The relationships between live animal measurements and the physical and chemical composition of dairy cows

Author(s):  
D.I. Lamont ◽  
D.R. Neilson ◽  
G.C. Emmans ◽  
J. Fraser ◽  
J.H.D. Prescott

A knowledge of the chemical composition of the dairy cow is Important in interpreting the interacting influences of body reserves, diet and feed intake on milk production. An investigation has designed to obtain information from a representative sample of Friesian/Holstein cows at different stages of lactation, different ages, and of different yield potential. This information is expensive to collect due to the costs Involved in slaughtering and analysing dairy cows, especially if they are high yielding cows at peak production. The animals used in the investigation have therefore all been Planned culls with sixteen in the later stages of lactation with only three killed in early lactation. It is intended to continue this investigation for several years to obtain a comprehensive data set on the chemical composition of the dairy cow.

Dairy ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 218-230
Author(s):  
Marcia Franco ◽  
Tomasz Stefański ◽  
Taina Jalava ◽  
Marja Lehto ◽  
Minna Kahala ◽  
...  

Vegetable by-products have great potential for use as animal feeds and thus could improve the sustainability of the food system. The objective was to evaluate the milk production potential of potato by-product (PBP) replacing cereal grains in grass silage-based total mixed ration (TMR). Additionally, a laboratory scale experiment was conducted to assess the effect of PBP and chemical preservatives on the aerobic stability of TMRs. A change-over dairy cow feeding experiment was conducted to evaluate the inclusion of 135 g/kg (on a dry matter (DM) basis) of PBP in TMR. Additionally, the aerobic stability of TMR was evaluated by preparing TMRs with increasing levels of PBP and treated with different doses of formic and propionic acid or salt-based preservatives. The inclusion of PBP in dairy cow diets decreased feed intake, but organic matter digestibility was greater in the PBP diet, resulting in only slightly decreased production (milk protein 1435 vs. 1363 g/day, p < 0.05; milk lactose 1716 vs. 1606 g/day, p < 0.05). The aerobic stability of TMR was negatively affected by the inclusion of PBP, but it could to a limited extent be prolonged using chemical preservatives. The inclusion of PBP decreased feed intake and milk production to some extent when included in the diet of high-producing dairy cows. The utilization of PBP may, however, be justified from a sustainability point of view, as it provides a way to circulate the nutrients of a non-human edible feed material back into the food chain.


Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1704
Author(s):  
Christie K. M. Ho ◽  
Martin J. Auldist ◽  
Marlie M. Wright ◽  
Leah C. Marett ◽  
Bill Malcolm ◽  
...  

The economics of grazing dairy cows offered a range of herbage allowances and fed supplements as a partial mixed ration (PMR) were examined where profit was defined as the margin between total milk income and the cost of pasture plus PMR supplement. The analysis made use of milk production and feed intake data from two dairy cow nutrition experiments, one in early lactation and the other in late lactation. In early lactation and at a PMR intake of 6 kg DM/cow per day, the profit from the cows with access to a medium herbage allowance (25 kg DM/cow per day) was AUD 1.40/cow per day higher than that for cows on a low allowance (15 kg DM/cow per day). At a higher PMR intake of 14 kg DM/cow per day, the profit from the cows on a medium herbage allowance was AUD 0.45/cow per day higher than the cows on a low allowance; there was no additional profit from increasing the herbage allowance from medium to high (40 kg DM/cow per day). In late lactation, the profit from the cows fed a PMR with a medium herbage allowance (20 kg DM/cow per day) was only higher than the cows on a low allowance (12 kg DM/cow per day) when the PMR intake was between 6 and 12 kg DM/cow per day. There was also a difference of AUD +0.50/cow per day between the PMR with medium and high herbage allowance (32 kg DM/cow per day). It was concluded that farmers who feed a PMR to dairy cows should offer at least a medium herbage allowance to optimize profit. While feeding additional PMR increases milk production and profit, further gains would be available by offering a higher herbage allowance. These findings provide an estimate of the net benefits of different herbage allowances when feeding a PMR and will enable farmers to manage their feeding systems more profitably.


2014 ◽  
Vol 54 (3) ◽  
pp. 263 ◽  
Author(s):  
A. Akbari-Afjani ◽  
A. Zali ◽  
M. Gangkhanlou ◽  
M. Dehghan-Banadaky ◽  
S. M. Nasrollahi ◽  
...  

The present study investigated the effects of substitution of chopped lucerne hay (LH) for maize silage on feed intake, rumen pH and fermentation, digestibility, milk production and feed efficiency of dairy cows. Fifteen Holstein dairy cows in early lactation (37 ± 10 days in milk) were randomly assigned to three dietary treatments in a completely randomised design. The experiment lasted for 80 days, with 10 days of adaptation and 70 days of data collection. Treatment diets consisted of 60% concentrate and 40% forage, comprising 30 : 10 (MS30), 20 : 20 (MS20) or 10 : 30 (MS10) of maize silage (MS) to LH ratio (MS : LH). Cows were fed ad libitum as total mixed ration. Water was added daily to adjust the moisture content of the feed to be similar across diets. Decreasing the ratio of MS : LH resulted in linear and quadratic decreases of DM intake and physically effective neutral detergent fibre, without affecting apparent digestibility in the total digestive tract. Decreasing MS : LH also linearly reduced total chewing time and tended to reduced chewing index (min/kg DM intake), but had limited effects on rumen pH and fermentation characteristics. Increasing the substitution of LH for MS decreased milk production (33.1, 31.7, and 29.8 kg/day for MS30, MS20, and MS10, respectively), and tended (P = 0.06) to decrease 4% fat-corrected milk and fat yield. However, milk content of protein (2.70%, 2.77% and 2.77%) and fat improved, and tended to improve by decreasing the MS : LH ratio, respectively. The efficiency of milk production, expressed as either milk yield/kg DM intake or 4% fat-corrected milk/kg DM intake, was not affected by the treatments. Results indicated that under the current feeding conditions, decreasing the ratio of MS : LH was not recommended to maintain milk production and DM intake.


1998 ◽  
Vol 1998 ◽  
pp. 19-19
Author(s):  
A.R. Henderson ◽  
P.C. Garnsworthy ◽  
J.R. Newbold ◽  
P.J. Buttery

Sinclair et al. (1993) found that a diet formulated to be synchronous with regard to hourly release of nitrogen and energy increased microbial protein synthesis by 14% in sheep. Dairy cows in early lactation experience a shortfall of energy and protein, with available protein determining the overall efficiency of metabolism (MacRae and Lobley, 1986) and subsequent milk production. It is therefore necessary to maximise microbial protein yield during this period. In this study diets were designed for lactating dairy cows to contain the same feed ingredients, but to release nitrogen and energy in the rumen at different times. Rumen fermentation parameters, nutrient flows to the small intestine and production performance were investigated.


Dairy ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 684-694
Author(s):  
Lenka Krpálková ◽  
Niall O’Mahony ◽  
Anderson Carvalho ◽  
Sean Campbell ◽  
Gerard Corkery ◽  
...  

Identification of the associations of cow feed efficiency with feeding behaviour and milk production is important for supporting recommendations of strategies that optimise milk yield. The objective of this study was to identify associations between measures of feed efficiency, feed intake, feeding rate, rumination time, feeding time, and milk production using data collected from 26 dairy cows during a 3 month period in 2018. Cows averaged (mean ± standard deviation) 2.2 ± 1.7 lactations, 128 ± 40 days in milk, 27.5 ± 5.5 kg/day milk, 1.95 ± 0.69 kg feed/1 kg milk—the measure used to express feed conversion ratio (FCR), 575 ± 72 min/day rumination time, and 264 ± 67 min/day feeding time during the observation period. The coefficient of variation for rumination time (min/d) was 12.5%. A mixed linear model was selected for analyses. The most feed inefficient cows with the highest FCR (≥2.6 kg feed/1 kg milk) showed the lowest milk yield (24.8 kg/day), highest feed intake (78.8 kg), highest feeding rate (0.26 kg/min) and BCS (3.35 point). However, the relative milk yield (milk yield per 100 kg of body weight) was the highest (4.01 kg/day) in the most efficient group with the lowest FCR (≤1.4 kg feed/1 kg milk). Our study showed that the most efficient cows with the lowest FCR (≤1.4 kg feed/1 kg milk) had the highest rumination time (597 min/day; p < 0.05), feeding time (298 min/day; p < 0.05), rumination/activity ratio (4.39; p < 0.05) and rumination/feeding ratio (2.04; p < 0.05). Less active cows (activity time 164 min/day; p < 0.05) were the most efficient cows with the lowest FCR (≤1.4 kg feed/1 kg milk). The behavioural differences observed in this study provide new insight into the association of feed behaviour and feed efficiency with milk performance. Incorporating feeding behaviour into the dry matter intake model can improve its accuracy in the future and benefit breeding programmes.


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