The influence of whole grain inclusion in pelleted broiler diets on proventricular dilatation and ascites mortality

1. Pelleted diets, incorporating whole or ground wheat or barley in the pellets, were fed to broiler chickens and proventricular dilatation, digesta characteristics and mortality were recorded. 2. The incidence of proventricular dilatation was reduced when whole grain was incorporated into pelleted diets at 200 g/kg. 3. Enzyme application did not influence proventricular dilatation. 4. Digesta contents of intestinal sections were greater and pH lower in anterior intestinal sections when birds had dilated proventriculi. 5. Consideration of overall ascites mortality suggests that the incidence of the condition may be curtailed by whole grain inclusion in pelleted diets. 6. Production efficiency may be enhanced with whole grain inclusion in pellets when feed processing costs and flock health responses are considered.

The effect of dietary copper sulfate on infectious proventriculitis

Oral inoculation of day-old broiler chicks with a crude homogenate of affected proventricular tissue, or the same homogenate filtered through a .2 micron filter caused proventricular lesions similar to those responsible for carcass contamination of broilers at processing. Dietary copper sulfate (CUS) has also been shown to produce similar lesions. In this study, we investigated the interaction between crude proventriculus homogenate or filtered proventriculus homogenate and 1 g/kg CUS added to a standard chicken diet. Cobb x Cobb female broiler chicks were distributed into six groups with four replicate battery pens per group. Birds were fed either a standard broiler starter diet or the same diet with 1 g/kg CUS. Each dietary treatment was inoculated per os with 1 mL of either sterile saline, unfiltered homogenate, or filtered homogenate. Both crude and filtered homogenates had a much stronger affect on proventriculus score than did Cu by itself, resulting in no interaction between either homogenate or filtrate and CUS. There was a significant and possibly antagonistic interaction on proventriculus relative weights in the CUS by filtrate group during Week 1 and a synergistic interaction in the CUS by homogenate group during Week 4. Body weights were decreased in birds fed homogenate or CUS, but not in birds fed filtrate. There was a protective effect shown by filtrate on body weight of birds fed both filtrate and CUS only during Week 1. There was a synergistic decrease in body weight of birds fed homogenate and CUS during Week 2. Overall feed conversion efficiency was significantly decreased in the homogenate treatment (P = .04) and decreased in the birds fed CUS (P = .1). There was a (4.2 vs 2.3) (P = .1) decrease in feed conversion efficiency in birds fed both homogenate and CUS. Natural exposure to low levels of the infectious agent present in the homogenates may interact with excess dietary CUS, resulting in increased proventriculus size and decrease in body weight and feed conversion efficiency.

Experimental reproduction of proventriculitis using homogenates of proventricular tissue

Proventriculitis is a problem affecting the processing of broiler carcasses, particularly those processed at 4 to 5 wk of age. The proventriculus and the gastric isthmus connecting the proventriculus to the gizzard are enlarged and swollen and often rupture during processing, causing carcass contamination. This study suggested that a filterable agent found in homogenated proventriculi can cause lesions similar to those seen in field cases. Proventriculitis was produced independently of an effect on growth, and only unfiltered homogenate caused stunting. Field birds with severe proventriculitis were shown to have increased body weights compared with birds without proventriculitis or with milder lesions. Intestinal weakness was not associated with proventriculitis and field birds with the most severe proventriculitis had stronger intestines. Although infectious proventriculitis has generally been reported as one of the lesions associated with stunting syndrome, these data suggest that it may have an independent etiology.

Noted difference in the digestive system in caged and floor-reared commercial egg-type pullets

Two trials were conducted with Single Comb White Leghorn pullets reared from 0 to 19 weeks of age in cages and on litter at the same environmental temperature. Samples were obtained to determine if digestive system differences existed. Criteria measured were gizzard weight and intestine length. Results showed that floor-reared pullets had heavier gizzards with longer intestines than cage-reared pullets. The difference may be caused by consumption of litter by the floor-reared birds.