The impact of hair coat color on longevity of Holstein cows in the tropics

Background

Over two decades of observations in the field in South East Asia and Hawai‘i suggest that majority of the commercial dairy herds are of black hair coat. Hence a simple study to determine the accuracy of the observation was conducted with two large dairy herds in Hawaii in the mid-1990s.

Methods

A retrospective study on longevity of Holstein cattle in the tropics was conducted using DairyComp-305 lactation information coupled with phenotypic evaluation of hair coat color in two large dairy farms. Cows were classified into 3 groups: a) black (B, >90%); b) black/white (BW, 50:50) and c) white (W, >90%). Cows with other hair coat distribution were excluded from the study. In farm A, 211 out of 970 cows were identified having 4 or more lactations. In farm B, 690 out of 1,350 cows were identified with 2 or more lactations for the study.

Results

The regression analyses and the Wilcoxon-Log-rank test for survival probability showed that Holstein cattle with 90% black hair coat had greater longevity compared to Holstein cattle with 90% white hair coat.

Conclusions

This study suggests that longevity of Holstein cattle in tropical regions was influenced by hair coat color and characteristics.

First Report of Leaf Spot Caused by Cercospora fukushiana on New Guinea Impatiens in Korea

New Guinea impatiens, Impatiens hawkeri W. Bull, is widely cultivated as a potted plant and garden plant. In July 2013, hundreds of young plants (cv. Fanfare) showing symptoms of leaf spot with approximately 50% incidence were found in polyethylene tunnels in Yongin City, Korea. Leaf spots were circular to oblong, reaching 6 mm or more in diameter. The spots were initially uniformly brown to reddish brown, turning gray with reddish brown margin. Diseased plants defoliated prematurely and were abandoned without marketing due to signs of discoloration and yellowing on leaves. A cercosporoid fungus was consistently observed in association with disease symptoms. Stromata were brown, small, and composed of a few swollen hyphal cells. Conidiophores were emerging through the cuticle, fasciculate (n = 2 to 20), olivaceous to brown, paler toward the apex, straight to mildly curved, geniculate, 30 to 260 μm long, 3.5 to 5 μm wide, 1- to 6-septate, and with conspicuous conidial scars. Conidia were hyaline and acicular. Smaller conidia were straight and longer conidia were mildly curved. Conidia were subacute to obtuse at the apex, truncate to obconically truncate at the base, 2- to 18-septate, 30 to 320 × 3.5 to 5.5 μm, and with thickened, darkened hila at the base. Morphological characteristics of the fungus were consistent with the previous reports of Cercospora fukushiana (Matsuura) W. Yamam. (1). Voucher specimens were housed in the Korea University herbarium (KUS). An isolate from KUS-F27438 was deposited in the Korean Agricultural Culture Collection (Accession No. KACC47640). Fungal DNA was extracted with DNeasy Plant Mini Kits (Qiagen Inc., Valencia, CA). The complete internal transcribed spacer (ITS) region of rDNA was amplified with the primers ITS1/ITS4 (4) and sequenced. The resulting sequence of 497 bp was deposited in GenBank (Accession No. KJ620981). This showed >99% similarity with sequence of C. fukushiana (EF600954) on I. balsamina from Korea. Isolate of KACC47640 was used in the pathogenicity tests. Hyphal suspensions were prepared by grinding 3-week-old colonies grown on PDA with distilled water using a mortar and pestle. Five plants were inoculated with hyphal suspensions and five plants were sprayed with sterile distilled water. The plants were covered with plastic bags to maintain a relative humidity of 100% for 24 h and then transferred to a 25 ± 2°C greenhouse with a 12-h photoperiod. Typical symptoms of necrotic spots appeared on the inoculated leaves 10 days after inoculation, and were identical to the symptoms observed in the field. C. fukushiana was re-isolated from symptomatic leaf tissues, confirming Koch's postulates. No symptoms were observed on water-inoculated control plants. Previously, leaf spots of Impatiens spp. associated with C. apii, C. balsaminae, and C. fukushiana have been reported (1,2,3). To our knowledge, this is the first report of C. fukushiana on I. hawkeri in Korea. Our observations in the nurseries of I. hawkeri suggest that low humidity with good ventilation as well as plant hygiene in greenhouses might be main strategies for preventing this disease. References: (1) C. Chupp. A Monograph of the Fungus Genus Cercospora. Ithaca, NY, 1953. (2) D. F. Farr and A. Y. Rossman. Fungal Databases. Syst. Mycol. Microbiol. Lab., online publication, ARS, USDA, retrieved March 25, 2014. (3) J. M. Soares et al. Plant Dis. 93:1214, 2009. (4) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990.

Feed consumption, growth performance and carcass evaluation of Korean Holstein bulls fed either conventional or organic diets

Feed consumption, bodyweight gain and carcass evaluation of Holstein bulls fed either conventional (CON) or organic (ORG) diets were compared. Animals were randomly assigned to either CON (n = 15) or ORG (n = 15) treatments when 6 months old. Inclusion rates of the ingredients were similar in CON and ORG diets formulated for growing (6–12 months of age) and fattening (13–18 months of age) periods. Ingredients of organic origin were used to formulate ORG growing and fattening diets. The bulls on the CON diet were vaccinated, de-wormed and treated conventionally (with antibiotics) against any sign of illness. No dietary or implant growth promotant was used. The bulls on the ORG diet were vaccinated although they were not de-wormed or treated against illness using conventional methods. Instead they were allowed to recover naturally from illness for 3 days. However, if the illness persisted beyond 3 days, they were treated using conventional methods. Consumption of concentrate and rice straw during growing, fattening and overall periods (6–18 months of age) was the same in bulls fed the CON or ORG diets. Bodyweight gain, total dry matter (concentrate and straw) intake and feed to gain ratio during growing and fattening were not affected by the treatments. Daily feed cost and feed cost for unit gain were greater in bulls fed the ORG diet than those fed the CON diet. Weight of cold carcass and different carcass cuts of the bulls were not affected by the treatment. According to the Korean beef grading system, the carcasses from bulls fed either CON or ORG diets were graded similarly but were of lower quality. The Korean beef quality grade is primarily determined by marbling score. The bulls in this study were slaughtered earlier (at 18 months of age) than the conventional slaughtering age of beef cattle (~30 months) in Korea to produce highly marbled beef. It is concluded that the bulls fed ORG diets performed equally, and produced carcasses of similar quality, to those fed CON diets. However, feed costs for a unit bodyweight gain were significantly greater in the ORG diet compared with the CON diet.

19 EFFECTS OF ESTRADIOL OR GnRH ON FOLLICULAR WAVE EMERGENCE AND PREGNANCY RATES FOR A CIDR-BASED TIMED AI PROTOCOL IN REPEAT BREEDER DAIRY COWS

Repeat breeding of a high yielding cow causes enormous economic loss to the dairy producers. In this study, we examined the effect of estradiol benzoate (EB) or GnRH on follicular wave emergence and follicular development, and on pregnancy rates for a CIDR-based timed AI (TAI) protocol in repeat breeder dairy cows. Repeat breeder cows received a CIDR device (InterAg, Hamilton, New Zealand), with an injection of 1 mg EB (SY Esrone�; Samyang, Seoul, Korea) plus 50 mg progesterone (P4; SY Ovaron�; Samyang) (EB + P4 group, n = 36) or with an injection of 250 �g Gonadorelin (GnRH, Fertagyl�; Intervet, Boxmeer, The Netherlands) (GnRH group, n = 35) at the beginning of the experiment (Day 0). On Day 7, CIDR devices were removed and all cows received PGF2� (Lutalyse�; Pharmacia & Upjohn, Puurs, Belgium). Thereafter, cows in the EB + P4 group received an injection of 1 mg EB on Day 8, and TAI 30 h later; those in the GnRH group received an injection of 250 �g GnRH on Day 9, and TAI 19 h later. In a subset of cows for both groups (15 cows from each group), the ovaries of the cows were examined by transrectal ultrasonography (Sonoace 600 with 7.5 MHz linear-array transducer; Medison Co., Seoul, Korea) every 24 h from Days 0 to 8, on Day 10, and on Day 13 for the EB + P4 group, and every 24 h from Days 0 to 9, on Day 11, and on Day 14 for the GnRH group, to observe changes in ovarian structures (follicles and corpora lutea). Pregnancy was diagnosed 35 to 60 days after TAI, using both ultrasonography and rectal palpation. Data were analyzed using Fisher's exact, Student's t-, and chi-square tests. Follicular wave emergence occurred within 7 days in 12/15 EB + P4-treated and 13/15 GnRH-treated cows (P > 0.05). The mean diameters of preovulatory follicles were smaller (P < 0.05) in the EB + P4 group (12.1 � 0.1 mm) than in the GnRH group (13.8 � 0.1 mm). However, the proportion of cows with synchronized ovulation and pregnancy rates to TAI did not differ (P > 0.05) between the EB + P4 (11/15 and 19.4%, respectively) and the GnRH (13/15 and 34.3%, respectively) groups. In conclusion, treatment with either EB or GnRH for a CIDR-based TAI protocol in repeat breeder dairy cows results in synchronous follicular wave emergence, follicular development, and ovulation, and thus similar pregnancy rates to TAI.

239 HORMONE PROFILE AND OVARIAN FOLLICLE DIAMETER IN EARLY POSTPARTUM LACTATING COWS

The purpose of this study was to assess the ovarian follicle diameter and hormone status during early postpartum in cows. Eighteen Holstein cows, aged 3.5–5.5 years and of 400–600 kg BW with normal calving, were examined every 3rd day starting from Day 15 until Day 33 postpartum. Blood samples for hormonal (progesterone (P4) and estradiol-17β (E2)) analyses were withdrawn from the coccygeal vein every 3rd day until the end of the experiment. The ovarian follicular number and size were verified and measured using a sector vaginal transducer ultrasound scanner (6.5 MHz probe, SA 600; Medison Co., Seoul, Korea). The least squares means (±SEM) are presented for each day (GLM of SAS). In postpartum cows, E2 levels were 27.09 ± 5.22 pg, 24.50 ± 5.76 pg, 26.92 ± 4.62 pg, 25.53 ± 3.74 pg, 27.47 ± 5.72 pg, 26.48 ± 8.06 pg for Days 15, 18, 21, 24, 27, 30, and 33, respectively, 28.01 ± 7.52 pg; P4 levels were 1.35 ± 1.14 ng, 2.41 ± 1.70 ng, 2.85 ± 2.26 ng, 2.88 ± 1.90 ng, 2.91 ± 1.91 ng, 3.04 ± 2.31 ng, and 4.04 ± 3.70 ng for Days 15, 18, 21, 24, 27, 30, and 33, respectively. The ovarian follicle diameter was 12.36 ± 3.31 mm, 11.91 ± 2.99 mm, 13.09 ± 3.37 mm, 13.55 ± 2.76 mm, 14.55 ± 3.68 mm, 15.64 ± 5.53 mm, 17.45 ± 3.22 mm for Days 15, 18, 21, 24, 30, and 33, respectively. The present results show that mean plasma concentration of P4 and mean follicle diameter gradually increased from Day 15 to Day 33 postpartum. It is concluded that monitoring of P4 and E2 during early postpartum period would be useful to predict the ovarian starts for early rebreeding in dairy cows.

The first discovery of a brachiosaurid from the Asian continent

Described here is a sauropod tooth from the Early Cretaceous of South Korea, similar to Brachiosaurus. The crown of the tooth is beveled off lingually so that when worn it presents a chisel-like edge. This find confirms the presence of a brachiosaurid in East Asia during the Early Cretaceous.

The oldest known tracks of web-footed birds from the lower Cretaceous of South Korea

We describe the oldest tracks of web-footed birds from the Early Cretaceous in South Korea. The tracks are characterized by a wide divarication angle and a long reversed hallux. The web is semipalmate and restricted to the proximal portion of the three forward digits. The tracks from the Early Cretaceous in South Korea are smaller than those of the Late Cretaceous, therefore confirming the trend of size increasing in the early evolution of birds as shown by skeletal fossils. The discovery of web-footed tracks with abundant non-web-footed tracks indicates that there was a considerable diversification of shore birds as early as the Early Cretaceous.