Silicon in broiler drinking water promotes bone development in broiler chickens.

Skeletal abnormalities, bone deformities and fractures cause significant losses in broiler production during both rearing and processing. Silicon is an essential mineral for bone and connective tissue synthesis and for calcium absorption during the early stages of bone formation. Performance was not affected by the addition of silicon. However, broilers receiving silicon showed a significant increase of phosphorus, zinc, copper, manganese and ash in the tibia. In conclusion, broiler performance was not impaired by adding the tested silicon product to the drinking water. In addition, bone development improved, as demonstrated by higher mineral and ash content. Further studies are required to determine the optimal concentration of silicon, including heat stress simulations, to better understand the effects of silicon on bone development.

Densitometric and biochemical values of broiler tibias at different ages.

The objective of this experiment was to determine the normal values of bone radiographic density (BRD) by using the optical densitometry in radiographic images and the biochemical values represented by serum calcium, ash percentage, and minerals (calcium, phosphorus, and magnesium) from tibia ash of Cobb broilers at 8, 22, and 43 d of age. A total of 14 broilers were used for densitometric analysis, and 15 were used for biochemical dosages. The BRD values increased (P < 0.05) with age and in all tibia regions (proximal epiphysis, diaphysis, and distal epiphysis), concluding that growth was a determinative factor for bone performance, demanding a higher BRD during broiler development. Tibia proximal epiphysis presented higher BRD values in relation to the other bone regions (P < 0.05), as a result of a possible biomechanical adaptation to ligaments and tension of the muscle tendons at this region, allowing the support of the muscle mass increase. The serum calcium values were kept constant, as a result of the appropriate nutritional levels of the diet that supported the animal homeostasis. The bone ash and mineral percentage increased (P < 0.05) at 22 d of age, due to the higher mineral requirement in this age. The correlation between bone densitometry and the invasive techniques showed that the bone densitometry can substitute the determination of mineral percentage in the ash. This experiment presented normal values of the noninvasive and invasive methods more used in aviculture, allowing us to compare, subsequently, pathological and physiological values or results of broilers fed with different diets.

Plasma calcium, phosphorus, 25-dihydroxyvitamin D3, and 1-25-dihydroxyvitamin D3 of hens with fatty liver syndrome.

Plasma was obtained from normal laying hens, 30 weeks of age, and from laying hens, 60 weeks of age, with fatty liver syndrome (FLS). The 60-week-old hens were divided into two groups based on whether they were laying or nonlaying. Plasma phosphorus and calcium was significantly higher for hens with FLS. The younger hens had significantly lower 25-dihydroxyvitamin D3 (25-OH-D3) plasma levels than the older hens. The older hens that were laying had significantly lower 25-OH-D3 plasma levels than the nonlaying hens. Old nonlaying hens with FLS had lower 1, 25-OH-D3 than young hens or old laying hens with FLS; however, the levels were not different for the two groups of laying hens.

Interrelationship between phosphorus, sodium, and chloride in the diet of laying hens.

Two experiments were conducted with commercial egg production type hens to determine the effects of dietary phosphorus, sodium, and chloride levels as related to levels of plasma calcium and phosphorus, blood acid-base balance, and production characteristics. Sodium and chloride were supplied to the diet as sodium bicarbonate and hydrochloric acid, respectively. In Experiment 1, five treatment groups were fed diets ad libitum containing .2, .6, 1.0, 1.4, and 1.8% total phosphorus. The remaining treatment group was fed a diet containing .4% total phosphorus from 1400 to 2030 hr and 1.4% total phosphorus from 600 to 1100 hr. In Experiment 2, a 3 X 4 factorial arrangement of treatments was used that consisted of three levels of total phosphorus (.2, .6, and 1.4%) and four levels of added sodium (0, .06, .22, and .45%) provided by sodium bicarbonate. Three other treatment groups were fed diets containing .36% supplemental chloride supplied by hydrochloric acid and either .2, .6, or 1.4% total phosphorus. Egg production was decreased in hens fed diets containing 1.8% total phosphorus. Egg specific gravity was decreased by both low and high phosphorus levels. Hens fed .4% total phosphorus in the afternoon produced eggs with higher specific gravity as compared with hens fed 1.4% total phosphorus during the entire experiment. At 1.4% dietary phosphorus, a significant increase in specific gravity was observed when .2 or .8% sodium bicarbonate was added to the diet. Increasing dietary phosphorus resulted in elevated plasma phosphorus and calcium concentration. Plasma phosphorus of hens fed .2 through 1.8% total phosphorus declined slowly from oviposition until 6 hr after oviposition and then reached a peak at 21 hr after oviposition.(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma phosphorus at 0, 6, and 21 hours postoviposition in hens laying in the morning or afternoon.

Two experiments were conducted using White Leghorn hens. Blood samples were collected immediately following oviposition (0 hr) or 6 or 21 hr postoviposition from hens laying in the morning or afternoon. Plasma phosphorus was determined at each time period. In Experiment 1, plasma phosphorus at oviposition was essentially the same for hens laying in the morning or afternoon (3.95 and 4.10 mg/dl, respectively). At 6 hr postoviposition plasma phosphorus was lower than that observed at 0 hr (3.22 and 3.15 mg/dl, respectively). When comparing plasma phosphorus levels at 21 hr postoviposition of hens laying in the morning or afternoon a higher (P less than or equal to .05) phosphorus level was observed for hens that laid in the morning (5.90 vs. 4.91, respectively). In Experiment 2, plasma phosphorus levels at 0 and 6 hr postoviposition were 3.32 vs. 3.18 and 2.81 vs. 2.74 mg/dl for hens laying in the morning and afternoon, respectively. At 21 hr postoviposition, phosphorus values of 5.30 vs. 3.65 mg/dl were reported for hens laying in the morning and afternoon, respectively. Data also indicated that on the day a hen does not lay an egg, plasma phosphorus does not rise. An hypothesis is offered to explain the difference in egg shell quality between eggs laid in the morning or afternoon.

Interrelationship between sodium chloride, sodium bicarbonate, calcium, and phosphorus in laying hen diets.

Three experiments were conducted with Hy-Line W-36 laying hens housed in individual wire cages in open type houses. The first and second experiments were designed to investigate the effects of sodium chloride and sodium bicarbonate fed at two levels of dietary total phosphorus (.30 and .60%). The third experiment was designed to study the interrelationships between age and sodium source. Supplementing sodium chloride at two levels (.37 and 1.11%) did not effect hen performance, except that egg production was better at the lower NaCl. Egg production was greater when .60 rather than .30% dietary phosphorus was fed. Egg specific gravity and egg weight were decreased at the lower dietary phosphorus. The addition of 1.6% sodium bicarbonate in the sodium chloride-free diets was deleterious to hen performance in all experiments. High mortality was observed in both experiments in which hens were fed diets containing high sodium and low chloride. Plasma calcium and phosphorus levels were significantly depressed in hens fed diets containing the lower phosphorus. Blood pH, base excess, bicarbonate, and total carbon dioxide were significantly increased by sodium bicarbonate supplementation, and these values were found to be inversely related to dietary phosphorus levels.