Biomedical subjects

F G Owen

Publications and source records attributed to F G Owen.

15 recordsLinked to original sources

PubMed1994

Comparison of sorghum and corn grains in early and midlactation diets for dairy cows.

Two trials were conducted to compare the effects of corn and sorghum grains on performance of early and midlactation Holstein dairy cows. In trial 1, 36 multiparous midlactation cows were assigned to one of four diets in a 2 x 2 factorial arrangement for 10 wk: 1) grain mixture containing 77% rolled corn fed in a TMR, 2) same grain fed separately from forage, 3) grain mixture containing 77% finely ground sorghum fed in a TMR, and 4) same grain fed separately from forage. Grain source and feeding methods had similar effects on milk yield, milk fat percentage, SNF, SCM, and BW. Cows fed sorghum had higher DMI; cows fed corn had greater efficiency of milk yield. In trial 2, 36 multiparous early lactation cows were assigned to one of four TMR in a 2 x 2 factorial arrangement for 9 wk: 1) TMR containing 35.5% rolled corn, 2) TMR containing 35.5% finely ground corn, 3) TMR containing 35.5% rolled sorghum, and 4) TMR containing 35.5% finely ground sorghum. Grain source produced no differences in DMI, milk yield, milk fat percentage, SCM, and BW. Cows fed finely ground grain yielded more milk than those fed rolled grain. Finely ground sorghum promoted higher milk protein and SNF percentages than did finely ground corn. Total tract starch digestibility was greater for corn than for sorghum. These two trials indicate that sorghum grain, when finely ground, supports milk yield and composition similar to that of corn.

Animal Feed↗

PubMed1989

High amounts of soyhulls for pelleted concentrate diets.

Twelve multiparous Holstein cows were used in a balanced, two-period, changeover design to evaluate soyhulls as a replacement for corn grain in lactation diets. Soyhulls constituted 0 (corn), 50 (corn-soyhull), and 95% (soyhulls) of the concentrate mixture, which was prepared as a 4.8-mm pellet. These concentrate mixtures were mixed with alfalfa silage (50:50 DM) and fed ad libitum as complete diets. Mean DM intakes averaged 23.7 kg/d and were similar for corn, corn-soyhulls, and soyhull diets. Corresponding daily milk yields averaged 29.8, 28.9, and 27.3 kg and milk fat averaged 3.13, 3.33, and 3.49%, resulting in similar 3.5% FCM yields and feed efficiency. Dry matter digestibility was higher for the corn diet (70%) and the corn-soyhull diet (69%) compared with the soyhull diet (61%). Digestibilities (%) of NDF were 55, 63, and 58; ADF were 56, 62, and 55; and CP were 66, 64, and 59 for corn, corn-soyhull, and soyhull diets, respectively. The gastrointestinal passage rate of alfalfa and of soyhulls was similar among diets. The energy value of soyhulls appears to be equal to corn in pelleted concentrates. The fat-depressing effect of pelleting a high starch (corn) concentrate was minimized by including soyhulls.

Animal Feed↗

PubMed1989

Relation of intake to digestibility of diets containing soyhulls and distillers dried grains.

Fifty-four multiparous Holstein cows were used to compare the influence of intake on digestibility of three diets. All diets contained a 50:50 ratio (dry basis) of ammoniated corn silage and concentrate. The control concentrates consisted of corn, oats, and soybean meal. The two test concentrates contained either 43.8% soyhulls or 71.6% corn distillers dried grains with solubles. Each diet was fed at three intakes. Dry cows were fed one times maintenance intake, cows producing 10 to 20 kg milk daily were fed at twice maintenance, and cows producing 27 to 49 kg daily were fed ad libitum (four times maintenance). Digestibilities of DM for the control, distillers grains, and soyhull diets, respectively, were: for dry cows, 84.1, 66.6, and 78.8%; for medium producers, 76.6, 53.8, and 74.2% and for high producers, 60.5, 44.3, and 62.8%. At ad libitum intake, the DM, NDF, ADF, and CP digestibilities were lower for control than for the soyhulls diet. Discounts per unit of maintenance of 9.3, 11.2, and 6.8% were obtained for the control, distillers grains, and soyhull diets. These results confirm the generally accepted concept of energy discounts for grain-soybean meal diets, but discounts were higher than reported previously. Compared with the control diet soyhulls appears to lower, and distillers grains increase, the discount.

Animal Feed↗

PubMed1989

Corn gluten meal and blood meal mixture for dairy cows in midlactation.

Twelve midlactation Holstein cows were assigned to a switchback design with 4-wk periods to compare a corn gluten meal and blood meal mixture with soybean meal as supplemental protein sources. All experimental diets contained 60% ammoniated corn silage, on a dry basis, and a corn and oats (2:1) basal concentrate mixture. Diets were: urea control (12.5% CP); soybean meal (16.1% CP); low protein (14.3% CP) corn gluten and blood meal mixture; and high protein (16.8% CP) corn gluten and blood meal mixture. Cows fed the control diet consumed less DM, and produced less milk containing a lower percentage of protein than cows fed other diets. Protein efficiency and milk fat percentage were higher for cows fed the control diet than for cows fed the natural protein diets. Fat-corrected milk and fat yields did not differ among diets. The high protein diets (16.1 and 16.8% CP) decreased protein efficiency and increased SNF percentage. Milk yield per unit of DM intake was higher when cows fed the lower degradable protein source (corn gluten-blood meal) than when they were fed soybean meal. The low degradable protein mixture produced a similar lactation response to soybean meal at both the high and low concentrations of total dietary protein. This study indicates that the dietary protein and undegradable protein concentration needed by midlactation Holstein fed complete mixed diets may be lower than generally recommended.

Amino Acids↗

PubMed1988

Effect of beta-carotene supplementation on reproductive performance of lactating Holstein cows.

Fifty-four lactating Holstein cows were assigned by parity and calving date to a 2 X 3 factorial arrangement of a randomized block design to determine effects of beta-carotene supplementation and ration fiber content on reproduction. Because ration fiber treatments did not differ in their effects on reproductive performance, data for beta-carotene analyses were pooled over the three rations. From 3 to 98 d postpartum, cows were individually fed either 0 or 300 mg supplemental beta-carotene daily by adding it on top of their complete mixed ration. By wk 3 postpartum, concentrations of beta-carotene in blood serum were higher in cows fed supplemental beta-carotene and remained higher throughout the experimental period. Feeding supplemental beta-carotene had no effect on the interval from the time of parturition to uterine involution, ovulation, first observed estrus, or conception. Feeding beta-carotene did not influence incidence of cystic follicles based on palpation, ovarian cyclicity based on blood progesterone patterns, peak progesterone concentrations, or first service conception rate. Cows fed supplemental beta-carotene required fewer treatments for clinical mastitis. Reproductive performance in lactating Holstein cows was not improved by feeding supplemental beta-carotene.

Animals↗

PubMed1984

Raising dairy replacement heifers: a review of NC-119 cooperative research.

Scientists at 16 experiment stations have been involved in cooperative research to study methods of increasing efficiency and for improving management of dairy replacements. This research is part of the Regional Research Project NC-119 "Improving Large Dairy Herd Management Practices." Research objectives have concerned means of increasing efficiency of producing replacements for large dairy herds. Through cooperative research, important answers were found to questions involving nutrition, housing, and management for replacement animals. Between 1977 and 1982, over 50 articles have been published in journals and trade magazines on replacement animal rearing from research of the NC-119 project. These results should have wide impact and use on livestock management.

Animal Feed↗

PubMed1983

Effects of selenium, vitamins, and ration fiber on placental retention and performance of dairy cattle.

One hundred and twenty Holstein cows were assigned to a randomized complete block design to determine effects of selenium, vitamins, and ration fiber on incidence of placental retention and other health and reproductive problems. The selenium treatment (50 mg selenium, 680 IU vitamin E) was administered as a single injection approximately 3 to 4 wk prepartum. The vitamin treatment (3 million IU vitamin A, 450,000 IU vitamin D3, 300 IU vitamin E) consisted of two injections, one administered at 3 to 4 wk prepartum and another at 2 to 3 wk postpartum. Fiber treatments were: control, 15.7% crude fiber; beet pulp, 19.3% crude fiber; and soyhull, 19.0% crude fiber. Feeding of experimental rations was begun 1 day postpartum, and the ration effect on placental retention was examined only at subsequent parturition. The overall placental retention rate of 28% was not affected by either selenium, vitamin, or combined treatments. Ration treatments did not affect the placental retention rate of 42% at subsequent parturition. Cows receiving the soyhull ration required fewer services per conception. Incidence of foot problems tended to be higher in the cows that received the combined selenium and vitamin A, D, E treatments. Supplemental selenium, vitamins A, D, and E, and ration fiber treatments did not reduce incidence of placental retention or improve most other health and reproductive measures.

Animals↗

PubMed1983

Relation of age, season, production, and health indices to iodine and beta-carotene concentrations in cow's milk.

Milk samples were collected from 82 Holstein cows during the 1st yr of a 2-yr study and from 44 of these again in the 2nd yr to determine relationships of iodine and beta-carotene concentrations in milk to age, season, placental retention, uterine infections, clinical mastitis, services per conception, and milk yield. Composite milk samples were collected twice weekly at the morning milking. Milk samples from each cow were pooled prior to analyses for the following three times: 1 to 7 wk and 8 to 14 wk postpartum in yr 1 and 1 to 6 wk postpartum in yr 2. Beta-carotene concentrations of milk were inversely related to milk yield and positively related to milk fat percentage. Concentrations tended to be higher for cows experiencing health problems, probably because of lower milk yields and the concommitent higher milk fat content. The relatively low milk iodine concentrations were not generally related to cow age, season of calving, milk yield, milk fat percentage, or to health and performance measures.

Age Factors↗

PubMed1971