678. The effect of variations in nutrient intake upon the yield and composition of milk II. Factors affecting rate of eating roughage and responses to an increase in the amount of concentrates fed

Abstract

With 5 Figures)The practical application of the results of closely controlled experiments on the effects of different levels of concentrate intake may be affected by the lack of control of roughage intakes of individual cows which occurs in most dairy herds. Individual cows show considerable variation in their ability to ingest and utilize roughage (1,2,3), which, together with the effects of competition, can give rise to considerable differences in individual plane of nutrition when roughages are rationed on a 'herd' basis. Responses to additional concentrates might therefore be expected to be maximal in those cows which are on the lower planes of nutrition due to low roughage intakes. The experiment to be described was therefore designed in an attempt to assess the importance of the effects of variations in individual rates of eating roughage upon responses to a standard increase in the concentrate ration under a system of feeding and management commonly used in dairy herds in the South of England. MATERIAL AND METHODSTwenty-nine Ayrshire cattle were used. They were divided into two groups (fourteen cows and fifteen heifers) and were housed in separate but adjacent covered yards fitted with mangers for individual feeding. The animals were given a daily 3 hr. exercise period on a bare paddock and were milked in a milking parlour. No concentrates were fed in the milking parlour. The daily feeding routine was as follows: 4.15 a.m., half of the daily allowance of concentrates; 5.0 a.m., milking; 6.30-7.30 a.m., half the daily allowance of hay; 9.45-11.0 a.m., marrowstem kale; 11.0 a.m.-2.0 p.m., exercise; 2.45 p.m., the other half of the concentrates; 4.0 p.m., milking; 5.0-6.0 p.m. the other half of the hay.The animals had access to water at all times except when tied in the yokes for feeding. Table 1. Mean age, stage of lactation and milk yield at the start of the experiment Mean S.D.

Repeatability of traits for characterizing feed intake patterns in dairy goats: a basis for phenotyping in the precision farming context

“…The increase in the rate of intake as goats get older is in agreement with previous trials on cows: primiparous cows ate more slowly than multiparous ones (Burt, 1957;Beauchemin and Rode, 1994;Neave et al, 2017). Moreover, lactating animals tend to eat more than dry ones as their requirements are higher (Campling and Morgan, 1981).…”

“…As observed since a long time in cows, there is a high variation among individuals in feed intake pattern (Burt, 1957). The present study has clearly shown that there was a rather good repeatability for a given goat of its feed intake pattern across 2 years.…”

“…Feeding behaviour variables are parameters involved in feed efficiency (Phocas et al, 2014). However, feeding behaviour shows a high variation among individuals within an experiment (Burt, 1957;Jarrige et al, 1995). It is a key factor to explain the differences in susceptibility of animals to acidosis when they receive a diet with a high proportion of concentrate to meet their requirements in intensive systems (Brown et al, 2000;Desnoyers et al, 2011;Gao and Oba, 2014).…”

Responses to grain feeding by grazing dairy cows

“…However, the initial milk yields and the range of yields of these experiments were relatively low. Given a wide range in milk yields, current yield rather than stage of lactation may be the major determinant of production response (Burt 1957). In the current experiments, production responses similar to those reported in early lactation of at least 1 kg milk/kg supplement were achieved in mid-late lactation, with cows producing greater than 18 kg milk/cow.day.…”

Effect of various dietaries on milk composition and efficiency of production of dairy cows

“…Reviews by Blaxter (1956b), Burt (1957a), J awe tz (1956) and Reid (1956) summarize the early experimental work in dairy rations wherein different planes of nutrition (energy) were fed. They report both long-and short-term experiments in which feeding at an increased plane of nutrition has resulted in higher levels of FCM production, but with a diminished re sponse for each additional increment of energy.…”