L. O. Gilmore’s research while affiliated with The Ohio State University and other places

Records from 8,627 new-born calves by 532 sires were subjected to a least-squares analysis of variance from which were partitioned the effects of year and month of conception, twin versus single births, and services per conception on the frequency and type of abnormalities produced. Pertinent data were recorded on 4,796 Holstein-Friesians, 2,030 Guernseys, and 1,081 Jerseys from 132 Ohio herds. Highly significant differences were found associated with year and month of conception. There was a highly significant lower frequency of organismic abnormalities, stillbirths, and total affected calves among single (1.76, 2.66, 6.26%) as compared to twin births (6.00, 14.06, 22.37%, respectively), with a breed interaction found. A sex-breed interaction appeared in the percentage of abnormalities for the classes for bone, cartilage, and joints, and for the proportion of all calves with abnormalities. A greater number of stillbirth and total calves affected were found for calves resulting from three or more services than for those resulting from two or fewer services. Sex-ratio was found not to be associated with the number of services required for conception. A gene component apparently influences the number of calves affected by organismic, bone-cartilage-joint, and total abnormalities. A sex difference appeared in the frequency with which generalized abnormalities occurred.

Six different least-squares analyses were carried out on 280 records from first through fourth completed lactations on milk yield and the percentages, respectively, of total solids, fat, nonfat-solids (NFS), protein, and pregnancy NFS. These rec- ords were from 121 Holstein cows in one herd. Two-factor interactions between lac- tion nmnber, gestation length, and season of calving also were considered. Milk yield of a cow increased as site advanced successively from one lactation to another, with concomitant decrease in content of total solids. For protein content there was no significant difference among lactations. Cows pregnant for seven months or more produced significantly (P < 0.05) higher protein content in their mill< than those pregnant for a shorter time. Cows l.}rcg'nant for five to seven months and three to five months during their 305-day lactation did not (lifter significantly in their protein content, although those having gestations of three months or less pr(,- ,bleed significantly (P < 0.05) less l)r(,- t,in. Cows calving during autumn a,,l winter produced milk significantly big'her in fat content tl:an those salving (Iuri~g spring and summer. The highest pr()tein content was found in milk from the second lactation of eows calving durillg sitting' and smmner. ()l' the eonstitnents studied, fat was the ,Host variable one, folh)wed by total solids, protein, and NFS.

The rate of milk secretion does not seem to be related to intramammary pressure when the milking interval does not exceed 12 hr and daily production does not ex- ceed 65 to 70 lb. At higher levels of production there is a question as to whether the secretion rate is diminished or whether the apparent decrease in secretion rate is due to reabsorption. The question of complementary milk and its effect on the rate of nfilk secretion during the next milking interval has been the subject of numerous research reports (2, 4, 6, 8-10, ;12, 13). The production level of the cows used and the length of the experimental periods were quite variable. In general, it has been concluded that the back pressure within the mammary gland does not affect the milk secretion rate until the milking interval is somewhere between 12 and 16 hr~ or until 80% of the udder storage ca- pacity is used (2, 5, 9, 12, 13, 16). The feeding programs in the above experiments were not discussed. The importance of properly evaluating daily milk production when oxytocin is used has been recognized and discussed by Adams and Allen (1), Donker et al. (5), and Zaks and Pavlov (16). The level of oxytocin required for normal letdown and for removal of comple- mentary milk has been determined by Donker et al. (5) and Cuto et al. (3) for the cow and by Kon and Cowie for the goat (7). Normal letdown can be accomplished with 0.5 to 1.0 IU of oxytocin, and a mininmm of 1.5 IU of oxytoein will remove complementary milk. It was of interest to determine if high-producing cows, being fed to express their maximum pro- ducing ability, would have the same milk secre- tion rate on 2 X- as on 4X-a-day milking. Materials and Methods Eight cows (four Jerseys and four Holsteins) from the Ohio Agricultural Research and De- velopment Center herd were assigned to this experiment. Two types of rations were used,

The purpose of this paper is to indicate the frequency of congenital anomalies in cattle and to record data dealing with the influence of environmental and hereditary factors on their occurrence.Approximately 5,000 calves of the Holstein, Guernsey, and Jersey breeds were divided into normal and abnormal animals. Abnormality was defined as any anatomical defect observed by the cooperating dairymen. The abnormalities reported were divided into five major groups: general abnormalities, abnormalities of ectodermal, mesodermal, and neurectodermal derivatives and calves born dead with no other observable defect. Environmental and genetic factors were tested for an association with the number of abnormal animals reported and the type of abnormality reported, by the chi-square test of independence; 6.26% of the calves born were abnormal. A significant association of sire, with the number of abnormal animals reported, was demonstrated. A highly significant association of twins and abnormal gestation length with the number of abnormal animals was shown. Twins were highly significantly associated with type of abnormality reported, as was breed. No significant association was found between sex, number of services required for conception, breed, level of herd production or inbreeding, and the number of abnormal animals reported. No significant association could be shown between number of services required for conception or sex and type of abnormality reported.