Contrasting effects of high-starch and high-sugar diets on ruminal function in cattle

Abstract

The experiment reported in this research paper aimed to determine whether clinical and subclinical effects on cattle were similar if provided with isoenergetic and isonitrogenous challenge diets in which carbohydrate sources were predominantly starch or sugar. The study was a 3 × 3 Latin square using six adult Jersey cows with rumen cannulae, over 9 weeks. In the first 2 weeks of each 3 week experimental period cows were fed with a maintenance diet and, in the last week, each animal was assigned to one of three diets: a control diet (CON), being a continuation of the maintenance diet; a high starch (HSt) or a high sugar (HSu) diet. Reticuloruminal pH and motility were recorded throughout the study period. Blood and ruminal samples were taken on day-1 (TP-1), day-2 (TP-2) and day-7 (TP-7) of each challenge week. Four clinical variables were recorded daily: diarrhoea, inappetence, depression and ruminal tympany. The effects of treatment, hour of day and day after treatment on clinical parameters were analysed using linear mixed effects (LME) models. Although both challenge diets resulted in a decline in pH, an increase in the absolute pH residuals and an increase in the number of minutes per day under pH 5.8, systemic inflammation was only detected with the HSt diet. The challenge diets differentially modified amplitude and period of reticuloruminal contractions compared with CON diet and both were associated with an increased probability of diarrhoea. The HSu diet reduced the probability of an animal consuming its complete allocation. Because the challenge diets were derived from complex natural materials (barley and molasses respectively), it is not possible to assign all the differential effects to the difference in starch and sugar concentration: non-starch components of barley or non-sugar components of molasses might have contributed to some of the observations. In conclusion, substituting much of the starch with sugar caused no substantial reduction in the acidosis load, but inflammatory response was reduced while feed rejection was increased.

Effects of substituting soybean meal with corn on immune function and gene expression of gut TLR4 pathway of growing goats

“…In our study, the concentration of Bas was increased in CRS, which was unexpected. Similarly, a previous study has shown that an increase in the count of circulating neutrophils was observed in cattle fed a high starch diet ( Francesio et al, 2020 ). It is possible that the high level of dietary starch may be a factor resulting in the increased concentration of Bas.…”

What is the optimum design for my animal experiment?

“…The cow milk production study could use a cross-over design (figure 9) as a diet intervention is considered reversible and a wash-out period equivalent to the diet exposure should be sufficient. 69 The experiment would take longer than a CRD approach, but far fewer animals would be needed. Wellek and Blettner 70 provide an efficiency conversion factor between a CRD and a two-period crossover design with a factor of interest with two levels using the measurement error and the between-subject variance.…”

A review on the potentials of using feeds rich in water‐soluble carbohydrates to enhance rumen health and sustainability of dairy cattle production

“…51 A recent study with non-lactating Jersey cows investigated the effects of two iso-energetic high-starch and high-sugar diets on ruminal pH and other health and fermentation parameters associated with ruminal acidosis. 52 Although the duration of ruminal pH below 5.8 was longer when 2.2 kg of the 5.53 kg of barley were replaced by molasses, thus aggravating the SARA, the acute phase response with the high-sugar diet (sugar content 176 g kg −1 DM versus 20 g kg −1 DM) was not as pronounced compared to that with the high-starch diet (starch content 599 g kg −1 DM versus 358 g kg −1 DM). It should be noted, however, that the starch content also of the high-sugar diet exceeded 300 g kg −1 DM, a level considered to increase the risk of SARA considerably.…”