Postpartum ovarian activity of Santa Ines lactating ewes fed diets containing soybean hulls as a replacement for coastcross (Cynodon sp.) hay

The Santa Ines, a Brazilian hair sheep, has a non-seasonal breeding activity. Data regarding the duration of the postpartum anestrous period in Santa Ines lactating ewes is lacking and the objective of this trial was to determine the effects of replacing neutral detergent fibre (NDF) provided by coastcross (Cynodon sp.) hay with NDF contained in soybean hulls (SH) on the postpartum ovarian activity-as measured by the serum progesterone (P(4)) concentration. Fifty-six lactating ewes (body weight 56.1 +/- 6.8 kg) were individually penned and used in a randomized complete block design with 14 blocks and four treatments. The SH NDF replaced 33 (SH33), 67 (SH67), or 100% (SH100) of the NDF contributed by coastcross hay in the control diet (SHO). This resulted in a SH inclusion at rates of 0, 25, 54, and 85% of the dietary dry matter (DM). Blood samples were collected twice weekly from the 14th to 84th day postpartum and the serum P(4) concentrations determined by radioimmunoassay (RIA). It was estimated that the 1st postpartum ovulation occurred 6 days before the date that a serum P(4) >= 1 ng/ml concentration was first recorded. The mean body condition score (BCS; 0-5 scale) was 3.0 +/- 0.19 on day 14 postpartum and the mean BCS at day 56 postpartum increased linearly (P<0.01) with the inclusion levels of SH (3.09, 3.24, 3.34, and 3.36, respectively). Treatments did not differ significantly in the induction of postpartum days to the resumption of ovarian luteal activity (34.1 +/- 15.3 days postpartum). On days 25, 50, and 75 postpartum 36.80, and 100% of the ewes had resumed ovarian activity, respectively. Nonesterified fatty acid concentration decreased quadratically (P<0.05) with the SH inclusion, with values of 0.323, 0.244, 0.204, and 0.216 mequiv./l for the SHO, SH33, SH67, and SH100 treatments being recorded, respectively. Replacement of the NDF provided by coastcross hay with the NDF from the SH did not influence the duration of the postpartum anestrous period in Santa Ines lactating ewes. Considering a 150-day gestation period and the 34 days postpartum anestrous demonstrated in the present study, the current production system of a lambing interval of 8 months (3 lambing events in 2 years) may not be optimizing the production potential and a system in which the lambing interval is shortened by at least 1 month may be feasible. (C) 2008 Elsevier B.V. All rights reserved.

Influence of Osteopontin in Bovine Uterine Tube Fluid on Sperm Binding and Fertilization in RCA-1 Lectin-treated Oocytes

This study was conducted to determine the effect of pre-exposure of oocytes to Ricinus communis (RCA-1) lectin and osteopontin (OPN) in uterine tube fluid (UTF) on in vitro sperm-egg binding and fertilization. In vitro-matured bovine oocytes were incubated (39 degrees C, 5% CO(2) in air) for 2 h in the following treatments: (i) 500 mu l of fertilization medium (FM); (ii) 250 mu l of FM with 0.25 ml of non-luteal ampullary uterine tube fluid (NLAUTF); (iii) 250 mu l of FM with 250 mu l of NLAUTF and 4 mu l of RCA-1 lectin; (iv) 250 mu l of FM with 250 mu l of NLAUTF, a rabbit polyclonal antibody (1:200) against purified bovine milk OPN, and RCA-1 lectin; (v) 500 mu l of FM and RCA-1 lectin. Following incubation, oocytes were washed, placed in FM with 2 mu g heparin, and incubated with 1 x 10(5) frozen-thawed spermatozoa per 10 oocytes. Oocytes used to assess sperm binding were stained with Hoescht 33342, and the number of sperm bound per zona pellucida counted. The remaining oocytes were fixed in acid alcohol, stained with 1% acetate-orcein and observed to determine the presence of pronuclei. More sperm bound to the zona pellucida (mean +/- SEM) when oocytes were incubated in treatment 3 (59.0 +/- 5.5) than in treatments 2 (46.4 +/- 5.6), 4 (18.1 +/- 5.4), 5 (33.4 +/- 5.6) or 1 (32.5 +/- 5.6). More oocytes were fertilized when incubated in treatment 3 (91% +/- 3.0) than in 2 (84% +/- 3.0), 4 (40% +/- 3.0), 5 (77% +/- 3.0) or 1 (76% +/- 3.0). As in previous studies, this study suggests that RCA-1 lectin enhances binding of UTF-derived OPN to bovine oocytes, resulting in increased sperm-egg binding and fertilization in vitro and a possible role in fertilization.

Sequence variation of the alpha-lactalbumin gene in Holstein and Nellore cows

The alpha-lactalbumin is a subunit of lactose-synthase, an enzyme responsible for lactose production, a disaccharide that influences milk production. Sequence variations of bovine alpha-lactalbumin have been associated with differences in milk yield. This study aimed to analyze allelic frequency differences at position-1689 (g. AG) and+15 (g. AG) of the alpha-lactalbumin gene in Holstein (Bos taurus) and Nellore (Bos indicus) cows. Blood samples were analyzed from 34 Holstein, 104 Nellore, and 99 Dairy Nellore cows using PCR-RFLP. The different RFLP patterns were sequenced and a novel sequence variation on nucleotide-46 was identified. An adenine at this position was designated as the A allele and a guanine was designated B allele. The frequencies of alleles A-1689, A-46, and A+15 differed between Holstein and both Nellore breeds. The results show that differences in alpha-lactalbumin allelic variants in the 5`-flanking and the 5`-UTR region might be associated with differences in milk production between Holstein cows and cows from Nellore breeds. However, the lack of difference between Nellore and Dairy Nellore suggests that other sequence variantions that regulate milk production might be responsible for the selection of Dairy Nellore cows with superior milk production.

The low fertility of repeat-breeder cows during summer heat stress is related to a low oocyte competence to develop into blastocysts

It was hypothesized the lower fertility of repeat-breeder (RB) Holstein cows is associated with oocyte quality and this negative effect is enhanced during summer heat stress (HS). During the summer and the winter, heifers (H; n = 36 and 34, respectively), peak-lactation (PL; n = 37 and 32, respectively), and RB (n = 36 and 31, respectively) Holstein cows were subjected to ovum retrieval to assess oocyte recovery, in vitro embryonic developmental rates, and blastocyst quality [terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-positive cells and total cell number]. The environmental temperature and humidity, respiration rate, and cutaneous and rectal temperatures were recorded in both seasons. The summer HS increased the respiration rate and the rectal temperature of PL and RB cows, and increased the cutaneous temperature and lowered the in vitro embryo production of Holstein cows and heifers. Although cleavage rate was similar among groups [H = 51.7% +/- 4.5 (n = 375), PL = 37.9% +/- 5.1 (n = 390), RB = 41.9% +/- 4.5 (n = 666)], blastocyst rate was compromised by HS, especially in RB cows [H = 30.3% +/- 4.8 (n = 244) vs. 23.3% +/- 6.4 (n = 150), PL = 22.0% +/- 4.7 (n = 191) vs. 14.6% +/- 7.6 (n = 103), RB = 22.5% +/- 5.4 (n = 413) vs. 7.9% +/- 4.3 (n = 177)]. Moreover, the fragmentation rate of RB blastocysts was enhanced during the summer, compared with winter [4.9% +/- 0.7 (n = 14) vs. 2.2% +/- 0.2 (n = 78)] and other groups [H = 2.5% +/- 0.7 (n = 13), and PL = 2.7% +/- 0.6 (n = 14)] suggesting that the association of RB fertility problems and summer HS may potentially impair oocyte quality. Our findings provide evidence of a greater sensitivity of RB oocytes to summer HS.

Effects of Ethanol on Synthesis of Prostaglandin F2 alpha in Bovine Females

Ethanol stimulates the production of prostaglandins in many species. The purpose of this study was to verify the effect of ethanol on the production of prostaglandin F2 alpha (PGF2 alpha) and luteolysis in bovine females. In the first experiment, Holstein cows at day 17 of the oestrous cycle were treated with 100% ethanol (0.05 ml/kg of body weight, IV; n = 5), saline (0.05 ml/kg of body weight, IV; n = 4) or synthetic prostaglandin (150 mu g of D-cloprostenol/cow, IM; n = 4). The plasma concentrations of 13, 14-dihydro-15-keto PGF2 alpha (PGFM; the main metabolite of PGF2 alpha measured in the peripheral blood) were assessed by radioimmunoassay (RIA). There was an acute release of PGFM in response to ethanol comparing to other treatments (p <= 0.05). However, only cows treated with PGF2 alpha underwent luteolysis. In the second experiment, endometrial explants of cross-bred beef cows (n = 4) slaughtered at day 17 of the oestrous cycle were cultured for 4 h. During the last 3 h, the explants were cultured with medium supplemented with 0, 0.1, I, 10 or 100 mu l of 100% ethanol/ml. Medium samples were collected at hours 1 and 4 and concentrations of PGF2 alpha were measured by RIA. Ethanol did not induce PGF2 alpha production by the endometrium. In conclusion, ethanol does not cause luteolysis in cows because it stimulates production of PGF2 alpha in extra-endometrial tissues.

Evaluation of somatic cell count thresholds to detect subclinical mastitis in Gyr cows

The objectives of this study were (1) to determine the sensitivity (Se) and specificity (Sp) of somatic cell count (SCC) thresholds to identify subclinical mastitis in Gyr cows caused by major and minor pathogens; (2) to study the effects of month of sampling, rear or front mammary quarters, herd, intramammary infection (IMI), and bacterial species on SCC at quarter level; and (3) to describe the prevalence of IMI in Gyr cows in commercial dairy herds. In total, 221 lactating Gyr cows from 3 commercial dairy farms were selected. Milk samples were collected from individual quarters once a month for 1 yr from all lactating cows for SCC and bacteriological analysis. Mammary quarters were considered the experimental units and the SCC results were log(10)-transformed. Four SCC thresholds (100, 200, 300 and 400 x 10(3) cells/mL) were used to determine Se and Sp to identify infected mammary quarters. The overall prevalence of IMI in quarter milk samples of Gyr cows was 49.8%, and the prevalence of minor pathogens was higher (31.9%) than that of major pathogens (17.8%). Quarter samples with microbial isolation presented higher SCC compared with negative samples. Sensitivity and Sp of selected SCC thresholds varied according to the group of pathogen (major and minor) involved in the IMI definition. Sensitivity increased and Sp decreased when mammary quarters with only major pathogens isolation were considered positive. The use of a single SCC analysis to classify quarters as uninfected or infected in Gyr cows may not be a useful test for this breed because Se and Sp of SCC at the studied thresholds were low. The occurrence of IMI and the bacterial species are the main factors responsible for SCC variation in mammary quarters of Gyr cows. Milk samples with major pathogens isolation elicited higher SCC than those with minor pathogens.

Comparison of gonadorelin products in lactating dairy cows: Efficacy based on induction of ovulation of an accessory follicle and circulating luteinizing hormone profiles

This study evaluated whether the four gonadorelin products that are commercially available in the United States produce comparable ovulation responses in lactating cows. Dairy cows at 7 d after last gonadotropin-releasing hormone (GnRH) treatment of Ovsynch (Day 7), with a corpus luteum (CL) >= 15 mm and at least one follicle >= 10 mm, were evaluated for response to GnRH treatment. Selected cows were randomized to receive (100 mu g; im): (1) Cystorelin (n = 146): (2) Factrel (n = 132): (3) Fertagyl (n = 140); or (4) Ovacyst (n = 140). On Day 14, cows were examined for Ovulation by detection of an accessory CL. Circulating luteinizing hormone (LH) concentrations were also evaluated in some cows after treatment with 100 mu g (n = 10 per group) or 50 mu g (n = 5 per group) GnRH. Statistical analyses were performed with the procedures MIXED and GLIMMIX of the SAS program. Percentage of cows ovulating differed (P < 0.01) among groups, with that for Factrel being lower (55.3%) than that for Cystorelin (76.7%), Fertagyl (73.6%), or Ovacyst (85.0%), There was no effect of batch, parity, or follicle size on ovulation response. but increasing body condition score decreased Ovulation response. There was a much greater LH release in cows treated with 100 mu g than in those treated with 50 mu g, but there were no detectable differences among products in time to LH peak, peak LH concentration, or area under the LH curve and no treatment effects nor treatment by time interactions on circulating LH profile. Thus, ovulation response to Factrel on Day 7 of the cycle was lower than that for other commercial GnRH products, although a definitive mechanism for this difference between products was not demonstrated. (C) 2009 Elsevier Inc. All rights reserved.

Tooth Replantation After Use of Euro-Coffins Solution or Bovine Milk as Storage Medium: A Histomorphometric Analysis in Dogs

Purpose: Euro-Collins solution was developed for the preservation of organs for transplantation, whose characteristics have raised interest for its use as a storage medium for avulsed teeth before replantation. This study evaluated histologically and morphometrically the healing process of dog teeth replanted after storage in Euro-Collins solution or bovine milk. Materials and Methods: Eighty roots of 4 young adult mongrel clogs were randomly assigned to 4 groups (n = 20) and the root canals were instrumented and obturated with gutta-percha and a calcium hydroxide-based sealer. After 2 weeks, the teeth were extracted and subjected to the following protocols: GI (negative control), replantation immediately after extraction; GII (positive control), bench-drying for 2 hours before replantation; GIII and GIV, immersion in 10 mL of whole bovine milk and Euro-Collins solution at 4 C, respectively, for 8 hours before replantation. The animals were sacrificed 90 days postoperatively. The pieces containing the replanted teeth were subjected to routine processing for histologic and histometric analyses under light microscopy and polarized light microscopy. Results: Root resorption was observed in all groups. GII exhibited the greatest loss of dental structure (P < .01), and inflammatory resorption was predominant in this group. Storage in milk showed poorer results than immediate replantation and storage in Euro-Collins solution (P < .01). The teeth stored in Euro-Collins solution presented similar extension of root resorption and periodontal ligament reorganization to those of immediately replanted teeth. Conclusions: The findings of this study suggest that the Euro-Collins solution is an adequate storage medium for keeping avulsed teeth for up to 8 hours before replantation. Crown Copyright (C) 2010 Published by Elsevier Inc on behalf of American Association of Oral and Maxillofacial Surgeons. All rights reserved. Oral Maxillofac Surg 68:111-119, 2010

Characterization of baboon (Papio hamadryas) milk proteins

The major proteins of baboon milk were identified as beta -lactoglobulin (beta LG), alpha -lactalbumin (alpha LA), lysozyme, lactoferrin, casein, and albumin by immobiline isoelectric focusing, SDS-PAGE, immunoblotting of gels with rabbit antisera to human alpha LA, lysozyme, and albumin and bovine beta LG and casein, and N-terminal sequencing of proteins blotted from gels. The first 30 N-terminal residues of baboon polymorphism at residue 2. The complete cDNA sequence and derived amino acid composition of beta LG were elucidated using RT-PCR amplification of poly(A)(+) mRNA purified from lactating mammary gland. Baboon beta LG identified to date. beta LG and alpha LA polymorphisms with three (A, B, and C) and two (A and B) variants, respectively, were detected by immobiline IEF, pH 4-6, of individual baboon milk samples at varying stages of lactation.

Polychlorinated Dibenzodioxins and Dibenzofurans in Butter from Different States in Australia

Nine samples of butter from producers in various states of Australia were analysed for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Detectable concentrations of 2,3,7,8-chlorine substituted PCDD/Fs were found in all samples. The mean PCDD/F concentration expressed as 2',3,7,8-TCDD equivalents (TEQs) was 0.19 pg TEQ g(-1) fat. The highest concentration (0.46 pg TEQ g(-1) fat) was observable in a sample from Victoria which is the most densely populated state. Overall the results indicate that PCDD/F concentrations in dairy products from Australia are low in comparison to the levels in dairy products of industrialized countries on the Northern Hemisphere. As expected, this study provides evidence that the environmental and consequently the human body burden of PCDD/ Fs to be relatively low in Australia.