Mineral supplementation of dairy heifers in Marandu-Grass pasture in spring and summer seasons
ABSTRACT Here in this study we assessed dairy heifers kept in tropical grasslands during spring and summer seasons to observe the effects of two supplementation strategies upon their performance. Sixteen dairy heifers (Holstein 5/8 x Gyr 3/4) with 135.25 kg of body mass were randomly assigned in two...
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| Published in: | Revista brasileira de saúde e produção animal Vol. 21 |
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| Main Authors: | , , , , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
UFBA - Universidade Federal da Bahia
2020
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| Subjects: | |
| Online Access: | Get full text |
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| Summary: | ABSTRACT Here in this study we assessed dairy heifers kept in tropical grasslands during spring and summer seasons to observe the effects of two supplementation strategies upon their performance. Sixteen dairy heifers (Holstein 5/8 x Gyr 3/4) with 135.25 kg of body mass were randomly assigned in two supplementation treatments (e.g., mineral salt and protein salt supplement) during spring and summer seasons, divided into two groups of eight animals that represented 4.29 animal unit ha. Initial and final fasted weights (i.e., feed and water withheld for 16h) were obtained before to start and at the end of each grazing cycle (28 days), and then the weight gain (kg animal-1) per grazing cycle was calculated by the difference between final and initial weights. There was no significant effect (P <0.05) on the intake of dry matter, crude protein, ether extract, neutral detergent fiber, and dry matter digestibility, between treatments (P <0.05). However, there was a significant effect (P <0.05) between seasons; e.g., respective means of dry matter intake (kg day-1,% BW g / kg 0.75), intake of crude protein (g day-1 g / kg 0.75), ether extract (g day-1), neutral detergent fiber (g day-1 and% BW) were 3.95 and 2.88 kg, 2.54 and 1.65%, 89.27 and 59.56 g kg0.75, 429.89 and 298.43 g day-1, 9.72 and 6.18 g kg0.75, 118.79 and 84.07 g day-1, 2.90 and 2.05 kg day-1, 1.86 and 1.18%, for Spring and Summer seasons. Moreover, the dry matter intake (% BW and g kg 0.75 of DM) were higher (P < 0.05) during the spring season (e.g., 2.53 vs 1.64 % BW; and 89.26 vs 59.56 g kg0.75 DM).
RESUMO Objetivou-se neste trabalho avaliar o desempenho de novilhas leiteiras em recria sob duas estratégias de suplementação mineral. Foram utilizadas 16 novilhas Holandês x Zebu com peso vivo médio inicial de 135,25 kg, divididas em 2 tratamentos (sal proteinado e sal mineralizado) e manejadas em pastagem de Brachiaria brizantha cv. Marandu, em sistema rotacionado. Ao final de cada ciclo de 28 dias, os animais foram pesados e o peso utilizado para cálculos de GMD e taxa de lotação. A altura do pasto e a massa de forragem foram mensuradas antes da entrada e após a saída dos animais, onde foram retiradas amostras para análises bromatológicas e estimativas de consumo. Os suplementos foram fornecidos ad libidum. Não houve diferença (P>0,05) entre os tratamentos, estações e interação tratamento vs estação para o GMD que foram 301,12 e 357,13 g dia-1. Observou-se efeito significativo (P<0,05) entre as estações (Primavera/Verão). O consumo médio de matéria seca, proteína bruta, extrato etéreo, fibra em detergente neutro foram respectivamente, 3,94 e 2,87 kg; 2,53 e 1,69%; 89,26 e 59,56 g kg0,75; 429,89 e 238,42 g dia-1; 9,74 e 6,17g kg0,75; 118,79 e 84,07 g dia-1; 2,98 e 2,05 kg dia-1; 1,86 e 1,17%, para as estações avaliadas. O consumo de proteinado foi superior (P<0,05), observando-se 36,50 e 65,50 g 100 kg-1PV. A digestibilidade da MS foi significativa (P<0,05) para interação, tratamento vs estação, cujo valores foram respectivamente 49,76 e 46,80 para os tratamentos. Os efeitos dos suplementos utilizados foram equivalentes. |
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| ISSN: | 1519-9940 1519-9940 |
| DOI: | 10.1590/s1519-9940210432020 |