The NAHMS Report on Nursery Pig Management
Livestock Update, June 2002
Allen Harper, Extension Animal Scientist, Swine, Tidewater AREC
The National Animal Health Monitoring System (NAHMS) is a study branch of the USDA Animal and Plant Health Inspection Service. NAHMS periodically conducts extensive survey assessments of livestock and poultry farms to determine the most prevalent animal health problems and the current state of animal management systems that effect animal health and performance. In March of this year part II of NAHMS' "Reference of Swine Health and Management, 2000" was released to the public. Swine nursery management was one of several key topic areas covered in this NAHMS report. The following are highlights of this swine nursery management portion of this recent report.
Sites with a Nursery Phase. The 2000survey indicated that 50.4 % of swine farm sites had a specific nursery phase of production. This is down from 64.2% reported in 1995. No apparent reason for this decline was given. However, it is likely that the increased use of separate site production systems in which individual hog farm sites deal specifically with one phase of production (breeding-farrowing, nursery, or grow-finish) contributed to this finding. The survey found that weaned pigs were moved from the source farm to a separate site nursery on 36.4 % of the sites reporting. Another likely reason for reduced number of sites with a nursery phase is the increased use of wean-to-finish production systems, in which pigs are weaned directly into a specially prepared finishing barn and remain there until reaching market weight.
Age of Pigs Entering and Leaving the Nursery Phase. The site average of weanling pigs entering the nursery ranged from 18 to 26 days. However, it was apparent that larger farms practice earlier weaning. For sites with less than 2,000 hogs and pigs in inventory, average age of pigs entering the nursery was 26 days. For medium size farms (2,000 - 9,999 head inventory), the average age of pigs entering the nursery was 18 days and for large farms (greater than 10,000 head inventory) the average age was 19 days. The typical age of pigs leaving the nursery phase was 62 to 65 days across all farm sizes.
Type of Nursery and All-In, All-Out Management. Over 84 % of the swine farms with a nursery phase housed nursery pigs in totally enclosed nursery buildings with no pig access to the outside. These sites represented over 97 % of all nursery pigs produced. Most nursery pigs (87.4 %) were raised utilizing all-in, all-out production in which every animal in any given room is removed and the room completely washed and disinfected before another group of weanling pigs is introduced into the room.
Nursery Pig Death Loss and Disease. Nursery pig death rates reported by NAHMS was 2.6 %. This is similar to the nursery death rate of 2.4 % reported in 1995. Causes of nursery deaths reported by producers included respiratory disease (28.9 %), other known causes (24.5 %), unknown causes (20.7%), scours (12.6%), and starvation (13.3%). The most prevalent disease problems reported in nursery aged pigs were Streptococcus suis (31.6%), greasy pig disease (25.3 %), Escherichia coli diarrhea (24.0 %), Mycoplasma pneumonia (19.6 %), roundworms (18.0 %), and Porcine Reproductive and Respiratory Syndrome or PRRS virus (17.5 %). PRRS virus problems were more prevalent on farms with large herd sizes. Roundworm infections were more prevalent on small farms.