Effects of Dietary Sodium and Chloride on Slaughter Performance, Digestive Tract Development and Tibia Mineralization of Geese

This study evaluated the slaughter performance, digestive tract development and tibia mineralization effects of sodium (Na) and chloride (Cl) on geese. Four hundred and thirty-four male geese at 29 days were randomly assigned into nine groups with six replicates (eight in each). The experiment employed a 3 × 3 factorial design, with two instances each of three Na levels (0.10%, 0.15%, and 0.20%) and three Cl levels (0.15%, 0.20%, and 0.25%). All experimental birds were husbanded for 42 days. Dietary Na and Cl levels and their interactions (Na ×Cl) had no significant effect on the slaughter, breast, thigh, abdominal fat yield, and digestive tract index of geese (p > 0.05). However, dietary Na and Cl level significantly affected the crypt depth of the jejunum and tibial development. Variations in Na and Cl levels had a significant interaction on the crypt depth of jejunal (p < 0.05), 0.20% Na × 0.25% Cl had a minor crypt depth. Dietary variations in Na and Cl significantly affected the tibial strength, and there was a significant interaction between them (p < 0.05). When Na and Cl were at their maximum (0.20% Na and 0.25% Cl), the strength of the tibia was the lowest. In addition, a single factor (Na or Cl) had no effect (p > 0.05), but its interaction significantly affected the calcium (Ca) content of bone (p < 0.05). When the Na and Cl levels were 0.15% and 0.15%, respectively, the Ca content in bone was the highest. These results suggest that dietary Na and Cl had interactive effects on geese, especially in the development of the tibia. High dietary Na and Cl levels adversely influenced the tibia and intestinal crypt morphology. Therefore, we do not advocate supplementing too much Na or Cl in the diet. Combined with our previous results, for 29-70-day-old geese, it is recommended that dietary Na and Cl levels should be 0.10% and 0.15%, respectively.

Effects of Dietary Phytosterol Supplementation on the Productive Performance, Egg Quality, Length of Small Intestine, and Tibia Quality in Aged Laying Hens

This study aimed at investigating the effects of phytosterols on the productive performance, egg quality, length of small intestine, and tibia quality in aged laying hens. A total of 960 Dawu Jinfeng commercial laying hens (75 weeks of age) were randomly assigned to three groups. Each group had 16 replicates and every replicate contained four cages (five birds/cage). The control group hens received the basal diet without phytosterols. The hens in the experimental groups received a diet containing phytosterols at concentrations of 20 mg/kg and 40 mg/kg for 7 weeks. The results showed that phytosterols had a linearly increasing effect on egg weight, eggshell surface area, albumen height, and haugh unit at week 5 of experiment (p < 0.05). Supplemental phytosterols linearly and quadratically increased eggshell thickness (p < 0.05). At week 7 of the experiment, dietary supplementation of phytosterols linearly increased egg weight and eggshell weight (p < 0.05). Supplementation of 20 mg/kg, but not 40 mg/kg, phytosterols increased the length of the small intestine. However, dietary phytosterols had no effect on the laying rate, mortality, or liver index (p > 0.1). The results of tibia quality detected by micro-CT also showed no difference in the treatment of phytosterols. Therefore, supplementation with 20 mg/kg phytosterols in the diet improves egg quality and increases the length of small intestine, but has no effects on the quality of the tibia.

Effect of dietary 25-hydroxycholecalciferol supplementation and high stocking density on performance, egg quality, and tibia quality in laying hens

This study was conducted to determine the effects of 25-hydroxycholecalciferol (25-OH-D₃) on performance, egg quality, tibia quality, and serum hormones concentration in laying hens reared under high stocking density. A total of 800 45-week-old Lohmann laying hens were randomly allotted into a 2 × 2 factorial design with 2 levels of dietary 25-OH-D₃ levels (0 and 69 μg/kg) and 2 rates of stocking densities [506 (low density) and 338 (high density) cm²/hen]. Laying hens were monitored for 16 wk. High stocking density decreased laying rate, egg weight, and feed intake compared with low stocking density (P < 0.01) during 1 to 8 wk and 1 to 16 wk. Overall, high stocking density increased eggshell lightness value and decreased shell redness and yellowness value, strength, thickness, and relative weight compared with low stocking density (P < 0.05). Dietary supplementation with 25-OH-D₃ reduced the value of the eggshell lightness and increased its yellowness and eggshells weight (P ≤ 0.05). The increase in eggshell thickness was more pronounced when 25-OH-D₃ was supplemented to layers under high stocking density (interaction, P < 0.05). Layers under high stocking density had lower ash content and calcium content in the tibia than layers under low stocking density (P = 0.04); dietary 25-OH-D₃ increased tibia strength compared with no addition (P = 0.05). Layers under high stocking density had higher serum concentrations of 25-OH-D₃, corticosterone (CORT), lipopolysaccharide (LPS), and osteocalcin (OC; P < 0.05), lower content of parathyroid hormone (PTH) compared with layers under low stocking density (P < 0.01). Dietary 25-OH-D₃ increased serum concentration of 25-OH-D₃, carbonic anhydrase (CA), and calcitonin (CT) (P < 0.01) and reduced corticosterone, lipopolysaccharide and osteocalcin concentration (P ≤ 0.05). The increase effect in PTH was more pronounced when 25-OH-D₃ was supplemented to layers under high stocking density (interaction, P = 0.05). Overall, the results gathered in this study indicate that high stocking density result in reducing production performance, shell color and quality, and tibia health, whereas dietary 25-OH-D₃ was able to maintain tibia health and to mitigate the negative impact of high stocking density on productive performance.

Effects of dietary canthaxanthin and 25-hydroxycholecalciferol supplementation on the antioxidant status and tibia quality of duck breeders and newly hatched ducklings

This study evaluated the effects of dietary canthaxanthin (CX) and 25-hydroxycholecalciferol (25-OH-D3) supplementation on the antioxidant status and tibia quality of duck breeders and newly hatched ducklings. In total, 780 female and 156 male duck breeders were randomly allotted to 2 treatments. Duck breeders were fed either a commercial diet (containing 3,000 IU/kg vitamin D3) or the same diet plus a mixture of CX (6 mg/kg) and 25-OH-D3 (0.069 mg/kg) for 40 wk. The antioxidant status of duck breeders, egg yolk, and ducklings; tibia quality of duck breeders and ducklings; and shell quality of breeder eggs were investigated. The total antioxidant capacity of breeder female liver (P = 0.028), breeder male testis (P = 0.049), egg yolk (P = 0.032), one-day-old duckling liver (P = 0.024), and one-day-old duckling yolk sac (P = 0.012) were increased by dietary supplementation of the mixture of CX and 25-OH-D3 The inclusion of CX and 25-OH-D3 decreased liver protein carbonyl of breeder females (P = 0.030), and liver malonaldehyde (P = 0.050) and protein carbonyl (P = 0.030) of breeder males. Yolk (P < 0.001), shank (P < 0.001), and yolk sac pigmentation (P < 0.001) of one-day-old ducklings were increased by the supplementation of the CX and 25-OH-D3 mixture. No differences (P > 0.05) were observed in tibia quality or eggshell quality between treatments. In conclusion, the inclusion of the mixture of CX and 25-OH-D3 in a diet sufficient in vitamin D3 increased antioxidant status but not tibia quality of duck breeders and newly hatched ducklings.