Protein Degradability and Calcium Salts of Long-Chain Fatty Acids in the Diets of Lactating Dairy Cows: Reproductive Responses

Abstract

Multiparous Holstein cows (n = 45) were assigned at calving to one of four diets arranged in a 2 x 2 factorial design. The two main factors were dietary concentration (dry matter basis) of 1) degradable intake protein (11.1 or 15.7%) and 2) supplemental fat (Ca salts of long-chain fatty acids; 0 or 2.2%). Soybean meal and urea were replaced with less degradable protein meals (corn gluten meal, meat and bone meal, fish meal, and blood meal). During the first 9 wk postpartum, cows fed diets containing the greater concentration of highly degradable protein demonstrated less follicular development on their ovaries, were delayed in their first luteal activity postpartum (25.2 vs. 38.6 d), accumulated less luteal tissue (< 15 vs. > 70 mm), and had lower plasma progesterone accumulated over time. The supplementation of Ca salts of long-chain fatty acids to the 15.7% degradable protein diet doubled the number of corpora lutea, reduced time to first rise in progesterone by 6 d, doubled the number of normal luteal phases, and restored the pattern of accumulated plasma progesterone concentrations to a pattern that was similar to that induced by other diets. Cows were synchronized to estrus and inseminated at approximately 65 d postpartum. Pregnancy rate was increased from 52.3 to 86.4% when fat was supplemented. Cows fed fat tended to have more corpora lutea and a larger corpus luteum and accumulated more plasma progesterone than did cows not fed fat. Diets containing excess degradable protein or Ca salts of long-chain fatty acids influenced ovarian structures and reproductive performance.

Effect of dietary energy source on energy balance, production, metabolic disorders and reproduction in lactating dairy cattle

“…A part of the presented studies in Figure 4b do not specify the determination of timing of AI [65,118,119,121]. Most studies applied a waiting period till first AI ranging from 39 to 90 DIM [15, 62,105,126], other studies inseminated the cows after synchronization with a prostaglandin analogue [104,132].…”

Efeito da sobrealimentação com fontes de proteína de diferentes degradabilidades sobre a ovulação em ovelhas Santa Inês

“…Apenas dois trabalhos foram encontrados na literatura consultada e em ambos a taxa de ovulação não foi relacionada à concentração plasmática de ureia (Fahey et al, 2001) ou de N-ureico (Bishonga et al, 1996. Em vacas, Garcia-Bojalil et al (1998b) relataram que menor atividade ovariana nos primeiros 50 a 57 dias pós-parto esteve associada ao consumo de uma dieta com 15,7% de PDR, em comparação à outra com 11,1% de PDR. A menor atividade ovariana foi relacionada à maior concentração de N-ureico e a menor concentração de insulina no plasma (Garcia-Bojalil et al, 1998a).…”

“…Em vacas, Garcia-Bojalil et al (1998b) relataram que menor atividade ovariana nos primeiros 50 a 57 dias pós-parto esteve associada ao consumo de uma dieta com 15,7% de PDR, em comparação à outra com 11,1% de PDR. A menor atividade ovariana foi relacionada à maior concentração de N-ureico e a menor concentração de insulina no plasma (Garcia-Bojalil et al, 1998a). Visek (1984) propôs que a alta concentração de amônia no sangue pode inibir as células betapancreáticas, ocasionando diminuição do estímulo da glicose sobre a liberação de insulina, o que reduziria a concentração de insulina na circulação sanguínea.…”

Effects of eCG in Milking Dairy Cows with High Levels of BUN and Synchronized with Ovsynch Protocol

“…Higher plasma P4 levels ameliorate some of the adverse effects of BUN on fertility after AI in dairy cows 11 . Garcia-Bojalil et al (1998) showed negative effects of RDP on plasma P4, which could be restored by the inclusion of fat in the diet, resulting in an increase of pregnancy rate with fat supplementation 18 . The increased P4 have been done by inducing formation of an accessory CL with hCG or GnRH treatment.…”

“…Garcia-Bojalil et al (1998) showed a negative effect of RDP on plasma P4, which could be restored by the inclusion of fat, resulting in an increased pregnancy rate with fat supplementation 18 .…”