The effect of monensin on milk production, milk urea nitrogen and body condition score of grazing dairy cows

Merwe, B.J. Van der; Dugmore, T.J.; Walsh, KP

doi:10.4314/sajas.v31i1.3847

Cited by 10 publications

(8 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…However, the highest MUN levels on the present study's grazing-based farms were much higher than what is typically found on confinement farms. Of all (n 5 144) MUN concentrations (mg/dl) measured on the study farms, 43% exceeded 15 and 15% exceeded 18, levels that could adversely impact the fertility of Holstein dairy cows that graze (van der Merwe et al, 2001).…”

Section: Munmentioning

confidence: 99%

Determinations of feed–milk–manure relationships on grazing-based dairy farms

Powell

Aarons

Gourley

2012

animal

View full text Add to dashboard Cite

Feed conversion into milk, nutrient excretion in manure and subsequent environment impacts of manure management are highly influenced by the diets that farmers feed their lactating cows (Bos taurus). On confinement-based dairy farms, determinations of diet composition are relatively straightforward because the types, amounts and nutrients contained in stored feeds are often well known. However, on grazing-based dairy farms, diet composition is more difficult to determine because forage intake during grazing must be estimated. The objectives of this study were to determine relationships between (1) feed N intake (NI), milk production, milk urea N (MUN), feed N use efficiency (FNUE) and excreted manure N (ExN); and (2) between feed P intake (PI), dung P concentrations (g/kg dry matter (DM)) and excreted manure P (ExP) for grazing-based lactating cows having a very wide range of diets and milk production. An additional objective was to evaluate how well these relationships compare with similar relationships based on more direct measurement of feed-milk-manure on confinement-based dairy farms. Four dairy farms located in southeastern Australia were visited during autumn and spring, and data were collected on feed, milk and dung of 18 cows on each farm. Estimated dry matter intake (DMI) from pasture comprised 12% to 75% of total diet DMI, and the crude protein (CP) concentrations in the total diets ranged from 167 to 248 g/kg. During spring, as diet CP increased FNUE declined. Total diet DMI and NI provided the best predictors of ExN, and PI provided the most accurate prediction of ExP. These results indicated accuracy in the study's indirect estimates of pasture DMI. Likely due to high levels and great variability in dietary CP and P concentrations associated with use of diet supplements, MUN did not appear to be a good indicator of dietary CP, and P in dung was not a good indicator of dietary P.

show abstract

Section: Munmentioning

confidence: 99%

Determinations of feed–milk–manure relationships on grazing-based dairy farms

Powell

Aarons

Gourley

2012

animal

View full text Add to dashboard Cite

show abstract

“…Uma vez que o efeito desse antibiótico sobre o teor de N-ureico depende da degradabilidade protéica dos alimentos utilizados na dieta, animais em pastejo podem apresentar diminuição na excreção de nitrogênio plasmático, que pode não ser evidente em animais alimentados com dieta à base de feno, como neste experimento. Van der Merwe (2001) observou que animais em pastejo consumindo dieta suplementada com monensina apresentaram teor de N-ureico em média 9,77% inferior ao do grupo controle. A ausência de efeito da monensina sobre o teor plasmático de ureia neste estudo corrobora os resultados obtidos por Stephenson et al (1997) e Duffield et al (2001), sugerindo que os efeitos da monensina sobre o metabolismo proteico foram inferiores ao efeito sobre a disponibilidade de glicose.…”

Section: Resultsunclassified

Perfil metabólico e desenvolvimento da glândula mamária de novilhas leiteiras sob manejo para crescimento compensatório

Costa¹,

Queiróz²,

Rodrigues³

et al. 2012

R. Bras. Zootec.

View full text Add to dashboard Cite

RESUMO -Objetivou-se avaliar o efeito do manejo para crescimento compensatório e da suplementação com ionóforo five months of age were used in a completely randomized design with a 2 × 2 factorial arrangement. The treatments were arranged in a factorial arrangement (2 × 2) and the animals were randomly allocated in each one of the combinations. The factor 1 consisted of the feeding regime (conventional and compensatory growth) and the factor 2, of the use or not of ionophore (200 mg of monensin/animal/day). The animals in the conventional regime received ad libitum feeding, while those in the compensatory growth regime were submitted to a nutritional management with two different periods: period of energy restriction (90 days) and realimentation period (60 days). Heifers submitted to the compensatory growth regime showed larger concentration of plasma urea nitrogen and lower DNA:RNA ratio in the mammary gland. When period was analyzed, the levels of high density lipoprotein (HDL) increased in the realimentation period, while the urea N decreased. In addition to the alteration in the levels of urea N, the energy balance to which the heifers in compensatory growth were submitted increased the non-esterified fatty acids. Blood glucose levels reduced in the animals in compensatory growth during the realimentation period. Supplementation with ionophore results in lower concentration of non-esterified fatty acids during the realimentation period. IntroduçãoA adequada nutrição na fase pré-púbere é fundamental para que novilhas leiteiras expressem todo o seu potencial genético para produção de leite. Isso ocorre porque há um período crítico no desenvolvimento mamário, chamado crescimento alométrico, em que o crescimento do tecido e o perfil metabólico são sensíveis ao manejo nutricional.

show abstract

“…Conforme GANDRA et al (2010), a redução de consumo é mais evidenciada em vacas no terço médio e fi nal de lactação. VAN DER MERWE et al (2001) Muitos são os estudos que mostram os efeitos dos ionóforos diretamente relacionados à dieta, em que maior proporção de carboidrato é capaz de reduzir o consumo sem infl uenciar no ganho de peso, gerando, assim, uma melhora na condição alimentar (VARGAS et al, 2001). De acordo com VARGAS et al (2001), a monensina foi capaz de diminuir o consumo de matéria seca a partir do aumento gradativo de concentrado (25%.…”

Section: Introductionunclassified