Effects of pasture management and supplementation on the productive performance of recently lambed ewes.

The hypothesis was tested that the performance of lactating ewes is affected by the supplementation level and pasture management. Two supplementation levels (0.5 and 1.0% of body weight, BW) and two pasture managements (mowed and non-mowed) were tested. Forty adult ewes (2 years old) with an average weight at lambing of 62.97 ± 7.0 kg (day 0) and an average the body condition score of 2.5 points (day 0) were evaluated. Verminosis was monitored with periodic deworming. The number of eggs per gram of feces (EPG) of ewes at lambing was used as a covariate for performance assessments. Ewes lost an average of 7.5 kg over the 90 days post-partum (12% BW). The weaning rate was 53%. The body condition of the ewes was influenced by the post-partum period. The ewes mobilized their body reserves in the first 30 days of lactation. Mowing management negatively affected the nutritive value of the forage. Supplementation with 0.5% BW was sufficient for nutritional management post-partum. Pasture management (mowed vs. not mowed) cannot prevent post-partum weight loss. Supplementation levels and pasture management altered the morphological and chemical components of the pasture.

Hepatogenic photosensitization in lambs supplemented with different levels of extruded urea in Brachiaria spp. pastures in the Brazilian Cerrado: Case report.

The aim was to report cases and risk factors for hepatogenous photosensitization in lambs kept on Brachiaria spp. pastures and supplemented with levels of extruded urea (EU). The herd consisted of 69 Texel crossbred lambs with known parentage (fathers and mothers adapted to the consumption of forage of the genus Brachiaria), randomly divided into 5 groups and distributed in individual paddocks for each group. The animals were supplemented with increasing levels of EU (Amireia® 200S): 0, 6, 12, 18, and 24 g of EU per 100 kg-1 of body weight (BW). The concentration of protodioscin was estimated in the mixed pastures of Brachiaria spp. (cv. Marandu and cv. Basilisk), structural components (leaf, stem, and dead material), samples of each cultivar, and in the months of December (2018), February, and April (2019). The animals were examined daily, and when behavioral changes were identified, they underwent clinical examinations and anamnesis. Weighing was performed every 14 days, followed by necropsy and serum biochemical analysis, including gamma-glutamyltransferase (GGT). The highest concentrations of protodioscin (p < 0.0001) were found in the pastures used by animals supplemented without extruded urea (7.07 ± 0.56), in the Basilisk cultivar (11.35 ± 0.06), in the leaf blade components (2.08 ± 0.05), and thatch (2.20 ± 0.00), and in the month of April (7.34 ± 0.29) (the month with the lowest rainfall), respectively. Fourteen (20.29%) cases of photosensitization were observed in lambs, of which six recovered, and eight died. Serum GGT levels ranged from 42.2 to 225 IU/L; however, in animals that died, values ranged from 209.4 to 225 IU/L. The use of levels 12 g and 18 g per 100 kg-1 of body weight of extruded urea may contribute to the lower occurrence of photosensitization, as the animals selected pastures with lower protodioscin content, presenting a smaller number of cases.

Powder and agglomerated free-choice minerals for grazing cattle: animal responses and chemical and physical alterations of the mineral mixture.

The aim was to evaluate the animal response and the chemical and physical changes of free-choice mineral mixtures fed to grazing cattle. Growing beef cattle were fed either powder (POW) or agglomerated (AGL) mineral mixtures in three different experiments (Exp.), carried out in pastures of Brachiaria grass. In Exp. 1 and 2, the mineral mixtures were disposed in unsheltered troughs (POWun vs. AGLun), being delivered once (D0, Exp.1) or twice (D0 and D8, Exp. 2), throughout 14-day periods. In Exp. 3, POWun and AGLun were additionally compared to POW in sheltered troughs (POWshe), and the mineral mixtures were disposed in D0, throughout 21-day periods. Non-consumed supplement was removed and sampled on D14 (Exp. 1 and 2) or D21 (Exp. 3). Evaluations included average daily body weight gain (ADG), daily disappearance of the supplement (DSD), penetration force of the supplement mass, faecal chemical composition and serum levels of Ca, P and Mg. In Exp. 1, no effects were observed on ADG and faecal mineral concentrations, however, changes in mineral concentrations and a 40% reduction in Na concentration in the supplement were observed, compared to the initial concentration. AGLun had a lower penetration force. In Exp. 2, there were no effects on DSD and faecal mineral concentrations. POWun showed a smaller reduction in Na content compared to AGLun, and AGLun showed lower penetration force. In Exp. 3, the treatments did not affect ADG, but there was a trend towards higher DSD and serum phosphorus (P) concentration for AGLun (p = 0.08). Higher faecal Na concentration was observed for AGLun and higher Na concentration occurred in non-consumed mixture of POWshe. Mineral supplements offered in uncovered troughs showed altered chemical and physical characteristics, with possible effects on supplement intake. However, the general changes are unlikely to alter animal performance.

Carcass traits and meat quality of Texel lambs raised in Brachiaria pasture and feedlot systems.

Our hypothesis suggests an improvement in carcass and meat quality of pasture-finished animals by introducing concentrate feed into diets. This study aimed to evaluate the effect of different levels of protein-energy supplementation on carcass and meat characteristics of Texel lambs raised on Brachiaria pastures, and compare the results with those obtained from confined animals. Thirty 2-month-old intact lambs were divided into five treatments: pasture with mineral supplementation, pasture containing daily supplies of 0.8, 1.6, and 2.4% BW protein-energy supplementation, and confinement (reference treatment). All animals were slaughtered 104 days after the beginning of the experiment. Lambs submitted to 1.6% and 2.4% BW supplementation presented similar characteristics to animals kept in confinement and were superior to animals treated with 0 or 0.8% of BW supplementation levels (p < .05). Increases of subcutaneous fat thickness were verified for 0.0, 0.8, 1.6, 2.4% BW, and confinement treatments, being respectively of 0.25, 0.74, 1.61, 1.69, and 1.98. Conversely, treatments had no influence on meat physical-chemical characteristics, being all considered moderately soft, juicy (tender), and with mild tastes and odors. Lambs raised on Brachiaria pastures have high-quality meat, but more protein-energy supplementation is needed to be an alternative for the feedlots for young animals.