Enhanced genetic selection of dairy sheep for the Southern US

Project Overview

FS08-229
Project Type: Farmer/Rancher
Funds awarded in 2008: $9,486.00
Projected End Date: 12/31/2010
Region: Southern
State: Virginia
Principal Investigator:
Marcia McDuffie
Allen's Creek Farm

Commodities

Not commodity specific

Practices

  • Animal Production: animal protection and health, genetics

    Summary:

    Ewes from a cross using East Friesian (dairy) sheep and two “hair” breeds (St. Croix, Katahdin) were bred and tested for their ability to transmit traits associated with low-input dairy production in the heat and humidity of the southeastern United States. Data on milk production, parasite resistance, and penetrance of the “hair” (shedding) trait were collected on a total of 178 sheep born on this farm between 2008 and 2010. A scoring system, based on these traits, was used to select optimal breeding stock to continue development of the line for each breeding season. The result show that the sheep produced from this breeding scheme can provide commercially viable seasonal milk production and relative parasite resistance on a largely forage-based diet. This project demonstrates the feasibility of rapid selection of a productive dairy sheep flock for the Southeastern United States.

    Introduction

    The sustainability of traditional small farming operations is rapidly declining. Factors contributing to this decline include the following:

    • diminishing/unreliable sources of labor

      rapidly increasing costs for fuel to support farm operations and transport of product

      rapidly increasing costs for inorganic fertilizer and non-renewable plant resources

      requirement for increasingly intensive, costly management of biological threats

      low market prices for commodities requiring off-farm processing or distribution.

    Most sustainable small farms will need to be manageable by a single individual, operating either alone with occasional hired labor or with a partner employed full-time off the farm. From recent farm census data, it is also clear that the primary farmer will increasingly be female and may have little or no background in farming. In order to be profitable, small farming operations cannot rely on heavy mechanical input or support a large recurring investment in seed stock, fertilizer, or health management costs. They will also require a focus on farm-based “value-added” strategies and the development of local markets to minimize transport, distribution, and storage costs. In return for operating with these constraints, however, small farms should have advantages of improved flexibility in response to changes in environmental conditions and shifts in local consumer demand.

    One farming opportunity that will meet these requirements is a dairy sheep operation producing aged ewe’s-milk cheeses. Given reasonable availability of feed generated offfarm or adequate pasture, an operation milking 50-60 ewes over a 5-month season should produce sustainable income for a single farmer-operator in the Southeast region with a limited requirement for extra labor, land, or expensive equipment. However, there are impediments to realizing this opportunity.

    The dairy breeds currently available in the US, East Friesian (EF) and Lacaune, are handicapped by extremely limited genetic variability and poor health performance under conditions of high heat and humidity. The limited genetic variability, which may play a role in their high risk for developing pneumonia and serious worm infestations, limits the ability of breeders to optimize both general health and the components in milk (fat, protein) that are required for high-quality cheese production.

    These breeds are also poorly suited to production of meat lambs for a supplemental income stream, require routine shearing for optimal performance in very warm, humid areas, and produce wool of low quality. At present, there are few sheep breeds of any sort that thrive and are highly productive in the southern US. Consequently, sheep production in this region has reached very low levels, and few in the farming community have the expertise in husbandry, breeding, and health maintenance required to manage sheep as a profitable enterprise.

    Development of a dairy sheep breed that will thrive under low-input conditions in the Southern region will require a focused effort involving individuals with expertise in breeding for the selection of complex traits and in the husbandry of small ruminants, as well as a network of individuals capable of working together to expand and test the breeding stocks under development. This proposal addresses both issues.

    Project objectives:

    The original goal of this proposal was to support a systematic analysis of genetic variation in a foundation flock of crossbred sheep carrying 50-60% East Friesian (dairy) genetics, to develop a composite tool for selection of genetically determined parasite-resistance, and to generate an expansion flock suitable for selection based on milk volume and quality. To support data collection and flock management, I proposed the development of an interactive database with links for lineage analysis and pedigree plotting.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.