The ability to authenticate the feed given to animals from the animal products has become a major challenge for scientists, monitoring bodies and commercial entities alike. This study compared two methods based on the use of the visible reflectance spectrum of the fat to discriminate pasture-fed (P) from stall concentrate-fed (S) lamb carcasses. A total of 307 (143 P and 164 S) Limousine lambs ...

The objective of this research was to compare the growth performance, incidence of prolapse and mortality, carcass characteristics, blood hormone concentration, and N balance of lambs implanted with increasing dosages of zeranol. One hundred forty-four crossbred lambs (29.6 ± 4.9 kg) were used in a completely random design and placed into 16 feedlot pens (4 pens/treatment) for a 116 d finishing...

Reopening of the ductus arteriosus after successful indomethacin-induced closure has become a major problem with indomethacin treatment. In full-term human newborns and lambs, the ductus behaves like ischemic tissue after its initial constriction. Its ability to continue to relax or contract depends on the amount of left-to-right shunt through the ductus lumen. To see if ductus constriction in ...

To investigate the role of renal sympathetic nerves in modulating cardiovascular and endocrine responses to hemorrhage early in life, we carried out three experiments in conscious, chronically instrumented lambs with intact renal nerves (intact; n = 8) and with bilateral renal denervation (denervated; n = 5). Measurements were made 1 h before and 1 h after 0, 10, and 20% hemorrhage. Blood press...

This study was conducted to investigate the effects of rumen-protected γ-aminobutyric acid (GABA) on feed intake, growth performance and expression of related genes in growing lambs. A total of 24 lambs weaned at age of 50 days were divided into four block of six based on their BW, six lambs within a block were allocated to three pairs, which were then assigned randomly to three treatments with...

Lambs were used to evaluate the effect of acute heat stress (HS) or restraint and isolation stress (RIS) on endocrinological and immunological functions. In Exp. 1, lambs were exposed to HS (35 degrees C) and control lambs (CN) were exposed to 21 degrees C for 24 h in two replicates (n = 8 lambs total per treatment). Samples of serum were obtained at frequent intervals for evaluation of cortiso...

In two separate 2 x 2 factorial arrangements, 69 male, crossbred lambs were allotted randomly to the following treatments: 1) nonimplanted (NI) rams, 2) implanted (I) rams, 3) NI wethers, and 4) I wethers. In Trial 1, 36 lambs were allotted to treatment groups at birth (n = 9) and I lambs were implanted with 12 mg of zeranol between 1 and 3 d of age and again at weaning (average age of 62 d). L...

We examined mitochondrial oxidative function 5 minutes and 2 hours after a gradual asphyxial insult in newborn lambs. We subjected 16 ventilated newborn lambs to 75-90 minutes of hypoxia and hypercarbia that resulted in bradycardia and systemic hypotension over the final 15 minutes of the insult. At the end of asphyxia, the lambs were resuscitated and returned to control ventilator settings. Sa...

We have studied maturational changes in the kinetics of the proximal tubule Na+/H+ antiporter. Microvillus membrane vesicles were prepared from renal cortex of fetal and newborn lambs. Amiloride-sensitive uptake of 22Na+ by these vesicles was measured and Woolf-Augustinsson-Hofstee plots were used to determine the Michaelis constant (Km) and rate of maximal uptake (Vmax). Initial studies of fet...

Homozygous grey and white Karakul lambs suffer from a lethal genetic factor causing death after weaning. Previous studies revealed large milk-filled rumens in the grey and white lambs which was attributed to a significant decrease in the number of myenteric ganglia and neurons in the rumen wall. This study was undertaken to determine the effect of milk on the epithelial lining of the forestomac...