RESUMO

Bovine anaplasmosis causes considerable economic losses in dairy cattle production systems worldwide, ranging from $300 million to $900 million annually. It is commonly detected through rectal temperature, blood smear microscopy, and packed cell volume (PCV). Such methodologies are laborious, costly, and difficult to systematically implement in large-scale operations. The objectives of this study were to evaluate (1) rumination and activity data collected by Hr-Tag sensors (SCR Engineers Ltd.) in heifer calves exposed to anaplasmosis; and (2) the predictive ability of recurrent neural networks in early identification of anaplasmosis. Additionally, we aimed to investigate the effect of time series length before disease diagnosis (5, 7, 10, or 12 consecutive days) on the predictive performance of recurrent neural networks, and how early anaplasmosis disease can be detected in dairy calves (5, 3, and 1 d in advance). Twenty-three heifer calves aged 119 ± 15 (mean ± SD) d and weighing 148 ± 20 kg of body weight were challenged with 2 × 107 erythrocytes infected with UFMG1 strain (GenBank no. EU676176) isolated from Anaplasma marginale. After inoculation, animals were monitored daily by assessing PCV. The lowest PCV value (14 ± 1.8%) and the finding of rickettsia on blood smears were used as a criterion to classify an animal as sick (d 0). Rumination and activity data were collected continuously and automatically at 2-h intervals, using SCR Heatime Hr-Tag collars. Two time series were built including last sequence of -5, -7, -10, or -12 d preceding d 0 or a sequence of 5, 7, 10, or 12 d randomly selected in a window from -50 to -15 d before d 0 to ensure a sequence of days in which PCV was considered normal (32 ± 2.4%). Long short-term memory was used as a predictive approach, and a leave-one-animal-out cross-validation (LOAOCV) was used to assess prediction quality. Anaplasmosis disease reduced 34 and 11% of rumination and activity, respectively. The accuracy, sensitivity, and specificity of long short-term memory in detecting anaplasmosis ranged from 87 to 98%, 83 to 100%, and 83 to 100%, respectively, using rumination data. For activity data, the accuracy, sensitivity, and specificity varied from 70 to 98%, 61 to 100%, and 74 to 100%, respectively. Predictive performance did not improve when combining rumination and activity. The use of longer time-series did not improve the performance of models to predict anaplasmosis. The accuracy and sensitivity in predicting anaplasmosis up to 3 d before clinical diagnosis (d 0) were greater than 80%, confirming the possibility for early identification of anaplasmosis disease. These findings indicate the great potential of wearable sensors in early identification of anaplasmosis diseases. This could positively affect the profitability of dairy farmers and animal welfare.

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RESUMO

Poor-quality roughages are widely used as fiber sources in concentrate-based diets for ruminants. Because roughage quality is associated with the efficiency of energy use in forage-based diets, the objective of this study was to determine whether differing the roughage source in concentrate-based diets could change the energy requirements of growing lambs. Eighty-four 1/2 Dorper × 1/2 Santa Inês ram lambs (18.0 ± 3.3 kg BW) were individually penned and divided into 2 groups according to primary source of dietary roughage: low-quality roughage (LQR; sugarcane bagasse) or medium-quality roughage (MQR; coastcross hay). Diets were formulated to be isonitrogenous (2.6% N) and to meet 20% of physically effective NDF. After a 10-d ad libitum adaptation period, 7 lambs from each group were randomly selected and slaughtered (baseline). Twenty-one lambs in each diet group were fed ad libitum and slaughtered at 25, 35, or 45 kg BW. The remaining 28 lambs (14 from each diet group) were submitted to 1 of 2 levels of feed restriction: 70% or 50% of the ad libitum intake. Retentions of body fat, N, and energy were determined. Additionally, 6 ram lambs (44.3 ± 5.6 kg BW) were kept in metabolic cages and used in a 6 × 6 Latin square experiment designed to establish the ME content of the 2 diets at the 3 levels of DM intake. There was no effect of intake level on diet ME content, but it was greater in the diet with LQR than in the diet with MQR (3.18 vs. 2.94 Mcal/kg, respectively; P < 0.01). Lambs fed the diet with LQR had greater body fat (g/kg of empty BW) and energy concentrations (kcal/kg of empty BW) because of a larger visceral fat deposition (P < 0.05). Using a low-quality roughage as a primary source of forage in a concentrate-based diet for growing lambs did not change NEm and the efficiency of ME use for maintenance, which averaged 71.6 kcal/kg(0.75) of shrunk BW and 0.63, respectively. On the other hand, the greater nonfibrous carbohydrate content of the diet with LQR resulted in a 17% better efficiency of ME use for gain (P < 0.01), which was associated with a greater partial efficiency of energy retention as fat (P < 0.01). This increased nutritional efficiency, however, should be viewed with caution because it is related to visceral fat deposition, a nonedible tissue.

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Avaliaram-se as características fermentativas e a qualidade das silagens de seis variedades de milho, de ciclos precoce e superprecoce - BRS Caatingueiro, BRS Assum Preto, BR 5033 Asa Branca, BR 5028 São Francisco, Gurutuba e BRS 4103 - indicadas para a região semiárida brasileira. Foram utilizados silos experimentais, em delineamento inteiramente ao acaso, com seis tratamentos (variedades) e quatro repetições. Avaliaram-se: matéria seca (MS), matéria orgânica (MO), proteína bruta (PB), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA), extrato etéreo (EE), carboidratos totais (CHO), carboidratos não fibrosos (CNF), pH, nitrogênio amoniacal como parte do nitrogênio total (N-NH3/NT), ácidos orgânicos e digestibilidade in vitro da matéria seca (DIVMS) das silagens. Os valores médios encontrados para a silagem foram: MS= 28,7 por cento; MO= 94,9 por cento; PB= 8,3 por cento; FDN= 49,9 por cento; FDA= 27,5 por cento; EE= 3,8 por cento; CHO= 82,7 por cento; CNF= 32,8 por cento; pH= 3,8; N-NH3/NT= 2,9 por cento/NT; ácido láctico = 7,6 por cento; ácido acético = 0,6 por cento; ácido butírico = 0,3 por cento e DIVMS= 57,9 por cento. As variedades BR 5028 - São Francisco e Gurutuba destacaram-se das demais em relação ao teor de matéria seca. A variedade BRS Caatingueiro apresentou maior teor de carboidratos não fibrosos em relação às demais. As silagens de todas as variedades foram classificadas como de excelente qualidade, por apresentarem potencial para ensilagem no semiárido brasileiro.

The fermentation characteristics and silage quality of six maize varieties of early and super early cycles were evaluated. They are recommended for the Brazilian semi-arid region (BRS Caatingueiro, BRS Assum Preto, BR 5033 - Asa Branca, BR 5028 - São Francisco, Gurutuba and BRS 4103). Experimental silos were used, in a completely randomized design, with six treatments (varieties) and four replicaties. The evaluated parameters were: dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), ether extract (EE), total carbohydrates (CHO), non-fibrous carbohydrates (NFC), pH, ammoniacal nitrogen as part of the total nitrogen (N-NH3/TN), organic acids, and in vitro dry matter digestibility (IVDMD) of the silages. The mean values found for silage were: DM= 29.6 percent; OM= 94.9 percent; CP= 8.2 percent; NDF= 49.9 percent; ADF= 27.5 percent; EE= 3.8 percent; CHO= 82.7 percent; NFC= 32.8 percent; pH= 3.8; N-NH3/TN= 2.9 percent/TN; lactic acid = 7.6 percent; acetic acid = 0.6 percent; butyric acid = 0.3 percent; and IVDMD = 57.9 percent. Varieties BR 5028 - São Francisco and Gurutuba stood out (P<0.05) from others in relation to dry matter. The BRS Caatingueiro showed higher (P<0.05) level of non-fiber carbohydrates in relation to the others. The silages from all the varieties were considered of excellent quality, with potential to be conserved as silage in the Brazilian semi-arid.

Assuntos

RESUMO

Avaliaram-se as características fermentativas e a qualidade das silagens de seis variedades de milho, de ciclos precoce e superprecoce - BRS Caatingueiro, BRS Assum Preto, BR 5033 Asa Branca, BR 5028 São Francisco, Gurutuba e BRS 4103 - indicadas para a região semiárida brasileira. Foram utilizados silos experimentais, em delineamento inteiramente ao acaso, com seis tratamentos (variedades) e quatro repetições. Avaliaram-se: matéria seca (MS), matéria orgânica (MO), proteína bruta (PB), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA), extrato etéreo (EE), carboidratos totais (CHO), carboidratos não fibrosos (CNF), pH, nitrogênio amoniacal como parte do nitrogênio total (N-NH3/NT), ácidos orgânicos e digestibilidade in vitro da matéria seca (DIVMS) das silagens. Os valores médios encontrados para a silagem foram: MS= 28,7 por cento; MO= 94,9 por cento; PB= 8,3 por cento; FDN= 49,9 por cento; FDA= 27,5 por cento; EE= 3,8 por cento; CHO= 82,7 por cento; CNF= 32,8 por cento; pH= 3,8; N-NH3/NT= 2,9 por cento/NT; ácido láctico = 7,6 por cento; ácido acético = 0,6 por cento; ácido butírico = 0,3 por cento e DIVMS= 57,9 por cento. As variedades BR 5028 - São Francisco e Gurutuba destacaram-se das demais em relação ao teor de matéria seca. A variedade BRS Caatingueiro apresentou maior teor de carboidratos não fibrosos em relação às demais. As silagens de todas as variedades foram classificadas como de excelente qualidade, por apresentarem potencial para ensilagem no semiárido brasileiro.(AU)

The fermentation characteristics and silage quality of six maize varieties of early and super early cycles were evaluated. They are recommended for the Brazilian semi-arid region (BRS Caatingueiro, BRS Assum Preto, BR 5033 - Asa Branca, BR 5028 - São Francisco, Gurutuba and BRS 4103). Experimental silos were used, in a completely randomized design, with six treatments (varieties) and four replicaties. The evaluated parameters were: dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), ether extract (EE), total carbohydrates (CHO), non-fibrous carbohydrates (NFC), pH, ammoniacal nitrogen as part of the total nitrogen (N-NH3/TN), organic acids, and in vitro dry matter digestibility (IVDMD) of the silages. The mean values found for silage were: DM= 29.6 percent; OM= 94.9 percent; CP= 8.2 percent; NDF= 49.9 percent; ADF= 27.5 percent; EE= 3.8 percent; CHO= 82.7 percent; NFC= 32.8 percent; pH= 3.8; N-NH3/TN= 2.9 percent/TN; lactic acid = 7.6 percent; acetic acid = 0.6 percent; butyric acid = 0.3 percent; and IVDMD = 57.9 percent. Varieties BR 5028 - São Francisco and Gurutuba stood out (P<0.05) from others in relation to dry matter. The BRS Caatingueiro showed higher (P<0.05) level of non-fiber carbohydrates in relation to the others. The silages from all the varieties were considered of excellent quality, with potential to be conserved as silage in the Brazilian semi-arid.(AU)

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