Artificial Induction of Lactation in Cattle: Initiation of Lactation and Estrogen and Progesterone Concentrations in Milk

Sawyer, GJ; Fulkerson, WJ; Martin, Graeme; Gow, C. B.

doi:10.3168/jds.s0022-0302(86)80570-7

Cited by 7 publications

(5 citation statements)

References 23 publications

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“…The concentration of total protein in the bitransgenic calf milk was high (47.3 g/L), whereas Jewell (2002) found an average concentration of 38 g/L, higher than that observed in noninduced Jersey cows (33 g/L). Similarly, Sawyer et al (1986) reported that percentages of protein and fat were higher in milk from lactation-induced heifers than in milk from heifers after normal calving for the first 14 d. In the present study, increased protein concentration did not alter the proportion of 80% caseins to 20% whey proteins. An increase in β-CN (almost 50% of the caseins) was observed in milk, whereas the other major casein (i.e., α-CN) remained at normal concentrations (21-25 g/L).…”

Section: Discussionsupporting

confidence: 68%

Detection of recombinant human lactoferrin and lysozyme produced in a bitransgenic cow

Kaiser

Mucci

González

et al. 2017

Journal of Dairy Science

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Lactoferrin and lysozyme are 2 glycoproteins with great antimicrobial activity, being part of the nonspecific defensive system of human milk, though their use in commercial products is difficult because human milk is a limited source. Therefore, many investigations have been carried out to produce those proteins in biological systems, such as bacteria, yeasts, or plants. Mammals seem to be more suitable as expression systems for human proteins, however, especially for those that are glycosylated. In the present study, we developed a bicistronic commercial vector containing a goat β-casein promoter and an internal ribosome entry site fragment between the human lactoferrin and human lysozyme genes to allow the introduction of both genes into bovine adult fibroblasts in a single transfection. Embryos were obtained by somatic cell nuclear transfer, and, after 6 transferences to recipients, 3 pregnancies and 1 viable bitransgenic calf were obtained. The presence of the vector was confirmed by fluorescent in situ hybridization of skin cells. At 13 mo of life and after artificial induction of lactation, both recombinant proteins were found in the colostrum and milk of the bitransgenic calf. Human lactoferrin concentration in the colostrum was 0.0098 mg/mL and that in milk was 0.011 mg/mL; human lysozyme concentration in the colostrum was 0.0022 mg/mL and that in milk was 0.0024 mg/mL. The molar concentration of both human proteins revealed no differences in protein production of the internal ribosome entry site upstream and downstream protein. The enzymatic activity of lysozyme in the transgenic milk was comparable to that of human milk, being 6 and 10 times higher than that of bovine lysozyme present in milk. This work represents an important step to obtain multiple proteins or enhance single protein production by using animal pharming and fewer regulatory and antibiotic-resistant foreign sequences, allowing the design of humanized milk with added biological value for newborn nutrition and development. Transgenic animals can offer a unique opportunity to the dairy industry, providing starting materials suitable to develop specific products with high added value.

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Section: Discussionsupporting

confidence: 68%

Detection of recombinant human lactoferrin and lysozyme produced in a bitransgenic cow

Kaiser

Mucci

González

et al. 2017

Journal of Dairy Science

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“…Preocupados com a qualidade do leite oriundo de vacas ou novilhas submetidas a protocolo de indução de lactação, vários investigadores conduziram pesquisas nessa área (12,83%), como a avaliação da composição do leite (NARENDRAN et al, 1974) e os níveis de caseína ou de E2 e P4 no leite (HARNESS et al 1978;NARENDRAN et al, 1979;SAWYER et al, 1986).…”

Section: Resultsunclassified

Protocolo de indução de lactação: uma abordagem histórica

Freire,

Andreazzi,

Cavalieri

et al. 2023

OLEL

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O leite de vaca é o leite mais produzido e consumido mundialmente. Assim, vários manejos e técnicas são empregados a fim de fomentar sua produção, como o protocolo para indução da lactação. O objetivo deste estudo foi realizar, por meio da cienciometria, uma análise histórica qualiquantitativa das publicações científicas que abordaram sobre o emprego de protocolos de indução da lactação em animais de produção. Foi avaliada a produção científica na Web of Science e na SciELO, empregando os descritores indução da lactação e protocolo de indução da lactação. A busca resultou em 39 artigos que foram analisados, de forma descritiva, quanto ao ano de publicação, escopo da pesquisa e periódicos com maior número de publicações. A evolução histórica revelou artigos publicados em periódicos de elevado rigor científico, entre os anos de 1965 a 2021, com destaque para a década de 70 e, a maioria versava sobre indução da lactação em vacas e novilhas (76,92 %), cujos principais eixos temáticos foram estudos sobre os parâmetros bioquímicos e fisiológicos das vacas submetidas aos protocolos (28,22%).

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“…It should be pointed out that 40% of Induced heifers become pregnant with only one insemination, supporting the finding of previous studies, which suggests a positive effect of induced lactation on fertility. It is possible that the high serum concentrations of estradiol during pre-lactation have interfered in the uterine environment and follicular population of these animals [8]. Furthermore, it is possible that the hormonal combination used has a central effect on the synthesis and release of gonadotrophins and/or an effect on the ovarian follicular population.…”

Section: Discussionmentioning

confidence: 99%

Endocrine Profile and Reproductive Performance in Heifers Induced to Lactation

Luz

Maffi

Xavier

et al. 2019

Acta Scientiae. Vet.

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Background: Low reproductive efficiency has been one of the main factors that lead to dairy herd culling in the reproductive age. In multiparous animals, such inefficiency and culling can occur because of various factors and may be associated with occasional endocrine failures. To avoid revenue losses that incur due to lack of lactation, lactation is artificially induced in the animals that are not pregnant, using a defined protocol. The aim of this study was, therefore, to evaluate and compare the reproductive performance of heifers submitted to the induction protocol with that of pregnant heifers during the transition period. Materials, Methods & Results:Sixty Holstein heifers, 32 ± 0.6 months of age, were divided into two groups: Control Group (Control, n = 30) comprising pregnant heifers that were accompanied since 21 days before the expected calving date until 224 days in milk (DIM) and an Induction Group (Induction, n = 30) comprising non-pregnant heifers submitted to a lactation induction protocol, accompanied from the beginning of the protocol until 224 DIM. For evaluation of the endocrine profile (progesterone and estradiol concentrations) of these animals, blood samples were collected at two periods: the pre-lactation (weeks -3, -2 and -1) and post-lactation (weeks 1 and 4). Heifers from both groups were submitted to weekly reproductive evaluations, from the beginning of lactation until 35 DIM. Uterine examinations were performed using ultrasonography and vaginoscopy to evaluate uterine content, cervical opening, and mucosal aspect. Females in good reproductive health were subjected to a hormonal protocol for timed artificial insemination (TAI). The pregnancy rate of heifers that could reproduce (Control, n = 13, and Induction, n = 20) were evaluated and inseminated until 49 DIM. Progesterone levels were similar (P > 0.05) in the two groups at both pre-and post-start of lactation. Estradiol concentrations were different (P < 0.01) among groups only in the pre-lactation period. Higher levels of progesterone (P = 0.06) were observed in the induced heifers (Induction Group = 1.07 ± 0.23 ng/mL and Control Group = 0.38 ± 0.28 ng/mL). Therefore, in the fourth week, induced heifers exhibited higher luteinic activity, the progesterone concentration was above 1 ng/mL in 42% of the animals, while just 12.5% of the Control heifers had it. The overall pregnancy rate was 47.75%. The pregnancy rate recorded for induced heifers and Control heifers was 40% and 55.55%, respectively. Discussion: Progesterone and estradiol evaluations were performed in the first week after the beginning of the lactation to evaluate the metabolism and physiological concentration of the hormones used during the protocol. The measurements were again performed in the fourth week to evaluate the return to cyclicity of the heifers in both groups. The high serum concentrations of estradiol attained during the induction, in the pre-lactation period, may have possible interfered with the uterine environment and follicular population of these anima...

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Artificial Induction of Lactation in Cattle: Initiation of Lactation and Estrogen and Progesterone Concentrations in Milk

Cited by 7 publications

References 23 publications

Detection of recombinant human lactoferrin and lysozyme produced in a bitransgenic cow

Detection of recombinant human lactoferrin and lysozyme produced in a bitransgenic cow

Protocolo de indução de lactação: uma abordagem histórica

Endocrine Profile and Reproductive Performance in Heifers Induced to Lactation

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