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Fatores que influenciam a temperatura corporal de vacas da raça holandesa lactantesDrago Filho, Eraldo Laerte January 2017 (has links)
Orientador: Jose Luiz Moraes Vasconcelos / Resumo: O objetivo do experimento foi avaliar a temperatura vaginal em parâmetros produtivos e reprodutivos. Vacas Holandesas lactantes n = 641 (209 primíparas 36,9 ± 6,54 kg de leite / d; 432 multíparas 43,9 ± 9,77 kg de leite / d) tiveram a temperatura vaginal monitorada através de termômetros, anexados a um dispositivo intravaginal como parte de um protocolo de IATF. A temperatura vaginal foi registrada a cada 10 minutos durante três dias. A temperatura ambiente e a umidade relativa (ITU) foram mensuradas usando um termômetro externo colocado dentro do barracão. Os dados foram analisados com SAS 9.4 usando correlação de Pearson, ANOVA e regressão logística. Calculou-se o estresse térmico com base na porcentagem de tempo que a vaca ficou com uma temperatura vaginal ≥ 39,1°C (PCT). As vacas foram classificadas através de quartis (AltaPCT (3º quartil; PCT-60%) e BaixaPCT; PCT-16%) para PCT e o mediana para produção de leite, que eram diferentes para primíparas e multíparas. Houve uma baixa correlação entre ITU e produção de leite com PCT (r = 0,01), indicando maior variação na termorregulação. O BaixaPCT (22,4 e 13,9%) e o AltaPCT (12,6 e 9,7%) reduziram significativamente o P/AI no dia 30 e 52 pós-IA (P < 0,01) e sem interações com ordem, escore de condição corporal e ITU observados. A cor da pelagem e a espessura do couro não influenciaram o PCT (P > 0,1). Entretanto houve interação entre cor de pelagem, PCT e produção de leite, onde independente da PCT e produção de leite, vacas d... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre
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Equipamento de ordenha, manejo e fatores de risco para patologias não infecciosas das tetas de vacas leiteirasGouvêa, Fábio Lucas Rezende de January 2019 (has links)
Orientador: José Carlos de Figueredo Pantoja / Resumo: Os objetivos deste estudo foram descrever características do equipamento e manejo de ordenha, características morfológicas das tetas, prevalência de patologias não infecciosas, e identificar fatores de risco para tais patologias. Quarenta rebanhos foram visitados para realização de levantamento de dados produtivos e de manejo, avaliação estática do equipamento de ordenha, avaliação dinâmica de parâmetros de vácuo coletados no conjunto de ordenha e dos procedimentos adotados pelos colaboradores. Houve grande heterogeneidade nas dimensões das tetas avaliadas. A prevalência de edema, anel de base, cianose, hemorragia petequial e hiperqueratose grave foi 7,81%, 45,47%, 14,69%, 0,63% e 11,88%, respectivamente. Formato e posição da teta foram associados à observação de hiperqueratose. Paridade, extração automática do conjunto, nível de vácuo e duração da fase B do ciclo de pulsação foram associados à prevalência de edema. Paridade, formato da teta e tempo de ordenha foram associadas à prevalência de anel de base. Fluxo de leite bimodal, extração automática, condição da teteira, sobreordenha, nível de vácuo na cabeça da teteira e comprimento da fase B foram associados à prevalência de cianose. Práticas indesejáveis, tais como uso de teteiras desgastadas, falta de manutenção do equipamento, ausência de extração automática, longo tempo de ordenha e sobreordenha e rotina de trabalho sequencial foram mais frequentemente observadas em rebanhos com até 50 vacas, destacando dificuldades té... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objectives of this study were to describe characteristics of milking equipment and management, teat morphological characteristics, prevalence of noninfectious pathologies, and to identify risk factors for such pathologies. Forty herds were visited to collect production and management data, evaluation of the milking equipment, dynamic evaluation of vacuum parameters collected from the milking cluster, and milking procedures adopted on the farms. There was great heterogeneity in teat dimensions. The prevalence of edema, ring at the teat base, cyanosis, petechial hemorrhage, and severe hyperkeratosis was 7.81%, 45.47%, 14.69%, 0.63%, and 11.88%, respectively. Teat shape and position were associated with teat-end hyperkeratosis. Parity, automatic extraction of clusters, vacuum level, and length of the pulsation cycle´s B phase were associated with prevalence of edema. Parity, teat shape and milking duration were associated with prevalence of ring at the teat base. Bimodal milk flow, automatic extraction, liner condition, overmilking, vacuum at the mouthpiece chamber, and phase B´s length were associated with prevalence of cyanosis. Undesirable practices, such as the use of worn liners, lack of equipment maintenance, lack of automatic extraction, long milking and overmilking times, and sequential working routine were most often observed in small herds (< 50 cows), highlighting technical and structural difficulties faced by producers. Results of this study contribute to improve... (Complete abstract click electronic access below) / Mestre
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The Effects of Feeding Chelated Metal Proteinates on Milk Production and Reproductive Performance in Holstein Dairy CowsHardcastle, Ben James 01 May 1995 (has links)
Twenty-two primiparous Holstein heifers were allocated to one of two treatments. Treatments consisted of: l) basal ration plus 226.8 g inorganic mineral supplement (control); and 2) basal ration plus 226.8 g inorganic mineral and metal proteinate supplement (50:50). Individual heifer performance was measured during the final l 0 weeks of the prepartum period. Feed intake and refusals were recorded daily. Individual heifer body weights recorded weekly did not differ significantly. Blood samples taken at 4-week intervals did not differ in plasma concentration between treatments. Calf birth weights for control heifers were not significantly higher than calves from the treatment heifers.
The same twenty-two Holstein heifers used in the prepartum period were assigned to the same treatment groups for the 20-week postpartum lactation period. Treatments consisted of: 1) basal ration plus 453.6 g inorganic mineral supplement (control); and 2) basal ration plus 453.6 g inorganic mineral supplement and metal proteinate supplement (50:50). Dry matter intake and milk yield were recorded daily. Milk composition and body weights were recorded weekly. Feed and fecal samples were collected to determine apparent nutrient digestibility, using acid insoluble ash as an internal marker. Blood samples taken at. 4-week intervals showed no significant difference (Ρ < .05) in plasma mineral composition. No statistical difference was observed in milk yield between treatments (Ρ < .05). Percent lactose in milk samples from the treatment group was significantly higher (Ρ < .05) than that of the control group. Apparent nutrient digestibilities did not differ between treatment groups. Starting on day 5 postpartum, cows were observed for signs of estrus and bred at first observed estrus after 60 days postpartum. Days to first estrus were significantly lower (Ρ< .05) in the treatment group. The feet of each heifer were critically evaluated and scored according to six separate criteria at the start and at the finish of the trial. The texture category of the hoof evaluation score was significantly lower (Ρ < .05), favoring the treatment group over the control group.
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Validity of Hourly Breast Milk Expression in Estimating Maternal Milk Production and Infant Breast Milk IntakeRoznowski, Dayna M. 25 July 2019 (has links)
No description available.
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Associations of Pre- and Post-Partum Lying Time with Metabolic Status, Health, Survival, and Performance of Dairy CowsPineiro, Juan M., Pineiro 27 July 2018 (has links)
No description available.
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Epidemiologic investigations of mycobacterium avium subspecies paratuberculosis infections in Ohio dairy herdsNaugle, Alecia Larew 06 August 2003 (has links)
No description available.
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Effects of Growth Hormone and Insulin-Like Growth Factor-I on Milk Protein Gene Expression and Nutrient Uptake and Cell Proliferation in Clonal Bovine Mammary Epithelial CellsZhou, Yinli 13 September 2007 (has links)
The overall objective of this research was to further understand the mechanism by which growth hormone (GH) stimulates milk production in cattle. Three studies were conducted toward this objective. In the first study, the effects of GH and insulin-like growth factor-I (IGF-I), a major mediator of GH action in vivo, on cell proliferation, nutrient transport, and milk protein gene expression in bovine mammary epithelial cell line MAC-T cells were determined. GH increased (P < 0.01) expression of four major milk protein genes in MAC-T cells transfected with GHR expression plasmid. Cotransfection analyses indicated that GH also stimulated (P < 0.01) luciferase reporter gene expression from the promoters of the four milk protein genes in MAC-T cells. These findings together with the fact that GHR mRNA and protein are expressed in the epithelial cells of the bovine mammary gland suggest that GH may directly stimulate milk protein gene expression in the mammary gland. This study also showed that IGF-I increased the proliferation (P < 0.01) and amino acid transport (P < 0.05) in MAC-T cells. Because GH is known to stimulate IGF-I production in animals, IGF-I-mediated mammary epithelial cell proliferation and amino acid uptake may be additional mechanisms by which GH increases milk production in cattle. In the second study, the role of connective tissue growth factor (CTGF) on IGF-I-stimulated proliferation of MAC-T cells was investigated. A microarray analysis revealed that IGF-I decreased CTGF mRNA expression in MAC-T cells (P < 0.01). This effect of IGF-I was further found to be mediated through the PI-3 kinase/Akt signaling pathway from the IGF-I receptor (IGF-IR). CTGF alone stimulated MAC-T cell proliferation (P < 0.01). However, together with IGF-I, CTGF attenuated the proliferating effect of IGF-I on MAC-T cells, and this attenuation was reversed by additional IGF-I. Therefore, IGF-I inhibition of CTGF expression may benefit IGF-I stimulation of MAC-T cell proliferation. CTGF had no effect on IGF-I-induced phosphorylation of IGF-IR or total IGF-IR expression in MAC-T cells, suggesting that CTGF may attenuate IGF-I stimulation of MAC-T cell proliferation through a postreceptor inhibition of the IGF-IR signaling pathway. In the third study, whether a milk yield-associated T/A polymorphism in exon 8 of the bovine GHR gene affected GHR signaling was determined. It was found that the two corresponding GHR variants did not differ in mediating GH induction of gene expression, suggesting that the two GHR variants are not functionally different and hence are unlikely to mediate different effects of GH on milk production. In summary, the results of this dissertation research suggest that GH may directly stimulate milk protein gene expression and indirectly stimulate mammary epithelial cell proliferation and amino acid uptake through IGF-I, thereby stimulating milk production in cattle. The results also suggest that IGF-I stimulation of mammary epithelia cell proliferation may involve an inhibition of CTGF expression in the cells. / Ph. D.
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Pre- and postpartum nutritional effects on milk production, milk composition, calf weaning weight and postpartum reproductive performance of commercial beef cowsKearnan, Jeffrey Mark 12 March 2009 (has links)
The purpose of this study was to investigate the effect of prepartum and postpartum nutrition on milk production of commercial beef cows. Forty-three Angus or Angus X Holstein females, ranging in age from 2 to 6 yr, were randomly assigned by age and percentage Holstein within age to one of two prepartum grazing treatments (PRE). All females, regardless of PRE, were assigned at calving to receive the same post-calving nutritional energy. Females were assigned at calving by age, percentage Holstein within age, prepartum nutritional treatment and calving date to one of two milking groups. Milk weight (grams), milk composition (fat, protein, lactose, solids-not-fat, somatic cell count), dam body condition score (1 to 9), dam body weight, dam backfat thickness, loineye area, calf weaning weight and postpartum interval to estrus were all evaluated. Milk removal occurred biweekly by vacuum milking machine after intravenous injection of 20 IU of oxytocin. Samples were weighed and taken for milk analysis and determination of milk components. At 76± 10 d post-calving, females were assigned by age, percentage Holstein within age, prepartum nutritional treatment, and calving date to receive one of two postpartum nutritional treatments (POST). Females continued to be milked by machine biweekly until calves were weaned 199 ± 10 d. Differences in grazing level prior to calving significantly effected calf birth weights, with dams on the prepartum restricted grazing being lighter in weight at birth, 36.69 ± .68 and 38.95 ± .81 kg for PRE-L and PRE-H groups, respectively, however grazing differences did not effect calf weaning weight, calf gain or calf average daily gain. POST nutritional treatments significantly effected all calf performance traits with 37.10±.70, 38.54±.88; 196.89±4.9, 213.33±6.2; 159.79±4.8, 174.78±6.0; .809±.024, .888±.030; for birth weight, weaning weight, calf gain and calf average daily gain from cows on the POST -M or POST -H nutritional treatments, respectively. Pre-partum nutrition effected milk production (P < .001) with dams from the PRE-L grazing group producing less milk, 5622 ± 75 vs 6888 ±80 g. Postpartum energy also effected milk production with dams on the POST-H energy level producing more milk than dams from the POST-M group. Percentages of fat, protein, lactose and solids-not-fat were not different between the prepartum or postpartum diets (P>. 10). Somatic cell count was negatively correlated with dam milk production (P< .03). Postpartum interval to estrus was shorter for the PRE-L group than for the PRE-H, 43 ± 4 vs 53 ± 4 d. / Master of Science
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Comportamento ingestivo e produtividade de vacas das raças jersey e holandesa em pastagens de azevém anual / Ingestive behaviour and productivity of cows of jersey and holstein s breeds in annual ryegrass pasturesMaixner, Adriano Rudi 02 December 2011 (has links)
A trial was conducted to evaluate the ingestive behavior, pastures dynamics and productivity
of cows of the Jersey and Holstein s breeds grazing annual-ryegrass (Lolium multiflorum) in
northwestern Rio Grande do Sul. From April 29th to October 29th of 2010, eleven tester-cows
of each breed group, and a variable number of regulator-cows, were managed in rotational
grazing with variable stocking rate and received a commercial concentrate at a rate of 1 kg of
concentrate for every 3 liters of milk produced up to 15 liters/cow/day. Eight tester-cows of
each breed group, two of each stage of lactation, were used in evaluations of ingestive
behavior, held on September 27th and October 27th and during the two-day occupation of the
paddocks. Pastures management allowed similar conditions between the two tested herds and
showed to not limit production of pasture and animals. Adopted supplementation criteria
reflected in the provision of large quantities of concentrate for Holstein cows, which had
individual milk productions, milk corrected to 4% of fat and total solids higher than the Jersey
breed. The Holstein herd was managed with higher stocking rates than the Jersey herd, which
reflected directly in superiority on animal production and supply of concentrate per area for
the Holstein s herd. For each kilogram of concentrate supplied individually, the Jersey cows
had higher individual productions than Holstein, suggesting advantages for the Jersey breed
on the conversion of the supplement in animal products and on the economic aspect. The
advance of the grazing season and structural changes in the sward conditioned reductions in
grazing time and increased rumination, for both breeds, but did not affect the time required for
completing other activities. Jersey cows spent more time on grazing activities and less on
rumination than Holstein breed, probably to compensate the lower level of supplementation.
Only in the second evaluation time (October) difference was found in bite rate between the
breeds, with superiority for the Holstein cows, and for both breeds, late lactation cows
presented larger number of steps between feeding stations than the cows in early lactation.
Additionally, in Holstein, the increase in the number of steps between feeding stations was
accompanied by a reduction in sward height of the grazing site visited. Differences between
stages of lactation were seen only on variables that represent choices at the level of grazing
patches (sward height of the grazing site visited and the number of steps between feeding
stations), indicating that adaptations of animals in different physiological stages occur at the
level of displacement through the pasture and realization of the bit. / Foram estudados o comportamento ingestivo, a dinâmica das pastagens e a produtividade de
vacas das raças Jersey e Holandesa em pastagens de azevém anual (Lolium multiflorum) no
noroeste do Rio Grande do Sul. O experimento foi conduzido de 29/04/2010 a 29/10/2010,
sendo utilizadas, no total, onze vacas-testes de cada grupo racial e um número variável de
vacas-reguladoras. Oito vacas de cada grupo racial, duas de cada estágio de lactação, foram
utilizadas nas avaliações do comportamento ingestivo, realizadas em 27/9 e 27/10 e durante
os dois dias de ocupação dos potreiros. Os animais foram manejados em pastoreio rotativo
com lotação variável e receberam concentrado comercial à razão de 1 kg de concentrado para
cada 3 litros de leite produzidos acima de 15 litros/vaca/dia. O manejo das pastagens permitiu
condições de pastejo semelhantes entre as duas raças testadas e se mostrou não limitante à
produção de pasto e dos animais. O critério de suplementação adotado refletiu no
fornecimento de maiores quantidades de concentrado para as vacas da raça Holandesa, que
apresentaram produções individuais de leite, leite corrigido a 4% de gordura e de sólidos
totais superiores às da raça Jersey. As vacas da raça Holandesa foram manejadas com carga
animal superior às da raça Jersey, o que refletiu diretamente em superioridade na produção
animal e no fornecimento de concentrado por unidade de área para a raça Holandesa. Para
cada quilograma de concentrado fornecido individualmente, as vacas da raça Jersey
apresentaram produções individuais superiores às da raça Holandesa, sugerindo vantagens
para a raça Jersey quanto à conversão do suplemento em produto animal e sob o aspecto
econômico. O avanço do período de utilização das pastagens e as alterações estruturais do
dossel forrageiro condicionaram a redução dos tempos de pastejo e o aumento dos de
ruminação, para ambas as raças, mas não alterou o tempo destinado à realização de outras
atividades. Vacas da raça Jersey desprenderam mais tempo em atividades de pastejo e menos
em ruminação que as da raça Holandesa, provavelmente para compensar o menor nível de
suplementação. Apenas na segunda época de avaliação (outubro) foi verificada diferença na
taxa de bocados entre as raças, com superioridade para as vacas da raça Holandesa, e, para
ambas as raças, as vacas de final de lactação desenvolveram maior número de passos entre
estações alimentares que as de início de lactação. Adicionalmente, na raça Holandesa, o
incremento no número de passos entre estações alimentares foi acompanhado pela redução da
altura do sítio de pastejo visitado. Diferenças entre os estágios de lactação foram percebidas
apenas em variáveis que representam escolhas em nível de patch de pastejo (altura do sítio de
pastejo visitado e número de passos entre estações alimentares), indicando que as adaptações
dos animais nos distintos estágios fisiológicos se dão ao nível de deslocamento na pastagem e
realização do bocado.
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Impact of supplemental phosphorus source and form on utilization in lactating dairy cattleLager, Kevin John January 1900 (has links)
Master of Science / Department of Animal Sciences and Industry / Micheal J. Brouk / Supplemental phosphorus (P) in varying forms and sources: pellet (PELLET), meal (MEAL), liquid (LIQUID) and corn dried distiller’s grains with solubles (DDGS) were compared in twelve multiparous Holstein cows producing approximately 43 kg of milk (115 [plus minus] 55 DIM) in a 4x4 Latin square with 21d periods. PELLET and MEAL diets contained monocalcium phosphate with a wheat middlings carrier, and the LIQUID contained ammonium polyphosphate in a cane molasses base. The DDGS supplied an organic P source. Cows were blocked by parity, DIM and milk production and randomly assigned to treatments. Data were analyzed using the MIXED model procedure of SAS. Phosphorus intakes of 116, 116, 119 and 118 g/d were similar for PELLET, MEAL, LIQUID and DDGS diets, respectively. Cows consuming the LIQUID diet experienced greater sugar intakes (P<0.001). Fat intake was lower (P<0.001) for the PELLET, MEAL and LIQUID diets compared to the DDGS diet (1.14, 1.12, 1.07 and 1.36 kg/d, respectively). NEL intake was similar for all treatments (P=0.55). Milk yield differences (P=0.05) occurred with the DDGS diet yielding the most milk (34.6, 35.4, 34.1 and 36.5 kg/d). No differences resulted for either milk fat (P=0.26) or milk protein (P=0.33) percentages or for daily lactose production (P=0.22).
Excretion of P in feces tended (P=0.07) to differ between treatments (67.4, 66.3, 57.5 and 60.0 g/d) resulting in a trend (P=0.10) for greater P retention in diets excreting less P. Secretion of P in milk did not differ (P=0.51) between treatments.
Differences (P=0.04) occurred in P concentration between diets (0.47, 0.47, 0.49 and 0.47%), but the amount of P fed was not different (P=0.83). With similarities for DMI and P concentration in refusals (P=0.21) it may be deduced that sorting of the P supplement did not occur.
These data show that supplemental P sources do not affect DMI or P intake, however P source resulted in slight differences in P utilization, but it was not related to sorting of the diet. Utilizing DDGS showed similar responses to inorganic P mineral supplements with favorable production yields making it an adequate substitute for mineral sources of P.
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