Search

The effect of floor types on the incidence of feather follicle infection and breast blisters in caged broilers was investigated in two trials. Broilers were reared on corn-soybean meal diets with warm-room brooding. Floor types included litter (control), wire, wire covered with various types of plastic mats, and wire woven with surgical tubing. In trial 1, the effect of a coccidiostat (monensin, 120 mg/kg of feed) was investigated for broilers not on litter, and in trial 2, the effect of supplemental zinc was investigated. Broilers were processed in the laboratory processing plant when they were 51 (trial 1) and 53 days old (trial 2). Carcasses were evaluated for the occurrence of fleshing downgrades, crooked keels, feather follicle infection, and breast blisters. Incidence of feather follicle infection was low for broilers on litter or wire floor and high for broilers reared on plastic mats. Breast blister incidence was low for broilers on litter and plastic mats and was high for broilers on the wire floor. Overall carcass quality for litter (control) was superior to any of the cage treatments. Neither the coccidiostat nor supplemental zinc affected the incidence of breast blisters or feather follicle infection.

A total of 21,000 broilers was used in four experiments (one experiment per season) to evaluate the grow-out performance and carcass quality of five commercially available broiler crosses. The crosses were Hubbard × Hubbard, Hubbard × H&N, Hubbard × Shaver, Ross × Hubbard and Ross × Arbor Acre. Each experiment consisted of three replicate pens (175 birds/pen) per sex per cross. Egg weight differences for the combined experiments were nonsignificant. However, a summary of the four experiments revealed significant broiler cross differences in both day-old male and female chick weights. Both Hubbard × Shaver and Ross × Arbor Acre crosses had lower percentages of saleable chicks. At 28 days of age, male progeny differed statistically in both body weight and feed conversion. At 56 days, Hubbard × Hubbard and Ross × Hubbard females were significantly heavier than other crosses. Numerically, the combined sexes weighed 2063, 2053, 2019, 2013, and 2003 g for Hubbard × Hubbard, Ross × Hubbard, Hubbard × Shaver, Hubbard × H&N, and Ross × Arbor Acre, respectively. Male and combined sex feed utilization differed statistically at this age. No significant broiler cross differences were found in 28 or 56 day mortality or disease condemnations. Carcass quality, as determined by causes of downgrading, revealed Ross sired male progeny had fewer downgrades due to conformation, breast blisters and breast bruises than did Hubbard paternal crosses. In females, statistical paternal cross differences were found only in conformation downgrades. No significant differences were recorded in fleshing, leg bruises and broken or dislocated bones downgrades.

A completely random design consisting of three replicates of 25 broiler chickens (Hubbard x Hubbard) at each of four treatments was used to evaluate the effects of low level, chronic aflatoxicosis on performance and various processing parameters. The treatments in Trial 1 were control, .075, .225, and .675 and in Trial 2 control, .3, .9, and 2.7 micrograms/g toxin in feed (ppm). The chickens were maintained on these treatments from day-old to 7 weeks of age with feed and water available ad libitum. All aflatoxin dose levels in Trial 1 significantly (P less than .05) decreased live, dressed, and chilled eviscerated weight, whereas only 2.7 ppm significantly (P less than .05) decreased live and dressed weight in Trial 2, with chilled eviscerated weight being significantly (P less than .05) decreased at .3 and 2.7 ppm in Trial 2. Parts weights and dimension measurements reflected the aflatoxin-induced decrease in dressed weight. Breast yield (%) was significantly (P less than .05) decreased by aflatoxin while back, wing, drum, and thigh yields were significantly increased by aflatoxin. No effect of aflatoxin was seen on the incidence of crooked keel, feather follicle infection, breast blisters, or conformation. A hypocarotenoidemia and hepatic hyperlipemia were clearly a result of chronic aflatoxicosis in these broiler chickens. These data demonstrate that the toxicity of aflatoxin is dependent on the environment in which broiler chickens are exposed.(ABSTRACT TRUNCATED AT 250 WORDS)