Body composition changes in lactating ewes estimated by serial slaughter and deuterium dilution

Abstract

Changes in body composition during lactation were measured in 12 Border Leicester x Scottish Blackface ewes by serial slaughter at 12, 41 and 111 days of lactation. Ewes suckled twin lambs and were given daily 1-6 kg dry matter of a complete diet containing 151 g crude protein and 10-2 MJ metabolizable energy/kg dry matter. Live weights of ewes averaged 60-2, 58-9 and 55-8 kg at 12, 41 and 111 days of lactation respectively. There were no significant changes in weights of stomach, small and large intestine and liver. The weight of body fat averaged 9-19, 2-28 and 1-19 kg at 12, 41 and 111 days respectively (P< 0-001) and weight of ash increased from 1 -72 kg at 12 days to 2-30 kg at 111 days (i> < 0-001). Water to protein ratios at the three stages of lactation were 2-94, 3-36 and 3-18 (/ > <0-10). The energy value of weight loss varied from 68 to 17 MJ/kg, depending on the relative changes in total body water and fat. Live-weight change was therefore a poor indicator of change in body energy during early lactation. Body fat could be predicted from its combined relationships with live weight and total body water (residual s.d. ± 0-70 kg), but when deuterium oxide space was used to estimate body water separate equations were necessary for early and later stages of lactation. This was apparently due to differences between stages of lactation in the time required for deuterium oxide to equilibrate with water in the reticulo-rumen.

Leptin secretion and hypothalamic neuropeptide and receptor gene expression in sheep

“…Food intake increases after birth, reaching a plateau between 2 and 3 wk postpartum (24,60). Nevertheless, ewes suckling two or more lambs lose ϳ5 kg in body weight, mostly because of loss of fat from adipose tissue during the first 5-6 wk of lactation (22,23,24,60). Ewes suckling a single lamb do not appear to lose adipose tissue lipid, whereas ewes suckling three lambs lose an amount of adipose tissue lipid similar to those suckling two lambs (66).…”

Estimating fat reserves in Rasa Aragonesa ewes: A comparison of different methods

“…There is generally more interest, for both practical and economic reasons, in methods that can be used on the live animal. These methods range from the simple, such as body condition scoring (Russel et al 1969), liveweight, and fat thickness assessed using ultrasound (Kempster et al 1982), to the complex and expensive such as techniques for estimating body water, using dilution markers such as deuterium oxide and tritiated water (Cowan et al 1979), and magnetic resonance imaging (MRI) (Baulin 1997). After slaughter empty liveweight and carcass weight are the most common predictors, but the size of adipocytes in various fat depots has also been used (Vernon et al 1981).…”

Relation entre l'espace de diffusion de l'eau lourde mesurée in vivo et le volume hydrique corporel des bovins en croissance

“…L'estimation de la composition corporelle, grâce à des critères simples mesurés sur l'animal après abattage Robelin, 19731. Cette méthode donne de bons résultats chez les ovins (Foot et Greenhagh, 1970 ;Robelin, 1977 ;Cowan et al, 1979 ;Tissier, Kay, 1974). L'extraction de l'eau du sang prélevé après l'injection et le dosage de l'eau lourde ont été effectués selon la méthode décrite précédemment (Robelin, 1977 ;Tissier et al, 1978).…”