Short- and long-term effects of postpartum oral bolus v. subcutaneous Ca supplements on blood metabolites and productivity of Holstein cows fed a prepartum anionic diet.

Little information is available regarding the calcium (Ca) dynamics and how its concentration is influenced following the Ca treatment (injection or bolus) after calving in dairy cows. To evaluate the short- and long-term effects of different sources of Ca supplement to animals fed anionic diets during the pre-partum period, 36 multiparous Holstein cows were randomly assigned to 1 of 3 treatments: (1) control group without Ca supplement (CON); (2) subcutaneous injection of 500 ml of 40% w/v Ca borogluconate immediately post-calving (SUB) and (3) oral supplement of Ca bolus containing 45 g Ca immediately and 24 h post-calving (BOL). Serum concentrations of Ca, P and Mg were measured. Serum concentration of Ca was affected by treatments at 48 h of post-calving (P < 0.01). The mean Ca at 6 h was greater in SUB compared to CON group (2.34 v. 2.01 mmol/l; P < 0.002). The lowest Ca concentration at 12 h was related to CON cows compared with BOL and SUB cows (1.90, 2.16 and 2.14 mmol/l, respectively; P < 0.02); a similar trend was observed 24 h post-calving (P < 0.02). Serum concentrations of P and Mg were not influenced by treatments. Yield of milk, milk protein and fat-corrected milk were lowest (P < 0.05) in SUB cows within 3 weeks of lactation in comparison with CON and BOL cows. However, milk yield and milk composition did not show any difference among treatments throughout the first 3 months post-calving. In general, under conditions of this experiment, Ca supplements to fresh cows as an oral bolus are recommended in comparison with subcutaneous injection.

Calculation of protein and energy requirements in beluga sturgeon (Huso huso) using a factorial approach.

This study tried to determine the protein and energy requirements of growing beluga sturgeon Huso huso using a factorial approach. The experiment was composed of four small-scale growth trails covering different weight ranges. The fish fed at 0, 20, 40, 60, 80 and 100% of satiation. DWG had a steady increase throughout the experiment following a non-linear equation as Y = 1.433 (±0.056) × Ln(X) -2.740 (±0.261); r(2) = 0.99, p < 0.001, where Y = weight gain (g/day) and X = fish weight (g). The daily requirement of digestible energy (DE) for maintenance amounted to 79.09 kJ × BW (kg)(0.8) . The daily requirement of DP for maintenance calculated as 0.93 g × BW (kg)(0.7) . The relationship between DE intake (X) and DE gain (Y) expressed as Y = -0.0004 (±0.000) X(2) + 0.600 (±0.082) X -44.95 (± 6.72). Also, the relationship between DP intake (X) and protein gain (Y) was expressed as Y = -0.019 (±0.006) X(2) + 0.548 (±0.062) X - 0.498 (±0.121). The daily requirements of energy and protein were estimated as 79.09 kJ × BW (kg)(0.8) + 2.94 × DE gain and 0.93 g × BW (kg)(0.7) + 2.63 × DP gain. Apparently, beluga sturgeon is inefficient in converting energy and protein into body tissue. Therefore, energy content of the diet should be sufficiently high to satisfy large energy demands in beluga sturgeon and also to reduce the catabolism of protein.

Effect of microbial inoculants on the nutritive value of corn silage for beef cattle.

This study investigated the effect of a new microbial inoculant product on the composition and nutritive value of corn silage in big silo over one year that used beef cattle. Six Holstein beef steer (BW = 225 +/- 17) were allotted to 2 x 2 repeated Latin square design at two 21 days periods (adaptation, 14 days and sample collection, 7 days) for evaluation the effect of microbial inoculation on the composition and nutritive value of corn silage for beef cattle. Two treatments, forages were untreated or treated at ensiling with Lactobacillus plantarum and Propionibacterium acidipropionici silage inoculants. After 45 days from ensiling, the ration that contained 94.5 and 5, 0.2, 0.2, 0.1% of DM silage and ground barely, mineral-vitamin, dicalcium phosphate, salt, respectively, were offered for free choice consumption. Treatment with Lactobacillus plantarum and Propionibacterium acidipropionici inoculant increased daily dry matter intake and subsequently NDF, ether extract, crude protein and ash. Apparent digestibility of DM and nutrients were significantly increased by microbial inoculation. Microbial inoculation can improve the nutritive value of corn silage for beef cattle.