Search

This study evaluated the effect of different grazing systems on yield and quality of milk in Holstein cows. Four silvopastoral systems (SP) were compared, as follows: kikuyo (Cenchrus clandestinus) and ryegrass (Lolium ssp) (R); ryegrass, tree marigold (Tithonia diversifolia) and alder (Alnus acuminata) (sspR); kikuyo, tree marigold and alder (sspK); and ryegrass, kikuyo, tree marigold and alder (sspRK). The response variables were daily milk traits: yield, (PL), lactose, (L), fat, (G), and protein, (P); milk constituents of protein (% P) and fat (% G), and milk urea nitrogen (MUN) of 60 holstein cows from 1 to 6 parities. We used mixed generalized additive models with smoothed semiparametric effect for days in lactation (DEL), fixed effects of SP, number of calvings, and the random effect of lactation. According to the results, the SspR system had higher PL, L, P, and G compared with the other systems (P < 0.05), demonstrating the potential of silvopastoral systems in the high tropics. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the effect of different grassland renovation methods on the Lolium sp. productivity during rainy and dry seasons in the high tropic of the Nariño department. Materials and Methods: The essay was conducted between January and August, 2018. Two experiments were established in the Pasto and Sapuyes municipalities. An experimental design of complete randomized blocks was used, with five treatments and three replicas (T1: farmer's conventional management; T2: grassland renovator; T3: harrowing twice; T4: rigid chisel plow once, harrowing once and subsoiling once; T5: vibratory chisel plow once and harrowing once). The variables cover percentage, height, green forage and dry matter yield, were evaluated. For the statistical analysis, the software R V 3.5.1 was used. Variance analysis and Tukey's test were carried out for comparison among means (p < 0,05). Results: In the rainy season, in the Pasto locality, the variable plant height showed significant differences among treatments (p < 0,001). T5 showed the highest value (38 cm). In turn, significant differences were found in the green matter and dry matter yield among treatments, T3 being the one with the best performance (16,2 and 2,6 t ha-1, respectively). In the Sapuyes locality, T1 reached the best results for the variables cover percentage, plant height, green forage and dry matter yield (96,0 %; 67,5 cm; 34,2 t ha-1 and 4,19 t ha-1, respectively). In the dry season, in the Sapuyes locality, the variable green forage yield showed significant differences among treatments, T1 being the most outstanding one (21,1 t ha-1). Conclusions: During the rainy and dry seasons, T3 reached the best values in green forage and dry matter yield for the Pasto locality; while for Sapuyes, T1 showed the best values. [ABSTRACT FROM AUTHOR]

To evaluate dynamics in nutritional composition of tropical forages used in cattle production in Colombia a systematic research was made, using a regular search engine, for studies published in Colombia between 1985 and 2015, Those studies had to include chemical composition data, such as crude protein, neutral detergent fiber, acid detergent fiber and in vitro dry matter digestibility (CP, NDF, ADF, IVDMD). Likewise studies that reported productive parameters such as daily weight gain (DWG Kg/d), milk yield (MY Lt/d), Animals per hectare (UGG/ha), were included. A lineal regression model was used for chemical components and productive parameters for the period studied. Starting from the global research, 105 studies were included from 17 research database, from which 9 species were selected (species with more than 5 studies published). No lineal trends were observed in the time lapse analyzed, for neither chemicals fractions nor productive parameters related to forage quality. However for Brachiaria sp and Paspalum sp a positive trend was detected for UGG/ha (r2=0.54 y 0.53,respectively). Despite the low significance of the coefficients of determination of lineal regression model for the 9 species selected, an overall lineal increase in CP and IVDMD was observed, and also a lineal reduction for ADF (except for Lolium sp and Dichantium sp). Regarding to productive parameters, a slight positive trend was observed for the UGG/ha in most of the species analyzed. This kind of study becomes in a valuable tool in order to explain and to predict the nutritional behavior of the forage species and its effect on livestock productive parameters. [ABSTRACT FROM AUTHOR]

The objective of the study was to evaluate three ryegrass (Lolium perenne L.) cultivars with dairy cows, in the high tropic of Nariño-Colombia, in two localities: Pasto (PAS) and Cumbal (CUM). In each locality nine cows were used, in a Latin square design (3 x 3) with three treatments (T), corresponding to each cultivar to be evaluated: T1: ryegrass Columbia, T2: ryegrass Samson, T3: ryegrass Ohau. The dry matter intake (DMI) and milk production (MP) were estimated, and samples were collected to analyze: fat, protein, total solids and milk ureic nitrogen (MUN). There was no statistical difference in the DMI among the ryegrasses in the localities. In PAS significant differences were found among cultivars in the variable milk production (p < 0,05); with Samson and Ohau higher production was obtained (17,5 and 17,1 kg/cow/day) with regards to Columbia (15,5 kg/cow/day). In the content of fat and non-fatty solids in the milk, there were no differences among the treatments in any of the two localities. However, significant difference (p < 0,05) was found in the milk protein in PAS (3,48; 3,61 and 3,47 % for Columbia, Samson and Ohau, respectively). For the variable MUN (mg/dL), significant difference (p < 0,05) was observed in the PAS locality. It is concluded that L. perenne showed similar nutritional characteristics in the two localities where they were established. The response in milk production and compositional quality was considered good, taking into consideration that the animals did not receive supplementation and the trial was conducted in the dry season, in which the pasture yields decrease. [ABSTRACT FROM AUTHOR]

Forages are the prevailing feeding alternative within the different livestock production systems in the tropic; nevertheless, they often show limitations in quantity and quality. The objective of this study was to evaluate the productivity and quality of 18 forage species for their use in the high tropic of Nariño, Colombia. The trials were established in two localities (Pasto and Sapuyes). The design was completely randomized blocks, with 18 treatments and three repetitions: ten ryegrass cultivars, three naturalized pastures (kikuyu, Yorkshire fog and cock's foot), three legumes and two forage creeping non-legume plants (broadleaf plantain and common chicory). During the seasons of high and low rainfall, the following variables were evaluated: dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and net lactation energy (NLE). During the two periods of high and low rainfall, the ryegrasses Aubade and Italiano; the perennial cultivars Yorkshire fog, Columbia and Boxer; the legume vetch and the non-legume creeping plants common chicory and broadleaf plantain showed the best CM, CP, NDF, ADF and NLE values in the two localities. The adaptation of the different ryegrass cultivars is a characteristic that affected the quality of the produced biomass. [ABSTRACT FROM AUTHOR]

A trial was conducted in order to evaluate the effect of Leucaena leucocephala cv. Peru on the rumen microbial population of Zebu crossbred bulls, in the two stages of the fattening cycle. The system, integrated by five strips of grasses associated with L. leucocephala and five without association, consecutively alternated in 25 ha, allowed the fattening of 80 animals, from which eight were used for the microbiological studies. The samplings of rumen liquid were made bimonthly (February-March, April-May, June-July) and four-monthly (August-November). The cellulolytic bacteria reached values between 15,94 and 46,13 106 CFU.mL-1 when the bulls grazed L. leucocephala associated with grasses. The highest population of rumen cellulolytic fungi was found in the rumen of animals in the system with L. leucocephala, in the August-November samplings. The concentration of rumen ammonia had values of 8,76 and 24,09 mmol.L-1 in the system with grasses and the one of L. leucocephala associated with grasses, respectively (p < 0,001). The pH in rumen was significantly higher, the population of total viable bacteria was 2,9 times higher and the protozoans decreased when L. leucocephala participated in the ration. It is concluded that the system with L. leucocephala associated with grasses is advantageous, because it propitiates increases in the populations of total viable bacteria and fiber-degrading microorganisms; this, along with the depressing effect of protozoans, guarantees a favorable ecological environment for rumen cellulolysis, which would contribute in a sustained way to the productive increase of the animal husbandry system. [ABSTRACT FROM AUTHOR]

Colombian dairy systems are based on grasslands; therefore, it is necessary to define forages response under different environmental conditions. The objective of this study was to assess the establishment and production of five perennial ryegrass and three clovers into two regions of Colombian highlands (Tuta, Boyacá and Mosquera, Cundinamarca). Three 8 m² plots of each species were established. Establishment variables were evaluated twice a month during the initial five months. The variables of production and nutritional quality were evaluated in rainy (April and May) and drought (June and July) season. The variables were analyzed through a randomized complete block with repeated measures, between November 2015 and July 2016. During the establishment period, ryegrass and clovers coverage and adaptation degree were greater between the days 45 and 60, and 105 and 150, in Tuta and Mosquera, respectively. Maturity increase reduced the lactation net energy (between 7% and 15%) and increased the daily dry matter production per hectare (between 20 and 78 kg). Evaluation day presented a greater influence regarding the variety and the rainy season on the evaluated establishment and regarding the production variables in ryegrass and clover forages, in the Colombian highlands. [ABSTRACT FROM AUTHOR]

The objectives were evaluating the combined effects of different rates of both inoculum (Rhodococcus fascians) and nitrogen on forage production of grasses and to perform a cost - benefit economic analysis. The species analyzed were Avena sativa L, Lolium multiflorum Lam, and Triticum durum L through the following treatments: inoculation, nitrogen fertilization (0, 30, 60 kg N ha-1) and a combination of inoculation and fertilization. The species were established under irrigated conditions in a clay loam soil with 6.7 pH, and 0.34 % organic matter. The microorganism was sprayed on the seed and later, on the plants after each forage harvest. Forage production was evaluated in terms of metric tons (t) of dry matter (DM) ha-1. The economic study was performed using marginal analysis, where the indicators were cost variables, forage production and net benefits. The experiment was carried out using a completely randomized design with a 2x3x3 factorial arrangement with four replications, where the first factor was inoculation; the second factor, species; and the third factor, N rate. The results show that the combined use of an inoculum and 30 kg N ha-1 produces 50 % more DM (approximately 11 t) than when only N is used, especially in Avena sativa L. and Lolium multiflorum Lam. The economic analysis showed that the best treatment was inoculation plus 30 kg N ha-1 for Avena sativa L, presenting a marginal return rate of over 60 %. [ABSTRACT FROM AUTHOR]

The objective of the present study was to assess perennial ryegrass seasonal herbage accumulation, growth rate (GR), tiller population density (TPD) and weight (TW) at different grazing frequencies and intensities. Treatments consisted of two grazing frequencies (14 and 21 d in the rainy season and 35 and 42 d in the dry and cold seasons) and three grazing intensities: (hard 4-6 cm); medium (6-8 cm) and lax (8-10 cm) in a completely randomized block design with a factorial 2×3 arrangement and three replicates. In the rainy season herbage accumulation was 28 % greater (P<0.05) at 21 d grazing frequency than at 14 d grazing frequency (4,457 vs 3,457 kg DM ha-1). In the cold and dry seasons herbage accumulation at 35 d interval produced 27 % more herbage than at 42 d interval (2.270 vs 1,787 kg DM ha-1). Medium intensity grazing yielded more herbage than both hard and lax in the three seasons. The highest GR was recorded in the rainy season, especially in August at 21 d frequency and medium intensity. The highest TPD (8,042 tillers m-2) was recorded also in August and tended to drop in September. Tiller weight had the greatest influence on herbage yield at 21 d frequency in the rainy season, and TPD increased herbage yield at the beginning of the following rainy season. [ABSTRACT FROM AUTHOR]

Land application of organic materials is a common practice in sustainable agriculture. Our aim was i) to study the effectof the incorporation of organic material at different maturity stages on the ryegrass (Lolium peremne L.) growth, and ii) to estimate the stage capable to produce the product more efficient in providing nitrogen to the plant nutrition. Four compost samples consisted of pruning waste, leaves and grass clippings were selected from four different piles at different stages of the composting process: initial non-decomposed material, 2 months old at the end of the bio-oxidative stage, 7 months old during the maturation phase, and 12 months old at the end of the maturation phase. These compost samples were used to ryegrass growing assays, and they were also added to a clay silty soil. Dry matter values were lower in Tl and T2 than in T3 and T4. Similar results were quantified when the same materials were incorporated to a soil. Nitrogen leaf content revealed that soil N immobilization had ocurred in Tl and T2 treatments. A compost, which had 7 months old during the maturation phase, did not cause any negative effect on the evaluated parameters. This compost seems to be sufficiently stable and its use would save time in compost process, compared with a compost 12 months old. [ABSTRACT FROM AUTHOR]