William (Billy) Flowers North Carolina State University

Publish Date: July 17, 2006

North Carolina State University Swine Nutrition Research from 2002. A total of 6,024 pigs (initial BW = 20.2 kg) was used to determine the impact of reducing supplemental trace mineral (TM) levels during the grower-finisher phase on fecal mineral excretion. Pigs were randomly distributed into 4 blocks of 2 barns, ensuring that each block of barns was filled at the same time. Barns were then allotted within block to receive either diets with low or high TM supplementation. Four diet phases were fed with 135, 125, 105, and 85 ppm added Zn, 13.5, 12.5, 10.5, and 8.5 ppm added Cu, and 113, 104, 87.5, and 70 ppm added Fe for the high TM diets and 30 ppm added Zn, 6 ppm added Cu, and 30 ppm added Fe for all low TM diets. Diets were analyzed to contain 181, 155, 142, and 135 ppm Zn, 17, 21, 19, and 18 ppm Cu, and 506, 477, 352, and 299 ppm Fe for the high TM diets and 80, 75, 79, and 80 ppm Zn, 12, 8, 10, and 10 ppm Cu, and 389, 368, 270, and 271 ppm Fe for the low TM diets. During the period that the second diet phase was fed, fecal samples were obtained randomly, from at least 8 pigs in each barn. Samples were combined within barn and analyzed for Zn, Cu, and Fe. Pigs fed low TM diets had lower levels of Zn (363 vs 1,146 ppm; P = 0.05), Cu (94 vs 147 ppm; P = 0.004), and Fe (1,683 vs 2,534 ppm; P = 0.01) in feces (on a DM basis) than pigs fed the high TM diets. Analysis of individual slaughter records indicated that pigs fed low TM diets had greater carcass weight (89.5 vs 88.3 kg; P < 0.06), carcass weight payment ($110.54 vs 108.53; P < 0.04), and total payment ($112.98 vs 111.07; P < 0.02) compared to pigs fed high TM diets. Backfat thickness, loin depth, % lean, and lean premium payment were not affected (P > 0.10) by dietary treatments. Results indicate that reducing trace mineral levels in diets for grower-finisher pigs reduced fecal mineral excretion of Zn, Cu, Fe, and Mn by 68, 36, 34, and 45% respectively, without negatively affecting carcass characteristics.

Publish Date: November 3, 2007

North Carolina State University Swine Reproduction Research from 2001. Sixty boars were randomly assigned to a factorial arrangement of treatments involving age at first collection, 160 or 190 days of age, and collection frequency, once or twice per week (n=15 per treatment combination). The total number of spermatozoa per ejaculate was monitored until the boars were 24 months of age. Total number of spermatozoa per ejaculate increased then appeared to plateau for each treatment combination. This plateau was considered to be an estimate of the adult level of spermatozoa production for boars. Semen production reached adult levels between 10 and 11 months of age for boars whose collection regimen was initiated at 190 days of age compared with 13 to 14 months of age for boars whose collection regimen began at 160 days of age. However, once the adult level of semen production was reached, no differences in the total number of spermatozoa per ejaculate were observed between boars collected for the first time at 160 and 190 days of age. These data indicate that initiation of collection regimens at 160 days of age does not have a significant, long-term effect on semen production in boars.

Publish Date: July 31, 2007

Detection of estrus or standing heat is one of the most critical components of a successful swine breeding program. The widespread adoption of artificial insemination (AI) in the swine industry has shifted the responsibility of detecting estrus from boar to breeding technician. Accurate and consistent detection of estrus is necessary to ensure insemination occurs near the time of ovulation and to identify open females. Errors in detection of estrus reduce reproductive performance and increase herd non-productive days. Since accurate heat checks are so vital, all individuals involved must know the typical signs that females approaching estrus in their herd exhibit and how to best use a boar to stimulate females to express estrus. Reviewed: April 2021

Publish Date: June 3, 2006

Daily care and management of sires in an artificial insemination (AI) center can have a large influence on semen quality and sperm output. A typical boar produces from 1100 to 1200 doses of semen per year (22 doses/wk x 52 wks) and therefore, semen quality of a single sire influences a large number of matings and services per year. A rule of thumb is that each female inventoried will require about six doses of semen on an annual basis (2.2 L/S/Y x 2.2 matings per service x 80% FR x 10% semen wastage (unused doses) . Therefore, each sire inventoried in the boar stud could meet the semen needs for 150 to 200 females inventoried on the breeding farm. The following are some important points to consider for optimal management of sires maintained in a commercial AI center.

Publish Date: June 3, 2006

Herd boars influence the swine breeding program in two important ways. One, they provide a source of genetic improvement and two, they have an effect on farrowing rate and litter size. In addition, replacement boars can be a potential source for the introduction of disease into a herd. The following guidelines provide information to help make decisions when purchasing new boars, acclimating them to their new environment and managing them for productive service as mature boars. This article is based on PIH-1 (12/93).

Publish Date: June 3, 2006

Plants and animals may serve as excellent hosts for many fungi. Spores from fungi (molds) are primarily spread by water and air and come into contact with plants in the field or with grain in storage facilities. Factors that influence the degree of fungal infestation in grain are moisture, temperature and availability of oxygen. Other factors such as insect population, physical condition of grain or susceptibility of certain grain hybrids will also influence whether fungal proliferation will occur under a given set of environmental conditions.