The voluntary hay intake by ewes during the first weeks of lactation

Abstract

In eight experiments, ewes nursing one or two lambs were offered restricted amounts of concentrate in the range 285 to 605 g dry matter (DM) per day and hay ad libitum, from lambing until day 42 of lactation.Hay intake increased sharply during the first 2 weeks and reached its maximum during the 5th or the 6th week. Ewes' body weight at lambing, ewes' body-weight change, and milk production (estimated by litter growth rate) were significantly related to hay intake which depended also on breed (Romanov × Limousine ewes eating more than pure Limousine, P < 0·001) and age (mature ewes eating more than old ewes, P < 0·001) but not on number of suckled lambs.Replacement rate of concentrates for forage increased as lactation progressed (0·53 to 0·86 from first to third fortnight) and varied with hay neutral detergent fibre (NDF) concentration (0·42 or 0·89 for hays with 700 or 500 g NDF per kg DM). Daily hay DM intake decreased by 1·28 g for each gram of hay NDF content increment. The NDF effect was increasingly more important as lactation progressed.Utilization of present results in formulating diets for lactating ewes is discussed.

The effect of concentrate level on the intakes of silages or hays by ewes in the 1st month of lactation

“…Bocquier, Kann and Theriez, 1990;Rhind et al, 1992) interact in complex ways to determine the degree of intake limitation. NDF (Bocquier et al, 1987;Carro, Lopez, Gonzalez and Ovejero, 1991) and ADF (Hovell, Ngambi, Barber and Kyle, 1986) can be used to predict intakes of hays because they are an index of the food component with the slowest rate of digestion and are related to the rate of particle breakdown (Gill, 1986). NDF (Bocquier et al, 1987;Carro, Lopez, Gonzalez and Ovejero, 1991) and ADF (Hovell, Ngambi, Barber and Kyle, 1986) can be used to predict intakes of hays because they are an index of the food component with the slowest rate of digestion and are related to the rate of particle breakdown (Gill, 1986).…”

“…Bocquier et al (1987) presented predictive equations for intakes by lactating ewes which include NDF concentration of hays, but found that terms for the CP and OMD contents were not significant. When NDF was substituted for OMD in the equation to predict the intake of hays, the R 2 value was 55-1; marginally less than for equation 1.…”

“…Treacher, 1984 and1989) have shown the importance of hay or silage quality when attempting to satisfy these requirements. More recently, Bocquier, Theriez and Brelurut (1987) measured replacement rates of forage by concentrates when eight different hays were offered to ewes rearing lambs indoors. The requirements for energy and protein in early lactation are, however, even higher than those just before lambing.…”

The voluntary intake and utilization of forage-concentrate diets by ewes in late pregnancy

“…Physical limitation of intake during the last week of pregnancy impedes meeting the high requirements of this physiological state (Forbes, 1970). Quality of forage and amount of concentrate can modify voluntary intake of forage depending on changes in digestibility and palatability of the diet (Bocquier et al, 1987;Orr and Treacher, 1984;Orr et al, 1985).…”

Factores genéticos y ambientales de los niveles de ácidos grasos en la leche de oveja de raza Churra = Genetic and environmental factors influencing variation of fatty acids composition in Churra sheep milk

“…Durante el primer mes de la lactación, las hembras pueden sufrir un estrés nutricional cuando la ingestión de alimentos no satisface la alta demanda de nutrientes de la producción láctea, lo que viene motivado por que la capacidad de ingestión de las ovejas no alcanza su máximo hasta la cuarta-sexta semana postparto (Bocquier et al, 1987a(Bocquier et al, y 1987b. La consecuencia de esta limitación en la ingestión es el balance energético negativo en que se encuentran generalmente las ovejas en esta fase de lactación, lo que exige la utilización de las reservas corporales para satisfacer las demandas de la producción.…”