Effect of weaning age on hair sheep lamb and ewe production traits in an accelerated lambing system in the tropics.

This study was designed to evaluate the impact of weaning age on lamb and ewe productivity in an accelerated lambing system. St. Croix White (STX) and Dorper × St. Croix White (DRPX) lambs were assigned at birth based on breed, gender, and litter size to be weaned at 63 (Early-1; 106 lambs and 68 ewes) or 90 d of age (Late-1; 99 lambs and 60 ewes) in Exp.1 or at 63 (Early-2; 77 lambs and 57 ewes) or 120 d of age (Late-2; 75 lambs and 56 ewes) in Exp. 2. After weaning, lambs were weighed weekly and fed a concentrate ration (2% BW·lamb·d) while grazing guinea grass pastures. In Exp. 1, weaning weight was greater ( < 0.0001) for Late-1 lambs than for Early-1 lambs (14.6 ± 0.3 vs. 11.0 ± 0.3 kg, respectively) and greater ( < 0.008) for DRPX lambs than for STX lambs (13.9 ± 0.4 vs. 11.5 ± 0.4 kg, respectively). Litter weaning weight was greater ( < 0.004) for Late-1 ewes than for Early-1 ewes (20.9 ± 0.8 vs. 17.4 ± 0.8 kg, respectively). Ewe efficiency ([ewe BW at weaning/litter weaning weight] × 100) was greater ( < 0.004) for Late-1 ewes than for Early-1 ewes (50.7 ± 1.9 vs. 42.3 ± 1.8%, respectively). Lamb weight gain between 63 and 90 d of age was lower ( < 0.03) for Early-1 lambs than for Late-1 lambs (2.7 ± 0.2 vs. 3.6 ± 0.3 kg, respectively). In Exp. 2, weaning weight was greater ( < 0.0001) for Late-2 lambs than for Early-2 lambs (18.7 ± 0.4 vs. 11.8 ± 0.4 kg, respectively) and greater ( < 0.008) for DRPX lambs than for STX lambs (16.9 ± 0.5 vs. 13.3 ± 0.5 kg, respectively). Litter weaning weight was greater ( < 0.0001) in Late-2 ewes than in Early-2 ewes (27.2 ± 1.0 vs. 17.5 ± 0.9 kg, respectively). Ewe efficiency was greater ( < 0.0001) for Late-2 ewes than for Early-2 ewes (68.1 ± 2.2 vs. 41.9 ± 2.0%, respectively). Lamb weight gain between 63 and 120 d of age was not different ( > 0.06) between Early-2 and Late-2 lambs (5.1 ± 0.2 vs. 5.6 ± 0.3 kg, respectively). In Exp. 1 and 2, ewe BW at breeding and lambing and weaning and lambing rate were not different among weaning ages of lambs ( > 0.17). The Early-1 ewes exhibited estrus earlier than Late-1 ewes (10.9 ± 0.9 vs. 13.9 ± 1.0 d, respectively) but there was no difference ( > 0.63) between Early-2 and Late-2 ewes. Weaning hair lambs at 90 or 120 d of age can be done in an accelerated lambing system with no detrimental effect on lamb or ewe productivity. Late weaning resulted in a decreased number of days that lambs received high-cost, imported feed without a reduction in growth, resulting in savings of US$6 to $15 per lamb.

Anatomic explanation of mobile systolic clicks: implications for the clinical and echocardiographic diagnosis of mitral valve prolapse.

An echocardiogram (echo) is often ordered for suspected mitral valve prolapse (MVP). Using echo as the gold standard, we conducted a meticulous physical examination on 61 patients with this referral diagnosis. Ninety percent of patients with negative physical examination and echo results for MVP had physical examination findings likely to have been misinterpreted as MVP by the referring physician. Redundant portions of the mitral valve apparatus were found in 57% of patients with MVP on our physical examination but not on echo. A carefully performed physical examination (including dynamic auscultation) can exclude MVP. Not all mobile systolic clicks are associated with anatomic echo prolapse; they can be generated by redundant chordae tendineae and, in the absence of echo prolapse, probably by redundant leaflets. Patients with mobile systolic clicks should have an echo to determine the portion of the spectrum of echo prolapse present and to determine risk stratification and management.