Scielo RSS <![CDATA[Revista Brasileira de Zootecnia]]> vol. 45 num. 1 lang. pt <![CDATA[SciELO Logo]]> <![CDATA[Effects of calcium to non-phytate phosphorus ratio and different sources of vitamin D on growth performance and bone mineralization in broiler chickens]]> ABSTRACT - A 7 × 2 factorial experiment was designed to test the effects of calcium (Ca) to non-phytate phosphorus (NPP) ratio (1.14, 1.43, 1.71, 2.00, 2.29, 2.57, and 2.86) and different sources of vitamin D (1α-hydroxycholecalciferol (1α-OH-D3) and 25-hydroxycholecalciferol (25-OH-D3)) on growth performance and bone mineralization in 1- to 42-d-old broiler chickens. On the day of hatch, 700 female Ross 308 broilers were weighed and randomly assigned to 14 treatments with five stainless steel cages of 10 birds each. Dietary Ca levels were 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, and 10.0 g kg−1 and the NPP content was 3.5 g kg−1. The dose of 1α-OH-D3 or 25-OH-D3 was 5 µg kg−1. Diets were not supplemented with cholecalciferol (vitamin D3). Results showed that the Ca to NPP ratio, vitamin D source, and their interaction affected body weight gain (BWG), feed intake (FI), feed efficiency (FE), and carcass and breast yields, as well as tibia weight and length and ash weight in broiler chickens from 1 to 42 d of age. Broilers fed 1α-OH-D3 had higher BWG and FI as well as tibia breaking strength, weight, length, diameter, and ash weight than birds fed 25-OH-D3 at 42 d of age. The Ca to NPP ratio had a quadratic effect on BWG, FI, mortality, as well as tibia breaking strength, weight, length, ash weight, and ash and P contents in 42-d-old broilers. Broiler chickens at 42 d of age obtain optimal growth performance and bone mineralization at the Ca to NPP ratio of 2.32 when 1α-OH-D3 or 25-OH-D3 are used as the vitamin D source. <![CDATA[Comparison of growth performance and carcass traits of Japanese quails reared in conventional, pasture, and organic conditions]]> ABSTRACT - This study was conducted to compare live weight, feed intake, feed conversion, mortality rate, and some carcass characteristics of Japanese quails reared under organic and conventional conditions. A total of 180 one-day-old quail chicks were randomly divided into six groups ― Conventional, consuming conventional feed ad libitum; Control (C), consuming organic feed ad libitum; C+P, consuming organic feed ad libitum + pasture; 80C+P, consuming 80% of control + pasture; 70C+P, consuming 70% of control + pasture; and 50C+P, consuming 50% of control + pasture ― with three replicates. The conventional group was kept for 6 weeks, while the control, C+P, 80C+P, 70C+P, and 50C+P groups were reared until the end of 10 weeks of age. Raising systems significantly affected live weight, feed intake, and feed conversion. The analysis showed that the meat yield of quail raised in organic conditions had better results than those raised in conventional conditions in terms of appearance, color, aroma, and flavor. The group consuming 50% of control plus pasture was more advantageous than the other organic groups and the conventional group at the end of the 10-week fattening period. The organic production system can be a good system to meet the demand of consumers who seek more natural products. <![CDATA[Supplementation with a mixture of whole rice bran and crude glycerin on metabolic responses and performance of primiparous beef cows]]> ABSTRACT - This study investigated the effect of a supplement containing whole rice bran and crude glycerin for 21 days before mating on metabolic, productive, and reproductive responses of 28 primiparous suckling beef cows. Cows were randomly assigned to a control group (CON, n = 14), grazing on grasslands, and a supplemented group (SUP, n = 14), grazing on grasslands and supplemented daily individually with 1 kg dry matter (DM) of whole rice bran + 550 mL crude glycerin (224 g kg−1 DM of methanol) per cow. After 33 days of natural mating, cows that had not expressed estrus were subjected to a fixed-time artificial insemination protocol. Ten days after the insemination program, bulls were reintroduced for 21 days. Supplementation increased milk yield (SUP: 5.7±0.2 vs. CON: 5.0±0.2 kg d−1), milk protein content (SUP: 3.1±0.2 vs. CON: 2.8±0.2%), and body weight of cow (SUP: 379±2 vs. CON: 373±2 kg) and calf (SUP: 150±2 vs. CON: 142±2 kg). Supplementation improved the energy balance, increased plasma concentrations of cholesterol (SUP: 223.2±6.4 vs. CON: 202.1±6.4 mg dL−1) and glucose (SUP: 72.0±1.2 vs. CON: 68.6±1.2 mg dL−1), and reduced non-esterified fatty acids (SUP: 0.45±0.02 vs. CON: 0.56±0.02 mmol L−1). The percentage of cows on superficial anestrous after supplementation was greater in SUP than in CON group (57 vs. 21%, respectively); however, no difference in final pregnancy rate was found (SUP: 79 vs. CON: 64%). There was no evidence that the ingestion of crude glycerin with high content of methanol induced clinical or hepatic disorders. Supplementation of whole rice bran and crude glycerin is not toxic, and can improve the energy balance, reflecting in increase in milk yield and calf growth, with a slight effect on the reproductive activity. <![CDATA[Spineless cactus as a replacement for wheat bran in sugar cane-based diets for sheep: intake, digestibility, and ruminal parameters]]> ABSTRACT - The objective of this study was to evaluate the effect of replacing wheat bran by spineless cactus (0, 25, 50, 75, and 100%) in sugar cane-based diets on intake and nutrient digestibility and ruminal parameters of sheep. Five sheep (Santa Inês; average initial weight of 34.0±3.6 kg) were fitted with cannulas in the rumen and then assigned to a 5 × 5 Latin square design. The maximum dry matter (DM; 1414 g d−1), digestible organic matter (658 g d−1), and neutral detergent fiber corrected for ash and protein (NDFap; 425 g d−1) intakes were estimated by replacing 80.2, 89.9, and 50.5% of wheat bran. Dry matter and crude protein digestibility increased by 0.60 and 0.85 g kg-1 of DM. With the replacement of 57.1 and 62.2% of wheat bran, a maximum rate of NDF ingestion (0.70 h−1) and NDF ruminal pool (7.31 g) was obtained. Rumen pH increased with the inclusion of spineless cactus, while the maximum concentration of ammonia N (33.3 mg dL−1) and total volatile fatty acids (57.7 μmol mL−1) were estimated at the levels of 72.3 and 63.7% of replacement of wheat bran. It is recommended to replace 63% of wheat bran by spineless cactus in sugar cane-based diets, to promote better animal performance. <![CDATA[Crude glycerin levels in pearl millet-based diets for Nellore young bulls in feedlot]]> ABSTRACT - The objective of this study was to find the best level of inclusion of crude glycerin (0, 60, 120, and 240 g kg−1 of dry matter of diet) in substitution of pearl millet in a feedlot diet. Twenty-eight Nellore young bulls with mean age of 18 months and average weight of 357±23.56 kg were used. The animals were distributed in a completely randomized design with four treatments and seven replications. The intakes of dry matter, crude protein, neutral detergent fiber, and total digestible nutrients were similar among the dietary levels of crude glycerin. The ether extract intake decreased with increase in the levels of crude glycerol in the diets. Apparent digestibility of dry matter, crude protein, and extract ether was similar among the dietary crude glycerin levels. Apparent digestibility of neutral detergent fiber was lower in the diets with inclusion of crude glycerin in relation the other diets. The increase in the levels of crude glycerin did not affect the total digestible nutrients content of the diets. Average daily gain increased linearly with the increase in crude glycerin. Feed conversion was not altered by the increase in the levels of crude glycerin in the diets. The dietary increase in crude glycerin level did not affect the carcass characteristics. The inclusion of up to 240 g kg−1 of crude glycerin in pearl millet grain-based diets for feedlot-finished Nellore young bulls increases average daily gain, but does not change the main carcass characteristics of economic importance.