From the results of the previously described experiments, the following conclusions were drawn: 1. Boric acid increases the solubility of calcium d-saccharate in water. An increase in the concentration of boric acid results in an increase in the solubility of the saccharate. 2. Boric acid in solution reacts with calcium d-saccharate to form a new compound to which the name calcium boro-saccharate has been given. 3. A solution containing 10 parts acid, 37.5 parts calcium d-saccharate and 100 parts calcium gluconate in 500 parts distilled water is stable and is less toxic for rabbits and no more toxic for cows, when injected intravenously, than is the commercial product, Calcium-Boro-Gluconate. 4. The intravenous injection of either of these solutions into cows causes an immediate, marked rise in the serum calcium level. This rise is followed by a rapid drop, and, in the case of C-B-S-G Solution, there is a second rise in about one-half hour after injection. 5. The special centrifuge tubes for the determination of serum calcium are not reliable. Changes in construction and technic are necessary before the efficacy of such tubes can be improved. / Master of Science

The purpose of this study was to investigate the effect of prepartum and postpartum nutrition on milk production of commercial beef cows. Forty-three Angus or Angus X Holstein females, ranging in age from 2 to 6 yr, were randomly assigned by age and percentage Holstein within age to one of two prepartum grazing treatments (PRE). All females, regardless of PRE, were assigned at calving to receive the same post-calving nutritional energy. Females were assigned at calving by age, percentage Holstein within age, prepartum nutritional treatment and calving date to one of two milking groups. Milk weight (grams), milk composition (fat, protein, lactose, solids-not-fat, somatic cell count), dam body condition score (1 to 9), dam body weight, dam backfat thickness, loineye area, calf weaning weight and postpartum interval to estrus were all evaluated. Milk removal occurred biweekly by vacuum milking machine after intravenous injection of 20 IU of oxytocin. Samples were weighed and taken for milk analysis and determination of milk components. At 76± 10 d post-calving, females were assigned by age, percentage Holstein within age, prepartum nutritional treatment, and calving date to receive one of two postpartum nutritional treatments (POST). Females continued to be milked by machine biweekly until calves were weaned 199 ± 10 d. Differences in grazing level prior to calving significantly effected calf birth weights, with dams on the prepartum restricted grazing being lighter in weight at birth, 36.69 ± .68 and 38.95 ± .81 kg for PRE-L and PRE-H groups, respectively, however grazing differences did not effect calf weaning weight, calf gain or calf average daily gain. POST nutritional treatments significantly effected all calf performance traits with 37.10±.70, 38.54±.88; 196.89±4.9, 213.33±6.2; 159.79±4.8, 174.78±6.0; .809±.024, .888±.030; for birth weight, weaning weight, calf gain and calf average daily gain from cows on the POST -M or POST -H nutritional treatments, respectively. Pre-partum nutrition effected milk production (P < .001) with dams from the PRE-L grazing group producing less milk, 5622 ± 75 vs 6888 ±80 g. Postpartum energy also effected milk production with dams on the POST-H energy level producing more milk than dams from the POST-M group. Percentages of fat, protein, lactose and solids-not-fat were not different between the prepartum or postpartum diets (P>. 10). Somatic cell count was negatively correlated with dam milk production (P< .03). Postpartum interval to estrus was shorter for the PRE-L group than for the PRE-H, 43 ± 4 vs 53 ± 4 d. / Master of Science

The objective of these experiments was to determine the effects of and/or interactions among estrous synchronization treatments, reproductive status, and stage of the estrous cycle on estrous response (ER), first service conception rates (CR), pregnancy rates (PR), and embryonic mortality (EM) after 25 d of gestation. Angus or Angus crossbred cattle (n=391) at two locations were assigned to receive either melengestrol acetate for 7 d (MGA-PGF; .5 mg/hd/d, n=136) or progesterone releasing intravaginal device for 7 d (PRID-PGF; n=139) or to serve as untreated controls (n=116). All animals in MGA and PRID treated groups coincidentally received 25 mg prostaglandin F₂α (PGF) on the final day of treatment. Real time, B-mode, ultrasound with a 7.5 mHz linear-array transducer was used to conduct three ovarian scans at 7-d intervals beginning 7 d prior to initiation of treatment. Jugular blood samples were collected at each scanning period. Serum was harvested and stored at 4°C until radioimmunoassayed for progesterone (P4). Serum P4 levels in conjunction with ovarian scans were used to determine cycling status and stage of the estrous cycle at initiation of treatment. Cattle treated with PRID-PGF exhibited a greater synchronized ER (P < .06) than MGA-treated cattle. Cycling animals had a greater ER than noncycling animals, regardless of treatment (P < .01). Anestrous postpartum cows and prepubertal heifers treated with PRID-PGF exhibited a greater ER (P < .05) within 7 d than either MGA-treated or untreated control animals. Conception rates of cattle treated with PRID-PGF beginning late (> Day 16) in the estrous cycle were improved over those of MGA-treated cattle (P < .13) at the same stage. Pregnancy rate at 21 d was higher in PRID-treated cattle than untreated controls (P < .01). Ultrasound scans for embryonic viability were conducted at 25, 45, and 65 d of gestation. Calving data was collected to characterize EM between 65 d and term. The majority of embryonic loss occurring after 25 d of pregnancy occurred before 45 d. Synchronization treatment had no effect on the extent of EM occurring after 25 d of gestation. Embryonic mortality occurring between d 45 and 65 (2%) and between d 65 and term (3%) when combined were similar in magnitude to EM occurring between 25 and 45 d of gestation (4.8%). In conclusion, PRID for 7 d combined with PGF was a superior synchronization treatment for the mixed group of cyclic and anestrous cattle. / Master of Science