Results 171 to 180 of about 148,897 (216)
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Sexual stimulation as a luteolytic inductor in beef heifers
Theriogenology, 2019The objective was to determine if the introduction of androgenized steers or females in oestrus has luteolytic effects during the advanced luteal phase (Day 12-13 of the cycle, Day of ovulation = Day 0) in heifers by analysing the changes in corpus luteum (CL) size and perfused area together with progesterone (P4) secretion.
María Victoria, Felipez +2 more
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Progestin and Prostaglandin for Estrous Synchronization in Beef Heifers
Journal of Animal Science, 1986Seventy-eight Simmental-Angus-Hereford crossbred yearling heifers, in 1983, and 99 similar heifers, in 1984, were used to compare two estrous synchrony regimens. One treatment group (SMB) was synchronized using the commercially available Syncro-Mate-B procedure, which involved placing a norgestomet implant in the ear for 9 d and giving an injection of ...
J C, Whittier +2 more
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The effect of parasite control on fertility in beef heifers
Veterinary Parasitology, 1991The effect of anthelmintic treatment on the growth and conception rate in beef heifers was studied in southwestern Virginia, USA. Forty mixed-breed heifers were divided into two groups at weaning and placed on experimental pastures. Control heifers did not receive anthelmintic treatment, while animals in the treatment group were given ivermectin (200 ...
A M, Zajac +3 more
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Serum copper concentrations in beef cows and heifers
Journal of the American Veterinary Medical Association, 1999Objective To characterize serum copper status of cows and heifers in beef cow-calf herds throughout the United States and to evaluate use of copper supplements in those herds. Design Cross-sectional survey. Animals 2,007 cows and heifers from 256 herds in 18 states.
D A, Dargatz +3 more
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Factors Influencing Calving Difficulty in Beef Heifers
Journal of Animal Science, 1989Records of 547, 2-yr-old heifers of three breed groups were used to evaluate the relative influence of dam's body and pelvic measurements, calf birth weight, sire birth weight and some relative measures (ratios) of calf birth weight and dam weight at calving on calving difficulty. The data were analyzed by regression and least squares procedures.
A, Naazie, M M, Makarechian, R T, Berg
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Endometrial biopsy inBos indicusbeef heifers
Reproduction in Domestic Animals, 2017ContentsAn endometrial biopsy allows for a comprehensive assessment of the uterine environment of a breeding female. Although routine in mares, devices used for endometrial biopsies are impracticable in heifers due to the size and structure of the cervix.
O Ramirez‐Garzon +5 more
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Nutritional management of replacement beef heifers: a review
Journal of Animal Science, 1993Systems to produce replacement heifers to calve initially at 2 yr of age and at 12-mo intervals thereafter require integrated forage-animal management plans. The process of developing heifers as replacements must begin during the cow-calf production phase.
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Factors affecting puberty in replacement beef heifers
Theriogenology, 2016Puberty is defined as when ovulation is accompanied by visual signs of estrus and subsequent normal luteal function. Age at puberty is an important trait in relation to reproductive success, productive life span, and profitability in beef operations. Although puberty and initiation of normal estrous cycles are complex events that require maturation of ...
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Nonpuberal estrus in beef heifers.
Journal of animal science, 1986The frequency of occurrence of behavioral estrus without subsequent development of functional luteal tissue (termed nonpuberal estrus, NPE), was determined in 43 Simmental X Hereford-Brahman heifers. Blood samples were collected weekly from the start of the study to first behavioral estrus and then daily from d 1 (d 0 = estrus) through d 14 following ...
L M, Rutter, R D, Randel
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Energy metabolism in lactating beef heifers.
Journal of Animal Science, 2000To obtain measurements of energy balance in lactating beef cows, respiration calorimetry and digestion trials were conducted using seven lactating (613 kg BW) and three nonlactating (598 kg BW) Hereford x Angus heifers fed a pelleted 75% alfalfa:25% concentrate diet.
C K, Reynolds, H F, Tyrrell
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