RESUMO

The objective of this study was to evaluate the influence of different heat-stress-reducing systems, i.e., sprinkler + artificial shade, shower + artificial shade, and artificial shade, on serum mineral, hormonal, hematological, and metabolite profiles, on milk production, and milk composition in lactating cows and pubertal heifers of Holstein and Jersey breeds. For this purpose, 12 animals were used: 3 Holstein cows with an average (mean ± SD) body weight of 600 ± 30 kg, 53 ± 11 months of age, and milk yield of 27 ± 3.5 kg/day; 3 Jersey cows with an average body weight of 370 ± 11 kg, 40 ± 6 months of age, and milk production of 11 ± 1.5 kg/day; 3 Holstein heifers (325 ± 25 kg and 16 ± 0.6 months of age); and 3 Jersey heifers (250 ± 25 kg and 13 ± 0.6 months of age). Animals were used in a replicated 3 × 3 Latin square design with a 3 × 2 × 2 factorial arrangement of treatments that included three treatments (sprinkler + artificial shade, shower + artificial shade, and artificial shade), two breeds (Holstein, Jersey), and two physiological stages (lactating cows, heifers). The experimental treatments influenced (P < 0.05) the concentrations of triiodothyronine, with the shower and shade systems showing greater and similar concentrations (99.5 and 96.3 µg/dL, respectively) when compared with sprinkler treatment (89.2 µg/dL). There was an effect (P < 0.05) of breed on the concentrations of Na + , K + , hemoglobin, hematocrit and mean corpuscular volume levels with the Holsteins having lower levels of Na + , K + , hemoglobin, hematocrit and mean corpuscular volume (101.1, 4.0 ng/mL, 11.2 g/dL, 24.7%, and 42.3 µm3, respectively) than the Jerseys (106.5 and 4.3 ng/mL, 12.4 g/dL, 27.7%, and 46.3 µm3, respectively. Total cholesterol and high-density lipoproteins were influenced by physiological stage (P < 0.05). Concentrations of cholesterol and high-density lipoproteins were higher for cows (94.1, and 56.9 mg/dL, respectively) than for heifers (56.9 and 42,9 mf/dL, respectively). Milk production and fat content were affected (P < 0.05) by breed (P < 0.05), with Holstein cows producing more milk (23.9 kg/day) than Jersey cows (12.0 kg/day), but Jersey cows had higher fat concentration (4.6%) than Holstein cows (3.0%). Therefore, the three different thermal-stress-reducing-systems tested were able to maintain the serum biomarkers within normal physiological ranges. However, the most appropriate thermal-stress-reducing-systems would be a sprinkler systema because it uses less water compared with the shower system.

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RESUMO

The objective of this study was to characterize calvings with low and high difficulty based on the productive and reproductive performance of dairy cows. Calvings were grouped in no calving assistance, calving with low assistance, and calving with high assistance. The original data set comprised 1,902 calving records obtained from a large dairy farm in Southeast Brazil. Factor analysis was applied using the SAS® Studio 3.8 statistical program through the factor procedure, considering the Multivariate Analysis category. Milk fat (0.92-0.79) and total solids (0.91-0.80) were strongly correlated with Factor 1. Calving interval (0.87- 0.68) and the number of AI (artificial inseminations) per conception (0.87-0.71) showed high correlations with Factor 2. Milk yield (0.84-0.76) and accumulated milk yield (0.84-0.77) were strongly correlated with Factor 3. Based on the results, we conclude that the three calving scenarios were characterized by well-defined and independent factors. Cows which required a high assistance at calving showed a lower variance explained by the model for milk fat and total solids contents, calving interval, and the number of AIs per conception.

O objetivo deste estudo foi caracterizar os partos com leve ou severa dificuldade e diferenciá-los com base no desempenho produtivo e reprodutivo de vacas leiteiras. Os partos foram agrupados em partos sem assistência, partos com baixa assistência e partos com elevada assistência. O banco de dados original continha 1902 registro de partos que foram obtidos de uma grande fazenda comercial localizada no Sudeste do Brasil. A análise fatorial foi aplicada através do programa estatístico SAS® Studio 3.8 por meio de procedimento fatorial, considerando a categoria de análise multivariada. Os teores de gordura do leite (0,92- 0,79) e de sólidos totais (0,91-0,80) foram altamente correlacionados com o fator 1. Intervalo entre partos (0,87-0,68) e número de IA (inseminações artificiais) por concepção (0,87-0,71) apresentaram alta correlação com o fator 2. Produção de leite (0,84-0,76) e produção acumulada de leite (0,84-0,77) foram altamente correlacionados com o fator 3. Baseados nos resultados, é possível concluir que as três situações de parto foram caracterizadas por fatores independentes e bem definidos. Vacas que necessitaram de alta assistência ao parto apresentaram menor variância explicada pelo modelo para teores de gordura e sólidos totais do leite, intervalo entre partos e número de IA por concepção.

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RESUMO

This study was carried out to evaluate the white mulberry tree (Morus alba) as a feedstuff for ruminantsin natura, as hay and as silage. A completely randomized design with five treatments and three replicateswas used, where the treatments were five types of mulberry forage: (1) in natura after cutting; (2) hay;(3) silage of mulberry in natura; (4) silage of wilted mulberry and (5) silage of mulberry with groundear corn. The content of crude protein (CP) did not differ between the silages (average of 19.03% ofdry matter - DM). The CP content of the silages was higher than in mulberry hay (15.26% DM) andsimilar to mulberry after cutting (17.00% DM). The neutral detergent fiber (NDF) content did not differbetween the silages (34.84% DM on average), but the NDF of silage with ear corn was lower than themulberry hay (33.77 vs. 39.36% DM). The acid detergent fiber (ADF) content did not differ betweensilages and mulberry hay (30.66% DM on average). The lowest value for ADF was observed in themulberry after cutting (26.06% DM). The aerobic stability of the silages was not broken during theseven days of aerobic exposure. The pH of silage of mulberry in natura was similar to silage of wiltedmulberry (4.80 on average), while the silage with ear corn showed a lower pH value (4.58) compared tothe other silages. The buffering capacity (BC) did not differ between the silage with ear corn and silageof wilted mulberry (84.91 meq 100 g DM-1 on average), while a lower value was observed for silageof mulberry in natura (56.69 meq 100 g DM-1). The highest value for ammonia nitrogen (NH3-N) wasdemonstrated in the silage of mulberry in natura (13.08% total N), and the lowest values were observedin the silage with ear corn and silage of wilted mulberry (7.49 and 9.58% total N, respectively)...(AU)

Objetivou-se por meio deste estudo verificar a viabilidade do uso da amoreira branca (Morus alba) comoforrageira na alimentação de ruminantes sob as formas in natura, de feno e de silagem. O delineamentoexperimental utilizado foi inteiramente casualizado com cinco tratamentos e três repetições, onde ostratamentos consistiram em cinco formas de utilização da amoreira como forrageira: (1) in natura sobcorte; (2) feno; (3) silagem de amoreira in natura; (4) silagem de amoreira pré-murchada e (5) silagemde amoreira com adição de milho desintegrado com palha e sabugo (MDPS). Não houve diferençano teor de proteína bruta (PB) entre as silagens (19,03% da MS). Os teores de PB das silagens forammaiores que do feno de amoreira (15,26% da MS) e semelhantes ao da amoreira in natura (17,00% daMS). O teor de fibra em detergente neutro (FDN) foi semelhante entre as silagens (média de 34,84%da MS), porém, o teor de FDN da silagem com MDPS foi menor que o do feno (33,77 vs. 39,36% daMS). O teor de fibra em detergente ácido (FDA) foi semelhante entre as silagens e o feno de amoreira(30,66% da MS). O menor valor de FDA foi observado na amoreira in natura (26,06% da MS). Nãohouve quebra da estabilidade aeróbia das silagens no período de sete dias de aerobiose. Os valores de pHforam equivalentes entre as silagens de amoreira in natura e pré-murchada (média de 4,80). A silagemcom MDPS apresentou menor valor de pH que as demais silagens (4,58). A capacidade tampão (CT)foi semelhante para as silagens de amoreira com MDPS e pré-murchada (média de 84,91 meq 100 g deMS-1). O menor valor dessa variável foi encontrado na silagem de amoreira in natura (56,69 meq 100 gde MS-1). O maior teor de nitrogênio amoniacal (N-NH3) foi verificado na silagem de amoreira in natura(13,08% do N total), enquanto nas silagens de amoreira pré-murchada e com MDPS os teores de N-NH3foram baixos (7,49 e 9,58% do N total)...(AU)

Assuntos

RESUMO

This study was carried out to evaluate the white mulberry tree (Morus alba) as a feedstuff for ruminantsin natura, as hay and as silage. A completely randomized design with five treatments and three replicateswas used, where the treatments were five types of mulberry forage: (1) in natura after cutting; (2) hay;(3) silage of mulberry in natura; (4) silage of wilted mulberry and (5) silage of mulberry with groundear corn. The content of crude protein (CP) did not differ between the silages (average of 19.03% ofdry matter - DM). The CP content of the silages was higher than in mulberry hay (15.26% DM) andsimilar to mulberry after cutting (17.00% DM). The neutral detergent fiber (NDF) content did not differbetween the silages (34.84% DM on average), but the NDF of silage with ear corn was lower than themulberry hay (33.77 vs. 39.36% DM). The acid detergent fiber (ADF) content did not differ betweensilages and mulberry hay (30.66% DM on average). The lowest value for ADF was observed in themulberry after cutting (26.06% DM). The aerobic stability of the silages was not broken during theseven days of aerobic exposure. The pH of silage of mulberry in natura was similar to silage of wiltedmulberry (4.80 on average), while the silage with ear corn showed a lower pH value (4.58) compared tothe other silages. The buffering capacity (BC) did not differ between the silage with ear corn and silageof wilted mulberry (84.91 meq 100 g DM-1 on average), while a lower value was observed for silageof mulberry in natura (56.69 meq 100 g DM-1). The highest value for ammonia nitrogen (NH3-N) wasdemonstrated in the silage of mulberry in natura (13.08% total N), and the lowest values were observedin the silage with ear corn and silage of wilted mulberry (7.49 and 9.58% total N, respectively)...

Objetivou-se por meio deste estudo verificar a viabilidade do uso da amoreira branca (Morus alba) comoforrageira na alimentação de ruminantes sob as formas in natura, de feno e de silagem. O delineamentoexperimental utilizado foi inteiramente casualizado com cinco tratamentos e três repetições, onde ostratamentos consistiram em cinco formas de utilização da amoreira como forrageira: (1) in natura sobcorte; (2) feno; (3) silagem de amoreira in natura; (4) silagem de amoreira pré-murchada e (5) silagemde amoreira com adição de milho desintegrado com palha e sabugo (MDPS). Não houve diferençano teor de proteína bruta (PB) entre as silagens (19,03% da MS). Os teores de PB das silagens forammaiores que do feno de amoreira (15,26% da MS) e semelhantes ao da amoreira in natura (17,00% daMS). O teor de fibra em detergente neutro (FDN) foi semelhante entre as silagens (média de 34,84%da MS), porém, o teor de FDN da silagem com MDPS foi menor que o do feno (33,77 vs. 39,36% daMS). O teor de fibra em detergente ácido (FDA) foi semelhante entre as silagens e o feno de amoreira(30,66% da MS). O menor valor de FDA foi observado na amoreira in natura (26,06% da MS). Nãohouve quebra da estabilidade aeróbia das silagens no período de sete dias de aerobiose. Os valores de pHforam equivalentes entre as silagens de amoreira in natura e pré-murchada (média de 4,80). A silagemcom MDPS apresentou menor valor de pH que as demais silagens (4,58). A capacidade tampão (CT)foi semelhante para as silagens de amoreira com MDPS e pré-murchada (média de 84,91 meq 100 g deMS-1). O menor valor dessa variável foi encontrado na silagem de amoreira in natura (56,69 meq 100 gde MS-1). O maior teor de nitrogênio amoniacal (N-NH3) foi verificado na silagem de amoreira in natura(13,08% do N total), enquanto nas silagens de amoreira pré-murchada e com MDPS os teores de N-NH3foram baixos (7,49 e 9,58% do N total)...

Assuntos