Short communication: Concentrate supplementation strategies in ryegrass pasture for productive performance in lambs

Abstract

This study evaluated the effect of two concentrate supplementation strategies on performance, metabolic profile and economic evaluation of suckling lambs and ewes in ryegrass (Lolium multiflorum) pasture. Twenty-seven ewes and 45 lambs were divided into three groups: (1) ryegrass pasture without supplementation - control (CON); (2) CON plus supplemented ewes and lambs at 1% of live weight (SEL), and (3) CON plus creep feeding supplemented lambs at 1% of live weight (CSL). Concentrate use increased (p<0.05) average daily gain (ADG) by 19.95% over CON (21.6 and 18.3% for SEL and CSL, respectively). Concentrate use contributed to minimizing forage quality fluctuation and provided greater ADG stability, mainly when ryegrass nutritional content and digestibility decreased. Blood metabolites profiles did not differ between groups, with exception of phosphorus which was higher for CON than SEL, and calcium which was higher for CSL than CON (p<0.05). Compared to CON, stoking rate values were greater to SEL (p<0.05). Compared to CSL, ewe and total stocking rate were greater (p<0.05) to SEL. Considering the control group as break even feed investment, SEL strategy had a positive economic return, while CSL showed economic losses. Concentrate use increased ADG of lambs and decrease the impact of nutrient quality changes of forage on daily gains, but must be considered that supplemental strategy used could affect negatively economic return.

Metabolic profile of female lambs on annual ryegrass pasture managed under different grazing intensities and methods

“…The homeostatic control of magnesium is not rigid, so blood magnesium concentration directly reflects the level of magnesium in the diet (González & Campos, 2003). Results found in this study are in agreement with Santos et al (2018) that affirms that different systems did not promote significant changes in the profiles. Similarly, low and moderate grazing intensity did not influence the metabolic profile of sheep kept in annual ryegrass.…”

“…Importantly, the low phosphorus concentrations in this study were not below the minimum concentration necessary to complete development, but lower than the values cited by Santos et al (2018) from 8.1 to 10.02mg/dL. Phosphorus contributes to the growth of young animals and maintenance of adult animals because it is an important component of bones, soft tissues, cell membranes and other body fluids.…”

“…Low grazing intensities are related to lower defoliation and plant growth and in advance of the physiological stage. According to Santos et al (2018), nutritional variation is likely due to physiological modifications in forage cycle, which causes reduction in leaves proportion, increased stem participation and lignification of plant.…”

The effect of concentrates on production traits, biochemical parameters and thyroid hormones concentration in Dubrovnik sheep fed forage based-diets

“…A limited supply of nutrients to the fetus is one of the most important reasons for its lower development at birth (WALLACE et al, 2005) and postnatal growth (McGOVERN et al, 2015). In the research by SANTOS et al (2018) concentrates used in diets increased the average daily gain of lambs.…”

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“…Nutritional management is a major influencing variable in the success of a production system (SANTOS et al, 2018). To assess whether the implementation of a feed strategy is economically viable, it is necessary to carry out the economic viability analysis, so it is possible to determine if the project can meet the expectations and demands of investors so that the decision to invest can be made (ROJAS, 2015).…”