From 2 to 4.5 months of age, 80 crossbred gilts were reared in a conventional grower unit where they were naturally exposed to mycoplasmal and bacterial pathogens that cause pneumonia and atrophic rhinitis. At 4.5 months of age, gilts were moved to environmentally regulated rooms (4.9 X 7.3 m) and assigned at random to 1 of 2 treatment groups: low aerial concentration of ammonia (4 to 12 ppm; mean, 7 ppm) or moderate aerial concentration of ammonia (26 to 45 ppm, mean, 35 ppm). Low concentration of ammonia was obtained by flushing of manure pits weekly, whereas moderate concentration of ammonia was maintained by adding anhydrous ammonia to manure pits that were not flushed. Gilts were weighed biweekly. Mean daily gain (MDG) was less (P < 0.01) for gilts exposed to moderate concentration of ammonia than for gilts exposed to low concentration of ammonia after 2 weeks in their respective environments. By 4 and 6 weeks, however, MDG was similar between the 2 treatment groups. After 6 weeks in these environments, 20 gilts from each treatment group were slaughtered, and prevalence and severity of lung lesions and snout grades were determined. At slaughter, body weight was greater (P < 0.01) in gilts exposed to low, rather than moderate, ammonia concentration (94.5 vs 86.8 kg; SEM, 3.3 kg). Percentage of lung tissue containing lesions (18 vs 12) and snout grade (2.8 vs 3.1) were similar between gilts exposed to low or moderate concentration of ammonia. The remaining 20 gilts in each treatment group were maintained in their respective environments, exposed daily to mature boars and bred at first estrus. Age at puberty was similar between gilts exposed to low or moderate concentration of ammonia (208 vs 205 days; SEM, 1.3 days), even though weight at puberty was less (P < 0.03) for gilts exposed to low concentration of ammonia than for gilts exposed to moderate concentration of ammonia (109.7 vs 118.2 kg; SEM, 4.5 kg).

Body condition scoring (using a 5-point with quarter-point divisions) was performed on 66 Holstein dairy cows that began their second or later lactation in August, September, or October 1988. Cows' body condition was scored beginning on postpartum day 4 (+/- 1) and subsequently at postpartum days (+/- 1) 18, 32, 46, 60, 73 and 87. Blood samples were obtained on the same dates. Reproductive health examinations were conducted by 1 of 2 veterinarians beginning at postpartum day 21. Reproductive performance was evaluated in relation to body condition score and serum urea nitrogen and cholesterol concentrations. Number of days to first recorded signs of estrus and first breeding were not related to body condition score at calving, amount of condition loss, cumulative 80-day milk yield, or 305-day fat corrected milk yield. Cows that calved with body condition score greater than or equal to 3.50 required more days to conceive. Cows losing > 0.75 points of condition had longer days of conception. Body condition score at calving and amount of condition lost were not related to services per conception or diagnosis of follicular cyst. Cumulative 80-day milk yield was not related to days to conception or services per conception. Cows that produced greater than or equal to the mean 305-day milk yield required more services and had longer days to conception than cows that produced < the mean 305-day milk yield. Cows with diagnosis of ovarian follicular cysts had greater cumulative 80- and 305-day milk yields than did cows that were not diagnosed with follicular cysts. Cows conceiving with less than or equal to 2 services did not differ in average daily milk production, body condition score, or serum urea nitrogen concentration from cows conceiving with > 2 services, but cows that conceived with less than or equal to 2 services had higher serum cholesterol values than did cows requiring more services.

Swine herds suspected to be infected with Leptospira interrogans serovar bratislava were vaccinated with bacterins containing 5 or 6 leptospiral serovars in which serovar bratislava was the unique component. The principal diagnostic feature indicating an infection by this organism was demonstration of antibody against serovar bratislava in sera from stillborn pigs. For 1 breeding cycle after vaccination of herds on 3 farms, 255 of 266 (95.9%) sows and gilts given the 6-serovar bacterin farrowed. In contrast, 233 of 311 (74.9%) sows and gilts given the 5-serovar bacterin farrowed. These results, as evaluated by analysis of variance techniques, showed a significant improvement (P less than 0.01) in reproductive performance for groups vaccinated against serovar bratislava.

Data from 34 yearling Hereford or Angus bulls were used to investigate relationships of testicular size, quantitative rates of sperm production, Sertoli cell numbers, numbers of germ cells supported per Sertoli cell, and the efficiency of spermatogenesis to daily sperm output and seminal quality. Two ejaculates were collected by electroejaculation from each bull on each of 2 days/week throughout the study. The percentage of progressively motile sperm and the percentage of morphologically normal sperm were determined from aliquots of fresh semen. Additional aliquots of semen were frozen in glass ampules or plastic straws and subsequently evaluated for postthaw motility and percentage of sperm with intact acrosomes. Sertoli cell numbers, the numbers of germcells per Sertoli cell, and the efficiency of spermatogenesis were unrelated to the quality of fresh or frozen semen (P greater than 0.05). In first ejaculates, the numbers of sperm and motile sperm were related (P less than 0.05) to testicular parenchymal weight (r = 0.38, and 0.50), daily sperm production (r = 0.45 and 0.53), and spermatids per gram of testicular parenchyma (r = 0.35 and 0.34). Testicular parenchymal weight and daily sperm production also were related to daily sperm output and to the average daily motile sperm output of these bulls (P less than 0.05), but could account for less than 25% of the variability in these end points among bulls.

Two-day old house fly adults were exposed to six insect growth regulators, flufenoxuron, teflubenzuron, triflumuron, diflubenzuron, methoxyfenozide, tebufenozide, as a feed additive (milk + 5% sugar + chemical) in the laboratory for 6 days. The number of eggs deposited by the exposed-adults, viability of the eggs, and F1 larval development were checked. All the IGRs tested were found to have no adverse effect on the reproduction of house fly, except methoxyfenozide (210ppm). The most effective inhibitor to egg hatch was flufenoxuron, followed by teflubenzuron, triflumuron, and diflubenzuron. Exposure to flufenoxuron (over 5ppm), teflubenzuron (over 25ppm), triflumuron (over 125ppm), and diflubenzuron (over 125ppm) reduced egg hatchability to 0 to 1.3%, but lower concentrations of these IGRs were less effective (6.3 to 46.3% egg hatchability). Almost all the larvae emerged from eggs deposited by the adults exposed to diflubenzuron (62.5ppm) and teflubenzuron (12.5ppm) failed to develop into pupae, causing total mortalities of 98% and 100%, respectively. However, two IGRs, methoxyfenozide and tebufenozide, did not inhibit egg hatch and F1 larval development, except methoxyfenozide (210ppm) treatment. These results suggest that these 4 IGRs may be used in the development of autosterilization system for house fly control. However, further work is required to develop delivery systems capable of transferring an effective dose to the fly under field conditions.

We investigated the effect of reproductive herd health program (RHHP) on the reproductive performance in high yielding dairy herds. Data collected from 205 lactations at Boeun County, Chungbuk from April 2001 to Dec. 2003 included postpartum reproductive and metabolic diseases, body condition score (BCS), reproductive performance and milking records. First we compared the reproductive performance of cows without RHHP (pre-RHHP group) and cows with RHHP (RHHP group).

The effects of melatonin and Light treatments on the reproductive performance of yearling Suffolk rams were investigated. The two groups (A, n = 8; B, n = 8) were given a priming period of long days (18 h Light (L): 6 h dark (D) during 1st February to 14th March. During 14th March to 9th September, group A was exposed to local light + melatonin Implants (Regulin) at 5 weekly intervals, group B was exposed to local light + melatonin Fed (M- 5250) alongwith the feed. The group (C, n = 8) in the local light during 1st February to 14th March and during 14th March to 9th September remained on local light + melatonin implants (Regulin) at 5-weekly intervals. However, the group (D, n=8) was treated as control and kept on local light environment (Lat. 51 degree 43'N) throughout the experiment. Testis diameter, sexual behaviours and semen quality were used to assess reproductive performances. The treatment to group A & B resulted in a significant advancement in high reproductive performance. The treatment to group C indicated that the abrupt application of melatonin in mid March resulted in a weak response in terms of all the criteria of assessment. The investigation indicated that seasonal fluctuations in reproductive behaviour and semen quality may be rephrased by the application of light and melatonin treatments and that these treatments may be considered for the preparation of rams for out of season breeding.