Scielo RSS <![CDATA[Revista Brasileira de Zootecnia]]> vol. 43 num. 9 lang. en <![CDATA[SciELO Logo]]> <![CDATA[Nutritional plans of digestible lysine for growing-finishing gilts]]> This experiment was conducted to evaluate nutritional plans of digestible lysine (DLys) for growing-finishing gilts. Eighty gilts with 63 days of age and an initial weight of 24.2±1.52 kg were distributed in a completely randomized block design, with five nutritional plans of DLys (9-8-7, 10-9-8, 11-10-9, 12-11-10, and 13-12-11 g/kg, from 63 to 103, 104 to 133, and 134 to 153 days of age, respectively) and eight replicates. Pigs were housed in pairs and fed their respective diets ad libitum throughout the experimental period (90 days). To monitor the animal development along the experiment at 103 and 133 days, gilts were weighed and subjected to analysis of ultrasound for evaluation of loin depth (longissimus dorsi) and backfat thickness. At the end of the experiment (153 days of age) the animals were weighed, and after slaughter carcasses were evaluated individually using a typifying pistol to evaluate the percentage and the content of carcass meat, loin depth and backfat thickness. From 63 to 133 days, there was no effect of the nutritional plans on daily feed intake, performance, or backfat thickness; however the loin depth was greater in the gilts that received plans with high levels of DLys (12-11; 13-12 g/kg) compared with the plan with the lowest level (8-7 g/kg). For the entire period (63 to 153 days), no influence of the nutritional plans was observed on the daily feed intake, performance variables, or carcass characteristics. A nutritional plan containing 9-8-7 g/kg of digestible lysine fed from 63 to 103, 104 to 133 and 134 to 153 days, respectively, meets the requirements for performance and carcass characteristics of growing-finishing gilts. <![CDATA[Daily activity patterns of Saanen goats in the semi-arid northeast of Brazil]]> The objective of the study was to characterize the daily feeding activity patterns of Saanen goats (Capra hircus) as a function of changes in climatic variables. The investigation was conducted in the municipality of Cruzeta, 300 km from the city of Natal, Brazil. Seventeen free-ranging female Saanen goats were selected for observation, wherein they were kept on a pasture with native vegetation and also received concentrated feed in a trough. Observational records of behavior on pasture were collected using focal animal and scan sampling for these specific behaviors: ruminating while standing or lying down, standing idly or lying down, walking, grazing and eating. Eating was the predominant activity observed. The frequency of some behaviors changed in accordance with certain climatic variables, with behaviors that require more active movement occurring in the morning hours, when temperatures are milder, exhibiting higher frequencies. These observations indicate that animals adjust their daily activities in order to minimize the effects of the stress caused primarily by environmental conditions. <![CDATA[The influence of covering methods on the nutritive value of corn silage for lactating dairy cows]]> The objective of this study was to evaluate the effect of covering methods on the nutritive value of corn silage and performance of dairy cows. Whole-plant corn was harvested at 340 g/kg of dry matter (DM) and ensiled for 135 d in horizontal silos covered with one of the following methods: oxygen barrier film (45-µm thick) + white-on-black polyethylene film (200-µm thick) over the oxygen barrier film (OB+WB); white-on-black polyethylene film (200-µm thick) (WB); black polyethylene film (200-µm thick) (B); or recycled black polyethylene film (200-µm thick) covered with a layer of 10 cm of sugarcane bagasse (RB+SB). Nutrient composition, fermentation profile, and yeast and mold counts in edible silages were similar across treatments. Silage temperature during the storage period was 24.6, 28.7, 28.4 and 33.1 °C for RB+SB, OB+WB, WB and B, respectively, and the proportion of spoiled silage ranged from 28.7 (for the RB+SB treatment) to 74.2 g/kg DM (for the B treatment). Dry matter intake was similar across treatments and averaged 21.9 kg/d. Milk production was higher for cows fed corn silage covered with RB+SB (34.4 kg/d) compared with those fed corn silage covered with B (30.4 kg/d), resulting in higher feed efficiency for RB+SB treatment. Silages covered with OB+WB and WB had intermediate values. In vivo digestibility of organic matter was higher for cows fed corn silage covered with RB+SB compared with those fed corn silage covered with WB and B, but were similar to those fed corn silage covered with OB+WB. The utilization of oxygen barrier films and the protection of polyethylene film with sugarcane bagasse are effective strategies to increase the recovery of digestible nutrients and, consequently, to enhance production efficiency of lactating dairy cows. <![CDATA[Lactose and milk urea nitrogen: fluctuations during lactation in Holstein cows]]> The objective of this study was to evaluate lactose and milk urea nitrogen (MUN) in milk from Holstein cows and their relationship with days in milk (DIM), milk yield, milk fat, milk protein, and somatic cell count (SCC). A total of 1,034 records corresponding to morning and afternoon milkings of 148 Holstein cows were used. Records were taken from 16 herds located in the Northern and Eastern dairy regions of Antioquia (Colombia). The curves were fitted using a generalized additive mixed model with smoothed estimates to find the best smoothing intensity factors involved in MUN and lactose concentration. Regarding MUN, the contemporary group effect was highly significant, but the parity effect was not significant. The DIM, lactose and milk fat smoothed covariates were highly significant, while milk yield and fat and SCC showed no statistical difference. Regarding lactose content, the contemporary group effect was highly significant, while the parity effect was not significant. Days in milk, MUN, milk fat, milk protein, and afternoon-milking SCC smoothed covariates were highly significant, while milk yield and morning-milking SCC were not significant. Lactose and milk urea nitrogen concentrations are affected by various factors throughout lactation, mainly by days in milk. <![CDATA[Mineral mixtures from solid salt residues for lambs]]> The objective of this study was to evaluate water, mineral, feed and nutrient voluntary intakes, in addition to dry matter and nutrient digestibility and the nitrogen balance of lambs fed three mineral supplements. The first treatment consisted of solid salt residue (SSR) from an aquaculture tank; the second contained SSR from desalination waste; and the third treatment was control, which corresponded to the supplementation of a commercial mineral supplement. The study lasted 20 days, the first 15 of which were used for animals to adapt to the pens and diets, and the last five days were used for data collection. Twenty-four castrated male lambs with a body weight of 19.72±2.52 kg were utilized in the experiment. The mineral supplements evaluated did not affect the intake and digestibility of the dry matter and nutrients, the water and mineral-salt intake or nitrogen balance. Mineral supplements produced from the SSR from aquaculture tanks and from the desalination waste did not reduce feed, nutrient and water intakes or nutrient digestibility, which suggests that these raw materials can be used in the elaboration of mineral mixtures for lambs. <![CDATA[Changes in composition, antioxidant content, and antioxidant capacity of coffee pulp during the ensiling process]]> The objective of the present study was to determine the nutritive value, the presence of antioxidant compounds, and the antioxidant capacity of coffee pulp ensiled or non-ensiled. Dry matter (DM), crude protein (CP), ash, acid detergent fiber (ADF), neutral detergent fiber (NDF), and lignin, as well as the antioxidant compounds present in coffee pulp and their antioxidant capacity, were determined. A completely randomized design was used. Data were analyzed by analysis of variance. Ensiling of coffee pulp increased the CP content from 98.6 to 111.6 g kg−1 DM, NDF from 414.6 to 519.5 g kg−1 DM, ADF from 383.9 to 439.3 g kg−1 DM, and lignin from 122.9 to 133.6 g kg−1 DM. Caffeine decreased from 5.72 to 5.02 mg g−1 DM. Three antioxidant compounds were detected. Caffeic acid decreased due to ensiling (16.49 vs 14.69 mg g−1 DM). Gallic acid (2.88 vs 2.58 mg g−1 DM) and chlorogenic acid (62.12 vs 56.00 mg g−1 DM) did not differ, and there was similar antioxidant capacity of non-ensiled (215.66 µmol trolox g−1 DM) and ensiled coffee pulp (206.59 µmol trolox g−1 DM). Despite the decrease in the caffeic acid content due to the ensiling process, it is possible to use either ensiled or non-ensiled coffee pulp for animal feeding because of its high antioxidant capacity. <![CDATA[Effects of herd management practices on somatic cell counts in an arid climate]]> The objective of this study was to evaluate associations between average lactation somatic cell counts (SCC) and herd management practices in an arid climate. A total of 38,530 average lactation SCC records for 10,216 Holstein cows gathered on 25 dairy farms from January 2009 to October 2012 in Isfahan (Iran) were analyzed. Average lactation SCC (cells × 1,000) was 250.79 ranging from 90.31 to 483.23 cells/mL across investigated farms. Herd-level management factors associated with average lactation SCC were determined separately using mixed linear models in the MIXED procedure with average lactation somatic cell score (SCS) included as the dependent variable. Some of the management practices associated with low average lactation SCS included sawdust combined with sand bedding, using automatic cup removers, disinfection of the teats by dipping into disinfectant, using washable towels for teat cleaning, free-stall barns, wet disposable tissue for udder washing, wearing gloves during milking and the use of humidifiers and shade. Lower-production herds and larger-size herds had lower average lactation somatic cell counts. Most herd management practices associated with average lactation SCC in dairy herds in the arid region of Isfahan are in agreement with most previous studies. However, different results are found for use of humidifier, bedding materials and herd size. <![CDATA[Management factors and cow traits influencing milk somatic cell counts and teat hyperkeratosis during different seasons]]> The objective of the study was to analyze the effect of season, parity, stage of lactation and milking procedures on teat-end condition, cow cleanliness and milk somatic cell count (SCC) and identify risk factors associated with milk somatic cell counts greater than 100,000 cells/mL. A group of 15 Italian dairy farms were visited three times during different seasons: the cold (3.8 °C), the hot (23.5 °C) and the mild (12.1 °C) seasons. Hygiene of udder, flanks and legs was scored on 2,330 cows based on a 4-point scale system, from very clean (score 1) to very dirty skin (score 4). On the same cows, a total of 9,201 teats were assessed for teat-end condition and assigned to four different classes of hyperkeratosis: No lesion (N), Smooth ring (S), Rough (R) and Very rough skin (VR). The average percentage of teats classified in the worst classes of hyperkeratosis (R and VR) equaled 15.9%. Teat hyperkeratosis, cow cleanliness and milk somatic cell count were significantly affected by the season. Teat condition was significantly better in primiparous than in multiparous cows and deteriorated during lactation. Cows with the lowest values of SCC, better teat conditions and better hygiene scores were found in the farms where more than one milking practice (among forestripping, pre-dipping and post-dipping) were performed. Multivariate logistic analysis confirmed that parity and days of lactation significantly influence the risk of high somatic cell count. Among environmental and management aspects, clean udders and pre-dipping are associated with a reduced likelihood to have individual cows with milk SCC greater than 100,000 cells/mL. Teat hyperkeratosis does not seem to be a risk factor of high SCC. Milk somatic cell count can be lowered by means of simple actions such as improvement of hygiene condition of cow environment and adoption of pre-dipping.