I. FALL LAMB PRODUCTION ANIMAL SCIENCE 41 LAMB PRODUCTION SYSTEMS Area - Sacramento & San Joaquin Valleys, and Southern Ca (western Riverside). - where feed is available in late Fall and early Winter. A. Flock Size: Ewes: Rams: B. Breeding - ewes are bred in May, June & July. - benefit: - disadvantage: Fresno - bred on the hot, dry grain stubble fields along the west half of the valley. Kern - bred at higher elevations and cooler temperatures. - high mountain pastures, as far as Nevada, Idaho & Oregon. - return to valley in the Fall - most replacements are purchased as ewe lambs from Texas, New Mexico, Idaho & Montana. Preference: - replacements are purchased in the Fall, "Spring-born" lambs. C. Feeding
- Oct to about Jan/Feb - on alfalfa - Feb to about April - forage growth in the western foothills provides good feed. Fresno: Kern: - June to Oct Fresno: on the dry grain stubble fields along the west half of the valley, some on the dried grass in the foothills. Kern: sheep are moved to higher mountain elevations, grass pastures. D. Lambing - lambing in Sept, Oct & Nov. - reason: lambing %: 100 to 110% (range 85 to 120%) weaning %: 90 to 100% lambing % often depends on where the ewes are bred (temperature) E. Weaning - weaning is market time, can be from 3 to 6 months of age. - months: F. Shearing - from Feb to July, shear earlier in the south due to weather. - Spring shearing is around Feb to March or about the time sheep are moved from the alfalfa fields to the grass in the foothills. - ewes tagged before lambing. - tagging: G. Health
- may vaccinate for Enterotoxemia (Pulpy-kidney disease, Overeating Disease) - Blue Tongue: some vaccinate while others spray sheep. Losses may be as high as 10 to 15% of the ewe flock. - Ketosis (Pregnancy disease, Lambing paralysis, Twin-lamb disease, Pregnancy toxemia) may occur in flocks held on grain stubble until lambing.
II. WINTER LAMB PRODUCTION Area - Northern CA and the North Coast Area - in areas where late Fall and early Winter feed is not available. A. Flock Size: Ewes: Rams: B. Breeding - ewes are bred in late July, Aug & Sept (early in the breeding season) - benefit: - disadvantage: - flushing: - most replacement ewes are purchased as ewe lambs from the Rocky Mt states. Bred as yearlings to lamb at 14 to 18 months of age on the average. C. Feeding - most producers depend on range forage for most of their feed year round. - feed at lambing time: - time on feed:
- Winter: - Summer: D. Lambing - Winter season Dec to Feb - open range lambing: - barn lambing: E. Weaning - weaning is market time, can be from 3 to 6 months of age. - gains of lambs are dependent on the amount & quality of the range forage available. - feed effects: F. Shearing - Spring & Fall G. Health - variable & related to area, should check with your veterinarian. - April to July: - worm all animals (internal parasites) - dip or spray sheep following Spring shearing for lice & ticks. - trim hooves & check for foot rot. - vaccinate ewes for abortion diseases such as vibriosis. - Dec to Feb: - vaccinate lambs at marking time for tetanus & clostridium perfringes type D. III. PRODUCTION SYSTEMS
A. Purebred Flocks - normally small, generally in the central, southern & eastern U.S. However, there are some large purebred flocks in the range states and an increasing number of small purebred flocks. - general objectives: - general characteristics (compared to commercial range producer): B. Commercial Flock - often times they are large (western states) with the main objective to produce lamb (and wool) as efficiently as possible with the conditions available. - slightly less intensive management than the purebred flock. Range Band Method - about 70% of U.S. sheep located in the western state range. - relative emphasis on lamb and wool production in the range area varies according to the rainfall and vegetation. 1. arid & semiarid regions of South West: 2. semiarid & semihumid area of the West: IV. GENERAL MANAGEMENT A. Selection of replacement ewes
criteria: B. Selection of rams criteria: C. Culling of breeding ewes reasons: - culling should be done shortly after weaning time. - average life span of the range ewe: