Short communication: Heat stress does not affect induced luteolysis in Holstein cows.

Heat stress (HS) has deleterious effects on bovine reproduction, including prolongation of the luteal phase in Holstein cows, perhaps due to compromised luteolysis. The objective was to characterize effects of HS on luteolytic responses of nonlactating Holstein cows given 25 or 12.5 mg of PGF2α on d 7 of the estrous cycle. Cows were randomly distributed into 2 environments: thermoneutral (n = 12; 25°C) or HS (n = 12; 36°C). In each environment, cows were treated with 2 mL of saline, 25 or 12.5 mg of PGF2α (n = 4 cows per group). The HS environment induced a significant increase in rectal temperature and respiratory rate compared with the thermoneutral environment. Heat stress did not have significant effects on luteolytic responses or circulating progesterone concentrations. Rapid and complete luteolysis occurred in all cows given 25 mg of PGF2α and in 4 of 8 cows given 12.5 mg; the other 4 cows given 12.5 mg had partial luteolysis, with circulating progesterone concentrations initially suppressed, but subsequently rebounding. Therefore, we conclude that HS does not change corpus luteum sensitivity to PGF2α.

Effects of altering the ratio of dietary n-6 to n-3 fatty acids on performance and inflammatory responses to a lipopolysaccharide challenge in lactating Holstein cows.

The study was designed to evaluate the effects of altering the ratio between n-6 and n-3 fatty acids (FA) in the diet and the intake of these FA by lactating dairy cows on lactation performance and inflammatory acute phase responses to a challenge with lipopolysaccharide (LPS). Multiparous Holstein cows (n=45) were blocked based on milk yield from d 6 to d 10 postpartum and, within each block, assigned randomly to 1 of 3 dietary treatments at 14d postpartum; treatments lasted for 90d. Diets were supplemented with a mixture of Ca salts of fish, safflower, and palm oils to create 3 different ratios of n-6 to n-3 FA; namely, 3.9, 4.9, or 5.9 parts of n-6 to 1 part of n-3 FA (R4, R5, and R6, respectively). During the first 5 wk of the study, blood was sampled weekly and analyzed for concentrations of metabolites and hormones. On d 75 postpartum, cows received an infusion of 10µg of LPS into one quarter of the mammary gland to evaluate inflammatory acute phase responses. Altering the ratio of dietary n-6 to n-3 FA was reflected in changes in the FA composition of plasma and milk fat. Reducing the ratio of n-6 to n-3 FA from R6 to R4 increased dry matter intake (24.7, 24.6, and 26.1±0.5kg/d for R6, R5, and R4, respectively), with concurrent increases in yields of 3.5% fat-corrected milk (43.4, 45.4, and 48.0±0.8kg/d), milk fat (1.53, 1.60, and 1.71±0.03kg/d), milk true protein (1.24, 1.28, and 1.32±0.02kg/d), and milk lactose (2.12, 2.19, and 2.29±0.04kg/d). After the LPS challenge, concentrations of IL-6 in plasma increased as the ratio of n-6 to n-3 FA increased (112.5, 353.4, and 365.1±86.6pg/mL for R4, R5, and R6, respectively). Elevations of body temperature and somatic cell count were greater for cows fed R5 compared with those fed R4 or R6 (41.3, 40.8, and 40.8±0.2°C; 4.33, 3.68, and 3.58±0.25×10(6)/mL, for R5, R4, and R6, respectively). Haptoglobin concentration was greatest at 24h after LPS challenge for cows fed R6. Phagocytosis and oxidative burst by neutrophils collected from circulation were unaffected by dietary treatment in the first 48h after intramammary LPS infusion. In conclusion, supplying the same quantity of FA in the diet of early lactation dairy cows but altering the ratio of the polyunsaturated FA of the n-6 to n-3 families influenced lactation performance and inflammatory responses to an LPS challenge.

Difficulties found by the technicians of animal health defense in the establishment of traceability in the supply chain of beef cattle in Brazil / Dificuldades encontradas pelos técnicos de defesa sanitária animal na implantação da rastreabilidade na cadeia produtiva de bovinos de corte no Brasil

The aim of the present study was to carry out a survey of the main difficulties found by the technicians of animal health defense in the establishment of beef cattle traceability, aiming to design indicators, suggest proposals to solve such difficulties and contribute to the formulation of national policies. A semi-structured qualitative questionnaire was designed containing 39 open and mixed multiple-choice questions sent to 125 veterinaries of the Latu sensu graduate course in Animal Health Defense of the Universidade Federal de Lavras (UFLA), Lavras, MG, Brazil. The data obtained were tabulated using EpiData® 3.1 software, with automatic control of data range and consistency, and afterward analyzed by means of descriptive and inductive statistics, using the statistical program PASW (Predictive Analytics SoftWare) version 18.0. The chief difficulties found by the techniques were concerned directly with the frequent changes in the legislation (97.6%), the lack of understanding of the norms (86.9%), and of the spread of traceability (62.8%). Among the advantages of identification and animal traceability mentioned by technicians include increasing knowledge of the quantity of livestock (97.5%), the opening and maintenance of current consumer markets (95.0%), and the control and supervision of the transit of animals (93.3%). Traceability, despite being a demand, above all of the importing consuming market, is still under evolution. Both the qualification and awareness of the raisers in relation to traceability are required.

O objetivo desta pesquisa foi realizar o levantamento das principais dificuldades encontradas pelos técnicos de defesa sanitária animal na implantação da rastreabilidade da cadeia produtiva de bovinos de corte, visando elaborar indicadores, sugerir propostas para reduzir a incidência de tais dificuldades e contribuir na formulação de políticas nacionais. Foi elaborado um questionário qualitativo semiestruturado contendo 39 questões de múltipla escolha, abertas e mistas encaminhados a 125 veterinários do curso de pós-graduação Latu sensu em Defesa Sanitária Animal da Universidade Federal de Lavras (UFLA), Lavras, MG. Os dados obtidos foram tabulados utilizando-se o programa EpiData® 3.1, com controle automático de amplitude e consistência de dados, e posteriormente analisados por meio de estatísticas descritivas e indutivas, utilizando-se o programa estatístico PASW (Predictive Analytics SoftWare) - versão 18.0. As principais dificuldades encontradas pelos técnicos relacionaram-se diretamente com as mudanças frequentes na legislação (97,6%), a falta de compreensão das normas (86,9%) e de divulgação da rastreabilidade (62,8%). Entre as vantagens da identificação e rastreabilidade animal mencionadas pelos técnicos, incluem o maior conhecimento da quantidade do rebanho (97,5%), a abertura e manutenção dos atuais mercados consumidores (95,0%) e o controle e fiscalização do trânsito de animais (93,3%). A rastreabilidade, apesar de ser uma exigência, sobretudo do mercado consumidor importador, ainda encontra-se em evolução. A qualificação e a conscientização dos pecuaristas em relação à rastreabilidade se fazem necessárias.

Efeitos do extrato da parede de levedura na digestibilidade, no escore fecal e na palatabilidade de dietas para gatos / Effects of spray-dried yeast cell wall on digestibility, score of feces, and palatability of diets for cats

Para avaliar o efeito do extrato seco da parede de levedura (EPL) sobre a digestibilidade, o escore fecal e a palatabilidade de dietas para gatos, foram realizados três ensaios experimentais. No primeiro, 20 animais adultos foram distribuídos ao acaso em quatro tratamentos: dieta comercial úmida (controle) e dieta-controle + 0,2, ou dieta-controle + 0,4 ou dieta-controle + 0,6 por cento de EPL na matéria seca. No segundo, utilizaram-se alimento seco e as mesmas proporções com o mesmo delineamento do primeiro experimento. No ensaio 3, de palatabilidade, 20 gatos adultos receberam simultaneamente dieta comercial úmida sem e com a inclusão de 0,4 por cento de EPL. No experimento 1, não foram observadas diferenças quanto à digestibilidade da matéria seca, proteína bruta, extrato etéreo, matéria orgânica e energia bruta, assim como no escore fecal; no segundo, houve aumento linear (P<0,46) no coeficiente de digestibilidade da matéria seca, e, no terceiro, observou-se efeito negativo da inclusão de 0,4 por cento sobre a palatabilidade da dieta (P<0,004). Conclui-se que a inclusão de EPL em dietas úmidas não influi na digestibilidade, mas pode comprometer a palatabilidade, e que em dietas secas há melhora da digestibilidade da matéria seca.

The effects of spray-dried yeast cell wall (YCW) were evaluated on digestibility, score of feces, and palatability of diets for cats were evaluated. Three trials were carried out. In the first, 20 adult cats were randomly allotted in four treatments: wet commercial diet (control) and control plus 0.2, 0.4, or 0.6 percent of YCW in dry matter. In the second, a commercial dry diet was tested in an equal arrangement concerning concentration of YCW and number of animals of the first trial. In the third, 20 adult cats were fed at the same time a wet diet with or without 0.4 percent YCW. In the first trial, no differences among treatments for dry matter, crude protein, ether extract, organic matter, gross energy digestibility, and faecal score were observed. In second trial, positive linear effect on dry matter digestibility (P=0.046) was observed. In the third, negative effect of 0.4 percent YCW inclusion (P=0.004) on palatability of diet was observed. It was concluded that YCW inclusion in wet diet did not effectively alter the nutrients digestibilities but it decrease the palatability. However, the YCW inclusion in dry diets can be important to improve dry matter digestibility.