Previous studies of dairy cattle have indicated that heifers and cows in hot, cold and moderate weather had different patterns of sexual activities. The purpose of this study was to compare distribution of sexual activities within estrus of dairy cattle. Three groups of lactating cows in hot, cold and moderate weather and a group of heifers in cold weather were observed. Estrus for each individual was divided into 12 equal periods. Sexual activities for 3 and 6 hours before and after estrus were also observed. The numbers of mounts and distribution of total sexual activities was analyzed. Mounts received per animal per period for all four groups were significantly different. Heifers had significantly more mounts than cows with 5.8 mounts per animal per period. Cows in hot weather had significantly less mounts than other groups with 1.2 mounts per animal per group. Cows in cold and moderate weather had similar numbers of mounts with 2.9 and 2.4 mounts per animal per period, respectively. This was significantly fewer mounts than were received by heifers but a significantly higher number of mounts than received by cows in hot weather. There was much individual variation; however, the distribution of mounts and activities per period did not significantly differ across groups. There were trends for cows in hot weather to have rest periods within estrus where less mounting occurred. Secondary sexual activities before and after standing estrus were less intense than during estrus. Secondary sexual activities were greater in the three hours before and after estrus compared to the three to six hours before and after estrus.

The cattle shown from 1981 to 1984 at the American Angus Breeders' Futurity were studied to determine the relationship between linear measurements and the judge's subjective placings. Linear measurements taken prior to the showing included wither height, hip height, and body length for both bulls and heifers. In addition body weight and scrotal circumference were recorded for bulls. A total of 624 cattle were studied-- 407 heifers and 217 bulls. The cattle were divided into five groups by age and sex to analyze the annual difference in means and standard deviations for all recorded measurements. Among all five groups of cattle, hip height increased at the fastest rate from 1981 to 1984. All measurements had a positive increase except body weight and scrotal circumference. The older bulls decreased by 61.67 lbs. in weight from 1981 to 1984 and decreased by 1.78 in. in scrotal circumference between 1983 and 1984. Coefficients of correlation were obtained using the recorded measurements along with age for all five groups. Wither height showed the closest association to other measurements. Among all five groups body length had the most inconsistent association to other measurements, primarily due to difficulty involved in obtaining an accurate body length measurement. Spearman's coefficient of rank correlation was conducted to determine which measurements the judges were giving most emphasis in the showring. It seems apparent that judges are continuing to select for larger framed cattle, placing greater emphasis on wither and hip height measurements and lesser emphasis on body weight and scrotal circumference. The findings in this study support the fact that judges are selecting for larger framed, later maturing cattle with little if any selection being placed upon present weight or indicators of future reproductive performance.

Crete Koate® product originally intended to be utilized for absorbing excess moisture and reducing knee abrasions of baby pigs raised in confinement, was tested as a hematinic for young pigs. Four treatments were studied: (1) T-NI, pigs receiving no iron; (2) T-IS, pigs receiving a 2 ml intramuscular injection of iron-dextran at 2 days of age; (3) T-CK, pigs raised in pens treated daily with Crete Koate; (4) T-ISCK, pics receiving an intramuscular injection of iron-dextran on day 2 whose pens received daily treatments of Crete Koate. Hemoglobin levels were used as an indicator of iron status in the body and weights were used as a measure of production. Blood samples taken at 14 days of age revealed differences (P<.01) in hemoglobin levels among treatments. Those treatments supplying iron, T-IS, T-CK, and T-ISCK, maintained higher (P>.01) hemoglobin levels than the control, T-NI. Weights did not significantly differ among treatment groups at either 14 or 28 days (P>.10). There was no observable difference in 'Knee scuffing among treatments. However, those pens receiving Crete Koate appeared to stay drier and cleaner. Results of this study suggest that Crete Koate may be capable of supplying iron for hemoglobin synthesis and production equivalent to that of iron-dextran.

The purpose of this study was to determine differences between littermate boars and barrows for performance and carcass traits in the Iowa and Northeast Iowa Swine Testing Stations. Data were obtained from 917 litters including 1,804 boars and 917 barrows. The data included 1,086 boars and 581 barrows from the Iowa Station at Ames, Iowa, and 718 boars and 336 barrows from the Northeast Iowa Station at New Hampton, Iowa. The Iowa Station data were obtained over a period of 12 seasons from the fall of 1979 through the fall of 1985, and the data from the Northeast Iowa Station were collected in eight seasons from the fall of 1981 through the spring of 1985. The spring testing season included pigs born from November through March, and the fall testing season included pigs born from May through September. Littermate boars and barrows from the following purebred breeds were used: Berkshire, Chester White, Duroc, Hampshire, Landrace, Poland China, Spotted, and Yorkshire. Boars grew .03 (2.21+/-.20 vs. 2.18+/-.21) and .10 (2.21+/-.18 vs. 2.11+/-.22) pounds/day faster (P<.01) than littermate barrows in the Iowa and Northeast Iowa Stations. Boars had .58 (.80+/-.08 vs. 1.38+/-.20) inches less (P<.01) backfat than littermate barrows (N=581) in the Iowa Station. In the Northeast Iowa Station, boars were significantly (P<.01) leaner than barrows when comparing average backfat of boars with carcass backfat measurements of Ilttermate barrows at the tenth rib (.76+/-.06 vs. 1.06+/-.21) or the average of three carcass backfat measurements (.75+/-.08 vs. 1.29+/-.18 and .79+/-.05 vs. 1.31+/-.19). Boars had .67 (5.49+/-.42 vs. 4.82+/-.67) and .66 (5.62+/-.28 vs. 4.96+/-.65) square inches larger (P<.01) loin eye areas than littermate barrows in the Iowa and Northeast Iowa Stations, respectively. The t test revealed no significant (P>.05) differences between boars and barrows for average daily gain among the eight major breeds in the Iowa Station. However, at the Northeast Iowa Station, the Duroc (2.39+/-.19 vs. 2.12+/-.21) and Hampshire (2.16+/-.17 vs. 2.07+/-.24) boars grew significantly faster (P<.01) than littermate barrows. The t test also revealed that boars averaged seven days (156.00+/-10.78 vs. 163.00+/-12.90) younger (P<.01) at 230 pounds than barrows in the Northeast Iowa Station. Although the sample size was small and the differences nonsignificant, there were some breeds in which barrows appeared to grow faster than boars. The I test for boar-barrow differences among breeds revealed that boars had significantly (P<.01) less average backfat than littermate barrows for eight major breeds in the Iowa Station and for seven breeds in the Northeast Iowa Station. For both stations, the differences in backfat thickness between boars and barrows was lowest for the Hampshire breed and the greatest differences were between boars and barrows in the Chester White, Yorkshire, Berkshire and Landrace breeds. The t test for loin eye area revealed that boars had significantly (P<.01 or .05) greater loin eye area than barrows for all breeds except Poland China in the Iowa Station and Landrace in the Northeast Iowa Station. The sex differences between littermate boars and barrows for backfat and loin eye area were significantly different (P<.01) for all years and seasons in the Iowa and Northeast Iowa Stations. The sex differences between littermate boars and barrows for backfat and loin eye area have been increasing in both stations with the largest increase occurring during the last five years. The differences between boars and barrows for days to 230 pounds were significantly different (P<.01) In all years and seasons for both stations. In comparing data for 1981 and 1985, both boars and barrows averaged ten days younger at 230 pounds In 1985 than in 1981. Coefficients of correlation for various measurements of performance and carcass cutability between littermate boars and barrows were determined. In general, there were positive associations between boar and barrow data; however, the correlations were relatively low. The predictive value of the barrow data appears to be of little use In estimating breeding values for boars. Although a limited number of Chester White pens were included in this study, the coefficients of correlation between littermate boars and barrows suggest that castration may have a different effect upon performance and carcass cutability of Chester White than for other breeds. Unfortunately for Chester White breeders, there appears to be a much higher positive correlation between average daily gain and beckfat thickness for Chester White boars and barrows than for other breeds. In other breeds, the correlation between growth rate and backfat is low enough to allow simultaneous progress for improving both traits. A similar desirable low correlation was found between growth rate and loin eye area for other breeds. The coefficients of correlation between backfat and loin eye area were greater for barrows than boars, suggesting that errors of measurement may have been prevalent in the boar data. Large errors In measurement of boar backfat could account for some or all of the increased difference in backfat thickness observed between littermate boars and barrows during recent years.

A study of the reproductive performance of 179 dairy cows during the period from December 1978 through March 1984 was conducted at the Western Kentucky University Farm, Bowling Green, Kentucky. The climatic data showed seasonal variation in temperature as follows: winter 3.10C, spring 15.7°C, summer 23.8°C, and fall 12.0°C. The seasonal humidity was similar for winter (81.2%), spring (83.4%), and fall (85.3%); but for summer it was considerably higher (89.4%). The conception rate varied through all the months but was lowest during the summer months. Seasonal data for conception rate were obtained and the results were as follows: winter 54.1%, spring 46.4%, summer 15.6% and fall 39.0%. Low fertility during summer months was associated with high air temperatures and high relative humidities. The coefficient of correlation for temperature vs. conception was low (-0.15) because there was low fertility in some winter months and in some summer months. The coefficient of correlation for humidity vs. conception was high (-0.65), and the coefficient of determination was 42%. A completely randomized design and analysis were used, resulting in significant differences among seasonal fertility rates but no significant differences among months within seasons. Significant differences were found for the following comparisons: winter vs. spring, summer, and fall; spring vs. winter, summer, and fall; and summer vs. spring, fall, and winter. The total services involved were 546, and the total conceptions obtained were 155--resulting in a service per conception ratio of 3.52. The average number of days open was 177 (79 cows). The average number of days in the calving interval was 457 (63 cows).

The calves born in the 1979 and 1980 calf crops at Sam Sells and Sons' Polled Hereford Farm in Moultrie, Georgia, were used in a study comparing immature body measurements with subsequent growth. The measurements taken at birth included weight, front leg length, front cannon bone length, and rear cannon bone length. In addition, hip height was measured at one hundred days, seven months, and twelve months of age. Weight was taken at seven months, twelve months and fifteen months of age. The data were analyzed in four groups according to year of birth and sex. Coefficients of correlation were determined for all measurement combinations. Birth measurements alone accounted for an insignificant amount of the variability in twelve-month weight. Among the four groups studied, seven-month weight showed inconsistent associations to height and weight at twelve and fifteen months of age. This was due primarily to the amount of environmental influences involved in weight at seven months. Multiple regression analyses were conducted using twelve-month weight as a dependent variable and immature body measures as independent variables. An equation using one hundred-day hip height alone accounted for seventy-six percent of the variability in twelvemonth weight. Another equation including two independent variables, one hundred-day hip height and seven-month weight, accounted for eighty percent of the variability in twelvemonth weight. When twelve-month height was used for a dependent variable, one hundred-day hip height and rear cannon bone length at birth accounted for seventy percent of the variability. The coefficients of correlation and multiple regression equations reported in this study support the fact that linear measurements are a more consistent measure of size in immature calves than weight alone. Also, linear measurements show little or no variation due to environmental conditions such as age of dam, unpartitioned maternal ability and physiological changes associated with puberty. The findings support the hypothesis that immature linear skeletal measurements are accurate predictors of subsequent growth in Polled Hereford cattle.

The effects of chemical additives on the fermentation pattern and subsequent feeding value of corn silage was investigated over a two year period. Corn plants harvested in August 1967 (Experiment I) were ensiled with no additive, 3.50 per cent area, or urea-mineral mix supplying an equal amount of urea. Those harvested in August 1968 (Experiment II) were ensiled with no additive, 0.50 per cent urea, or 0.75 per cent urea. The nutritive value of these silages was evaluated chemically and by lactation trials. :he addition of urea alone, or in combination with minerals elevated the initial pH and buffered against reduction of pH during fermentation. Urea-mineral combination exhibited a stronger buffering action than urea alone. Data obtained during the first 25 days of fermentation in Experiment II indicated that acetic acid essentially completed after 5 days. Lactic production was acid production continued throughout the 25-day period. The production of propionic, butyric, and lactic acids was significantly increased by increased amounts c: urea (P<.01). Acetic acid production was significantly increased (P<.01) by the addition of 0.75 per cent urea but was slightly, although not significantly, depressed by the addition of 0.50 per cent urea. In both experiments the treated silages tended to have less crude fiber, ether extract, and nitrogen-free-extract, but more ash and crude protein than the control silages. The crude protein content appeared to be elevated in an amount corresponding to the amount of urea added. The effects of fermentation on urea were studied in Experiment II. Approximately 72.7, 65.3, and 66.6 per cent of the initial nitrogen as urea in the control, 0.50 per cent urea, and 0.75 per cent urea silages, respectively, was converted to other forms. The increase in NH 3 -N accounted for 22.8, 44.4, and 24.8 per cent of this decrease in urea-N in the control, 0.50 per cent urea, and 0.75 per cent urea silages, respectively. In the lactation trials, 24 Holstein cows were arranged In a 3 x 3 Latin Square design. Experimental silages were fed ad libitum. The diets were isonitrogenous and isccaloric. No significant difference was noted in milk production, silage consumption, and body weight change between COWS fed the control and 0.50 per cent urea silages in both experiments. Cows fed the urea--ineral silage in Experiment I, produced significantly less milk, consumed significantly less silage, and gained significantly less body weight than did cows fed the control and 0.50 per cent urea silages (P<.01, P<.01, P<.05, respectively). In Experiment II, cows fed the control and 0.50 per cent urea silages consumed significantly more silage dry matter than cows fed the 0.75 per cent urea silage (P<.01). Cows fed the control silage gained significantly more weight than did those fed the 0.75 per cent urea silage (P<.05), whereas, cows fed 0.50 per cent urea silage were not different from either the control or 0.75 per cent urea group in this respect. No significant differences in FCM production were noted among treatment groups.

The purpose of this study was to evaluate the use of female selected sex-sorted semen and to determine the association of variables on the success of Western Kentucky University’s Dairy Farm. Official breeding and calving records (n=144) were used to determine the relation of lactation number, breeding season, breeding number, breeding year and semen type on pregnancy results, sex of offspring, and the mortality of the offspring. Previous research has shown pregnancy results can be influenced by lactation number, breeding season, number of breedings and semen type. Results from this study show that pregnancy results were not associated with lactation number (P=0.21), breeding year (P=0.22), breeding number (P=0.52) or semen type (P=0.99). Breeding season was associated with pregnancy results (P=0.04). Lactation number (P=0.40), breeding season (P=0.20) or breeding number (P=0.12) did not influence the sex of the offspring. The year of breeding and semen type (conventional or sexed) had a significant or close to significant effect on the sex of the offspring (P=0.01) and (P=0.06). The mortality of offspring was not associated with lactation number (P=0.46), breeding season (P=0.94), breeding year (P=0.76), breeding number (P=0.40) or semen type (P=0.49).

Excessive phosphorus (P) excreted by animals can affect water quality and cause eutrophication. Better understanding of factors that influence P utilization and excretion in horses may reduce the environmental impact of P. Two animal experiments were conducted that examined P excretion by horses. The efficacy of titanium dioxide as an external marker to calculate digestibility was studied concurrently with both animal experiments. Additionally, pasture P concentrations were evaluated over the growing season using near-infrared spectroscopy (NIRS). Experiment 1 examined P excretion by post-lactational mares fed a low P diet immediately prior to weaning compared to non-lactating controls fed an adequate P diet. Post-lactational mares excreted more P compared to controls. Experiment 2 compared P excretion in horses fed to lose, maintain, or gain weight. Horses fed to lose weight tended to excrete more fecal P compared to horses fed to gain weight and had increased markers of bone turnover. The efficacy of titanium dioxide for estimating fecal output from limited fecal grab samples was variable. Titanium dioxide may be useful in situations where many fecal samples are collected over 5 d, but may not be as accurate if one fecal grab sample is expected to be representative of fecal output. Experiment 3 focused on examining the changes in pasture mineral concentration over the season using NIRS. A discussion of how these results may inform equine P supplementation programs is included. Overall, the work in this dissertation suggests that factors that influence P excretion in the horse include the dietary availability of P, physiological status, and active weight change. These variables can be incorporated into feeding programs to meet horses’ needs more closely while minimizing P excretion in the environment.

Mastitis and milk quality affect every dairy farmer across the globe. Sand bedded freestalls are the industry standard for cow comfort, welfare, and the control of environmental mastitis. Compost bedded packs may be a viable alternative to the sand bedded freestall. Compost bedded packs are maintained at a consistent level of moisture, nutrients, and aeration to favor compost microorganisms. Greater bacteria counts in bedding have traditionally been associated with increased mastitis rates and mastitis pathogens can be found in the pack and on the teats of cattle housed in even well managed compost bedded pack barns. In spite of this, herd SCC often remains low in well managed herds. The relationship between stress and comfort in the housing environment was a primary focus of this research. Cows housed in environments with low stress and high comfort may be better able to defend themselves against pathogens. Establishing changes in immune function in response to housing environment would improve milk quality by contributing to the knowledge of how mastitis-causing pathogens are contracted. An additional goal of this research was to determine the effect of compost bedded pack barns on thermoduric bacteria populations. Due to the increased temperatures associated with composting, thermoduric bacteria capable of surviving pasteurization are of potential concern in compost bedded packs. This research will investigate potential differences in thermoduric bacteria counts between compost bedded packs and sand bedded freestalls.