Daiany Iris Gomes

Context: In the tropics, there is a substantial demand for a broader understanding of the impact of supplementation strategies on animal growth. Aims: The aim of this study was to evaluate the effects of different concantrate supplementation strategies during the dry, rainy, or both seasons on intake, digestibility, performance, and carcass weight of young Nellore bulls. Methods: Twenty-eight young Nellore bulls with an initial average liveweight (LW) of 327 ± 4.2 kg of were used. Animals had ad libitum access to a Urochloa brizantha pasture and a mineral mixture sequentially in dry and rainy seasons. Treatments consisted of the following four concentrate supplementation strategies: (1) no concentrate supplementation (−/−); (2) 8 g/kg LW in rainy season (−/+); (3) 8 g/kg LW in dry season (+/−); and (4) 8 g/kg LW in both dry and rainy seasons (+/+). Key results: Forage intake was lesser (P < 0.05) in cattle fed +/+ when contrasted against all other supplementation strategies. In the dry season, concentrate supplementation increased (P < 0.04) LW gain from 0.40 to 0.74 kg/animal.day. Considering performance in both the dry and rainy seasons, all supplementation strategies increased (P < 0.05) total LW gain, hot carcass weight, carcass fat and muscle when compared with the negative control treatment −/−. Bulls receiving +/+ had greater (P < 0.05) total LW gains and hot carcass weights than did −/+ and +/− treatments. Directly contrasting −/+ and +/−, supplementation in the rainy season tended (P < 0.10) to increase total LW gain and hot carcass weights. Conclusions: Under the conditions of this experiment, concentrate supplementation decreased forage intake but increased LW gain, hot carcass weight and carcass quality. Concentrate supplementation in both the dry and rainy seasons provided greater LW gain and hot carcass weights than did concentrate supplementation during only the dry or rainy seasons. Concentrate supplementation only during the rainy season produced greater hot carcass weights and LW gains than did concentrate supplementation only during the dry season. Implications: To achieve maximum LW gains and hot carcass weights, concentrate supplementation should be provided during both dry and rainy seasons. If supplementation costs are a limiting factor, concentrate supplementation during the rainy season is likely to provide greater LW gains and carcass weights than does concentrate supplementation only during the dry season. However, pasture nutritive value, carcass prices and supplement costs must be evaluated before selecting a supplementation strategy.

In this study, we analyzed the effects of including açaí kernel, in the experimental diets fed to horses on the intake and digestibility of their nutrient and the resultant effects on the behavior of horses. The experiments were conducted in Federal Rural University of Amazonia. Five mares with no defined breeds, were allocated to five treatments (the replacement of Mombaça grass (Megathyrsus maximus) with crushed açaí kernel at 0, 18.75, 37.50, 56.25, and 75% levels of dry matter), in a 5 × 5 Latin square design. The animals were housed in covered stalls with concrete floors, equipped with individual troughs and drinkers, and fed 80% roughage and 20% concentrate. The inclusion of açaí kernel altered the intake and digestibility of a few nutritional components and the feeding behavior of mares. Increasing levels of the substitution of Mombaça grass with crushed açaí kernel in the experimental diets increased the nutrient intake and digestibility of neutral detergent fiber, total carbohydrates, and non-fibrous carbohydrates (P < 0.05) while reducing the time spent on feeding by the animals. Crushed açaí kernel can, therefore, be included as a substitute for Mombaça grass at up to 37.5% in equine diets.

Context: Different methods of weaning have been validated to reduce the stress of calves. A novel approach has been described by ranchers whereby the zebu calves are kept in the same pasture with trainer’s cows, however, no scientific evidence is available to date. Aims: This study investigated the effect of different weaning methods on the physiological responses, temperament, and post-weaning performance of calves. Methods: One hundred and eighty three Nellore calves were used, including 93 males (initial bodyweight: 219.8 ± 3.25 kg (avg ± s.e.), initial age: 244 ± 14.3 days (avg ± s.e.) and 90 females (219.7 ± 3.25 kg, 246 ± 14 days (avg ± s.e.)). The calves were randomly assigned to three weaning methods: Abrupt – total separation of dam and calf; Fenceline – physical separation between dam and calf by wired fence; and Leadership – total separation between dam and calf and use of social facilitator cows. Heart rate, respiratory rate and blood samples for cortisol analysis were taken on Days 0, 1, 4, and 7 post-weaning. Temperament was assessed on Days 0, 7, and 82. Performance and body condition score (BCS) was measured at 0, 42, and 82 days post-weaning. Key results: No interaction (P > 0.05) between the weaning methods and sex of the calves was detected. Heart and respiratory rates were not influenced (P > 0.05) by weaning methods on Days 1 and 7 post-weaning. Furthermore, females showed higher heart rate at Day 7 post-weaning (P < 0.05). Weaning methods and sex of calves did not affect the cortisol levels (P > 0.05). Calves on Fenceline and Leadership weaning methods had higher final bodyweight and average daily gain (ADG) from weaning until 82 days post-weaning (P < 0.05) compared to the Abrupt weaning method, which had negative ADG (-26 g/day) on the first 42 days and the lowest bodyweight until 82 days post-weaning (P < 0.05). Conclusions: The presence of social facilitators at weaning, using dams in the Fenceline method or non-related cows in the Leadership method, ensures greater post-weaning performance. The Leadership method can be the most advantageous due to its easy handling. Implications: The weaning strategies contribute to good animal performance and shorten the post-weaning and finishing phases.

The effects of higher supplementation levels for young Nellore heifers fed tropical forages including their influence on puberty, need to be understood. This study investigated the influence of high and moderate supplementation levels on puberty onset and the productive performance of Nellore heifers. Thirty-six Nellore heifers (225 + 3.52 kg) were used in a completely randomized design, with three treatments: (I) no concentrate (control); (II) concentrate supplement at 4 g/kg body weight (BW); (III) concentrate supplement at 8 g/kg BW. Increased supplement level led to a linear increase in average daily gain (P < 0.05). The high supplementation level (8 g/kg BW) had the highest proportion of corpus luteum presence (82% of heifers), compared to the 4 g/kg BW treatment group (67%) and the control group (33%; P < 0.05). Our findings indicate that providing a high level of energy supplementation to Nellore heifers for approximately 100 d improves performance and increases the proportion of heifers that reach puberty

This study evaluated the effects of different pre-slaughter road transportation times on sensory evaluation and instrumental measurements of Nellore cattle meat quality. About 15 farms were classified according to transportation times (five farms per transportation time group) as follows: 1 — less than 2 h (2 and ≤4), and 3 — between 4 and 6 h (>4 and ≤6). The experiment was a completely randomized design with 15 replications and three treatments. Meat analyses were performed on steaks taken from the longissimus dorsi muscle from the 10th rib to the third lumbar vertebra. Road transportation times had no significant effects on pH and mean shear force values. Sarcomere length, myofibrillar fragmentation index, and creatine kinase levels were also not affected by transportation time. Furthermore, road transportation times had no effect on meat tenderness, flavour, odour, and overall acceptability when evaluated by consumers. Thus, a pre-slaughter road transportation time up to 6 h does not affect the sensory evaluation and instrumental measurements of Nellore cattle meat quality when raised using a grazing system.

This study explored the effects of different supplementation strategies in the dry and rainy seasons in the tropics on the carcass traits, meat quality, and economic viability of Nellore cattle produced under grazing conditions. For this purpose, twenty-eight non-castrated male animals (18 months) with an initial body weight of 327.93 ± 4.22 kg were used. The animals were equitably distributed in a randomized complete design thorough four supplementation strategies as follows: i) mineral supplementation (MS) in both dry and rainy seasons (MS/MS), ii) MS in the dry season and concentrate supplementation (CS) in the rainy season (MS/CS), iii) CS in the dry season and MS in the rainy season (CS/MS), and iv) CS in both dry and rainy seasons (CS/CS). Thereafter, carcass traits, primary carcass cut yields, meat quality traits, chemical composition of meat, and economic viability of cattle production across different supplementation strategies were determined. Data revealed that animals under CS/CS showed the greatest (P < 0.01) hot carcass weights among the other supplementation strategies evaluated. Conversely, supplementation strategy did not affect (P > 0.05) carcass traits (the ribeye area, final pH, and forequarter), meat quality traits (shear force, myofibrillar fragment index, sarcomere length, and color), and meat chemical composition (crude protein, fat, and moisture) of the animals. The effective operational cost, total cost, gross revenue, and profit of animals under CS/CS showed the greatest values, whereas the lowest ones were obtained for the animals under MS/MS. In conclusion, data suggest that concentrate supplementation during at least one season (dry or rainy) produces similar meat quality traits and chemical composition of meat, but different hot carcass weight, backfat thickness and hindquarter proportion to those observed when animals were supplemented with concentrate in both seasons. Additionally, CS/CS animals, despite having a higher total cost, have greater profitability when raised in tropical pasture.

This study evaluated the effects of dietary inclusion of cracked babassu coconut (CBC) in the supplement on nutrient utilization, performance, and milk fatty acid (FA) composition of dairy cows grazing Megathyrsus maximus cv. Mombasa. Five multiparous Holstein × Zebu mid-lactation cows (125 ± 16.5 days in milk) were assigned to five dietary treatments (replacement of 0%, 20%, 40%, 60%, and 80% of ground corn with CBC, on a dry matter (DM) basis) in a 5 × 5 Latin square design. The intake of DM from the supplement, crude protein (CP), non-fiber carbohydrate (NFC), fat (ether extract (EE)), and total digestible nutrients (TDNs) decreased linearly (P < 0.05), while the intake of DM from forage increased linearly (P < 0.05), with the increase in CBC inclusion in the supplement. Conversely, total DM intake was unaffected (P > 0.05). The DM, NFC, EE, and TDN digestibility decreased linearly (P < 0.05), while organic matter (OM) digestibility decreased in a quadratic fashion (P < 0.05), as CBC inclusion in the supplement increased. Nevertheless, digestibility of CP was unaffected (P > 0.05). Milk yield and composition (lactose, fat, protein, casein, and majority of FA) showed a linearly decreasing pattern (P < 0.05) with the increasing of CBC inclusion. However, proportions of trans-vaccenic acid, rumenic acid, total monounsaturated FA, and odd- and branched-chain FAs increased linearly (P < 0.05). On the opposite, total saturated FA (SFA) and the n-6:n-3 FA ratio in milk fat decreased linearly (P < 0.01). Hence, replacement of corn meal with CBC up to 80% in the supplement decreases nutrient intake and digestibility, as well as milk yield response in grazing dairy cows. However, CBC inclusion may enhance the nutritional properties of milk fat.

This study evaluated the use of babassu cake as a replacement for soybean meal and pineapple byproduct silage as roughage in the diets of feedlot sheep. Ten rumen-fistulated sheep were used and distributed in an experimental design consisting of two 5 x 5 Latin squares. Babassu cake replaced soybean meal at four concentration levels (0, 26.66, 53.33, and 80%), and pineapple byproduct silage was used as roughage. A treatment was also evaluated in which elephant grass silage was used as roughage and corn and soybean meal were used as the concentrate. No effect of babassu cake as a replacement for soybean meal on dry matter intake, neutral detergent fiber, or crude protein was observed. Higher babassu cake replacement levels in the diets resulted in linear reductions in the digestibility of the dry matter, neutral detergent fiber, organic matter, nonfiber carbohydrates and total carbohydrates. For the digestibility of the crude protein, no effect was observed after the addition of babassu cake. The replacement levels of the babassu cake had no effect on the intake and retention of the daily nitrogen, ammonia nitrogen and ruminal pH. Babassu cake could replace soybean meal at concentrations of up to 80% when the roughage source was pineapple byproduct silage. Compared with elephant grass silage, pineapple byproduct silage improves nutrient intake and digestibility and nitrogen intake, retention, and absorption without compromising the ruminal pH or ammonia nitrogen of feedlot sheep.

This study evaluated the chemical composition and ruminal degradability of dry matter (DM), neutral detergent fiber corrected for ash and protein (NDFap) and crude protein (CP) in byproducts of African oil palm (palm cake, kernel or fiber), macaúba (pulp cake and kernel cake), acai (acai fruit), babassu (kernel cake) and pineapple (peel, crown and bagasse silage). Nineteen rumen-fistulated sheep were kept in individual stalls, receiving a daily diet composed of elephant grass silage and corn and soybean concentrate. After preparation in nylon bags, the byproduct samples were incubated for 0, 3, 6, 12, 16, 18, 24, 48, 72, 96, 120 and 144 hours, with three replicates of each ingredient per incubation time. The divergence between the protein nutritional value and energy nutritional value, based on discriminatory variables between groups, was estimated by cluster analysis. The effective degradability of DM, NDFap and CP for the different byproducts was, respectively, 35.9, 26.9 and 59.0% for palm cake; 48.3, 34.3 and 76.4% for palm kernel; 21.1, 6.6 and 50.3% for palm fiber; 34.3, 15.0 and 52.8% for macaúba pulp cake; 58.1; 63.0 and 51.6% for macaúba kernel cake; 49.7, 49.6 and 41.8% for babassu cake; 53.4, 40.5 and 79.8% for pineapple bagasse silage; and 21.3, 17.0 and 38.9% for acai fruit. Based on their NDFap and CP characteristics, the feeds were clustered in up to four different groups.

The objective of this study was to evaluate the effect of the partial replacement of elephant grass silage with babassu (Orbignya speciosa) on the performance, intake, digestibility, and carcass weight gain of sheep. Fifty-four castrated male lambs (19.08±2.76kg) were distributed in a completely randomized design and administered one of the following treatments: 0.0, 12.5, 25.0, 37.5 or 50% dry matter (%DM) replacement of elephant grass silage with babassu cake. No difference (P> 0.05) was observed in the dry matter, crude protein, and neutral detergent fiber intake, but the ether extract intake increased (P< 0.05). The digestibility of the dry matter, neutral detergent fiber, and total digestible nutrients were unaffected. The crude protein digestibility decreased (P< 0.05), and the ether extract digestibility increased with the replacement of the elephant grass. There were no changes in mean daily weight gain and carcass weight gain. In the carcasses, a linear increase was observed in the proportion of the ether extract, and the crude protein decreased. The replacement of the silage with the babassu cake by up to 50% did not change the performance of sheep, however it led to an increase in fat deposit in the carcass.