compensatory growth after the restriction period.

Adipose Tissue↗
PubMed1983

[Ergotropic efficacy of 2,3-dimethylquinoxaline-1,4-dioxide and 2-methylquinoxaline-1,4-dioxide in growing broilers using hydrocolloid-rich rations as well as broiler fattening feed].

2,3-dimethyl-quinoxaline-1,4-dioxide and 2-methyl-quinoxaline-1,4-dioxide proved to be ergotropic in the feeding of a hydrocolloid ration as well as of a broiler fattening feed. They are at least equal to Nitrovin. The ergotropic effect of the hydrocolloid ration was higher than that of the conventional ration. For this reason methylated quinoxaline-1,4-dioxides are considered as belonging to the intestinal stabilisers. They increased nutrient and energy retention and decreased feed efficiency by approximately equal to 10%. Residues in the liver, the kidneys and the intestines could only be detected after 10 times the ergotropic amount.

Animal Feed↗
PubMed1987

[The energy and protein concentration of broiler rations in Cuba. 3. Male broilers in the summer].

A total of 1,900 male broilers of the variety White Plymouth Rock was tested with 4 energy concentrations (10.5, 11.5, 12.6 and 13.6 MJ metabolizable energy/kg) and 4 protein concentrations (15.0, 17.5, 20.0 and 22.5% CP) in their first 56 days of life in 16 test groups. The animals were kept in cages and were directly exposed to the natural Cuban summer temperatures from their 15th day of life onwards. As every test group was run with 6 repetitions, the results could be variance analytically calculated. In a comparison of the behaviour of the male animals in winter and in summer it can be stated that the animals took in between 3.4 and 25% more feed in winter than in summer. In general, a lower body protein and body fat amount could be found in all test groups in summer compared to that in winter. Feed expenditure and the utilization of energy and protein were not as good as in winter. It could be shown that both maximum live weight and live weight gain can be achieved in the 2nd fattening period in the Cuban summer if rations containing 12.6 MJ metabolizable energy and 20% CP are fed in a one-phase feeding system.

Analysis of Variance↗
PubMed1987

[Effects of factors of nutrition and husbandry on the heat production of rats and broilers. 1. Heat production of growing broiler chicks kept in groups depending on the environmental temperature].

In 2 experiments with young broiler chickens, origin Tetra B, heat production was measured in dependence on ambient temperature indirectly and with the gas exchange both over 24 h and in 20-minute periods beginning on their 5th day of live. The chickens, divided into 2 X 2 groups according to sex, were constantly kept in a climatic chamber changed in to a respiration chamber during the 8- or 11-week-long experiments. The maximum variation of the temperature was between 5 and 35 degrees C. In the periods of 24-h measurements over 4 days each, the ambient temperature was changed from day to day in steps of 5 degrees C. Heat production was influenced by the age of the chickens, energy intake and ambient temperature. The results of the measurements at the same age and the same energy intake and a temperature variation between 5 and 35 degrees C can well be described by polynomes of the 3rd degree up to the 8th week of live. The thermoregulatory conditioned heat production per 1 degree C below the critical temperature decreased with the age of the chickens. In the first few weeks of life it was 20 kJ, in the 6th and 7th weeks of life 10-15 kJ and then decreased to 4-5 kJ/kg life weight 0.75.d. degrees C. Based on the temperature of minimal heat production, the heat production of 16- to 30-day-old chickens increased to 60-80% at an ambient temperature of 5 degrees C; the metabolism of chickens older than 7 weeks was only increased by about 20%. For the first 2 weeks 35 degrees C were ascertained as critical temperature, for the 3rd to 6th weeks 30 degrees C and for the 7th and 8th weeks 25 degrees C.

Animals↗
PubMed2007

Feeding broiler breeder males. 1. Effect of feeding program and dietary crude protein during rearing on body weight and fertility of broiler breeder males.

A 2 x 2 factorial experiment was conducted to compare the effects of 2 male broiler breeder feed allocation programs (Concave or Sigmoid) during the rearing period to 26 wk of age and the interaction with dietary CP (12 or 17%) on BW and fertility. From 0 to 2 wk, all birds received a starter diet, after which, pens were randomly assigned to the 4 treatment combinations that ended at 26 wk of age. All males were weighed individually at 4, 8, 12, 16, 22, 26, 28, 32, 36, 40, 48, 52, 56, and 64 wk of age, and fertility was determined weekly from 27 to 32 wk of age and then every 2 wk to 64 wk of age. At 49 wk of age, the male feed allocation for all treatments was increased by 5 g/d. Even when fed the same as Sigmoid program males during the production period, males reared on the Concave feeding program lost BW from 32 to 40 wk of age and exhibited lower BW from 40 to 48 wk of age, which corresponded to a more rapid decrease in fertility. The 17% CP diet increased BW from 8 to 32 wk of age, but no significant differences were subsequently observed. The 12% CP rearing diet improved both weekly and cumulative fertility. A significant interaction between rearing feeding program and dietary CP during the third quartile period showed that the Concave program-17% CP diet combination was most negatively affected. The increase in male feed allocation at 49 wk restored fertility and caused differences among treatments to diminish. These data suggested that BW during the early rearing period did not affect fertility, but an increased BW due to either providing fast feed increments toward the end of the rearing period (Concave) or feeding a 17% CP diet produced males that were unable to sustain fertility after 40 wk of age without an appropriate allocation of feed.

Animal Feed↗
PubMed1985

Energy and protein relationships in the broiler. 1. Effect of protein levels and feeding regimens on growth, body composition, and in vitro lipogenesis of broiler chicks.

Male broiler chicks were fed ad libitum diets containing 18, 23, or 30% protein for 3 weeks. In addition, chicks were fed diets containing 12, 23, or 30% protein on a 3-day rotation. Finally, chicks were fed either the 23 or 30% protein on a schedule of 2 days on feed and 1 day off feed. These feeding schemes allowed chicks to consume low to excess protein coupled with either adequate or inadequate energy intake. Feed intakes were equal for the 18, 23, and rotational percent protein dietary groups and lower (P less than .05) for the 30% ad libitum group. Chicks fed the 18% protein diet ad libitum were the least efficient (P less than .05) at utilizing feed and the most efficient (P less than .05) at utilizing protein for weight gain. Compared to the ad libitum situation, restricted feeding improved feed and protein efficiency of chicks fed 30% protein diets but not of chicks fed 23% protein diets. Body composition data on a dry matter basis supported a positive relationship between dietary protein and percent lean tissue. Conversely, expressing data on a whole bird basis indicated that lean body mass was favored by feeding the diet containing 23% protein. In vitro lipogenesis was greatest (P less than .05) in chicks fed a 18% protein diet ad libitum and least (P less than .05) in chicks fed a 30% protein diets ad libitum.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Effect of protein and energy intake of broiler breeder hens on performance of broiler chicken offspring.

Two hundred and forty individually caged Hubbard x Hubbard broiler breeders (BB) were fed one of six diets at 150 g/bird per day, which provided 19 or 25 g protein and 325, 385, or 450 kcal nitrogen-corrected metabolizable energy. In Trial 1, chicks hatched from 29-wk-old BB were sexed and 12 females and 12 males placed in each of four replicate floor pens per treatment. A 23% crude protein (CP) starter (0 to 20 day), 20% CP grower (21 to 34 day) and 18% CP finisher (35 to 41 day) diets were fed. Protein intake of BB had no effect on body weight of offspring. Energy intake of BB had no effect on growth of female offspring; however body weights of 20 day-old-male offspring were 575, 586, and 601 g for low, medium, and high energy intake, respectively (P less than or equal to .01). Increasing BB energy intake increased carcass protein and reduced fat in male offspring (P less than or equal to .01) and decreased the percentage of Canada Grade B ratings for both sexes (P less than or equal to .05). In Trials 2 to 4, chicks from BB at 32, 36, and 40 wk were sexed and cage-reared to 21 days of age. The energy intake of BB had no effect on female offspring growth. Male offspring weighed 570, 563, and 585 g for the low, medium, and high energy intakes, respectively (P less than or equal to .01).

Animal Nutritional Physiological Phenomena↗
PubMed1988

Factors affecting broiler breeder performance. 7. Effect of varying levels of dietary protein on the development and reproductive performance of the dwarf broiler breeder.

Vedette dwarf broiler breeder female chicks were raised in floor pens and fed a standard starter ration. At 3 wk of age, 1,032 pullets were divided into four dietary treatment groups (258 bird/treatment). Birds were transferred into individual cages at 18 wk of age and at 21 wk of age assigned to one of four laying rations. Dietary treatments consisted of a 4 X 4 factorial design with four developer diets (12, 14, 16, and 18% protein) and four layer diets (12, 14, 16, and 18% protein). Body weight was determined at 6, 12, and 17 wk of age and thereafter at 4 wk intervals. Hen-day egg production was determined weekly from 21 to 58 wk of age. Specific gravity and egg weights were measured at 4-wk intervals on eggs collected over 4-day periods. Fertility and hatchability were measured at 32, 34, and 44 wk of age on the one-half of the birds in each treatment that had been artificially inseminated weekly with .05 mL of semen from Ross males. Embryonic mortality and chick weights of offspring were recorded when the breeder flock was 32 and 44 wk of age. Dietary treatment had a significant effect on body weight (P greater than .05) at Week 12, (12% and 14% vs. 16% and 18%) but by Week 17 differences were no longer significant. Significant differences in body and egg weights during the laying cycle were detected (P less than .05), with hens receiving the higher protein (16% and 18%) laying diets exhibiting heavier body and egg weights.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗