Feed Texture Research Articles

FEED TEXTURE EFFECTS ON THE PERFORMANCE OF ROASTER CHICKENS

Two experiments were conducted, each experiment involved 1600 day-old Arbor Acre male broiler chickens which were assigned to 20 pens divided into four blocks of five pens each with five feed texture treatments assigned to the pens within each block. The five treatments were (1) All mash — corn and wheat finely ground, (2) All mash — corn and wheat coarsely ground, (3) All mash — corn and wheat very coarsely rolled, (4) same as no. 1 but crumbled or pelleted and (5) same as no. 2 but crumbled or pelleted. Although feed texture had no overall significant (P > 0.05) effect on mortality, mortality was higher among birds fed the crumble-pellet diets compared with those fed the all-mash diets, this higher mortality was due to a higher incidence of Sudden Death Syndrome. Finely and very coarsely ground diets fed as mash resulted in significantly poorer feed conversion at both 21 d (P < 0.001) and 49 d of age (P < 0.01); however, there was no significant (P < 0.05) effect of feed texture on feed conversion at 63 d of age. Body weights were significantly (P < 0.01 to P < 0.001) affected by feed texture at 21, 49 and 63 d of age with the feeding of finely ground mash resulting in the lowest body weights with the heaviest final body weights exhibited by birds fed diets which were either fine or coarse ground mashes which had gone through the crumble and/or pellet process. Feed texture dietary treatments had no effect on the incidence of leg abnormalities. Monetary returns per bird started were significantly (P < 0.05) depressed by the feeding of finely ground mash to chickens while other feed texture treatments were not significantly (P > 0.05) different. Key words: Chicken (roaster), feed texture, ingredient particle size

EFFECT OF DIBASIC CALCIUM PHOSPHATE (AD LIBITUM) AND FEED TEXTURE ON THE GENERAL PERFORMANCE AND INCIDENCE OF LEG ABNORMALITIES OF ROASTER CHICKENS

A randomized complete block experiment was designed to evaluate the factorial effects of free-choice feeding of dibasic calcium phosphate and feed texture on general performance and incidence of leg abnormalities of roaster chickens. A total of 2000 male day-old Ross × Arbor Acre chicks were randomly assigned to 20 pens (14.61 m2) of 100 birds per pen. Ten pens of birds were randomly selected and provided dibasic calcium phosphate (DCP) ad libitum for the entire experiment. All birds were fed the starter diet in crumble form from 0 to 21 d of age (0–21 d). Five feed texture treatments (Mash; 100% Pellets (P); 95% P:5% Fines (F); 75% P:25% F; 50% P:50% F) were superimposed at 22 d of age on the mineral treatments. DCP ad libitum resulted in increased Ca and P intake, reduced Ca:aP ratio, reduced body weights, at 21 d only, higher overall mortality, incidence and severity of tibial dyschondroplasia (TD) and total leg abnormalities and (numerically) lower monetary returns. Roasters fed pelleted grower and finisher diets were heavier, at 51 d only, had (numerically) poorer feed conversion, higher incidence and severity of TD and a higher incidence of mortality due to Sudden Death Syndrome (SDS) compared with mash-fed birds. The effect of feed texture had significant trends on body weight (51 d only), DCP, Ca, P and aP intake, Ca:aP ratio, angular deformity of the tibia, TD and SDS. Although mean monetary returns were not significantly affected (P > 0.05) by the feed texture treatments applied, mash-fed birds realized on average 9.5C per bird more than birds fed pellets. Roasters raised on mash diets after 22 d reached market weight of 3.2 kg in 70 d. Key words: Calcium phosphate, feed texture, leg abnormalities, roasters

Effects of Reduced Feeding Time Using All Mash or Crumble-Pellet Dietary Regimens on Chicken Broiler Performance, Including the Incidence of Acute Death Syndrome

A total of 2400 commercial broiler chickens (1200 males and 1200 females) were used in an experiment designed to estimate the effect on performances of restricting feeding time to 8, 10, 12, 14, 16, or 24 hr per day from 21 to 49 days of age (slaughter age) and the effect of using an all-mash versus a crumble-pellet feeding regimen. Restricting the feeding time had a significant effect on the body weights of both males and females at 28 and 49 days, with body weights being heavier as feeding time increased. Significant effects among feeding times also occurred for monetary returns per bird over feed and chick cost, but a linear trend was not evident. Feeding crumble-pellet diets resulted in increased body weights at 21, 28, and 49 days, improved feed conversion, more grade A carcasses, and increased monetary returns. Mortality was also significantly higher for birds grown on the crumble-pellet feeding regimen. This higher mortality was attributed to deaths due to acute death syndrome (“flip-over”), which was significantly higher among males on the crumble-pellet dietary regimen than on the all-mash dietary regimen. There is no evidence that interactions between feeding time and feed texture occurred for any of the traits measured.

Feed Texture Effects on the Performance of Turkey Broilers

An experiment involving 2400 turkey broilers was conducted to compare feeding starter, grower, and finisher diets in the all-mash form or as crumbles and pellets. The effects of pelleted grower and finisher diets containing 0, 7.5, 15, 30, or 60% “fines” were also comparatively evaluated. Lower body weights and poorer feed conversion resulted when birds were fed the allmash diets, but mortality, carcass grades, and monetary returns were not affected significantly (P<.05). Similarly, as levels of fines in pelleted grower and finisher diets increased, feed conversion was adversely affected and body weights tended to be lower, but mortality, carcass grades, and monetary returns were unaffected (P<.05).

Assessing Minimum Amounts and Form of Roughages in Ruminant Diets: Roughage Value Index System

Ruminants require adequate amounts of coarse-textured feeds to avoid metabolic disorders and, in the case of dairy cows, reduced milk fat production. Coarse-textured feeds help to maintain both proper muscle tone in the digestive system and proper rumen pH, both of which contribute to productivity and health. Texture of feeds is quantitatively reflected in the chewing activity of ruminants, and chewing stimulates saliva secretion. Saliva contains bicarbonates and other buffers that alter rumen environment and help avert disorders. Because chewing time reflects feed texture, a series of experiments were conducted in which feed intake, chewing time and milk and fat production were measured. Roughage value indexes (RVI) were partitioned for feed ingredients from regression equations. In addition, an equation was developed that predicts RVI from sieving and chemical data: RVI = 10.86 + PS (21.59) − DMI (1.91) + NDF (.541), where RVI is minutes/kilogram, PS is particle size in mean diameter, DMI is dry matter intake in kilograms and NDF is neutral detergent fiber percentage. The minimum RVI for the production of 3.5% fat milk was determined. By coupling an RVI requirement of 31 min/kg with feed RVI, one can formulate, by computer, diets for lactating cows that not only are nutritionally adequate, but also are adequate in roughage value, and thus avert metabolic disorders. The RVI procedure is ready for field testing.

Feed Texture and Light Treatment Effects on the Performance of Chicken Broilers

A total of 4800 broiler chicks from a commercial parent genotype was used in two experiments to evaluate effects of feeding finisher diets containing different levels of “fines”. These experiments also included a comparison of incandescent continuous green lighting and white lighting with continuous and intermittent exposure at different intensities, including one treatment which was phased down to darkness at 21 days of age and continued to 49 days of age. Fines used in these diets were ground pellets having equivalent levels of protein, fat and fiber. Performance of birds fed crumbled starters (1–28d) and pelleted finishers (29–49d) was superior to birds fed all-mash starters and finishers. As the proportion of fines in finisher diets increased, there was a significant decrease in body weights and monetary returns.Performance under both intermittent white lighting vs. continuous white or green lighting had no differential impact with light intensity of .5 lux or 7 lux from 21 to 49 days of age. Broilers grown in darkness from 21 to 49 days performed well although body weights were reduced compared with birds grown in light. There was no evidence of an interaction between light and feed texture treatments.

The Influence of Feed Texture on Broiler Performance

Three broiler feeding experiments involving a total of 15,750 broilers were conducted to compare the effects of feed texture especially unsifted versus sifted pellets on broiler performance (weight and feed efficiency). Broiler chicks fed crumbles through the first four weeks of age were significantly heavier and required significantly less feed to produce a unit of body weight than those fed the all-mash diet. From 4 to 8 weeks of age the birds started on crumbles were fed: 1) pellets unsifted, 2) pellets sifted, 3) crumbles, and 4) one-half pellets and one-half crumbles. A detailed comparison between the broilers fed unsifted and sifted pellets revealed that their performances were almost identical. Therefore, the use of unsifted pellets would appear to be more economical for commercial broiler production than the more costly sifted pellets.

An Abnormality of the Proventriculus Caused by Feed Texture

NEWBERNE et al. (1956) described an abnormality of the proventriculus purified diets. The proventriculus in the affected birds occupied a space several times that of the normal organ and it was usually filled with a turbid liquid. Although the musculature was somewhat thinner the weight of tissue in the organ was considerably greater than normal. The water content of the tissue was not altered appreciably.Although this abnormality has been commonly observed in chicks reared on purified diets, it has never been observed in chicks that consumed a practical corn-soya type diet. Thus, it appeared that the protective effect of the practical ration must be related to either its texture or its chemical composition. This report deals with effect of feed texture on the incidence of enlarged proventriculi in growing chickens.EXPERIMENTAL PROCEDURESexed White Leghorn chicks were placed in electrically heated batteries at hatching and feed and water were …

The Utilization of Fats of Different Melting Points Added to Broiler Feed

CERTAIN fats have been shown by a number of investigators to enhance the value of chick rations. For this reason, they are being widely used in commercial feeds. For the most part, the fats used are low melting tallows and greases which improve the physical texture of feed as well as its nutritive qualities. These fats must be melted and added in liquid form to obtain uniform distribution, a factor which complicates the manufacture of feed. Hardened fats, particularly hydrogenated tallow, can be handled more readily and would be convenient fats for use in feeds, if they can be readily utilized by animals.There was some doubt in this respect since Carver and Johnson (1953) have shown that stearic acid was not well utilized by the chick when added at one or two percent levels to a semipurified diet. Hydrogenated tallow contains approximately 75 percent stearic acid in the glyceride …