LH surge in Nelore cows (Bos indicus), after induced estrus or after ovarian superestimulation

Considering, that there is limited information about the preovulatory LH surge in Zebu Cattle (Bos indicus). the purpose of the present work was to assess the LH surge in Nelore cows during the estrous cycle and after ovarian superestimulation of ovarian follicular development with FSH. This information is particularly important to improve superovulatory protocols associated with fixed-time artificial insemination. Nelore cows (n = 12) had their estrus synchronized with all intravaginal device containing progesterone (CIDR-B (R)) associated with estradiol benzoate administration (EB, 2.5 mg, i.m., Day 0). Eight days later all animals were treated with PGF2 alpha (Day 8) in the morning (8:00 h) and at night, when CIDR devices were removed (20:00 11). Starting 38 h after the first PGF2 alpha injection, blood sampling and ovarian ultrasonography took place every 4 h, during 37 consecutive hours. Frequent handling may have resulted in a stress-induced suppression of LH secretion resulting in only 3 of 12 cows having ovulations at 46.7 +/- 4.9 and 72.3 +/- 3.8 h, respectively, after removal of CIDR-B. Thirty days later, the same animals received the described hormonal treatment associated with FSH (Folltropin (R) total dose = 200 mg) administered twice a day, during 4 consecutive days, starting on Day 5. Thirty-six hours after the first injection of PGF2 alpha, to minimize stress. only seven blood samples were collected at 4 h interval each. and ultrasonography was performed every 12 h until ovulation. In 11 of 12 cows (92%) the LH surge and ovulation were observed 34.6 +/- 1.6 and 59.5 +/- 1.9 h. respectively. after removal of progesterone source. The maximum values for LH in those animals were 19.0 +/- 2.6 ng/ml (mean +/- S.E.M.). It is concluded that, in Nelore COWS submitted to a ovarian superstimulation Protocol, the LH surge occurs approximately 35 It after removal of intravaginal device containing progesterone, and approximately 12h before the LH surge observed after an induced estrus without ovarian superstimulation (C) 2008 Elsevier B.V. All rights reserved.

Nutritional strategies for the prevention of hypocalcaemia at calving for dairy cows in pasture-based systems

This review considers the current literature on the macro-mineral nutrition of the soon-to-calve, or transition, dairy cow. Calcium is the main focus, since milk fever (clinical hypocalcaemia) appears to be the most common mineral-related problem faced by the transition cow Australia-wide. The importance of minimising calcium intake and optimising the balance of the key dietary electrolytes, sodium, potassium, sulfate, and chloride, in the weeks before calving is highlighted. Excess dietary potassium can, in some situations, induce milk fever, perhaps even more effectively than excess calcium. Excess sodium remains under suspicion. In contrast, excess dietary chlorine and, to a lesser extent, sulfur can improve the ability of the cow to maintain calcium homeostasis. Diets that promote either a hypomagnesaemia or hyperphosphataemia have also the potential to precipitate milk fever at calving. Current prevention strategies focus on the use of forages with moderate to low levels of calcium, potassium, and sodium, and also rely on or utilise addition of chloride and sulfate in the form of 'anionic' feeds. Anionic salts are one example of an anionic feed. However, legitimate questions remain as to the effectiveness of anionic salts in pasture-feeding systems. The causes and prevention of milk fever are considered from the perspective of the variety of Australian feedbases. Impediments to the use of anionic feeds in Australia feeding systems are outlined. The potential for improving maternal reserves of calcium around calving to reduce the risk of milk fever is also discussed.

Use of GnRH agonist implants for long-term suppression of fertility in extensively managed heifers and cows

The ability of gonadotrophin releasing hormone (GnRH) agonist implants to suppress ovarian activity and prevent pregnancies, long-term, was examined in heifers and cows maintained under extensive management. At three cattle stations, heifers (2-year-old) and older cows (3- to 16-year-old) were assigned to a control group that received no treatment, or were treated with high-dose (12 mg, Station A) or low-dose (8 mg, Station B and Station Q GnRH agonist implants. The respective numbers of control and GnRH agonist-treated animals (heifers + cows) at each station were: Station A, 20 and 99; Station B, 19 and 89; Station C, 20 and 76. Animals were maintained with 4% bulls and monitored for pregnancy at 2-monthly intervals for approximately 12 months. Pregnancy rates for control heifers and control cows ranged from 60-90% and 80-100%, respectively, depending on the study site. The respective number of animals (heifers + cows) treated with GnRH agonist that conceived, and days to first conception, were: Station A, 9 (9%) and 336 3 days; Station B, 8 (10%) and 244 +/- 13 days; Station C, 20 (26%) and 231 +/- 3 days. Treatment with high-dose GnRH agonist prevented pregnancies for longer (similar to300 days) than treatment with low-dose GnRH agonist (similar to200 days). In the majority of heifers and cows treated with GnRH agonist, ovarian follicular growth was restricted to early antral follicles (2-4 mm). The findings indicate that GnRH agonist implants have considerable potential as a practical technology to suppress ovarian activity and control reproduction in female cattle maintained in extensive rangelands environments. The technology also has broader applications in diverse cattle production systems. (C) 2002 Elsevier Science B.V. All rights reserved.

Effect of hay on performance of Holstein calves at suckling and post-weaning

The objective of this work was to evaluate the performance of Holstein calves in suckling and post-weaning phases, intensively managed during suckling in the absence or presence of hay. Twenty-four male Holstein calves, at an average age of 15 days and initial weight of 43 kg were used in the experiment. The experimental design was completely randomized, consisting of two treatments and six replications. The treatments were as follows: 1) suckling with milk substitute + initial concentrate for calves, ad libitum + temperate grass hay (oat/ryegrass), ad libitum; 2) suckling with milk substitute + initial concentrate for calves, ad libitum. No significant difference was found between treatments for weight gain and feed conversion. However, the supply of hay caused an increase in daily dry matter intake (2.127 vs 1.894 kg). The intake of hay promoted greater stimulus to consumption of concentrate and greater weight at weaning.

Estudo de rendimentos queijeiros em leites das raças Holstein e Jersey numa exploração da ilha Terceira

Dissertação de Mestrado em Engenharia Zootécnica

In Vitro Methods for Specific IgE Detection on Cow’s Milk Allergy

Background: A new method for determining serum specific IgE (IMMULITE“ 2000 3gAllergy) has recently become available. Objective: To evaluate the clinical performance of IMMULITE 2000 in the diagnosis of cow’s milk allergy compared with that of UniCAP“. Additionally, we verified the behavior of both methods at two diagnostic decision points proposed by other authors. Methods: The study population consisted of 31 children with cow’s milk allergy (group A) and a control group of 19 atopic children without food allergy(group B). A blood sample from each child was tested using both methods and the results were compared. Results: In group A, the values for cow’s milk IgE ranged from 0.35 kU/L (the lowest common detection limit) to above 100 kU/L. In group B, the values were less than 1.1 kU/L for IMMULITE 2000 and less than 1.6 kU/L for UniCAP. An agreement of 90 % in IgE classes was obtained. Both methods demonstrated exactly the same diagnostic performance(sensitivity: 100 %; specificity: 78.9 %; negative predictive value: 100%; positive predictive value: 84.6%;efficiency: 90.2 %). The evaluation of the two methods at the two different decision points proposed in the literature showed a better positive predictive value with UniCAP, but we obtained equivalent performance with IMMULITE 2000 by choosing higher cutoff values. Conclusions: We conclude that IMMULITE 2000 is as effective as UniCAP in the diagnosis of cow’s milk allergy. Both methods can be used to obtain site-specific decision points that are population, age and disease dependent.

O Marquês de Sousa Holstein e a formação da Galeria Nacional de Pintura da Academia de Belas Artes de Lisboa

Neste trabalho definimos e desenvolvemos algumas ideias centrais sobre a Galeria Nacional de Pintura da Academia de Belas Artes de Lisboa, da formação do seu acervo a partir de 1834, com a extinção das ordens religiosas, até à abertura do Museu Nacional de Belas Artes e Arqueologia, em 1884. Em análise estão 50 anos de esforços empreendidos por vários agentes, com destaque para o marquês de Sousa Holstein, vice-­‐inspetor da Academia, em prol da organização, conservação, exposição, estudo, promoção e divulgação do seu acervo, assim como do seu enriquecimento por meio de transferências, aquisições ou doações que estão na origem do mais relevante museu público de arte nacional.

Estudo sôbre a variação da produção leiteira na raça holandesa malhada de preto

The authors studied the effects of calving time, season and time elapsed after calving on milk production of the Holstein Friesian Breed of the "Escola Superior de Agricultura "Luiz de Queiroz" (Piracicaba, Brasil), 180 lactation periods of 300 days were studied, with 15 calvings in each month. Statistical analysis of the data proved : 1. That calving in May, June, July or August, that is, in the driest months, the cows give a milk production 17,3% larger than calving in December, January, February, March or April. August is the best month for calving, and February is the worst. 2. Spring is the most favorable, and Autumn the most unfavorable season for milk production. 3. The decrease of milk production during the lactation period depends largely on calving time. But, on the whole, linear regression can be used as a good aproximation, with a correlation coefficient r = - 0,9926 and a monthly decrease, per month elapsed after calving, of 8,06 percent of the general mean. 4. Diagram 1 shows the effects of calving month on milk production. The limits of 5%, 1% and l%o of probabilities are given there.

Estudo comparativo entre silagem de milho e cana taquara na alimentação suplementar de vacas leiteiras

The A. A. compare corn silage (Zea mays L.) with sugar cane (Saccharum sinensis Roxb.) in the supplementary feeding of dairy cow. Both the feeds were studied in relation to the following points: composition and nutritive value; influence of milk production, milk fat, milk acidity and body weight; cost of production. Both corn silage and sugar cane were analysed by ordinary methods, and their digestibility was determined by means of digestibility coefficients; their composition and nutritive value are, practically, equivalent, but silage showed slight superiority. The feeding experiment was carried out with two groups of six Holstein Friesian cows each, of the Escola Superior de Agricultura "Luiz de Queiroz" herd. Both groups were fed with the same basic concentrates mixture, calculeted according to MORRISON. During the various periods of the experiment, only the roughage supplement varied. The supplementary feeding consisted of 15 kg of chopped sugar cane or corn, silage, per day and per cow, given in two daily meals in the barn. At 4,30 p.m., the cows are set free in the field, where they pass the over night. The experiment was divided into six periods, in which there was a gradative change of the supplementary feeding between the two groups. The milk was weighed every day; the analysis of milk fat and acidity and the weighing of the animals, were made only on the first three days of every week. The analysis of data showed that: a) Milk production was increased significantly by silage feeding; b) The ri was not any influence on milk fat; c) The silage caused higher milk acidity; d) The sugar cane gave a greater increase of body weight. The cost of production of corn silage was 2,12 time higher, than sugar cane, hence, although the silage gave a higher milk production, its use is not economical, compared with sugar cane, in our conditions.

Nota sôbre um possível fator sub-letal em gado Holstein-Friesian

In this note the A. A. relate the occurrence of a possible sub-lethal factor, on the Holstein-Friesian herd of Escola Superior de Agricultura "Luiz de Queiroz", Piracicaba. The sire Horto was mated with his own mother, Brisa, and so, were obtained two calves, a male and a female, consecutively. Both the calves presented flexion and deviation of the fore legs. The sire's death has not alloved further observations. The study of these history cases excludes the mother's nutritional deficiency, as the cause of related phenomenon. In the consulted literature, VEIGA and MEAD et al. relate similar cases, although these are observed in other breeds of cattle The A. A. admit that cause of occurrence is a possible sublethal recessive factor, put in evidence by inbreeding.

City of Holstein, June 30, 2003

City Audit Report

Effects of gradual replacement of rapeseed cake with linseed cake in a grass silage-based diet for dairy cows

Selostus: Rypsipuristeen asteittainen korvaaminen pellavapuristeella lypsylehmien säilörehuun perustuvassa ruokinnassa

The effects of added glycerol or unprotected free fatty acids or a combination of the two on silage intake, milk production, rumen fermentation and diet digestibility in cows given grass silage based diets

Selostus: Väkirehuun lisätyn glyserolin tai vapaiden rasvahappojen tai näiden yhdistelmän vaikutus maidontuotantoon ja pötsifermentaatioon ruokittaessa lypsylehmiä säilörehuun perustuvalla ruokinnalla

Evaluation of the spot urine sampling technique to assess urinary pseudouridine excretion in lactating dairy cows

Selostus: Mahdollisuus lyhytaikaisen virtsankeruun käyttöön lypsylehmien virtsan pseudouridiinin erityksen määrittämisessä