Control of PDD in dairy herds in the United States is essential for maximizing animal health, production, and profitability. A survey was conducted to determine use of footbaths on dairy farms in Northeastern NY and VT. The survey found, significantly more farms were using footbaths than were not (71 versus 27 farms, respectively). Copper sulfate (n = 59) was most frequently reported product used and footbath waste was disposed of to manure storage by 83.8% of farms. Research was conducted to examine these animal management and waste disposal practices on crop growth, soil, and manure storage. Greenhouse studies were conducted with objectives of determining effects of application of high Cu dairy manure on growth and quality of forage grasses and effect of excess of Cu applied from dairy manure on soil Cu concentrations. In 3 experiments, orchardgrass (Dactylis glomerata L.) and timothy (Phleum pretense L.), were tested. Treatments were 0, 5.6, and 11.2 kg Cu/ha from CuSO4 in dairy manure that was incorporated into a sandy loam (Study 1 and 2) or a silt loam (Study 2) soil. Study 3 evaluated 0, 27.1, 54.3, and 81.4 kg/ha of Cu incorporated in a silt loam soil. Two years of research were conducted with the objectives of evaluating effects of the application of dairy manure with high Cu concentrations on growth and yield of corn (Zea mays L.) for silage and soil Cu concentrations. Treatments were 0, 9.12, and 18.23 kg Cu/ha and were applied to the same plots in 2006 and 2007. The 3 treatment were tested on early and late maturity corn hybrids. Two studies were conducted to examine the effects of excess Cu on manure in storage. Study 1 was conducted in the summer of 2006 to examine the effects over time of excess Cu on stored manure. Study 2 was conducted in the summer of 2007 to examine the effects of excess Cu on manure after 2 weeks of storage and subsequent effects of application to orchardgrass, timothy, reed canarygrass (Phalaris arundinacea L.), and alfalfa (Medicago sativa L.). Finally, soils collected from all research projects were used to evaluate the relationship of the extraction of Cu by CaCl2, Modified Morgan’s, and Mehlich-3 to total Cu measured by nitric acid digestion, soil CEC (meq/100g), SOM (%), and Cu applications. From the greenhouse studies it was found that orchardgrass appeared to be more tolerant to high Cu application from dairy manure than timothy and root Cu concentration was consistently higher than shoot Cu concentration. Two annual applications of high-Cu dairy manure had no effects on growth, yield, or composition of corn. There was no evidence of vertical movement of Cu in the soil after 2 annual applications to corn. Copper treatments did not change manure composition and did not change manure differently over time. Total bacterial counts were not affected by increasing the Cu concentration in the manure. The concentration of available Cu in the manure increased as the Cu treatment and total Cu in the manure increased. A single application of high Cu manure did not affect the yield or quality of orchardgrass, timothy, reed canarygrass, or alfalfa that it was applied to. As reported in other research the Cu concentration of alfalfa was higher than that of the grasses. Overall, Cu application rate has a large affect on the measure of Cu concentration in the soil and the strongest relationship to Cu extracted by Mehlich-3. The Mehlich-3 and Modified Morgan’s extractions are both good predictors of Cu extracted by CaCl2. Mehlich-3 is a very good predictor of Cu extracted by Modified Morgan’s.

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This study is based on the hypotheses that technical advances have increased the efficiency with which factor-inputs are converted into output on dairy farms, and have induced shifts in the input structure of dairy farms. The method used to test these hypotheses has been to measure changes in: (⊥) the real savings in the use of factors during the period 1946 to 1954 and then to make a linear projection of the trend, which existed during the 1946 - 1954 period, into 1961; and (2) the relative importance of inputs over the period 1946 to 1954. Inputs have been divided into seven categories viz: feed purchased; custom work; labour; cost of operating farm machinery and repairs and maintenance of machinery, equipment and buildings; depreciation; interest on investment; and miscellaneous items. Milk was the only output considered in this thesis. Efficiency was measured as the ratio of total output to total input within a given year. The results of the study support the hypothesis. They show that shifts had taken place in the relative importance between labour, and the other factors of production, and that associated with these shifts had been an increase in overall efficiency between 1946 and 1954 of 20 percent, which if projected to 1961 would amount to 34 percent. Thus technological progress had resulted in gains in overall efficiency, with which inputs were converted into output on dairy farms. The study has also shown the types of adjustments on dairy farms which were necessary in order to achieve gains in overall efficiency. It has also been indicated that the dairy farm industry of the Lower Fraser Valley has the potentialities for increasing its output of milk in response to future increases in demand, which growth in population would render necessary. / Land and Food Systems, Faculty of / Graduate

The main objectives of this investigation were to determine class averages for crossbreds and for backcrosses, to study heterosis, results of polyallel analysis, sire combining ability and age of maximum milk production in crosses. Production records (60,931) of dairy cattle under test by the Dairy Herd Improvement Association in British Columbia for the years 1958-1961 inclusive were used. Out of these records, 56,765 were of purebreeds (including high grades), 3113 of cross breds and 1053 of backcrosses. To decide class averages for crossbreds, a t-test and F-test (using the average of milk and fat indexes for t-test and fat-corrected-milk values for F-test) were carried out. There were no significant differences between production records of various groups of crossbreds at 5% level of probability in both the tests. Therefore, these data indicate that a single set of class averages may be recommended for all crossbred dairy cows. Fat-corrected-milk values for purebreeds, crossbreds and backcrosses were compared. Nine out of 12 comparisons made indicated that backcrosses were closer in production to the parental breed used in backcrossing than to the crossbreds of the breeds concerned. Therefore, for the purposes of establishing base averages and of calculating indexes, it is considered that backcrosses should be classified with the parental breed used in backcrossing. Fat-corrected-milk values were also used for a comparison of purebreeds and their corresponding crossbreds to detect the presence or absence of heterosis. Hybrid vigour was demonstrated in all crossbreds except Holstein-Ayrshire. A polyallel analysis was applied to the data using the average of milk and fat indexes for the two-year-old and three-year-old production records of the crossbreds. It was found that the general combining ability and reciprical effect were highly significant. Specific combining ability was significant only at the 5% level. Heritability was calculated for fat-corrected-milk values and found to be 0.47. Purebreed and crossbreed daughter indexes were used from 10 artificial insemination sires for a within-breed-of-sire comparison. The analyses indicated that the best sire for purebreeding is not necessarily recommended for crossbreeding. The average production of crossbreds, grouped according to age, showed a sharp increase from 2 years to 4 years, followed by a relatively small increase from 4 years to 7 years. There was a gradual drop in production after the seventh year. Crossbreds reached their maximum milk production at 7 years of age. / Land and Food Systems, Faculty of / Graduate

Studies to monitor bovine ovarian function with regard to follicular growth and turnover, and corpus luteum (CL) growth and function, were carried out during three different reproductive states: the postpartum anestrus period, early pregnancy and during the artificial control of the estrous cycle with the synthetic progestin norgestomet. Ovarian function was monitored using a combination of ultrasound imaging and progesterone (P₄) profiling. Growth of large antral follicles (> 10mm) was found to commence very early in the postpartum period and ovulation occurred as early as the first week postpartum. Short first postpartum estrous cycles (< 18 days) were observed in a minority of the animals studied (4/10) and the occurance of a short first cycle was not associated with an early ovulation following parturition. Growth of large antral follicles occurred in a wave-like pattern during the postpartum estrous cycles with most cycles being composed of two waves of growth, the second wave resulting in the growth of the ovulatory follicle. A wave-like pattern of growth of large dominant follicles was also seen through the first 60 days of pregnancy. There was no difference between pregnant and non pregnant cows in the size of the dominant follicle found on day 20. In addition no effect of the CL could be found on the side on which the dominant follicle was found, it was as likely to be on the ipsilateral ovary to the CL as on the contra lateral. The gonadotrophin ihibitor norgestomet did not effect follicular dynamics in the presence of the CL, however in the absence of a CL the dominant follicle present was maintained for the duration of the norgestomet treatment and then went on to ovulate upon norgestomet removal. In addition there was no new growth of antral follicles in the absence of a CL. Norgestomet did not effect the temporal relationship between the onset of standing estrus, the LH surge and ovulation. The results of the three studies suggest that a wavelike pattern of growth of large antral follicles is a characteristic of the bovine ovary regardless of the reproductive state. / Land and Food Systems, Faculty of / Graduate

Please read the abstract in the section, 00front of this document</P< / Dissertation (MSc (Agric) Production Physiology)--University of Pretoria, 2008. / Animal and Wildlife Sciences / MSc Agric / unrestricted

The objectives of the studies described in this thesis were to quantify livestock behavior and improve animal wellbeing. Subjective and objective evaluation methods can be used as an estimation parameter of animal welfare. The first study used behavioral methods to evaluate the analgesic effects of a pharmaceutical drug in lame dairy cattle. Lameness pain was evaluated by measuring weight shifting, locomotion score, and visual analog scale score. Correlation analysis of the three methods determined cohesion among subjective methods. The second study measured the behavioral effects of ramp exposure during the nursery period of swine development. Loading can be a stressful event for hogs which may cause an increased incidence of stress. Conditioning methods and environmental enrichment reduced the duration of time spent on the loading ramp and decreased production inputs. Both trials identified methods to improve animal welfare and future efforts will aid in the development of positive management strategies.

A microcomputer simulation was developed as a tool for analyzing the dairy replacement enterprise. The simulation was constructed using a spreadsheet, and equations were developed using stepwise regression procedures. The simulation predicted BW, DMI, and fixed and variable costs for each week of a heifer's life from birth to calving. After calving, milk yield, feed costs, and fixed costs were predicted for first lactation. Variation was estimated for each predicted variable, thus enabling normal distribution of predicted values. The simulation was used to analyze profitability of various growth rate scenarios and marginal costs associated with changing feed costs, heat detection efficiency, death loss, and abortion rate. For the growth analysis, six scenarios were evaluated: 1) normal growth from 5 wk to calving, 2) Accelerated growth from 5 wk to calving, 3) slow growth from 5 wk to calving, 4) normal Growth from 5 wk to 14 mo and accelerated growth from 14 mo to calving, 5) accelerated growth from 5 wk to 14 mo and control growth from 14 mo to calving, and 6) slow growth from 5 wk to 14 mo and accelerated growth from 14 mo to calving. Average daily gain from birth to calving was 0.78, 0.90, 0.62, 0.78,0.75, and 0.80 kg/d, and age at calving was 25.1, 23.1, 27.4, 23.1, 23.0, and 23.1 mo,respectively. Total rearing cost from birth to calving was 1246, 1220, 1275, 1148, 1148, and 1138 $/heifer, and net profit through first lactation was 399, 407, 319, 441, 432, and 463 $/heifer, respectively. Results suggest modest growth rates from birth to calving (0.75 to 0.80 kg/d) with reduced first calving age <24 mo) is most desirable, and delayed calving (>24 mo) is costly and merits higher growth rates with earlier breeding. Increasing feed costs, death loss at birth through weaning, or abortion rate one percentage point increased rearing costs 7.33, 2.40, and 9.10 $/heifer. Improving heat detection efficiency one percentage point reduced rearing costs $2.80/heifer. For the heat detection analysis, the relationship between age at first calving and total rearing costs was -584.38 + 73.49 x calving age in mo (R-squared = 0.97), for ages at first calving from 24.4 to 26.6 mo. Results of this research agree with field observations that managers should strive for early calving (<24 mo) and modest growth rates (0.75 to 0.80 kg/d) to maximize profitability of the replacement enterprise. In addition, death loss, abortion rate, and heat detection efficiency are variables that a manager must control to minimize heifer rearing costs. / Ph. D.

Extensive research has been conducted to decrease the environmental impacts of dairy farming by using forages containing condensed tannins (CT). In this study, it was hypothesized that feeding CT-containing birdsfoot trefoil (Lotus corniculatus, BFT) to lactating dairy cows would result in a decrease in N degradation in the rumen, causing a shift in N partitioning into milk and manure outputs, compared with alfalfa hay. Urine N is more volatile and harmful to the environment compared with fecal N. By reducing urine N, overall N utilization efficiency can improve. It was our goal to verify how the changes in N partitioning would affect the overall N utilization efficiency by dairy cows fed BFT hay-based high-forage diet. The results in this report showed that feeding BFT-hay diet reduced protein degradation in the rumen, decreased N excreted to milk and urine, and increased N excretion into feces, resulting in decreased urinary-N:fecal-N ratio due to feeding BFT-hay diet. However, the change in the N excretion routes was not associated with N utilization efficiency, which may have resulted from poor nutritive quality of BFT hay. Although the BFT hay fed in the current study was in a very mature condition and was of poor quality, DM intake and milk yield were similar in both treatments. Therefore, it is implied that BFT hay can replace alfalfa hay in dairy rations, because even poor quality BFT hay compared with alfalfa hay led to similar lactational performance and a beneficial shift in N excretion into environment.

Microbial inoculants are forage additive products that contain viable bacteria and sometimes a combination of enzymes. Bacterial inoculants are used primarily for two reasons; first to gain rapid fermentation and second to decrease or inhibit spoilage. Inoculants work by shifting the fermentation of forage crops. The shift of fermentation causes preservation of nutrients, dry matter (DM) and occasionally increases animal performance. Most inoculants contain lactic acid producing bacteria to aid in shifting fermentation to lactic acid and away from acetic acid and ethanol production; however some inoculants aid in aerobic stability enhancement by production of acetic acid.. Although most inoculants are homoermenters, two other types are heterofermentative and combination inoculants. Prior to inoculation a few things should be considered, has there been peer-reviewed research published to support claims made by the company and does the inoculant meet your overall goal (i.e. fermentation enhancement, aerobic stability enhancement etc.).