Fatty acid profile, physicochemical composition and carcass traits of young Nellore bulls fed Acacia mearnsii extract

Fatty acid profile, physicochemical composition, and carcass traits of 32 young Nellore bulls were assessed following the supplementation of Acacia mearnsii extract at levels of 0, 10, 30, and 50 g/kg of total dry matter (DM) in a completely randomized experiment with four treatments and eight replicates. Adding 50 g/kg DM of condensed tannins (CT) from Acacia mearnsii in the bulls' diet reduced DM intake, average daily gain, and meat lipid oxidation (P ≤ 0.05). The pH, centesimal composition, collagen, and meat color indexes of the longissimus muscle were not altered by the addition of Acacia mearnsii (P > 0.05). Cooling loss increased (P = 0.049) linearly. Including Acacia mearnsii in diet reduced the Warner-Bratzler shear force (WBSF, P = 0.018) of longissimus muscle of the bulls. The concentration of C16:0, C17:0, C24:0, t9,10,11,16-18:1, c9t11-18:2, C18:2n-6, C20:4n-6, 20:5n-3, 22:5n-3, and 22:6n-3 in the muscle increased due to the addition of Acacia in the diet (P ≤ 0.05), with the highest muscle concentrations caused by the addition of 10 to 30 g Acacia. c9-18:1 and t16-18:1 reduced linearly. ƩSFA, ƩBI, Ʃcis- and ƩMUFA, Ʃn-3, Ʃn-6, and ƩPUFA (P ≤ 0.05) quadratically increased at higher concentrations of addition of Acacia, above 30 g/kg DM. It is recommended to include Acacia mearnsii extract up to 30 g/kg total DM in diets for young bulls as it improves CLA, PUFA and TI and reduces lipid oxidation. Acacia mearnsii extract as source of CT at 50 g/kg DM negatively impacted the young bulls performance.

Effects of Increasing Levels of Total Tannins on Intake, Digestibility, and Balance of Nitrogen, Water, and Energy in Hair Lambs

This study aims to evaluate the effects of increasing tannin levels from Mimosa tenuiflora hay on the intake, digestibility, and balance of nitrogen (N), water, and energy in hair lambs. Thirty-two Santa Ines lambs, at an average age of 150 days and body weight of 26.75 ± 2.29 kg, were randomly assigned to four treatments in a completely randomized design. The treatments consisted of four diets: a control diet, tannin-free, and three diets with increasing levels of total tannin, 26.2, 52.4, and 78.6 g tannin/kg dry matter (DM). Including the total tannins in the lambs' diet led to a quadratic increase in the intake of nutrients, N-retention (g/day), water intake, water absorption and retention, energy intake, and energy excretion in feces and gases. However, the digestibility of crude protein, neutral and acid detergent fibers, and total carbohydrates decreased. It was observed that there is a correlation between the variable nutrient digestibility and N-ingested and the N-absorbed, N-urinary, and N-retained. However, the N-excreted in feces did not correlate with any of the variables studied. It is recommended to include 33 g/kg DM of total natural tannins from Mimosa tenuiflora hay in the diet of hair lambs, as it improves intake, energy balance, dietary N, and body water composition while reducing the excretion of N-urinary and gas emissions to the environment.

Ruminal responses, digestibility, and blood parameters of beef cattle fed diets with different oilseeds

It aimed to evaluate the effects of different whole oilseeds in lipid-rich diets on nutrient intake, apparent digestibility, ingestive behavior, and ruminal and blood parameters of steers. A control diet (without oilseed) and four diets containing whole oilseeds (cotton, canola, sunflower, and soybean) were tested. All diets used the whole-plant corn silage at 400 g/kg as roughage. Five diets, being a control diet (without oilseed) and four diets containing whole oilseeds (cotton, canola, sunflower, and soybean), were tested. All diets used the whole-plant corn silage at 400 g/kg as roughage. Five rumen fistulated crossbreed steers, in a 5 × 5 Latin square design were distributed using five periods of 21 days. The steers fed cottonseed and canola diets had lower dry matter intakes (6.6 kg/day). Steers showed higher averages of time in rumination for treatments with sunflower, soybean, and cottonseed (406, 362, and 361 min/day, respectively). There was no treatment effect for the ruminal pH and ammonia (NH₃) variables. There was an effect of the treatment on the volatile fatty acid concentrations. The animals that received soybean showed a higher plasma urea concentration (50.7 mg/dL). Animals fed the control diet showed lower serum cholesterol levels (111.8 mg/dL) than those fed diets containing whole cottonseed, canola, sunflower, and soybean (152.7, 137.1, 146.9, and 138.2 mg/dL, respectively). We recommended using whole soybean or sunflower seeds to formulate lipid-rich diets with 70 g/kg of ether extract for crossbreed steers in the feedlot.

Use of spineless cactus associated with legume hay in the feedlot-finishing of lambs in semi-arid regions

The objective of this study were to examine the effects of diets containing spineless cactus associated with hays of different legume species [gliricidia (Gliricidia sepium), “catingueira” (Caesalpinia bracteosa), “sabiá” (Mimosa caesalpiniifolia Benth) and “catanduva” (Piptadenia moniliformis Benth)] on the intake, digestibility, performance and carcass traits of lambs. Twenty-four ½ Santa Inês × ½ Soinga lambs with an average body weight of 21.4 ± 2.53 kg were distributed into four treatments in a completely randomized design. Treatments consisted of diets formulated with the association of spineless cactus (Opuntia ficus-indica Mill) and hay of four legume species, namely, “catanduva”, “sabiá” “catingueira” and gliricidia. The lowest intakes (P<0.05) of dry matter (DM), organic matter (OM), neutral detergent fiber (NDF) and total carbohydrates occurred in the animals that received the diet containing catingueira hay. However, there were no diet effects (P>0.05) on the intakes of crude protein (CP), ether extract and non-fibrous carbohydrates. The diets also did not change (P>0.05) the weight gain (0.197 kg/day) or final weight (33.18 kg) of the lambs or the apparent digestibility coefficients of DM, OM, CP and NDF. Consequently, the parameters of live weight at slaughter (34.10 kg), hot carcass weight (14.81 kg), cold carcass weight (14.66 kg), hot carcass yield (45.60%) and cold carcass yield (45.07%) exhibited the no response to treatment. In addition to these variables, the diets also did not influence subcutaneous fat thickness (2.54 mm), longissimus muscle area (13.34 cm²), morphometric measurements of the carcass, or the proportions of muscle and fat. Therefore, legume hays associated with spineless cactus can be used to feed ½ Santa Inês × ½ Soinga lambs in the feedlot, as this strategy provides heavy animals at the time of slaughter and carcasses with desirable degrees of muscularity and adiposity.