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Prof. Oscar Balocchi
Universidad Austral de Chile, Valdivia, Chile

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Journal article
Published: 03 July 2021 in Soil and Tillage Research
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In southern Chile, there are over 1.3 million ha of pastures on volcanic ash soils. The climate change scenario and the need to increase yields are forcing farmers to increase irrigated surface areas. This implies an intensified soil use that must be analyzed to prevent soil degradation. Therefore, this study analyzed the impact of initial pasture defoliation (mowing and grazing) and short-term irrigation managements on soil structure dependent properties of a volcanic ash soil under different types of pastures. Field penetration resistance (PR) profiles (0–80 cm), soil water content measurements (0–10 cm) and undisturbed soil samples (0–3 cm) displayed the impact of animal trampling due to repeated loading events. Though this experiment did not determine significant interactions such as pasture x defoliation method x applied load, the early developmental stage of this experiment provided a basis for better understanding deformation processes due to animal trampling when different types of pastures are irrigated in the short-term. The plastic deformation caused by loads higher than precompression stress induced an increase in soil mechanical strength (e.g. Pc increased after the first grazing, but not after mowing), affecting the macropore volume and air permeability. The short-term effects ( mowed plots, showing footprint formation after 8 grazing events) and the higher sum of PR in non-irrigated pastures evidenced the increase of the cohesion between particles/aggregates after drying events. Therefore, it can be expected that in the medium-term (3-4 years), animal trampling could lead to significant soil deformation and a progressive increase in soil mechanical strength near the soil surface.

ACS Style

Dorota Dec; Sebastián Bravo; Rainer Horn; Daniel Uteau; Stephan Peth; Felipe Zúñiga; John Clunes; Stalin Granda; Óscar Martínez; Óscar Balocchi; Máximo Alonso; José Dörner. Analyzing the impact of grazing and short-term irrigation management on soil mechanical strength of a volcanic ash soil under different types of pastures. Soil and Tillage Research 2021, 213, 105130 .

AMA Style

Dorota Dec, Sebastián Bravo, Rainer Horn, Daniel Uteau, Stephan Peth, Felipe Zúñiga, John Clunes, Stalin Granda, Óscar Martínez, Óscar Balocchi, Máximo Alonso, José Dörner. Analyzing the impact of grazing and short-term irrigation management on soil mechanical strength of a volcanic ash soil under different types of pastures. Soil and Tillage Research. 2021; 213 ():105130.

Chicago/Turabian Style

Dorota Dec; Sebastián Bravo; Rainer Horn; Daniel Uteau; Stephan Peth; Felipe Zúñiga; John Clunes; Stalin Granda; Óscar Martínez; Óscar Balocchi; Máximo Alonso; José Dörner. 2021. "Analyzing the impact of grazing and short-term irrigation management on soil mechanical strength of a volcanic ash soil under different types of pastures." Soil and Tillage Research 213, no. : 105130.

Journal article
Published: 01 July 2021 in Journal of Dairy Science
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ACS Style

Juan P. Keim; José R. Rodriguez; Oscar A. Balocchi; Rubén G. Pulido; Pilar Sepúlveda-Varas; David Pacheco; Robert Berthiaume; Einar Vargas-Bello-Pérez. Effect of dietary inclusion of winter brassica crops on milk production, feeding behavior, rumen fermentation, and plasma fatty acid profile in dairy cows. Journal of Dairy Science 2021, 1 .

AMA Style

Juan P. Keim, José R. Rodriguez, Oscar A. Balocchi, Rubén G. Pulido, Pilar Sepúlveda-Varas, David Pacheco, Robert Berthiaume, Einar Vargas-Bello-Pérez. Effect of dietary inclusion of winter brassica crops on milk production, feeding behavior, rumen fermentation, and plasma fatty acid profile in dairy cows. Journal of Dairy Science. 2021; ():1.

Chicago/Turabian Style

Juan P. Keim; José R. Rodriguez; Oscar A. Balocchi; Rubén G. Pulido; Pilar Sepúlveda-Varas; David Pacheco; Robert Berthiaume; Einar Vargas-Bello-Pérez. 2021. "Effect of dietary inclusion of winter brassica crops on milk production, feeding behavior, rumen fermentation, and plasma fatty acid profile in dairy cows." Journal of Dairy Science , no. : 1.

Journal article
Published: 15 April 2021 in Agronomy
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The thermal time, expressed in accumulated growing degree-days (AGDD), was used as a predictor to describe and simulate the independent growth of two pasture crops, Lolium perenne L. and Bromus valdivianus Phil. Two sinusoidal models (four-parameter Logistic and Gompertz) were applied to the growth variables (total leaf blade length per tiller—LBL, and accumulated herbage mass—AHM). The nutritive value of pastures was predicted and modeled using regression equations (linear and quadratic), depending on each nutrient. Data for modeling were collected from a two-year study, in which LBL, AHM, and nutritive value variables for L. perenne and B. valdivianus pastures were measured at three-day intervals. Defoliation was determined according to the AGDD, such that the swards were defoliated at 90, 180, 270, 360, and 450 AGDD. The Logistic and Gompertz models presented similar values for the growth rate (GR) parameters, superior asymptote (A sup), inferior asymptote (A inf), and point of maximum growth (P max). In both species, the maximum growth was 260 AGDD. The GR was similar for both species in different seasons of the year, but the maximum AHM varied, with B. valdivianus presenting a higher value (+1500 kg DM ha−1) than L. perenne during the spring. The regressions accurately described the nutritive value, demonstrating a positive linear relationship between the AGDD and concentrations of neutral and acid detergent fiber (NDF, ADF), an inverse linear relationship with crude protein (CP), and a quadratic relationship with metabolizable energy (ME) and water-soluble carbohydrate (WSC) concentration.

ACS Style

Iván Calvache; Oscar Balocchi; Rodrigo Arias; Máximo Alonso. The Use of Thermal Time to Describe and Predict the Growth and Nutritive Value of Lolium perenne L. and Bromus valdivianus Phil. Agronomy 2021, 11, 774 .

AMA Style

Iván Calvache, Oscar Balocchi, Rodrigo Arias, Máximo Alonso. The Use of Thermal Time to Describe and Predict the Growth and Nutritive Value of Lolium perenne L. and Bromus valdivianus Phil. Agronomy. 2021; 11 (4):774.

Chicago/Turabian Style

Iván Calvache; Oscar Balocchi; Rodrigo Arias; Máximo Alonso. 2021. "The Use of Thermal Time to Describe and Predict the Growth and Nutritive Value of Lolium perenne L. and Bromus valdivianus Phil." Agronomy 11, no. 4: 774.

Journal article
Published: 24 March 2021 in Animals
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The aim was to determine the effect of the herbage allowance (HA) and supplement type (ST) on dry matter intake (DMI), milk production and composition, grazing behavior, rumen function, and blood metabolites of grazing dairy cows in the spring season. Experiment I: 64 Holstein Friesian dairy cows were distributed in a factorial design that tested two levels of daily HA (20 and 30 kg of dry matter (DM) per cow) and two ST (high moisture maize (HMM) and cracked wheat (CW)) distributed in two daily rations (3.5 kg DM/cow/day). Experiment II: four mid-lactation rumen cannulated cows, supplemented with either HMM or CW and managed with the two HAs, were distributed in a Latin square design of 4 × 4, for four 14-d periods to assess ruminal fermentation parameters. HA had no effect on milk production (averaging 23.6 kg/day) or milk fat and protein production (823 g/day and 800 g/day, respectively). Cows supplemented with CW had greater protein concentration (+1.2 g/kg). Herbage DMI averaged 14.17 kg DM/cow.day and total DMI averaged 17.67 kg DM/cow.day and did not differ between treatments. Grazing behavior activities (grazing, rumination, and idling times) and body condition score (BCS) were not affected by HA or ST. Milk and plasma urea concentration increased under the high HA (+0.68 mmol/L and +0.90 mmol/L, respectively). Cows supplemented with HMM had lower milk and plasma urea concentrations (0.72 mmol/L and 0.76 mmol/L less, respectively) and tended (p = 0.054) to have higher plasma β-hydroxybutyrate. Ruminal parameters did not differ between treatments.

ACS Style

Verónica Merino; Lorena Leichtle; Oscar Balocchi; Francisco Lanuza; Julián Parga; Rémy Delagarde; Miguel Ruiz-Albarrán; M. Rivero; Rubén Pulido. Metabolic and Productive Response and Grazing Behavior of Lactating Dairy Cows Supplemented with High Moisture Maize or Cracked Wheat Grazing at Two Herbage Allowances in Spring. Animals 2021, 11, 919 .

AMA Style

Verónica Merino, Lorena Leichtle, Oscar Balocchi, Francisco Lanuza, Julián Parga, Rémy Delagarde, Miguel Ruiz-Albarrán, M. Rivero, Rubén Pulido. Metabolic and Productive Response and Grazing Behavior of Lactating Dairy Cows Supplemented with High Moisture Maize or Cracked Wheat Grazing at Two Herbage Allowances in Spring. Animals. 2021; 11 (4):919.

Chicago/Turabian Style

Verónica Merino; Lorena Leichtle; Oscar Balocchi; Francisco Lanuza; Julián Parga; Rémy Delagarde; Miguel Ruiz-Albarrán; M. Rivero; Rubén Pulido. 2021. "Metabolic and Productive Response and Grazing Behavior of Lactating Dairy Cows Supplemented with High Moisture Maize or Cracked Wheat Grazing at Two Herbage Allowances in Spring." Animals 11, no. 4: 919.

Research article
Published: 07 December 2020 in Applied Animal Behaviour Science
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Recording grazing time is important because the time allocated for each grazing event is one of the limitations to achieving high intake levels. Grazing time can be measured via visual observation or, more recently, by devices calibrated for this purpose. The Kenz Lifecorder Plus (Suzuken Co. Ltda., Nagoya, Japan) has been used to record daily grazing time with high accuracy, but none of the previous studies have analyzed how pasture characteristics and grazing management influence the recording sensitivity of this device. Thus, the aim of this study was to evaluate the effect of pre-grazing herbage mass and season of the year on the activity level recorded by the Lifecorder Plus and its resulting threshold value used to determine a grazing event for dairy cows. A randomized 2 × 2 factorial design was used to evaluate the effect of two pre-grazing herbage masses (HM), medium herbage mass (MHM) and high herbage mass (HHM), in two seasons, winter (WIN) and spring (SPR), on the observed and predicted grazing time. In each period, two groups of six Holstein Friesian cows were fitted with a Lifecorder Plus in a collar attached to their neck. The pasture characteristics and observed and predicted grazing times were measured. There was no effect (P > 0.05) of HM on the observed grazing time. The grazing time in SPR was significantly higher (P < 0.001) than that in WIN. There was no effect (P> 0.05) of HM on the threshold value. The threshold value for SPR was significantly higher (P < 0.001) than that for WIN. The mean relative prediction error of all treatments was 0.07, which implies a precision of 0.93 in grazing detection and demonstrates a high level of precision in the estimation of daily grazing time. Determining an independent threshold value for each treatment was necessary to obtain a high degree of precision in estimating grazing time. In conclusion, changes in the structural sward characteristics caused by grazing management or the annual cycle of growth of the pasture affect both the activity level recorded using a Lifecorder Plus and the threshold value obtained to detect grazing events in dairy cows. When studies incorporate factors that might alter grazing behavior, a specific threshold value for the study conditions needs to be determined to estimate the grazing time of dairy cows with higher precision.

ACS Style

Luis F. Piña; Oscar A. Balocchi; Juan P. Keim; Rubén G. Pulido; Felipe Rosas. Threshold values to discriminate grazing activity of dairy cows by an uni-axial accelerometer as affected by grazing season and herbage mass. Applied Animal Behaviour Science 2020, 234, 105171 .

AMA Style

Luis F. Piña, Oscar A. Balocchi, Juan P. Keim, Rubén G. Pulido, Felipe Rosas. Threshold values to discriminate grazing activity of dairy cows by an uni-axial accelerometer as affected by grazing season and herbage mass. Applied Animal Behaviour Science. 2020; 234 ():105171.

Chicago/Turabian Style

Luis F. Piña; Oscar A. Balocchi; Juan P. Keim; Rubén G. Pulido; Felipe Rosas. 2020. "Threshold values to discriminate grazing activity of dairy cows by an uni-axial accelerometer as affected by grazing season and herbage mass." Applied Animal Behaviour Science 234, no. : 105171.

Journal article
Published: 02 December 2020 in Animals
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Under the predicted conditions of climate change, the productivity of temperate grasslands may be affected by drought stress, especially in spring and summer. In this scenario, water-deficit-tolerant species such as plantain and chicory are interesting alternatives for use in sheep production systems. In this study, we compared a mixture of plantain and chicory herbage (PCH) with a grass-based permanent sward (GBS) on the weight gain and meat quality of lambs finished on these grasslands. Fifteen weaned lambs (31.3 kg and 4 months of age) were assigned to each treatment for seven weeks in late spring and live weight gain (LWG), carcass and meat quality were evaluated. There was a tendency (p = 0.09) in final weight (40.3 ± 0.8 kg) and live weight gain (173 ± 10 g/d) to be higher in PCH compared to GBS. Carcass weight, dressing percentage and meat quality in terms of pH, color and tenderness did not differ (p > 0.05) and were considered to be of good quality. We concluded that both swards result in comparable lamb performance and good meat quality.

ACS Style

Romina Rodríguez; Oscar Balocchi; Daniel AlOmar; Rodrigo Morales. Comparison of a Plantain-Chicory Mixture with a Grass Permanent Sward on the Live Weight Gain and Meat Quality of Lambs. Animals 2020, 10, 2275 .

AMA Style

Romina Rodríguez, Oscar Balocchi, Daniel AlOmar, Rodrigo Morales. Comparison of a Plantain-Chicory Mixture with a Grass Permanent Sward on the Live Weight Gain and Meat Quality of Lambs. Animals. 2020; 10 (12):2275.

Chicago/Turabian Style

Romina Rodríguez; Oscar Balocchi; Daniel AlOmar; Rodrigo Morales. 2020. "Comparison of a Plantain-Chicory Mixture with a Grass Permanent Sward on the Live Weight Gain and Meat Quality of Lambs." Animals 10, no. 12: 2275.

Journal article
Published: 20 November 2020 in Agriculture
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The objectives of the experiment were to (i) examine the dynamics of WSC use and the recovery of leaf sheaths and blades of Bromus valdivianus Phil. and Lolium perenne L. subjected to two defoliation frequencies (DFs) determined by thermal time (TT); (ii) evaluate how DF influenced regrowth and accumulated herbage mass (AHM) during fall. Defoliation was carried out at frequencies of 135 and 270 accumulated growing degree days (AGDDs) for both species. Twelve plots were arranged in a three-block design. All plots had a conditioning period to establish the assigned DF prior to sampling. From the start of the experiment, “cores” were collected from each plot every three days until the DF was reached. Every core was separated into leaf and sheath material before measuring the WSC concentration. Lolium perenne had concentrated more WSCs than B. valdivianus. Both species adapted their WSC recovery according to the DF. The recovery of WSC was faster under a DF of 135 AGDDs than that of 270 AGDDs. Leaf sheaths contained more WSCs than leaf blades and were identified as WSC storage organs. This period can be used as the optimal defoliation interval in B. valdivianus and L. perenne grazing systems.

ACS Style

Iván Calvache; Oscar Balocchi; Máximo Alonso; Juan Keim; Ignacio López. Water-Soluble Carbohydrate Recovery in Pastures of Perennial Ryegrass (Lolium perenne L.) and Pasture Brome (Bromus valdivianus Phil.) Under Two Defoliation Frequencies Determined by Thermal Time. Agriculture 2020, 10, 563 .

AMA Style

Iván Calvache, Oscar Balocchi, Máximo Alonso, Juan Keim, Ignacio López. Water-Soluble Carbohydrate Recovery in Pastures of Perennial Ryegrass (Lolium perenne L.) and Pasture Brome (Bromus valdivianus Phil.) Under Two Defoliation Frequencies Determined by Thermal Time. Agriculture. 2020; 10 (11):563.

Chicago/Turabian Style

Iván Calvache; Oscar Balocchi; Máximo Alonso; Juan Keim; Ignacio López. 2020. "Water-Soluble Carbohydrate Recovery in Pastures of Perennial Ryegrass (Lolium perenne L.) and Pasture Brome (Bromus valdivianus Phil.) Under Two Defoliation Frequencies Determined by Thermal Time." Agriculture 10, no. 11: 563.

Journal article
Published: 01 October 2020 in Journal of Dairy Science
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ACS Style

J.P. Keim; J. Daza; I. Beltrán; O.A. Balocchi; R.G. Pulido; P. Sepúlveda-Varas; D. Pacheco; R. Berthiaume. Milk production responses, rumen fermentation, and blood metabolites of dairy cows fed increasing concentrations of forage rape (Brassica napus ssp. Biennis). Journal of Dairy Science 2020, 103, 9054 -9066.

AMA Style

J.P. Keim, J. Daza, I. Beltrán, O.A. Balocchi, R.G. Pulido, P. Sepúlveda-Varas, D. Pacheco, R. Berthiaume. Milk production responses, rumen fermentation, and blood metabolites of dairy cows fed increasing concentrations of forage rape (Brassica napus ssp. Biennis). Journal of Dairy Science. 2020; 103 (10):9054-9066.

Chicago/Turabian Style

J.P. Keim; J. Daza; I. Beltrán; O.A. Balocchi; R.G. Pulido; P. Sepúlveda-Varas; D. Pacheco; R. Berthiaume. 2020. "Milk production responses, rumen fermentation, and blood metabolites of dairy cows fed increasing concentrations of forage rape (Brassica napus ssp. Biennis)." Journal of Dairy Science 103, no. 10: 9054-9066.

Journal article
Published: 22 June 2020 in Animals
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The objective of this study was to determine the effect of perennial ryegrass (PRG) forages differing in their concentration of water-soluble carbohydrates (WSC) and crude protein (CP), and collected in spring and autumn, on in vitro rumen fermentation variables, nitrogen (N) metabolism indicators and methane (CH4) output, using a batch culture system. Two contrasting PRG pastures, sampled both in autumn and spring, were used: high (HS) and low (LS) sugar pastures with WSC concentrations of 322 and 343 g/kg for HS (autumn and spring), and 224 and 293 g/kg for LS in autumn and spring, respectively. Duplicates were incubated for 24 h with rumen inocula in three different days (blocks). Headspace gas pressure was measured at 2, 3, 4, 5, 6, 8, 10, 12, 18, and 24 h, and CH4 concentration was determined. The supernatants were analysed for individual volatile fatty acids (VFA) concentrations, and NH3-N. The solid residue was analysed for total N and neutral detergent insoluble N. Another set of duplicates was incubated for 4 h for VFA and NH3-N determination. The HS produced more gas (218 vs. 204 mL/g OM), tended to increase total VFA production (52.0 mM vs. 49.5 mM at 24 h), reduced the acetate:propionate ratio (2.52 vs. 3.20 at 4 h and 2.85 vs. 3.19 at 24 h) and CH4 production relative to total gas production (15.6 vs. 16.8 mL/100 mL) and, improved N use efficiency (22.1 vs. 20.9). The contrasting chemical composition modified in vitro rumen fermentation tending to increase total VFA production, reduce the acetate:propionate ratio and CH4 concentration, and improve N use efficiency through lower rumen NH3-N.

ACS Style

M. Jordana Rivero; Juan P. Keim; Oscar A. Balocchi; Michael R.F. Lee. In Vitro Fermentation Patterns and Methane Output of Perennial Ryegrass Differing in Water-Soluble Carbohydrate and Nitrogen Concentrations. Animals 2020, 10, 1076 .

AMA Style

M. Jordana Rivero, Juan P. Keim, Oscar A. Balocchi, Michael R.F. Lee. In Vitro Fermentation Patterns and Methane Output of Perennial Ryegrass Differing in Water-Soluble Carbohydrate and Nitrogen Concentrations. Animals. 2020; 10 (6):1076.

Chicago/Turabian Style

M. Jordana Rivero; Juan P. Keim; Oscar A. Balocchi; Michael R.F. Lee. 2020. "In Vitro Fermentation Patterns and Methane Output of Perennial Ryegrass Differing in Water-Soluble Carbohydrate and Nitrogen Concentrations." Animals 10, no. 6: 1076.

Journal article
Published: 27 April 2020 in Agronomy
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The herbage mass and nutritional value of harvested forage are fundamental determinants of the production potential of pastoral systems. The objective of this study was to evaluate the growth dynamics and accumulated herbage mass expressed in dry matter (DM) of perennial ryegrass (Lolium perenne L.) and pasture brome (Bromus valdivianus Phil.) pastures, using thermal time (TT) as a defoliation criterion. Thirty plots (15 of L. perenne and 15 of B. valdivianus) were distributed in three field blocks and subjected to five defoliation frequencies (DF) determined by TT, expressed as the accumulated growing degree-days (AGDD; DF1 = 90, DF2 = 180, DF3 = 270, DF4 = 360, and DF5 = 450 AGDD) for one year (2016), at the Austral Agricultural Experimental Station of the Universidad Austral de Chile. Every three days, the total leaf length (TLL) was measured, and the leaf elongation rate (LER, cm L−1), leaf growth rate (LGR, cm L−1), leaf appearance rate (LAR, d L−1), phyllochron (AGDD L−1), and accumulated herbage mass per hectare (kg DM ha−1) were calculated. Defoliations were scheduled according to AGDD, and a sample was taken from each cutting to determine (dry matter ‘DM’, crude protein ‘CP’, neutral detergent fiber ‘NDF’, acid detergent fiber ‘ADF’, water-soluble carbohydrates ‘WSC’ and metabolizable energy ‘ME’). The pastures that were allocated to DF5 presented higher DM yields (12,600 kg DM ha−1 year−1), TLL (54.6 cm), and LER (0.63 cm d−1) compared to pastures with high DF (90 and 180 ADGG). B. valdivianus presented a lower phyllochron than L. perenne (74.4 vs 87.9 AGDD L−1, respectively). Concentrations of CP and ME decreased from the shortest DF (90 AGDD) to the largest DF (450 AGDD), dropping from 221 to 138 g kg−1 CP and from 2.6 to 2.4 Mcal kg−1 DM of ME. All variables were affected by the season (Ssn) (p < 0.001). The AGDD can be used as a defoliation criterion and a tool to balance yield with nutritive value according to the farmer’s needs.

ACS Style

Iván Calvache; Oscar Balocchi; Máximo Alonso; Juan Pablo Keim; Ignacio F. López. Thermal Time as a Parameter to Determine Optimal Defoliation Frequency of Perennial Ryegrass (Lolium perenne L.) and Pasture Brome (Bromus valdivianus Phil.). Agronomy 2020, 10, 620 .

AMA Style

Iván Calvache, Oscar Balocchi, Máximo Alonso, Juan Pablo Keim, Ignacio F. López. Thermal Time as a Parameter to Determine Optimal Defoliation Frequency of Perennial Ryegrass (Lolium perenne L.) and Pasture Brome (Bromus valdivianus Phil.). Agronomy. 2020; 10 (5):620.

Chicago/Turabian Style

Iván Calvache; Oscar Balocchi; Máximo Alonso; Juan Pablo Keim; Ignacio F. López. 2020. "Thermal Time as a Parameter to Determine Optimal Defoliation Frequency of Perennial Ryegrass (Lolium perenne L.) and Pasture Brome (Bromus valdivianus Phil.)." Agronomy 10, no. 5: 620.

Journal article
Published: 28 January 2020 in Animals
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During the first hours after the allocation of a grazing strip (first grazing session, GS), dairy cows eat most of the daily dry matter (DM) available. There are few studies that analyze how the grazing-down process changes the characteristics of the pasture during the first GS. The objective of this study was to evaluate the effect of two pre-grazing herbage masses (HM; medium herbage mass (MHM) and high herbage mass (HHM) on the DM disappearance, grazing behavior of dairy cows, and the residual nutritive value of a pasture during the first GS. Two groups of twelve dairy cows were used to evaluate the grazing-down process, during a period of 62 days. The pre-grazing HM modified the bite rate, bite mass, and dry matter intake during the first GS. The pre-grazing HM affected the process of herbage disappearance of the pasture, especially during the first 60 min of the GS. The nutrient selection differential for acid detergent fiber was greater for HHM compared with MHM (0.93 vs. 0.86). In conclusion, pre-grazing HM affects the structural characteristics and the residual nutritive value of the pasture. The grazing process in the first GS was modified by the HM, affecting the defoliation and the DM disappearance rate of the pasture.

ACS Style

Luis Piña; Oscar A. Balocchi; Juan Pablo Keim; Rubén G. Pulido; Felipe Rosas. Pre-Grazing Herbage Mass Affects Grazing Behavior, Herbage Disappearance, and the Residual Nutritive Value of a Pasture during the First Grazing Session. Animals 2020, 10, 212 .

AMA Style

Luis Piña, Oscar A. Balocchi, Juan Pablo Keim, Rubén G. Pulido, Felipe Rosas. Pre-Grazing Herbage Mass Affects Grazing Behavior, Herbage Disappearance, and the Residual Nutritive Value of a Pasture during the First Grazing Session. Animals. 2020; 10 (2):212.

Chicago/Turabian Style

Luis Piña; Oscar A. Balocchi; Juan Pablo Keim; Rubén G. Pulido; Felipe Rosas. 2020. "Pre-Grazing Herbage Mass Affects Grazing Behavior, Herbage Disappearance, and the Residual Nutritive Value of a Pasture during the First Grazing Session." Animals 10, no. 2: 212.

Journal article
Published: 01 January 2020 in Animal
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Forage brassicas, such as summer turnip (ST; Brassica rapa) and forage rape (FR; Brassica napus), are used as supplementary crops during summer. However, studies with lactating dairy cows fed these forages are limited and report inconsistent productive responses. The aim of this study was to determine dry matter intake, rumen fermentation and milk production responses of dairy cows in mid-lactation supplemented with and without summer (‘ST’ or ‘FR’) brassicas. Twelve multiparous lactating dairy cows were randomly allocated to three dietary treatments in a replicated 3 × 3 Latin square design balanced for residual effects over three 21-day periods. The control diet consisted of 16.2 kg DM of grass silage, 2.25 kg DM of commercial concentrate and 2.25 kg DM solvent-extracted soybean meal. For the other two dietary treatments, 25% of the amounts of silage and concentrates were replaced with FR or ST. The inclusion of forage brassicas had no effects on milk production (24.2 kg cow/day average) and composition (average milk fat and protein 43.2 and 33.6 g/l, respectively). Dry matter intake was 0.98 kg and 1.12 kg lower for cows supplemented with FR and ST, respectively, resulting in a greater feed conversion efficiency (1.35 kg milk/kg DM for ST and FR v. 1.27 kg milk/kg DM for the control diet). Intraruminal pH was lower for cows supplemented with ST compared to the control diet; however, it did not decrease below pH 5.8 at any time of the day. After feeding, the concentrations of total short-chain fatty acids (SCFAs) in rumen contents increased with ST supplementation compared to the control diet. Inclusion of FR in the diet increased the molar proportion of acetate (68.5 mmol/100 mmol) in total SCFA at the expense of propionate, measured 6 h after feeding of the forage. The molar proportion of butyric acid was greater with ST and FR supplementation (13.1 and 12 mmol/100 mmol, respectively) than in control cows. The estimated microbial nitrogen (N) flow was 89.1 g/day greater when supplementing FR compared to the control diet. Based on the haematological measures, the inclusion of summer brassica forages did not affect the health status of the animals. These results indicate that mid-lactation dairy cows fed brassicas are able to maintain production despite the reduced intake, probably due to improved rumen fermentation and therefore nutrient utilization.

ACS Style

M. Castillo-Umaña; O. Balocchi; R. Pulido; P. Sepúlveda-Varas; D. Pacheco; S. Muetzel; R. Berthiaume; J. P. Keim. Milk production responses and rumen fermentation of dairy cows supplemented with summer brassicas. Animal 2020, 14, 1684 -1692.

AMA Style

M. Castillo-Umaña, O. Balocchi, R. Pulido, P. Sepúlveda-Varas, D. Pacheco, S. Muetzel, R. Berthiaume, J. P. Keim. Milk production responses and rumen fermentation of dairy cows supplemented with summer brassicas. Animal. 2020; 14 (8):1684-1692.

Chicago/Turabian Style

M. Castillo-Umaña; O. Balocchi; R. Pulido; P. Sepúlveda-Varas; D. Pacheco; S. Muetzel; R. Berthiaume; J. P. Keim. 2020. "Milk production responses and rumen fermentation of dairy cows supplemented with summer brassicas." Animal 14, no. 8: 1684-1692.

Journal article
Published: 29 December 2019 in Animals
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The aim of this study was to evaluate the short-term effects of daily herbage allowance (DHA, defined as the product of pre-grazing herbage mass and offered area per animal) on pasture conditions and milk production of Holstein-Friesian dairy cows. Forty-four early lactation dairy cows were randomly assigned to one of four treatments in a 2 × 2 factorial design that tested two levels of DHA (17 and 25 kg DM/cow.day) and two levels of maize silage supplementation (MSS, 4.5 and 9 kg DM/cow.day) over a 77-day period. Low DHA decreased the post-grazing herbage mass from 1546 to 1430 kg DM/ha and the compressed sward height from 5 to 4.4 cm, while the grazing efficiency remained unaffected. Low DHA induced a faster herbage mass reduction, while the sward-height and pasture characteristics did not differ from the high DHA regime. Low DHA decreased the tiller production rates and daily lamina growth, while the leaf-production rate was not affected by the DHA. Daily increases of herbage mass were greater in the high DHA than in the low DHA treatments. Individual milk production and milk protein concentration decreased at a low DHA compared to high DHA, while the milk fat concentration was greater and the milk output per hectare increased by 1510 kg. Neither the MSS level nor the interaction DHA by the MSS level had any effect on the sward characteristics or the productivity of the cows. From these results, it is suggested that, in a high-quality pasture, using 17 kg DM/cow.day was appropriate for improving both herbage utilization and milk production per hectare while maintaining the short-term conditions of a pasture grazed by dairy cows in the autumn.

ACS Style

Verónica M. Merino; Oscar A. Balocchi; M. Jordana Rivero; Rubén G. Pulido. Short-Term Effect of Daily Herbage Allowance Restriction on Pasture Condition and the Performance of Grazing Dairy Cows during Autumn. Animals 2019, 10, 62 .

AMA Style

Verónica M. Merino, Oscar A. Balocchi, M. Jordana Rivero, Rubén G. Pulido. Short-Term Effect of Daily Herbage Allowance Restriction on Pasture Condition and the Performance of Grazing Dairy Cows during Autumn. Animals. 2019; 10 (1):62.

Chicago/Turabian Style

Verónica M. Merino; Oscar A. Balocchi; M. Jordana Rivero; Rubén G. Pulido. 2019. "Short-Term Effect of Daily Herbage Allowance Restriction on Pasture Condition and the Performance of Grazing Dairy Cows during Autumn." Animals 10, no. 1: 62.

Communication
Published: 21 November 2019 in Animals
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Grazing ruminant systems can be sustainably intensified by improving efficiency while reducing their environmental impact. The objective of the present study was to examine the potential of pastures differing in water-soluble carbohydrates (WSC) and crude protein (CP) contents to affect milk production and composition as well as the behaviour of cows grazing perennial ryegrass (PRG) swards. By modifying the nitrogen (N) fertilisation rate (83 and 250 kg/ha per year) and the defoliation frequency (two or three leaves per tiller) in combination with cultivar selection (high-sugar vs. standard cultivars), we obtained two swards differing in WSC and CP contents. The two contrasting swards were each grazed by six dairy cows in nine daily strips in autumn. Pasture samples were collected to determine herbage mass and quality. Cow behaviour was recorded by direct observation. Herbage offered and apparently consumed were similar between swards (averaging 37.3 and 18.2 kg/cow, respectively), although the residual was lower in the high-sugar sward (1735 vs. 2143 kg/ha). Cows spent less time grazing in the high-sugar sward (66.9% v. 71.6%), but the rumination times was similar (14.6%). Milk production and composition were similar between groups, suggesting that high-quality pastures would require a greater difference in nutritional composition to affect animal performance.

ACS Style

Verónica M. Merino; Oscar A. Balocchi; M. Jordana Rivero. Milk Production, Milk Quality, and Behaviour of Dairy Cows Grazing on Swards with Low and High Water-Soluble Carbohydrates Content in Autumn: A Pilot Trial. Animals 2019, 9, 1012 .

AMA Style

Verónica M. Merino, Oscar A. Balocchi, M. Jordana Rivero. Milk Production, Milk Quality, and Behaviour of Dairy Cows Grazing on Swards with Low and High Water-Soluble Carbohydrates Content in Autumn: A Pilot Trial. Animals. 2019; 9 (12):1012.

Chicago/Turabian Style

Verónica M. Merino; Oscar A. Balocchi; M. Jordana Rivero. 2019. "Milk Production, Milk Quality, and Behaviour of Dairy Cows Grazing on Swards with Low and High Water-Soluble Carbohydrates Content in Autumn: A Pilot Trial." Animals 9, no. 12: 1012.

Journal article
Published: 13 November 2019 in Animals
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The objective of this work was to evaluate whether changes in time of herbage allocation and herbage mass (HM) (low (L) or medium (M)) modify the diurnal pattern of urinary nitrogen (N) concentration and ruminal ammonia (NH3) of lactating dairy cows. Four Holstein-Friesian cows fitted with rumen cannula were randomly allocated to one of four treatments: 1) low herbage mass in the morning (L-AM) (Access to new herbage allocation after morning milking with a herbage mass (HM) of 2000 kg DM/ha); 2) low herbage mass in the afternoon (L-PM) (Access to new herbage allocation after afternoon milking with a HM of 2000 kg DM/ha); 3) medium herbage mass in the morning (M-AM) (Access to new herbage allocation after morning milking with a HM of 3000 kg DM/ha); and 4) medium herbage mass in the afternoon (M-PM) (Access to new herbage allocation after afternoon milking with a HM of 3000 kg DM/ha). A four by four Latin Square design with four treatments, four cows, and four experimental periods was used to evaluate treatment effects. Rumen NH3 concentration was greater for L-AM compared to L-PM and M-PM at 13:00 and 16:00 h. Urine urea and N concentrations were lower for M-AM compared to L-AM. Urine N concentration was greater for L-AM than other treatments at 10:00 hours and greater for M-PM compared to M-AM at 16:00 hours. Results suggest that maintaining the cows in the holding pen at the milking parlor for two hours after morning grass silage supplementation for L-AM and for two hours after afternoon grass silage supplementation for M-PM, could allow collection of urine from cows at the holding pen and storage of urine in the slurry pit during the time of peak N concentration, returning cows to the pasture at a time of day when urinary N concentration is decreased.

ACS Style

Ignacio E. Beltran; Pablo Gregorini; José Daza; Oscar A. Balocchi; Alvaro Morales; Ruben G. Pulido. Diurnal Concentration of Urinary Nitrogen and Rumen Ammonia Are Modified by Timing and Mass of Herbage Allocation. Animals 2019, 9, 961 .

AMA Style

Ignacio E. Beltran, Pablo Gregorini, José Daza, Oscar A. Balocchi, Alvaro Morales, Ruben G. Pulido. Diurnal Concentration of Urinary Nitrogen and Rumen Ammonia Are Modified by Timing and Mass of Herbage Allocation. Animals. 2019; 9 (11):961.

Chicago/Turabian Style

Ignacio E. Beltran; Pablo Gregorini; José Daza; Oscar A. Balocchi; Alvaro Morales; Ruben G. Pulido. 2019. "Diurnal Concentration of Urinary Nitrogen and Rumen Ammonia Are Modified by Timing and Mass of Herbage Allocation." Animals 9, no. 11: 961.

Journal article
Published: 01 November 2019 in Animals
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The aim of the present study was to evaluate the nutritional value, the rumen in vitro fermentation, and the in situ degradation of Brassica oleracea (L.) ssp. acephala (kales) and Brassica napus (L.) ssp. napobrassica (swedes) for winter use. Five varieties of each brassica were used in three field replicates and were randomized in a complete block nested design. All forage varieties were harvested at 210 days post-sowing to analyze the chemical composition, in vitro gas production, volatile fatty acid (VFA) production and in situ dry matter (DM) and crude protein (CP) degradability. Kales presented higher DM and neutral detergent fiber (NDF) content (p < 0.01), whereas swedes showed higher CP, metabolizable energy (ME), glucose, fructose, total sugars, NFC, and nonstructural carbohydrate (NSC) content (p < 0.01). The kale and swede varieties differed in their CP and sugar concentrations, whereas the kale varieties differed in their DM and raffinose content. The rates of gas production were higher for swedes than for kales (p < 0.01). No differences between the brassica species (p > 0.05) were observed in the total VFA production, whereas kales had a higher proportion of acetate and swedes had higher proportions of butyrate (p < 0.05). Only the swede varieties showed differences in VFA production (p < 0.05). The soluble fraction “a”, potential and effective in situ DM degradability were higher in swedes (p < 0.01), but kales presented greater DM and CP degradation rates. Differences were observed between brassica species in the chemical composition, degradation kinetics, and ruminal fermentation products, whereas differences among varieties within species were less frequent but need to be considered.

ACS Style

Jose Daza; Daniel Benavides; Rubén Pulido; Oscar Balocchi; Annick Bertrand; Juan Keim; Daza; Keim. Rumen In Vitro Fermentation and In Situ Degradation Kinetics of Winter Forage Brassicas Crops. Animals 2019, 9, 904 .

AMA Style

Jose Daza, Daniel Benavides, Rubén Pulido, Oscar Balocchi, Annick Bertrand, Juan Keim, Daza, Keim. Rumen In Vitro Fermentation and In Situ Degradation Kinetics of Winter Forage Brassicas Crops. Animals. 2019; 9 (11):904.

Chicago/Turabian Style

Jose Daza; Daniel Benavides; Rubén Pulido; Oscar Balocchi; Annick Bertrand; Juan Keim; Daza; Keim. 2019. "Rumen In Vitro Fermentation and In Situ Degradation Kinetics of Winter Forage Brassicas Crops." Animals 9, no. 11: 904.

Journal article
Published: 19 June 2019 in Animals
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The aim of this study was to evaluate the effects of the order of grass silage (GS) and maize silage (MS) supplementation on milk yield, grazing behavior and nitrogen (N) partitioning of lactating dairy cows during autumn. Thirty-six Holstein-Friesian dairy cows were randomly assigned to one of three treatments, and cows remained on these treatments for a 62 days period: (1) MIX; cows supplemented with 3 kg of dry matter (DM) of silage containing 1.5 kg DM of MS and 1.5 kg DM of GS in both the morning and afternoon; (2) GS-MS; cows supplemented with 3 kg DM of GS in the morning and 3 kg DM of MS in the afternoon; (3) MS-GS; cows supplemented with 3 kg DM of MS in the morning and 3 kg DM of GS in the afternoon. All cows received a pasture allowance of 17 kg DM/cow/d and 3 kg DM of concentrate. Grazing time and pasture intake were unaffected by treatment; however, milk production was greater for MS-GS, while milk protein was greater for GS-MS. Urinary N excretion was greater for MS-GS than MIX. In conclusion, MS-GS resulted in high milk yield but also high urinary N excretion, while MIX resulted in low urinary N excretion but also decreased milk yield.

ACS Style

Ignacio E. Beltrán; Omar Al-Marashdeh; Ana R. Burgos; Pablo Gregorini; Oscar A. Balocchi; Fernando Wittwer; Rubén G. Pulido. The Order of Grass and Maize Silage Supplementation Modifies Milk Yield, Grazing Behavior and Nitrogen Partitioning of Lactating Dairy Cows. Animals 2019, 9, 373 .

AMA Style

Ignacio E. Beltrán, Omar Al-Marashdeh, Ana R. Burgos, Pablo Gregorini, Oscar A. Balocchi, Fernando Wittwer, Rubén G. Pulido. The Order of Grass and Maize Silage Supplementation Modifies Milk Yield, Grazing Behavior and Nitrogen Partitioning of Lactating Dairy Cows. Animals. 2019; 9 (6):373.

Chicago/Turabian Style

Ignacio E. Beltrán; Omar Al-Marashdeh; Ana R. Burgos; Pablo Gregorini; Oscar A. Balocchi; Fernando Wittwer; Rubén G. Pulido. 2019. "The Order of Grass and Maize Silage Supplementation Modifies Milk Yield, Grazing Behavior and Nitrogen Partitioning of Lactating Dairy Cows." Animals 9, no. 6: 373.

Journal article
Published: 20 May 2019 in Animals
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The objective of this study was to evaluate the pasture performance of different cultivars of perennial ryegrass, two "high sugar" and two standard cultivars, under two contrasting agronomic managements (aimed at either decreasing or increasing water soluble carbohydrates concentration), and their effects on the grazing preference of dairy cows. Eight treatments arising from the factorial combination of four cultivars and two managements were randomly applied to 31-m2 plots in three blocks. Pasture dry matter production and growth rate were measured for one year. Three grazing assessments were performed to establish the grazing preferences of six dairy cows in spring, summer and autumn. High sugar cultivars produced less dry matter per hectare than the standard cultivars. Cows consumed more grass and harvested a greater proportion of the pasture under the agronomic management aimed at decreasing sugar concentration, i.e., with a greater nitrogen fertilization rate and under a more frequent defoliation regime, which could be explained by the greater crude protein concentration achieved under this management. The results suggest that the genetic selection for greater levels of sugars was at the expense of herbage yield, and that cows preferred to graze herbage with a greater crude protein level instead of a greater sugar concentration.

ACS Style

M. Jordana Rivero; Oscar L. Balocchi; Fabián L. Neumann; Juan A. Siebald. Grazing Preference of Dairy Cows and Pasture Productivity for Different Cultivars of Perennial Ryegrass under Contrasting Managements. Animals 2019, 9, 253 .

AMA Style

M. Jordana Rivero, Oscar L. Balocchi, Fabián L. Neumann, Juan A. Siebald. Grazing Preference of Dairy Cows and Pasture Productivity for Different Cultivars of Perennial Ryegrass under Contrasting Managements. Animals. 2019; 9 (5):253.

Chicago/Turabian Style

M. Jordana Rivero; Oscar L. Balocchi; Fabián L. Neumann; Juan A. Siebald. 2019. "Grazing Preference of Dairy Cows and Pasture Productivity for Different Cultivars of Perennial Ryegrass under Contrasting Managements." Animals 9, no. 5: 253.

Original article
Published: 30 January 2019 in Grassland Science
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In intensive dairy pasture‐based systems, split applications of nitrogen (N) use throughout the growth cycle has played an important role in increasing the herbage production and additional forage supply at specific times across the pasture growth season. However, little is known about how the frequency of N applications can modify the crude protein content and their fractions. A mini‐sward study was conducted between August 2011 and January 2012 in Valdivia, Chile, to quantify the effect of frequency of N application on herbage yield, growth dynamics and protein fractions in perennial ryegrass swards. A single N rate equivalent of 250 kg N ha−1 year−1 of ammonium nitrate (27% N) fertilizer was applied in five patterns based on phyllochron. Thus, the mini‐swards were fertilized when they reached 1–2–4–8 phyllochrons, and there was a zero rate of fertilizer application. All mini‐swards were defoliated when the ryegrass reached two complete expanded leaves per tiller. The treatments were replicated four times in a completely randomized block design. Defoliations were carried out by harvesting each plot with hand shears to a stubble height of 5 cm. Crude protein fractions were analyzed using the Cornell Carbohydrate and Protein Scheme (CNCPS). The results showed that plants fertilized more frequently (1–2–4 phyllochrons) had a higher (p < 0.001) accumulated herbage mass than plants fertilized every 8 phyllochrons. On the other hand, the fertilization frequency modified the herbage production over the experimental period (p < 0.05). Total crude protein was higher in plants fertilized less frequently, but crude protein fractions were not affected by fertilization frequency.

ACS Style

Pablo Loaiza; Oscar Balocchi; Cristóbal De La Barra; Ignacio F. López. Perennial ryegrass productivity and nutritive quality as affected by frequency of nitrogen fertilizer addition. Grassland Science 2019, 65, 86 -92.

AMA Style

Pablo Loaiza, Oscar Balocchi, Cristóbal De La Barra, Ignacio F. López. Perennial ryegrass productivity and nutritive quality as affected by frequency of nitrogen fertilizer addition. Grassland Science. 2019; 65 (2):86-92.

Chicago/Turabian Style

Pablo Loaiza; Oscar Balocchi; Cristóbal De La Barra; Ignacio F. López. 2019. "Perennial ryegrass productivity and nutritive quality as affected by frequency of nitrogen fertilizer addition." Grassland Science 65, no. 2: 86-92.

Original article
Published: 28 January 2019 in Grass and Forage Science
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The objective was to evaluate water‐soluble carbohydrate (WSC) and crude protein (CP) concentration of perennial ryegrass (PRG) cultivars with different genetic potential for producing WSC under two contrasting agronomic managements in temperate climate (southern Chile). A 4 × 2 factorial design was randomly allocated to 24 plots (31 m2 each, three blocks): four PRG cultivars (diploid standard cultivar, “2nSt”; tetraploid standard cultivar, “4nSt”; diploid high sugar cultivar developed in New Zealand, “2nHSNZ”; and tetraploid high sugar cultivar developed in Europe, “4nHSEU”) and two agronomic managements (“favourable,” defoliations at three leaves per tiller and nitrogen (N) fertilization rate of 83.3 kg N ha−1 year−1; “unfavourable,” defoliations at two leaves per tiller and N fertilization rate of 250 kg N ha−1 year−1). Herbage samples were collected in early spring, spring, summer and autumn. Concentration of WSC did not differ among cultivars in spring and summer, averaging 194 and 251 g/kg DM, respectively. The cultivar 4nHSEU had the greatest WSC concentration in early spring and autumn (187 and 266 g/kg DM, respectively) and the greatest CP concentration across samplings (average 230 g/kg DM). Favourable management improved WSC concentrations in early spring and summer and decreased CP in spring, summer and autumn. Annual DM yield did not vary with cultivar or management, averaging 8.43 t/ha. Within a 12‐month study at one site in a temperate environment in southern Chile, PRG cultivars have not shown a consistent expression of the “high sugar” trait, where a genetic × environment interaction might be operating.

ACS Style

M. Jordana Rivero; Oscar A. Balocchi; Cristian J. Moscoso; Juan Agustín Siebald; Fabián Lukas Neumann; Don Meyer; Michael R. F. Lee. Does the “high sugar” trait of perennial ryegrass cultivars express under temperate climate conditions? Grass and Forage Science 2019, 74, 496 -508.

AMA Style

M. Jordana Rivero, Oscar A. Balocchi, Cristian J. Moscoso, Juan Agustín Siebald, Fabián Lukas Neumann, Don Meyer, Michael R. F. Lee. Does the “high sugar” trait of perennial ryegrass cultivars express under temperate climate conditions? Grass and Forage Science. 2019; 74 (3):496-508.

Chicago/Turabian Style

M. Jordana Rivero; Oscar A. Balocchi; Cristian J. Moscoso; Juan Agustín Siebald; Fabián Lukas Neumann; Don Meyer; Michael R. F. Lee. 2019. "Does the “high sugar” trait of perennial ryegrass cultivars express under temperate climate conditions?" Grass and Forage Science 74, no. 3: 496-508.