Responses to protein plus energy supplements of pregnant ewes eating mature grass diets

Abstract

Three experiments were conducted with ewes during late gestation (last 4 weeks) to examine metabolic and lamb birth weight responses to supplements. In a metabolism experiment, 18 ewes were divided into 2 groups and offered 800 g chopped Rhodes grass (Chloris gayanu, 1.1% N) with or without a supplement of 150 g cottonseed meal + 50 g molasses, daily until parturition. Supplementation was associated with significant increases in intake of digestible dry matter (37%) and crude protein (121%). Supplemented ewes had significantly greater liveweight gain (173 v. 39 g/day), plasma glucose (2.9 v. 2.5 mmol/L), glucose entry rate (20.6 v. 12.3 mmol/h), udder measurements (e.g. circumference, 548 v. 443 mm), and milk yields (measured at day 2 post-partum, 1748 v. 627 mL/day), and had heavier lambs at birth (3.9 v. 2.9 kg). In a second experiment, 10 ewes were pen-fed chopped Rhodes grass ad libitum, and 5 received individually 150 g cottonseed meal + 100 g molasses administered daily. Supplemented ewes were significantly heavier (47.8 v. 45.0 kg) in the last week before parturition. Supplementation was associated with improved ewe liveweight change (48 v. -33 g/day) and lamb birth weight (3.4 v. 2.4 kg). In a third experiment, 42 ewes grazed a 80-ha paddock during a dry season and received daily 1 of 3 individually administered treatments: control (20 mL water drench); 7 g urea + 4 g sulfate of ammonia in a 20 mL drench; 100 g meat and bone meal + 100 g molasses + 3 g urea administered as a slurry in a single drench. Performance and metabolic parameters for the 3 groups were ewe liveweight gain (38, 80, 131 g/day), rumen ammonia concentration (7.1, 10.0, 8.6 mmol/L), plasma glucose (2.6, 2.6, 2.1 mmol/L), plasma hydroxybutyrate (0.6, 0.5, 0.4 mmol/L), and lamb birth weight (3.5, 3.7, 4.0 kg). Differences were significant between the protein-supplemented and control groups for all parameters except rumen ammonia concentration. The data support the conclusion that protein supplements provide a production response in pregnant ewes that is sufficient to improve lamb survival rates when the nutrition from grass diets is inadequate.

Does offering concentrate supplement during late pregnancy affect twin- and triplet-bearing ewe and lamb performance?

“…These results combined could indicate that offering concentrate to ewes grazing a 6 cm sward height may have a positive effect on colostrum let down or production and, consequently, colostrum intake of the lamb. Offering concentrate supplement during late pregnancy to ewes grazing a low (Stephenson & Bird 1992) or high (Murphy et al 1996) herbage allowance has previously been shown to increase colostrum and milk production.…”

“…While offering concentrates to ewes grazing low-quality low herbage allowances in late pregnancy has been shown to have a positive effect on ewe and/or lamb performance (Hall et al 1992;Stephenson & Bird 1992;Banchero et al 2004), only a few studies have looked at offering concentrate on a high herbage allowance (Hinch et al 1996;Kerslake et al 2008Kerslake et al , 2009. The aim of this study was thus to investigate the effects of offering concentrate supplements during late pregnancy, to twin-and triplet-bearing ewes grazing a 6 cm sward height, on ewe and lamb performance.…”

Effect of concentrate supplement and sward height on twin-bearing ewe body condition and the performance of their offspring

“…Offering concentrate supplements on a low herbage allowance has previously been shown to have positive effect on ewe liveweight (Stephenson and Bird 1992). However, concentrate supplementation had no effect on the liveweight of ewes grazing 6-cm sward height pastures.…”

“…Several studies have looked at the use of concentrate supplements during late pregnancy when pasture availability is low (Hall et al 1992;Stephenson and Bird 1992;Hall and Holst 1996) and when pasture availability is high (Dawson et al 2005), with mixed results in production gain. Therefore, the aims of the present studies were to determine the effects of feeding a concentrate supplement to twin-bearing ewes grazing a 2-or 6-cm sward height pasture on ewe and lamb performance over 2 years.…”

Effects of molasses level in a concentrate mixture on performances of crossbred heifer calves fed a basal diet of maize stover

“…Molasses is usually used as a supplement for low-quality forages to stimulate intake (McLennan et al, 1981) and improve animal performance (Stephenson and Bird, 1992).…”