RESUMOO objetivo deste estudo foi avaliar o uso de minerais traços (cobre, zinco, selênio e manganês) e vitaminas A e E, na forma injetável, sobre a produção e composição do leite de vacas holandesas no final do período de transição até os 60 dias de lactação. Foram utilizadas 31 fêmeas holandesas divididas em dois grupos experimentais: grupo tratado (n=15) que recebeu suplementação de minerais (10 mg de cobre, 40 mg de zinco, 5 mg de selênio e 10 mg de manganês) e de vitaminas (175 mg de vitamina A e 250 mg de vitamina E) injetável (5 mL da solução dos microminerais e 5 mL das vitaminas pela via subcutânea) aos 225 dias de gestação, aos 255 dias de gestação e no dia do parto; e o grupo controle (n=16), que recebeu injeções de solução fisiológica (na dose de 5 mL pela via subcutânea) nos mesmos dias do grupo tratado. Amostras de leite foram coletadas nos dias sete, 14 e 21 após o parto, onde avaliou-se a produção, a qualidade (colostro), e a composição (gordura, lactose, proteína, extrato seco desengordurado, sólidos totais, ureia e contagem de células somáticas (CCS)) do leite. Os valores iniciais e valores mínimos estimados pelo modelo não indicaram diferença na produção de leite e na CCS entre os grupos. Para o restante dos componentes do leite, somente a ureia apresentou diferença significativa entre os grupos tratados e não tratados (p= 0,002). Também não foi verificada diferença significativa para qualidade de colostro. Portanto, conclui-se que o uso de solução injetável contendo Cu, Zn, Se, Mn e vitaminas A e E tem efeito sobre a composição da ureia do leite, porém não se observou efeito sobre CCS e os demais componentes do leite e na sua produção, porém mais estudos devem ser realizados.
New alternatives to increase the content of polyunsaturated beef fat are necessary. Feed supplements like microalgae are a strategy to enrich meat with omega 3. The aim of the study was to evaluate growth performance, fatty acid profile of meat and carcass characteristics of steers fed with microalgae in the diet. Sixteen steers (mean weight 299.6 ± 7.4 kg, seven months) were randomly assigned to two groups: the control group (CTL) and the microalgae group (ALG; daily feeding of 1.7% of dry matter as microalgae). The diet (40% corn silage and 60% concentrate) was offered twice daily for 84 days. Microalgae supplementation was associated with a 4.44-fold increase in total omega-3 fatty acids in the longissimus thoracis and lumbar muscle, reflecting a 3.6-fold reduction in the omega-6: omega-3 ratio. The concentration of 20: 5n3 and 22: 6n3 increased by 7 and 20.5 times, respectively, with the addition of microalgae. However, microalgae decreased the consumption of dry matter (P <0.0001) by 16.5%, the average daily gain (P = 0.035) by 19.1% and the muscle water-holding capacity (P = 0.02) by 5.5% compared to control. The use of microalgae reduces growth performance, but does not alter the characteristics of the carcass and has the potential to improve the FA profile of the omega 3 series. Consumers may be attracted to increase their intake of polyunsaturated omega 3 fat from beef. These results can support the decision of nutritionists and farmers to use microalgae in beef cattle, as it becomes economically viable.
The aim of this study was to assess the metaphylactic effect of subcutaneous doses of trace minerals (copper, zinc, selenium, and manganese) and vitamins A and E on biochemical (NEFA, BHBA, fructosamine, urea, triglycerides, HDL, and calcium) and hormonal parameters (cortisol, insulin, and IGF-1) of Holstein cows in the transition period. Sixty animals kept in a semi-confinement system, with an average production of 22 liters of milk per day (Farm 1) and 24 liters of milk per day (Farm 2) and a diet according to NRC (2001) with a low metabolic challenge, were divided into two groups: a treatment group, supplemented with trace minerals and vitamins (MTVG) (n=30), and a control group (CG) (n=30). The collection of blood samples was performed at the moments M1 (21 days prepartum), M2 (14 days prepartum), M3 (7 days prepartum), M4 (parturition day), M5 (7 days postpartum), M6 (14 days postpartum), and M7 (21 days postpartum). The experimental design was a randomized block design and the data were submitted to analysis of variance with repeated measures in time within the random variable cow. Differences were considered significant at 5% significance level and trend at 10% level. No difference was observed between treatment and the interaction treatment × day in the assessed parameters. However, some variables showed a significant difference of day. NEFA levels (P < 0.0001) were higher on the parturition day. BHBA concentrations were higher after parturition (P=0.0031), with a peak at the third week of lactation. Fructosamine showed increasing values until the parturition day (P=0.0373), in which higher concentrations were observed. Average values of HDL were higher at 21 days postpartum (P < 0.0001). Triglycerides levels remained high during the prepartum period but showed a sudden drop on the parturition day (P < 0.0001), with lower values postpartum. Regarding serum calcium and IGF-1, lower values were observed on the parturition day (P < 0.001) for both parameters. Cortisol presented a difference regarding day, with higher values on the parturition day (P=0.0151). Thus, the use of trace minerals and vitamins A and E in animals with an adequate body score and low metabolic challenge presents a low response to biochemical and hormonal parameters.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.