Serum mineral concentrations in relation to estrus and conception in beef heifers and cows fed conserved forage

Abstract

Small, J. A., Charmley, E., Rodd, A. V. and Fredeen, A. H. 1997. Serum mineral concentrations in relation to estrus and conception in beef heifers and cows fed conserved forage. Can. J. Anim. Sci. 77: 55-62. A study was undertaken to examine serum mineral concentrations in relation to estrus and first service conception (FSC) in beef cattle fed conserved forage. Blood samples were taken from yearling nulliparous heifers, and suckled 2-yr-old primiparous heifers and multiparous cows at first service which occurred within 12 h of observed standing heat and 21 d after. Serum was analyzed for calcium (Ca), phosphorus (P), magnesium (Mg), potassium (K), sulfur (S), sodium (Na), iron (Fe), copper (Cu), manganese (Mn), zinc (Zn) and boron (B) concentrations by ICAP. Heifers were fed in four groups based on parity and given 3.0 and 2.5 kg hd d -1 of a grain supplement, respectively, plus free-choice grass hay (1.71% K; 0.20% P; 8% protein; 41% ADF). Cows were individually fed ad libitum (21 g kg -1 body weight) grass-legume silage (2.82% K; 0.35% P; 14% protein, 34% ADF). Heifers and cows gained body weight over the breeding season and at turnout had body condition scores of 5 to 6 for heifers and 6 to 7 for cows. Rates of FSC were 53% (10/19), 48% (10/21) and 64% (18/28) for nulli-, primi-and multiparous groups, respectively. Serum Ca, Na, S, Cu, Fe, Zn and Mn did not differ (P > 0.05) between FSC groups, but Na and Cu were higher (P < 0.05) at estrus than at day 21, especially in nulliparous heifers. Concentrations of serum Mg were low (< 0.74 mmol L -1 ) and K high (> 4.5 mmol L -1 ) in heifers and cows but in nulliparous heifers only, serum Mg and K were lowest (P < 0.05) at estrus for those that conceived. Serum B concentrations were generally higher (P < 0.05) in animals that conceived especially on day 21 when B concentrations were higher (P < 0.05) than at estrus. Serum P concentrations were high (> 3.5 mmol L -1 ), but highest in animals that conceived especially on day 21. It is concluded that P and B may be dietary factors limiting first service conception in beef cows fed conserved forage. Nous avons entrepris une étude pour examiner les concentrations de minéraux dans le sérum à l'oestrus et à la conception en première insémination (CPI) chez des bovins à viande nourris de fourrages conservés. L'étude portait sur des génisses nullipares d'un an ainsi que sur des génisses primipares de deux ans et sur des vaches multipares, les deux dernières catégories étant encore allaitantes. Des prélèvements sanguins étaient effectués à la première insémination, soit dans les 12 heures d'état d'acceptation du chevauchement et 21 heures après. Le sérum était analysé par spectrophotométrie ICAP sur ses teneurs en Ca, P, Mg, K, S, Na, Fe, Cu, Mn, Zn et B. Les génisses réparties en 4 groupes recevaient en plus de foin à volonté (1,71 % K, 0,20 %, P; 8 % PB et 41 % ADF) un complément de grain à raison de 3,0 ou 2,5 kg par jour chacune selon qu'elles étaient nullipares ou primipares. Les vaches adultes nourries individuellemen...

Mineral elements in grasses growing in contrasting environmental conditions in southern Patagonia

“…Despite B, Cr, Ni, Rb and V potentially being toxic for sheep, these elements can be considered to be beneficial because at low concentrations they may be improve animal performance (Suttle 2010). For instance, an association between poor conception and low serum B concentration has been reported for beef cow herds (Small et al 1997). Similarly, Spears (1984) reported that supplementation of diets that have a Ni concentration range of 0.26-0.85 mg kg −1 with an additional 5 mg Ni as NiCl 2 , increased the ruminal urease, growth rate and feed conversion efficiency of lambs and steers.…”

Effect of average daily gain on body size, metabolism, and milk production of Italian Holstein heifers raised on two different planes of nutrition and calving at two different ages

“…Plasma Cp (and Cu) levels are affected by oestrus, with a particularly evident increase in heifers (Small et al, 1997), and the effect of oestrogen on plasma copper and Cp was well established (Cousins, 1985). It could be hypothesised that an earlier onset of oestrus cycle in H heifers, compared with M heifers, elicited consequences on plasma Cp.…”

Dietary Boron: Evidence for Essentiality and Homeostatic Control in Humans and Animals

“…Similar concentrations of boron (µg/mL) were reported in the plasma of humans (0.017-0.191) (Ferrando et al 1993;Hunt et al 1997;Iyengar et al 1990;Mauras et al 1986;Usuda et al 1997;Wallace et al 2002;Ward 1993), rats (0.038-0.039) (Seaborn and Nielsen 1994;Vaziri et al 2001), chicks (0.047-0.152) (Hunt 1989;Hunt 1996), cows (0.052-0.153) (Hunt 1996;Small et al 1997), lambs (0.163) (Hunt 1996), pigs (0.126) (Hunt 1996), and horses (0.227) (Hunt 1996). Liver boron concentrations (µg/g; dry weight) are similar in humans (1.1-5.4) (Shuler et al 1990;Ward 1987), rats (0.51) , chicks (1.01-4.4) (Rossi et al 1993), and cows (3.3) (Ward 1987); for brain tissue (µg/g; dry weight), similar in humans (0.87) (Shuler et al 1990), rats (0.64) , and chicks (1.01-1.05); for bone tissue (µg/g; dry weight), similar in humans (1.6) (Ward 1993), rats (1.3) , chicks (0.59-0.64) Hunt et al 1994;Wilson and Ruszler 1996), and mule deer (1.7) (Stelter 1980).…”