Low Incidence Of Tibial Dyschondroplasia Research Articles

Studies on the Efficacy of Twenty-Five-Hydroxycholecalciferol to Prevent Tibial Dyschondroplasia in Ross Broilers Fed Marginal Calcium to Market Age

Two experiments were conducted to evaluate the effect of 25-hydroxycholecalciferol [25-(OH)D ] 3 on tibial dyschondroplasia (TD) in broilers grown to market age. In Experiment 1, Ross cockerels were fed a mash diet marginal in calcium and adequate in phosphorus and cholecalciferol to 35 days of age in battery cages. Dietary 25-(OH)D was fed at 0 or 40 ug/kg during the starter (1-17 days) and grower (18-35 days) 3 phases. During the grower phase, there was third treatment in which 25-(OH)D was fed to 17 days of age 3 and then the control diet was fed to 35 days of age. Phytate phosphorus retention was measured at the end of each phase. In Experiment 2, Ross straight-run broilers were grown on litter and fed marginal calcium diets that were either crumbled (starter, 1-16 days) or pelleted (grower, 17-42 days; finisher 43-49 days). Dietary 25-(OH)D was fed at 0 or 69 ug/kg or a third treatment consisted of 69 ug/kg 25-(OH)D to 16 days 3 3 and the control diet to 49 days of age. Dietary 25-(OH)D did not affect growth performance or incidence of 3 TD in either experiment. In Experiment 1, phytate phosphorus retention was increased by feeding 25-(OH)D3 only in the grower phase. Bone ash at 35 days in Experiment 1 and bone strength at 48 days in Experiment 2 were not affected. The results show that Ross broilers have a low incidence of TD when marginal calcium is fed and do not require dietary 25-(OH)D to prevent TD or improve bone strength. 3

Effect of casein phosphopeptide and 25-hydroxycholecalciferol on tibial dyschondroplasia in growing broiler chickens

1. An experiment was conducted to investigate the influence of dietary casein phosphopeptides and 25-hydroxycholecalciferol on the incidence of tibial dyschondroplasia (TD) in 14-d-old commercial broiler chickens. 2. Three hundred and twenty broiler chicks (one day old) were randomly allocated to one of 4 dietary treatments. A standard broiler diet was used as the control with the three experimental treatments receiving the control diet supplemented with 10 g casein phosphopeptide/kg, 14 g casein phosphopeptide/kg or 69 µg 25-hydroxycholecalciferol/kg. 3. Those birds fed the diets supplemented with 14 g casein phosphopeptide/kg or 25-hydroxycholecalciferol had a lower incidence of TD than both the control and 10 g casein phosphopeptide/kg treatments when assessed grossly. 4. The body weight of birds fed the 10 g casein phosphopeptide/kg diet or the 25-hydroxycholecalciferol diet was higher than birds fed the control diet. Although not significant, the body weight of birds fed the 14 g casein phosphopeptide/kg diet was also greater than the control birds. 5. The current experiment demonstrated that both casein phosphopeptide and 25-hydroxycholecalciferol can reduce the incidence of TD in the young broiler chicken. More research is required to explain the unexpected increase in body weight described above.

Genetic variation of phytate phosphorus utilization from hatch to three weeks of age in broiler chicken lines selected for incidence of tibial dyschondroplasia

Ability to utilize dietary phytate P was evaluated in 1,387 broiler chicks of 45 sire and 180 dam families, by feeding a corn-soybean base diet supplemented with no inorganic P and a low level of Ca. These chicks were the progeny of high and low incidence of tibial dyschondroplasia (TD) selected divergently for 11 generations and a nonselected control line. Chicks from the control line utilized phytate P better than those from the high or low lines in terms of livability, mortality, and growth performance. Chicks did not differ in mortality and body weight between the high and low lines. Variation in livability and mortality was greater among lines than among families, whereas families accounted for a greater part of variation than lines in body weight. Dams accounted for a slightly larger proportion of variation than sires in traits studied. Genetic selection for improved utilization of dietary phytate P could be effective.

The effects of ultraviolet light and cholecalciferol and its metabolites on the development of leg abnormalities in chickens genetically selected for a high and low incidence of tibial dyschondroplasia

Four experiments were conducted to investigate the effects of ultraviolet (UV) light exposure and several cholecalciferol metabolites on the development of tibial dyschondroplasia (TD) and other parameters associated with vitamin D metabolism in chickens selected for high (HTD) and low (LTD) incidence of TD. In Experiment 1, exposure of chickens to UV light reduced the incidence and severity of TD more in LTD chickens than in HTD chickens, as evident by the significant interactions (P < 0.10 and 0.04). In Experiment 2, the addition of cholecalciferol to diets that were deficient in cholecalciferol linearly decreased the incidence of vitamin D rickets and increased bone ash, but increased the incidence of severe TD. The LTD chickens had a higher maximal bone ash of 40.0 +/- 0.7% than did the HTD chickens, which had a maximal bone ash of 37.0 +/- 0.7%. In Experiment 3, the addition of 5 micrograms/kg of 25-hydroxycholecalciferol [25-(OH)D3], 1-alpha-hydroxycholecalciferol, or 1,25- dihydroxycholecalciferol decreased the incidence and severity of TD in the LTD chickens and had no effect on TD in HTD chickens. In Experiment 4, increasing dietary 25-(OH)D3 increased plasma 25-(OH)D3 levels in both lines, but HTD chickens had higher plasma 25-(OH)D3 levels at 20 and 40 micrograms/kg of dietary 25-(OH)D3. The incidence and severity of TD were reduced in the LTD chickens by dietary 25-(OH)D3, but little effect was noted in HTD chickens. The LTD chickens reached a maximal bone ash at 9.7 +/- 1.9 micrograms/kg and HTD chickens reached the same bone ash at 33.0 +/- 7.0 micrograms/kg. These results indicate that UV light and vitamin D metabolites are not effective in preventing TD in HTD chickens, but that altered vitamin D metabolism does exist between HTD and LTD chickens.

Effect of Selection for High or Low Incidence of Tibial Dyschondroplasia for Seven Generations on Live Performance

An experiment was conducted to determine the effect of divergent selection for tibial dyschondroplasia (TD) on live performance of broilers. Broilers used in the experiment were produced from the parental lines selected for high (H) and low (L) incidence of TD and a randombred control (C) line. Diallel crosses were made between H and L lines. The offspring produced were HH, HL, LH, LL, and CQ where the first letter refers to sire line and the second letter refers to dam line. Body weights, average daily body weight gains, and exponential growth rates were determined at weekly intervals. The incidence of TD was recorded at 4 and 7 wk of age.There was no difference among body weights of lines up to 5 wk of age. Sire lines influenced body weights of birds from 5 to 7 wk of age. A significant interaction between sire and dam lines for body weight was the result of decreased body weights of birds in the HH line from 5 to 6 wk of age. There was a similar interaction for body weight gain, which resulted in a slower growth rate of birds in the HH line from 3 to 5 wk of age. Tibial dyschondroplasia incidence was 84.1 and 92.0% in the HH line, 5.6 and 5.4% in the LL line, and 7.0 and 13.2% in the CC line at 4 and 7 wk of age, respectively. It was suggested that genetic predisposition for TD was independent of body weight.

Sodium Zeolite A: Influence on Broiler Carcass Yields and Tibia Characteristics

This study considered the effect of dietary sodium zeolite A (SZA) on processing yields and tibia characteristics of male and female broilers divergently selected over three generations for high and low incidence of tibial dyschondroplasia (TD). Genetic lines included high and low incidence of TD and an unselected control line. Birds (ten replicate pens/line; thirty-five birds/pen) were fed either a standard diet or SZA-supplemented diet at levels of 0.25% and 0.50% from 1-21, 22-50, and 51-56 days of age, respectively.After the study, the high TD line had significantly (P < .01) higher body weight, chilled carcass weight, and carcass part weights than the low TD line. However, the yields (% of live weight) of carcass, thighs, and deboned breast did not differ (P>.05) among the lines. The SZA effect was significant (P < .05) for the yield of Pectoralis minor. Significant (P < .05) interaction between diet and sex indicated improvement only in yields of male broilers fed supplemented SZA. Inclusion of SZA in broiler diets resulted in an increased percent tibia ash (P < .05), but did not affect the incidence or severity of TD.

Correlated Responses to Selection for High or Low Incidence of Tibial Dyschondroplasia in Broilers

Selection for a high or a low incidence of tibial dyschondroplasia (TD) at 7 wk of age was practiced for four generations in broiler breeders keeping an unselected control (C) line and using low intensity X-ray imaging for TD diagnosis. The incidence of TD, BW at 4 and 7 wk of age, age at first egg, and egg production for the first 12 wk of production were determined in the four generations. Age at initial semen production and semen volume and concentration of males were determined only in Generations 3 and 4. The TD scores and BW at 7 wk were collected on 1,366, 1,301, and 1,389 broilers from the C, high (H), and low (L) incidence of TD lines. Incidence of TD at 7 wk in the fourth generation was 16.1, 61.9, and 3.5% for the C, H, and L lines, respectively. There were no significant differences in BW between the H and L lines in Generations 1, 3, or 4. However, in Generation 2, the H line was heavier (P < .01) than the L line. Second generation H line broilers with TD were heavier than those without TD at 4 and 7 wk of age (P < .01). There were no significant differences in age at first egg, age at semen production, or in semen volume between the H and the L lines. Egg production in the L line was greater (P < .01) than that of the H line in all four generations, and semen concentration was also greater (P < .01) in Generations 3 and 4. Correlated responses to selection in the H and the L line were estimated per generation and per weighted selection differential (WCSD) for the traits that were recorded in the four generations. Regression coefficients of cumulative response per generation and per unit of WCSD were not significant.

Effect of Diet on Growth and the Incidence of Tibial Dyschondroplasia in Broilers

Two experiments were conducted to study dietary factors affecting growth rate and the incidence of tibial dyschondroplasia (TD) in broiler cockerels grown to 3 wk of age. Chicks were fed corn-soy-bean meal-based diets containing one of the following: 3,145kcal ME/kg, 24% protein, and .50% available phosphorus (aP) (Diet 1); 2,900kcal ME/kg, 20% protein, and .35% aP (Diet 2); or 2,900 kcal ME/kg, 24% protein, and .50 aP (Diet 3). In experiment 1 chicks were fed Diets 1, 2, and 3ad libitum. During weeks 1 and 2, chicks fed Diet 1 were heavier and had better feed efficiency (g feed/g gain) than those fed Diets 2 and 3. Chicks fed Diets 2 and 3 had a lower incidence of TD (P<.05) than those fed Diet 1.In experiment 2 feed intake of Diet 1 was on an ad libitum and restricted basis (Diet 1-R) and Diet 2 was on an ad libitum basis. Beginning on day 2, chicks fed Diet 1-R were offered 90% of the amount of feed consumed the previous day by chicks fed Diet 1 free choice. Chicks fed Diet 1 were heavier than those fed Diet 1-R at 1 wk, and Diets 1-R and 2 at 2 and 3 wk. Chicks fed Diet 1 had higher incidence (P<.05) of TD lesions at 3 wk than those fed Diets 1-R and 2. No differences occurred (P>.05) in the incidence of TD lesions between chicks fed Diets 1-R and 2. The incidence of leg problems appeared to be related to rate of growth, rather than being a direct effect of dietary aP or calcium:aP ratio.

The Effect of Dietary Cholecalciferol, 25-Hydroxycholecalciferol and 1,25-Dihydroxycholecalciferol on the Development of Tibial Dyschondroplasia in Broiler Chickens in the Absence and Presence of Disulfiram

Four experiments were conducted to determine the effect of dietary cholecalciferol (vitamin D3), 25-hydroxycholecalciferol (25-OHD3) and 1,25-dihydroxycholecalciferol (1,25-(OH)2D3) on the changes in growth, feed efficiency and bone ash, and the incidence, severity and number of #3 scores of tibial dyschondroplasia caused by the addition of disulfiram to the diet. The basal diet used was low in calcium and high in phosphorus and chlorine and known to promote a high incidence of tibial dyschondroplasia in broiler chickens. The chickens in all experiments received enough ultraviolet radiation from fluorescent lights in the pens to nearly satisfy their need for vitamin D. The addition of disulfiram to the diet caused an increase in most of the measurements indicating development of tibial dyschondroplasia in all of the experiments, and caused a decrease in bone ash in two of the experiments and a decrease in growth and gain:feed in one experiment. The addition of D3 to a diet containing no D3 caused higher bone ash and lower incidence of tibial dyschondroplasia in the absence or presence of disulfiram. The effects of the addition of 25-OHD3 to diets containing approximately five times the requirement of D3 in the absence and presence of disulfiram caused variable results. The addition of 1,25-(OH)2D3 to the D3-supplemented diet in the absence or presence of disulfiram caused dramatic increases in bone ash and a decrease in most of the criteria used to measure development of tibial dyschondroplasia. There was no indication of interaction of the effects of D3, 25-OHD3 and 1,25-(OH)2D3 with the action of disulfiram.

Effects of Dietary Zeolite and Vitamin A on Tibial Dyschondroplasia in Chickens

Four experiments were conducted to determine the effects of dietary zeolites on tibial dyschondroplasia in chicks. All studies used a practical-type corn-soybean meal diet and male broiler chicks from 1 day to 14 or 16 days of age. Vitamin A was added to the diet in the first experiment at levels of 0 or 45,000 IU/kg in addition to full or half required levels of vitamin premix, and in the second experiment at levels of 0, 11,250, 22,500 and 45,000 IU/kg in addition to full requirement levels of vitamin premix. This was done in order to determine if vitamin levels affected expression of tibial dyschondroplasia and, if so, if this expression could be influenced by 1.0% dietary zeolite.A high level of dietary vitamin A caused a lower incidence of tibial dyschondroplasia in Experiment 1 but had no effect in Experiment 2. Zeolite at graded levels of 0, .25, .50, and 1.0% in Experiment 3 and at the 1.0% level in all other experiments consistently caused a hipher bone ash and a lower incidence and number of birds exhibiting severe tibial dyschondroplasia. The addition of zeolite to the diet generally had no effect on body weight or gain:feed ratio but reduced tibial dyschondroplasia scores in two of the four experiments. In Experiment 4, the addition of dietary zeolite increased 47 Ca absorption but did not influence biological half-life.

Effects of Different Soybean Meals on the Incidence of Tibial Dyschondroplasia in the Chicken

Interexperimental variation in the incidence of tibial dyschondroplasia of chickens that occurred in studies on the effect of dietary calcium, phosphorus and cholecalciferol metabolites was apparent from previous reports from this laboratory. Since the source of commercial soybean meal used in the diets was known to change, studies were conducted to evaluate different sources of soybean meal on the incidence of tibial dyschondroplasia. A series of experiments demonstrated that the soybean meals from one source consistently produced a high incidence of tibial dyschondroplasia (34–69%); whereas soybean meals from a different source consistently produced low incidences (14–28%). This same relationship was found with soybean meals from these two plants produced a year apart. When the levels of two soybean meals that produced a high incidence of tibial dyschondroplasia were reduced in the diet from 35 to 24 to 12% the incidence of tibial dyschondroplasia was reduced from 60 and 69% to 25 and 20% to 15 and 10%, respectively. The most striking difference between the meals observed by chemical analysis was in the high antitrypsin and urease values of the meals that induced tibial dyschondroplasia. Chickens fed the soybean meal that reduced tibial dyschondroplasia also had reduced pancreas size in one experiment but not another. The soybean meals that induced tibial dyschondroplasia caused an increase in testes size but had no effect on liver, adrenal and thyroid size or plasma levels of calcium, phosphorus and triiodothyronine (T3). No difference in the utilization of the diets as measured by metabolizable energy values and lipid calcium, phosphorus or phytin phosphorus retention was found between the soybean meals that induced high or low incidence of tibial dyschondroplasia with chickens at 19–21 d of age.

The Influence of Ascorbic Acid on the Occurrence of Tibial Dyschondroplasia in Young Broiler Chickens

Two distinctly different basal diets were used to test the influence of supplementary ascorbic acid on the occurrence of tibial dyschondroplasia. Addition of either .1 or .25% ascorbic acid to these diets did not alter the occurrence of tibial dyschondroplasia in 25-day-old broiler chickens. However, supplementary ascorbic acid did increase the amounts of ascorbic acid present in blood plasma. Also, individual differences in circulating ascorbic acid were not associated with this disease. Furthermore, two strains of chickens selected for high or low incidence of tibial dyschondroplasia had similar amounts of this vitamin in blood plasma. In contrast to the results reported for the Willow Ptarmigan, ascorbic acid does not appear to be involved in the development of tibial dyschondroplasia in the young broiler chicken.

Tibial Dyschondroplasia in Broilers: Comparison of Dietary Additives and Strains

The effects of broiler strain and various additives to practical corn-soy diets on the incidence of tibial dyschondroplasia (TD) were studied using broiler chicks maintained in battery brooders. At the termination of each experiment, birds were killed and examined for TD by cutting longitudinally along the tibia.No significant difference in the incidence of TD was found among the nine broiler strains compared. While the incidence of twisted legs was higher than TD among the nine strains there was no apparent correlation between the two leg disorders.Studies conducted using the following additives did not significantly increase the incidence of TD in broilers when compared to controls: monensin, sodium chloride, copper sulfate, magnesium sulfate, potassium sulfate, roxarsone, gentian violet, erythromycin, vitamin K, or vitamin D3. However, dietary ammonium chloride (1.5 or 30%) did increase the incidence of TD, whereas adding various fermentation products at levels of 10 and 20% either in the absence or presence of ammonium chloride failed to reduce the incidence of the disease. The incidences of TD among broiler chicks fed high dietary fluoride were nonsignificant; no evidence of the disease was found in Leghorn chicks fed the same diets.Chicks maintained in battery brooders in these studies, generally had a lower incidence of TD than that reported for commercial flocks in the field. Furthermore, manipulation of feed additives or ingredients in practical rations for broiler chickens did not increase the incidence of the disease.

Studies on the Pathogenesis of Tibial Dyschondroplasia in Chickens IV. Some Features of the Vascular Supply to the Growth Plates of the Tibiotarsus

Several features of the vascular supply to the growth plates of the tibiotarsus were compared in two strains of broiler chickens selected for a high and low incidence of tibial dyschondroplasia. No difference was found between the two strains in the area of the proximal growth plate of the tibiotarsus or in the distance of the nutrient foramen from the same growth plate. Vascular tunnels invading the zone of hypertrophy were significantly fewer in the proximal growth plate than in the distal growth plate, and tunnels invading the zone of hypertrophy of each growth plate were also fewer in the high-incidence chickens than in the low-incidence chickens.

Selection of Broiler Chickens for a High and Low Incidence of Tibial Dyschondroplasia with Observations on Spondylolisthesis and Twisted Legs (Perosis)

Radiography was used to select normal birds and birds affected with tibial dyschondroplasia from a commercial stock of broiler chickens. Birds were selected for three generations and mated like to like in an attempt to establish low and high incidence strains. Incidence of tibial dyschondroplasia in the low incidence strain was reduced to negligible levels while it was increased in the high incidence strain. Incidence of the defect in the high incidence strain could be influenced by diet. Observations during the selection program on the incidence of spondylolisthesis and twisted legs in birds younger than eight weeks of age indicated that these other skeletal defects were unrelated to tibial dyschondroplasia.

The Development of Tibial Dyschondroplasia in Broiler Chickens

Two strains of broiler chickens selected for a high and a low incidence of tibial dyschondroplasia were fed a standard broiler starter ration with and without added chloride. Development of tibial dyschondroplasia was studied by radiography and serial necropsies. Lesions of tibial dyschondroplasia were mild in the low-incidence strain, regardless of ratio. The defect was more severe in the high-incidence strain and most severe in those birds fed the high-chloride ration. An abnormal thickening of the growth plate was apparent in the high-incidence strain as early as 2 weeks of age and became progressively more severe with age. No significant differences were noted in serum calcium, phosphorus, alkaline phosphatase, pCO2, or bone ash between strains of birds or between birds of the same strain fed different rations. Birds fed the high-chloride ration had a higher serum chloride and a lower serum bicarbonate and blood pH than birds on the standard ration.

Studies on the Pathogenesis of Tibial Dyschondroplasia in Chickens. II. Growth Rate of Long Bones

The growth rate of the tibiotarsus, tarsometatarsus, and humerus was studied in two strains of chickens selected for a high and low incidence of tibial dyschondroplasia. The proximal growth plates grew more rapidly than the distal growth plates. The proximal growth plate of the tibiotarsus grew fastest, while those of the tarsometatarsus and humerus had growth rates that were respectively 4 and 33% slower. The bones averaged slightly faster growth in the high-incidence strain than in the low-incidence strain. A slowed growth decreased the incidence of tibial dyschondroplasia. However, lack of correlation between growth rate and the development of tibial dyschondroplasia in individual chickens suggested that growth rate may be no more than a contributing factor.