Birth and weaning weights were studied for purebred Finnsheep, Suffolk, Targhee and Minnesota 100; F1 Finnsheep crosses; F2: and standard breed and Finnsheep backcrosses. Finnsheep lambs were the smallest of all lambs at birth, but ranked second among purebreds in 70-day weaning weight (Suffolks, 21.0 kg vs Finnsheep, 17.6 kg). Ewe body weight, grease fleece production and total adjusted weight...

We investigated the utility of time-lapse photography to provide population estimates and lamb : ewe ratios of mountain sheep populations. We compared 2 methods of time-lapse data analysis: group sampling and frame sampling. We failed to reject the null hypothesis that population estimates and lamb : ewe ratios from time-lapse and direct observation sampling were the same.

Female reproductive trait were studied in four pure breeds (the Finnsheep, Suffolk, Targhee and Minnesota 100), the F1 crosses between Finnsheep rams and females of the other three breeds and F2 and backcross ewes. Precocity of sexual development, defined as the percentage of ewe lambs lambing at 12 months of age, was measured in 709 ewe lambs in 4 years. Lambing and weaning rates were measured...

A diallel cross involving three Moroccan breeds of sheep (Sardi, Beni Guil, and D'man) was analyzed by least squares procedures. A total of 456 ewes were mated to 22 rams and this resulted in 528 lambs born from 412 ewes. D'man ewes had by far the highest general performance as measured by total weight of lamb weaned, even though the average live weight per lamb was the lowest for the three bre...

The effects of melengestrol acetate (MGA) and P.G. 600 on ewe fertility outside the natural breeding season were evaluated. Rambouillet ewes were assigned to one of four groups: (1) control (C; n=92); (2) PG600 (n=86); (3) MGA (n=99); and (4) MGA+PG600 (n=92). A pellet with or without MGA (0.3mg/ewe/d) was fed at 0.15kg/ewe/d for 7d. On the last day of pellet feeding, ewes were given either sal...

the number of lambs sold per ewe mated in the breeding flock has a considerable impact on sheep operation profitability. this depends primarily on fertility, prolificacy (# of lambs), and lamb survival, mothering ability, milk production of the ewe and lamb growth rate. optimal reproduction does vary by environment and management system – some sheep operations don’t want a lambing rate over 200...

Anestrous ewes respond to the introduction of rams with either an ovulation within 2-3 days that may be followed by luteal phases of normal or short length, with delayed ovulations (5-6 days later), or with the luteinization of follicles. The aim of this work was to study the relationship between the growth status of the largest follicle present when rams are introduced and the type of ovarian ...

Production data from 681 yearling ewes were evaluated for the effect of ewe breed and management system on fertility, prolificacy, lamb birth weight, lamb survival, lamb weaning weight, ewe fleece weight, and total lamb weight weaned per ewe exposed. Two hundred seven straightbred Targhee (T) and 474 1/4 Finn-1/4 Dorset-1/2 Targhee (FDT) crossbred ewes managed in a range or farm flock system we...

Effects of selenium on certain indicators of sheep reproductive success and on Se level in the sheep’s blood serum were studied in 2001-2002 on 100 Polish merino sheep ewes kept in a Western Pomeranian sheep farm. The 100 ewes were picked out on random and divided into two equal groups: treatment and control. The blood samples for serum Se assays were collected prior to administration of sodium...