Four ruminally and duodenally cannulated Suffolk wether lambs (34.5 +/- 2.0 kg initial BW) were used in a 4 x 4 Latin square-designed experiment to examine the effects of ruminal protein degradability and supplementation frequency on site and extent of digestion in lambs consuming a low-quality forage diet. Wethers were fed a basal diet of mature crested wheatgrass hay (4.2% CP) for ad libitum ...

Cardiac defects associated with increased pulmonary blood flow result in pulmonary vascular dysfunction that may relate to a decrease in bioavailable nitric oxide (NO). An 8-mm graft (shunt) was placed between the aorta and pulmonary artery in 30 late gestation fetal lambs; 27 fetal lambs underwent a sham procedure. Hemodynamic responses to ACh (1 microg/kg) and inhaled NO (40 ppm) were assesse...

Chronic lung injury from prolonged mechanical ventilation after premature birth inhibits the normal postnatal decrease in pulmonary vascular resistance (PVR) and leads to structural abnormalities of the lung circulation in newborn sheep. Compared with normal lambs born at term, chronically ventilated preterm lambs have increased pulmonary arterial smooth muscle and elastin, fewer lung microvess...

Young crossbred lambs and Suffolk rams were exposed to photoperiods stimulatory to growth or reproduction respectively. Whereas long days are known to facilitate rate of gain, feed efficiency and carcass yield in young market lambs, exposure to decreasing daylengths or short days is necessary for successful reproduction of the species. Successful substitution of a "skeleton" long photoperiod (7...

Growth and carcass traits of St. Croix White (STX; n = 22) and Dorper X St. Croix White (DRP; n = 18) lambs fed a concentrate ration were evaluated. Starting two weeks after weaning (63 d of age) lambs were fed a commercial diet at 4 percent BW•hd-1•d-1. Lambs were slaughtered at a BW of 30 kg. Carcass weight, fat thickness over the 12th rib, rib eye area (REA), percent KPH and leg circumferenc...

Twenty-eight Suffolk-sired (Sx) and 28 Finnsheep-sired (Fx) lambs were implanted with either 0 or 12 mg zeranol. Zeranol significantly increased average daily gain over that of controls. Serum taken at biweekly intervals for 6 weeks was assayed for insulin, somatomedin-like activity (Sm) and fibroblast proliferative activity (FPA). Insulin appeared to increase with time, but there were no consi...

Two experiments were conducted to examine changes in usage of energy and visceral organ mass in Targhee lambs selected on the basis of improved rate and efficiency of growth. In Exp. 1, Targhee ram lambs from a breeding line selected for improved growth rate and feed efficiency and a control line that was maintained without selection for 20 yr were provided with either a high (ad libitum) or lo...

Stress is an important factor in animal welfare. Hair or wool cortisol concentrations are considered to be potential long-term indicators of stress experienced by animal. Using Swifter sheep, we investigated whether ewe parity and litter size affect the ewes their offspring. We hypothesized that multiparous offspring would have higher than primiparous offspring, with larger litters lower smalle...

This study aimed to analyze the economic feasibility of replacing soybean meal by sunflower cake in the diet of lambs. Twenty-eight non-castrated crossbred Suffolk lambs aged four months, with 21 kg average body weight ± 9 kg were used. These animals were distributed by weight category into 3 treatments (10, 20 and 30% dry matter (DM) addition of sunflower cake in replacing soybean meal) and co...

Sexual activity, body size and testis growth in the prepubertal period (120-210days of age) were studied in five male lambs of each of four dairy sheep breeds. Sexual responses developed earlier in Friesland than in Chios and Karagouniki and latest in Serres ram lambs. Friesland lambs expressed interest in females at 127days of age and 34kg live weight 18-36days younger and 3.4-6.3kg lighter th...