Merino ewes (n 108) joined to a single sire were allocated into three flocks, with ewes in one flock being chemically defaunated in the second month of gestation. Single lambs born to defaunated ewes (BF lambs) were heavier at birth and at weaning than lambs born to faunated ewes (F lambs). After weaning, all BF and F lambs were individually housed then half of the F lambs were chemically defau...

Weaned Targhee x Hampshire lambs (average BW 27.6 kg) were used to determine the effects of concentrate feeding, forage grazing, or finishing on concentrate after grazing upon growth and carcass tissue accretion. Lambs were assigned randomly and balanced by weight and sex to five replicated treatments (12 lambs/treatment): all-concentrate in drylot (DL); rotational grazing alfalfa (ALF); rotati...

Thirty-two Afshari lambs were used in a completely randomized design with a 2 × 2 factorial arrangement of treatments to evaluate a nutritional supplement designed to provide multiple gluconeogenic precursors during heat stress (HS). Lambs were housed in thermal neutral (TN) conditions and fed ad libitum for 8 d to obtain covariate data (period 1 [P1]) for the subsequent experimental period (pe...

A study was conducted to evaluate the relative resistance to a natural or induced gastrointestinal (GI) nematode infection in hair and wool breeds of lambs. In Experiment 1, natural GI nematode infection was evaluated among fall born Dorper crossbred (DO; n = 17) or St. Croix (SC; n = 17) lambs. Ewe and wether lambs were weaned at 84 ± 1.1 days of age and dewormed. Fecal egg counts (FECs) and b...

Carcasses of Churro Galego Bragançano purebred and Suffolk and Merino Precoce crossbred lambs reared under three different conventional production system of northeast of Portugal were evaluated. Carcasses of male lambs had larger muscle longissimus width (P < 0.05) and smaller subcutaneous fat thickness (P < 0.05) than the female lambs. Carcasses of crossbred lambs had higher (P < 0.05) compact...

Tannins may bind to alkaloids in endophyte-infected (E+) tall fescue and attenuate fescue toxicosis. To test this hypothesis, thirty-two 4-mo-old lambs were randomly assigned to 4 treatments (8 lambs/treatment) in a 2 by 2 factorial design that included a basal diet of tall fescue hay [E+ or endophyte-free (E-)] supplemented with (TS) or without (CS) bioactive Quebracho tannins. The concentrati...

Growth performance, feed conversion efficiency and nutrient utilization of mutton synthetic, selected and randombred Malpura populations of lambs (60days) were evaluated. The mutton synthetic lambs reached the 25kg body weight in 73days of intensive feeding while the selected and randombred Malpura populations of lambs reached the same weight in 91 and 136days, respectively (P<0.01). The fitted...

A reduction in food intake is a prominent feature of many infectious diseases. However, the underlying mechanisms of parasite-induced anorexia in sheep are poorly understood. Here, we tested the hypotheses (a) that the degree of parasite-induced anorexia in lambs is influenced by their growth potential and (b) that nematode infection results in elevated plasma leptin concentration in lambs. The...

Prolonged feeding of sericea lespedeza (SL) previously led to reduced serum concentrations of Mo, a cofactor in an enzyme complex that may be involved in weight gain. The current objective was to determine the effect of Mo supplementation on changes in serum, fecal, urine, and liver concentrations of trace minerals in lambs fed SL leaf meal pellets. Thirty ram lambs weaned in May (84 ± 1.5 d of...

We studied in meroxenic lambs, i.e. in lambs with a simplified digestive microflora, the effect of the microflora on the quantities of solid feed intake and on the main digestive parameters in the rumen. Axenic lambs were inoculated with a more or less complex flora, obtained by diluting (10(-8), 10(-7), 10(-8) a pool of rumen fluid taken either from young conventional lambs before weaning from...