Milk production, methane emissions, nitrogen, and energy balance of cows fed diets based on different forage systems

Abstract

Eight lactating Italian Friesian cows were housed in individual respiration chambers in a repeated Latin square design to determine their dry matter intake (DMI) and their milk and methane production, as well as to collect the total feces and urine to determine the N and energy balances. Four diets, based on the following forages (% of dry matter, DM), were tested: corn silage (CS, 49.3), alfalfa silage (AS, 26.8), wheat silage (WS, 20.0), and a typical hay-based Parmigiano Reggiano cheese production diet (PR, 25.3 of both alfalfa and Italian ryegrass hay). The greatest DMI was observed for cows fed PR (23.4 vs. 20.7 kg/d, the average of the other 3 diets). The DM digestibility was lower for PR (64.5 vs. 71.7%, the average of the other diets). The highest ash-free neutral detergent fiber digestibility values were obtained for CS (50.7%) and AS (47.4%). In the present study, no differences in milk production were observed between diets, although PR showed a higher milk yield trend. The highest milk urea N concentration (mg/dL) was found for the cows fed the WS diet (13.8), and the lowest was observed for the cows fed AS (9.24). The highest milk urea N concentration for the cows fed WS was also correlated with the highest urinary N excretion (g/d), which was found for the cows fed that same diet (189 vs. 147 on average for the other diets). The protein digestibility was higher for the cows fed the CS and WS diets (on average 68.5%) than for the cows fed AS and PR (on average 57.0%); dietary soybean inclusion was higher for CS and WS than for AS and PR. The rumen fermentation pattern was affected by the diet; the cows fed the PR diet showed a higher rumen pH and decreased propionate production than those fed CS, due to the lower nonfiber carbohydrate content and higher ash-free neutral detergent fiber content of the PR diet than the CS diet. Feeding cows with PR diet increased the acetate: propionate ratio in comparison with the CS diet (3.30 vs. 2.44 for PR and CS, respectively). Cows fed the PR diet produced a greater daily amount of methane and had a greater methane energy loss (% of digestible energy intake) than those fed the CS diet (413 vs. 378 g/d and 8.67 vs. 7.70%), but no differences were observed when methane was expressed as grams per kilogram of DMI or grams per kilogram of milk. The PR diet resulted in a smaller net energy for lactation content than the CS diet (1.36 vs. 1.70 Mcal/kg of DM for the PR and CS diets, respectively). Overall, our research suggests that a satisfactory milk production can be attained by including different high-quality forages in balanced diets without any negative effect on milk production or on the methane emissions per kilogram of milk.

Effects of Various Additives on Fermentation, Aerobic Stability and Volatile Organic Compounds in Whole-Crop Rye Silage

“…Agriculture in general and forage production in particular have been put under scrutiny regarding their impact on the environment, including greenhouse gas emissions [24][25][26][27][28]. The review by Hafner et al [29] focused on the range of volatile organic compounds (VOCs) produced in and potentially emitted from silage, their sources and environmental implications.…”

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“…similarly, previous findings confirm that CS and AS diet was not significantly varied on cows DMI, milk yield and fat composition. 30,31 Although crude protein content of alfalfa silage diet was higher but total dry matter digestibility was not differed among diets this may be a reason that diets not differed in cow's productivity. On the other hand, earlier finding showed that replacement DMI of AS with CS significantly decreases (p<0.01).…”

Mitigation of Enteric Methane Emission through Feed Modification and Rumen Manipulation

“…Sapi perah yang diberi hijauan pakan berupa silase jagung dan hay Italian ryegrass dibandingkan dengan yang diberi hay Italian ryegrass dan hay alfalfa (dihitung imbangan energi tercerna dan protein tercerna dalam pakan sebesar 78,23 MJ/1 kg PK vs 85,18 MJ/1 kg PK) memiliki produksi dan kualitas susu yang serupa. Tetapi retensi N dan energi yang lebih tinggi, serta penggunaan energi untuk produksi gas metana (Mkal/hari) yang lebih rendah pada sapi perah yang diberi hijauan pakan berupa silase jagung dan hay dari Italian ryegrass (Gislon et al 2020). Hasil penelitian ini menunjukkan bahwa meningkatnya efisiensi pakan dapat menekan produksi gas metana enterik.…”