Effect of parity and physiological state on intake, milk production and blood parameters in lactating mares differing in body size

Abstract

Voluntary food intake, milk production and blood characteristics were measured in mares between the 3rd month before foaling and the first 5 weeks of lactation. The effect of breed during pregnancy was determined using 15 light mares and eight heavy mares (522 and 763 kg live weight (LW) after foaling respectively). The effect of parity was studied on light mares (seven were primiparous and eight were multiparous). In lactation, only four primiparous and four multiparous light mares were retained. Diet consisted of 900 g hay and 100 g concentrates per kg and was offered ad libitum. Voluntary food intake in pregnancy was higher for heavy mares than for light mares: 15-2 v. 10-3 kg dry matter (DM) daily. This difference was explained by differences in LW, since DM intake was the same when expressed as a fraction of LW or metabolic weight (M). Energy and nitrogen supply exceeded requirements, in the same way for light and heavy mares. No significant variations in blood measurements were observed between light and heavy mares, except for glucose. Primiparous mares ate less DM than multiparous mares in pregnancy: 9-7 v. 10-8 kg DM (P > 0-05), significantly so relative to LW and M. DM intake per kg LW or M depended on the parity. This difference had no effect on blood measurements, except for acetate. During lactation, no other differences in voluntary food intake were observed with regard to parity, whatever the week of lactation. Milk yield was higher for multiparous mares than for primiparous mares (16-6 v. 14-6 kg daily). Gross energy of milk varied according to a similar pattern, principally because of variations in fat concentration (20-2 v. 16-5 g/kg for multiparous and primiparous mares respectively). Energy balance was significantly more positive for multiparous than for primiparous mares.

Daily intake and the selection of feeding sites by horses in heterogeneous wet grasslands

“…In view of the fact that there are considerable inter-individual variations in intake in some herbivores [6,23], and the small number of animals used in this study, the measures should be repeated. Nonetheless the slight variations between days on food intake (coefficient of variation: 12%) show that data from four days allow estimation of daily intake for horses on these pastures with reasonable accuracy.…”

Lactação em éguas da raça Mangalarga Marchador: produção e composição do leite e ganho de peso dos potros lactentes

“…Alguns autores observaram aumento da produção de leite de éguas criadas a pasto em resposta à suplementação protéica (Gibbs et al, 1982;Doreau et al, 1991a), enquanto Martin et al (1992) verificaram que éguas mantidas em pastagens de Cynodon dactylon sem suplementação produziram quantidade de leite equivalente à de éguas mantidas nesta mesma pastagem e recebendo dois quilogramas diários de ração concentrada contendo 24% de proteína bruta.…”

Age at reproductive debut: Developmental predictors and consequences for lactation, infant mass, and subsequent reproduction in rhesus macaques (Macaca mulatta)

“…Body condition (human: Dewey et al, 1994; Quinn et al, 2016; rhesus macaque: Hinde, 2007a; baboon: Roberts et al, 1985; marmoset: Tardif et al, 2001), parasite load (rhesus macaque: Hinde, 2007a), and nutritional intake (baboon: Roberts et al, 1985) have all been implicated in the capacity to synthesize milk in terms of quantity (volume/yield), quality (energetic density), or both (Hinde and Milligan 2011). Primparous mothers produce lower yields of milk than do multiparous mothers (Doreau et al, 1991; Miller et al, 2006), even controlling for body size (Hinde et al, 2009). Additionally, composition of milk produced by primiparous mothers can differ nutritional content (Doreau et al, 1991) and hormonal concentrations (human: Breakey, 2015; rhesus macaque: Hinde et al, 2015; Bernstein and Hinde 2016), but not always (dairy cow, Bos taurus : Fukasawa et al, 2008; rhesus macaque: Hinde et al, 2015, 2013, 2009).…”

“…Primparous mothers produce lower yields of milk than do multiparous mothers (Doreau et al, 1991; Miller et al, 2006), even controlling for body size (Hinde et al, 2009). Additionally, composition of milk produced by primiparous mothers can differ nutritional content (Doreau et al, 1991) and hormonal concentrations (human: Breakey, 2015; rhesus macaque: Hinde et al, 2015; Bernstein and Hinde 2016), but not always (dairy cow, Bos taurus : Fukasawa et al, 2008; rhesus macaque: Hinde et al, 2015, 2013, 2009). The effects of parturition timing on milk synthesis are less understood and have been evaluated pooling primiparous and multiparous mothers.…”